Ho Chi Minh City University of Food Industry HCM Entrance Exam Set

The question probes the understanding of sensory evaluation principles in food science, a core area for students at the Ho Chi Minh City University of Food Industry. The scenario describes a situation where a trained panel is evaluating the texture of a new rice noodle product developed by the university. The key is to identify the most appropriate method for quantifying subjective textural attributes. The options represent different sensory evaluation methodologies: * **Hedonic scale:** This measures consumer liking or preference, not specific textural attributes. While useful for overall product acceptance, it doesn’t provide granular data on texture components like firmness or chewiness. * **Descriptive analysis:** This method uses a trained panel to identify and quantify specific sensory attributes, including texture. Panelists are trained to recognize and rate the intensity of various textural characteristics (e.g., elasticity, cohesiveness, gumminess). This is ideal for detailed product characterization and quality control. * **Paired comparison:** This method compares two samples at a time to determine which is perceived as having a greater intensity of a specific attribute. It’s useful for discrimination but less so for detailed profiling of multiple attributes. * **Ranking:** This involves ordering samples based on a specific attribute. Similar to paired comparison, it’s for relative differences rather than absolute intensity measurement. Therefore, to precisely quantify subjective textural attributes like firmness, chewiness, and elasticity for a new rice noodle product at the Ho Chi Minh City University of Food Industry, descriptive analysis is the most suitable approach. It allows for the systematic identification and measurement of specific sensory characteristics by a trained panel, providing detailed insights into the product’s texture profile. This aligns with the university’s commitment to rigorous scientific inquiry and product development in the food industry.

The question assesses understanding of food processing principles, specifically focusing on the impact of processing parameters on product quality and shelf life, a core area for students at Ho Chi Minh City University of Food Industry. The scenario involves optimizing the blanching process for a novel Vietnamese vegetable, “Rau Mơ,” to preserve its vibrant green color and nutritional content while ensuring microbial inactivation. Blanching is a heat treatment used to inactivate enzymes, reduce microbial load, and soften tissues before further processing or preservation. The key parameters are temperature and time. To determine the optimal blanching conditions, one must consider the kinetics of both enzyme inactivation (e.g., chlorophyllase, which degrades chlorophyll) and microbial death, as well as the potential for undesirable changes like nutrient degradation or textural softening. The “decimal reduction time” (D-value) is a measure of the time required to reduce the microbial population by 90% at a specific temperature. Similarly, enzyme inactivation follows a similar kinetic model. For optimal preservation, blanching should be sufficient to inactivate target enzymes and reduce microbial load to acceptable levels without causing excessive degradation of desirable components. Consider the following: 1. **Enzyme Inactivation:** Chlorophyllase activity needs to be minimized to retain color. This enzyme is typically inactivated at temperatures above \(70^\circ\text{C}\). 2. **Microbial Inactivation:** Pathogenic bacteria and spoilage microorganisms must be reduced. A common target for general microbial inactivation in blanching is a reduction equivalent to achieving a \(5-\log_{10}\) cycle reduction in a target microorganism, often represented by a specific D-value. 3. **Nutrient and Quality Degradation:** Excessive heat or prolonged exposure can degrade heat-sensitive vitamins (like Vitamin C) and alter texture. The question asks for the most appropriate strategy. Let’s analyze the options: * **Option 1 (Focus on minimal time at high temp):** A high temperature (\(95^\circ\text{C}\)) with a short duration (\(1.5\) minutes) is often effective for rapid enzyme inactivation and microbial reduction. This approach minimizes exposure to heat, potentially preserving more heat-sensitive nutrients and maintaining a firmer texture. This aligns with the principle of achieving inactivation targets efficiently. * **Option 2 (Focus on moderate temp, longer time):** A moderate temperature (\(85^\circ\text{C}\)) for a longer duration (\(3\) minutes) might also achieve inactivation but could lead to greater degradation of heat-sensitive compounds due to the extended exposure. * **Option 3 (Focus on very low temp, very long time):** A very low temperature (\(65^\circ\text{C}\)) for an extended period (\(5\) minutes) is unlikely to be sufficient for effective inactivation of many common spoilage microorganisms and enzymes, potentially leading to poor shelf life and quality. * **Option 4 (Focus on very high temp, very long time):** An excessively high temperature (\(105^\circ\text{C}\)) for a prolonged time (\(4\) minutes) would likely cause significant degradation of color, nutrients, and texture, rendering the product unappealing and nutritionally inferior, even if microbial inactivation is achieved. Therefore, the strategy that balances effective inactivation with minimal quality loss, often a key consideration in food processing at institutions like Ho Chi Minh City University of Food Industry, is a higher temperature for a shorter duration. The specific values of \(95^\circ\text{C}\) for \(1.5\) minutes are commonly cited as effective for many green vegetables, suggesting a strong empirical basis for this approach in preserving desirable attributes. This strategy aims to achieve the necessary thermal processing objectives efficiently, aligning with the university’s focus on optimizing food production for quality and marketability.

The question probes understanding of food processing principles, specifically focusing on the impact of processing parameters on nutrient retention and quality, a core area within the Ho Chi Minh City University of Food Industry’s curriculum. The scenario involves optimizing blanching time for a specific vegetable to maximize vitamin C retention while ensuring adequate enzyme inactivation. Vitamin C is particularly sensitive to heat and oxidation. Blanching aims to deactivate enzymes like ascorbic acid oxidase, which degrades vitamin C, and also to reduce microbial load. However, prolonged or excessively high-temperature blanching leads to greater diffusion of vitamin C into the blanching medium and thermal degradation. To determine the optimal time, one must consider the kinetics of both enzyme inactivation and vitamin C degradation. Enzyme inactivation typically follows first-order kinetics, meaning the rate of inactivation is proportional to the enzyme concentration. Vitamin C degradation can also be modeled kinetically, often as a first-order process. The goal is to find a time where enzyme inactivation is sufficiently complete (e.g., 95% or more) but before significant vitamin C loss occurs. Let’s assume the enzyme inactivation follows a first-order decay model: \( E(t) = E_0 e^{-k_e t} \), where \( E(t) \) is the enzyme activity at time \( t \), \( E_0 \) is the initial enzyme activity, and \( k_e \) is the enzyme inactivation rate constant. Similarly, vitamin C degradation can be modeled as: \( C(t) = C_0 e^{-k_c t} \), where \( C(t) \) is the vitamin C concentration at time \( t \), \( C_0 \) is the initial concentration, and \( k_c \) is the vitamin C degradation rate constant. For effective blanching, we need to achieve a certain level of enzyme inactivation, say 95%, meaning \( E(t) / E_0 = 0.05 \). This occurs at time \( t_{inact} \) such that \( 0.05 = e^{-k_e t_{inact}} \), so \( t_{inact} = -\frac{\ln(0.05)}{k_e} \). We want to find a processing time \( t_{opt} \) that achieves sufficient enzyme inactivation while minimizing vitamin C loss. If we choose a time that inactivates 95% of the enzyme, the remaining vitamin C would be \( C(t_{inact}) = C_0 e^{-k_c t_{inact}} \). The ratio of vitamin C remaining to initial vitamin C would be \( \frac{C(t_{inact})}{C_0} = e^{-k_c t_{inact}} \). The question implies a trade-off. A longer blanching time increases enzyme inactivation but also increases vitamin C loss. A shorter time preserves vitamin C but might not fully inactivate enzymes. The optimal balance is achieved when the processing time is sufficient for enzyme deactivation, typically aiming for a specific reduction in enzyme activity, without causing excessive nutrient degradation. Consider a scenario where the rate constant for enzyme inactivation (\( k_e \)) is significantly higher than the rate constant for vitamin C degradation (\( k_c \)), which is common for ascorbic acid oxidase and vitamin C. For instance, if \( k_e = 0.05 \, \text{min}^{-1} \) and \( k_c = 0.01 \, \text{min}^{-1} \). To achieve 95% enzyme inactivation, \( t_{inact} = -\frac{\ln(0.05)}{0.05} \approx 60 \, \text{minutes} \). This calculation is incorrect as it implies a very long time. Let’s use more realistic values for blanching. Let’s assume the D-value (time for 90% reduction) for enzyme inactivation at a given temperature is 1 minute, and the D-value for vitamin C degradation is 3 minutes. This means \( k_e = \frac{\ln(10)}{1} \approx 2.3 \, \text{min}^{-1} \) and \( k_c = \frac{\ln(10)}{3} \approx 0.77 \, \text{min}^{-1} \). To achieve 95% enzyme inactivation (a reduction of 100-fold in enzyme activity, or 2 logs), the time required is \( t_{inact} = 2 \times D_{enzyme} = 2 \times 1 = 2 \) minutes. At this time, the remaining vitamin C would be \( C(2) = C_0 \times 10^{-(\frac{2}{D_{vitamin C}})} = C_0 \times 10^{-(\frac{2}{3})} \approx C_0 \times 10^{-0.667} \approx 0.215 \, C_0 \). This means about 78.5% of vitamin C is lost. This is too high. The question is about finding a balance. The optimal approach is to select a blanching time that achieves a significant reduction in enzyme activity (e.g., 90-95%) while minimizing the loss of heat-sensitive nutrients like vitamin C. This involves understanding the relative thermal stability of the target enzymes and the nutrient. A processing time that ensures enzyme deactivation without causing substantial nutrient diffusion or thermal breakdown is sought. Therefore, the most appropriate strategy is to identify the shortest time that effectively inactivates the target enzymes, thereby preserving the maximum amount of vitamin C. This aligns with the principle of minimal processing for optimal quality. The correct answer is the one that prioritizes enzyme inactivation to a sufficient degree while acknowledging the sensitivity of vitamin C to heat and diffusion, thus aiming for the shortest effective blanching duration. Final Answer: The shortest duration that effectively inactivates the target enzymes.

The question probes the understanding of sensory evaluation principles, specifically focusing on the impact of cross-contamination in taste panels. In a controlled sensory evaluation setting at the Ho Chi Minh City University of Food Industry, panelists are tasked with assessing distinct food products. If a panelist consumes a highly pungent or strongly flavored item, such as a spicy chili paste, immediately before evaluating a delicate product like a mild yogurt, the residual flavor compounds from the chili paste will interfere with the perception of the yogurt’s subtle taste and aroma. This interference is known as carry-over effect or cross-modal interaction in sensory science. The primary goal of a palate cleanser, like plain water or unsalted crackers, is to neutralize or remove these residual flavor molecules from the oral cavity, thereby resetting the palate to a neutral state. This ensures that the evaluation of each subsequent sample is based on its intrinsic sensory characteristics, rather than being influenced by the preceding sample. Without proper palate cleansing, the perceived flavor profile of the yogurt would be inaccurately skewed by the lingering spiciness, leading to unreliable and invalid data. Therefore, the most effective strategy to mitigate this sensory interference is to ensure a neutral palate between samples.

The question probes the understanding of fermentation processes, specifically focusing on the role of specific microorganisms in producing desirable flavor profiles in food products, a key area within the Food Technology and Biotechnology programs at Ho Chi Minh City University of Food Industry. The scenario describes a common challenge in artisanal food production: achieving consistent and complex flavor development. The core concept being tested is the metabolic pathways and enzymatic activities of lactic acid bacteria (LAB) and yeasts in the context of food fermentation. LAB, such as *Lactobacillus* and *Pediococcus* species, are primarily responsible for the production of lactic acid, which contributes to tartness and acts as a preservative. However, they also produce a range of secondary metabolites, including diacetyl (buttery flavor), acetoin, and various esters and aldehydes, which significantly contribute to the overall aroma and taste complexity. Yeasts, like *Saccharomyces cerevisiae*, are known for producing ethanol and carbon dioxide through alcoholic fermentation, but they also contribute to flavor through the production of esters (fruity notes) and higher alcohols. In the context of the Ho Chi Minh City University of Food Industry’s curriculum, understanding the synergistic or antagonistic interactions between these microbial groups is crucial for developing controlled fermentation processes for products like fermented vegetables, dairy, and baked goods. The question requires distinguishing between the primary metabolic products of these groups and their contribution to nuanced flavor profiles, moving beyond simple acid production. Option a) correctly identifies the combined action of specific LAB and yeasts in generating a complex flavor matrix through the production of diacetyl, esters, and other volatile compounds, which is essential for achieving the desired artisanal quality. Option b) is incorrect because while acetic acid bacteria produce acetic acid (vinegar), their primary role is in the oxidation of ethanol to acetic acid, which is not the primary driver of the described complex flavor profile in this context, and they are not typically the main contributors to buttery or fruity notes. Option c) is incorrect as it focuses solely on the production of bacteriocins by LAB, which are antimicrobial peptides and do not directly contribute to the desirable flavor complexity mentioned. Option d) is incorrect because while enzymes like amylase are important in food processing (e.g., starch breakdown), they are not the primary microbial agents responsible for the specific flavor compounds described in the scenario.

The question probes the understanding of sensory evaluation principles in food science, specifically concerning the impact of processing on perceived flavor profiles. The scenario describes a comparative analysis of two batches of canned lychees processed under different thermal treatment durations. Batch A received a shorter thermal processing time, while Batch B underwent a longer duration. The observed outcome is that Batch B exhibits a more pronounced “cooked” or “stewed” flavor, often associated with prolonged heat exposure, and a less vibrant, slightly muted sweetness compared to Batch A. This difference in sensory attributes is directly linked to the Maillard reaction and caramelization processes, which are accelerated and intensified by longer thermal treatments. These non-enzymatic browning reactions, while contributing to desirable color and aroma in some foods, can lead to the formation of complex compounds that alter the natural sweetness and introduce less desirable cooked notes, particularly in delicate fruits like lychees. The goal of thermal processing in canning is to achieve microbial inactivation for shelf-stability while minimizing detrimental changes to quality. Therefore, the batch with the shorter processing time (Batch A) would be considered to have maintained a more desirable sensory profile closer to the fresh product, demonstrating a better balance between safety and quality. The question requires identifying the processing parameter that most directly explains this sensory divergence. The duration of thermal processing is the primary variable manipulated between Batch A and Batch B, directly influencing the extent of chemical reactions that alter flavor.

The question probes the understanding of sensory evaluation principles in food science, specifically focusing on the role of trained panelists versus untrained consumers in product development at the Ho Chi Minh City University of Food Industry. Trained panelists undergo rigorous selection and training to develop a consistent and objective vocabulary for describing sensory attributes, allowing for precise identification of subtle differences and the impact of formulation changes. This precision is crucial for product optimization, quality control, and identifying specific areas for improvement in texture, flavor, and aroma. Untrained consumers, while valuable for gauging overall market acceptance and preference, provide more subjective and variable feedback, often influenced by personal biases and cultural backgrounds. Therefore, when the objective is to fine-tune a novel beverage formulation for specific textural improvements and to quantify the impact of a new sweetener on perceived bitterness, the most effective approach involves utilizing a panel of trained individuals. Their ability to provide consistent, quantifiable, and attribute-specific data is paramount for making informed decisions in the product development lifecycle, aligning with the rigorous scientific inquiry fostered at the Ho Chi Minh City University of Food Industry.

The question probes the understanding of critical quality attributes (CQAs) in food product development, specifically focusing on how sensory properties are managed during the formulation of a novel beverage at the Ho Chi Minh City University of Food Industry. The scenario describes a product developer aiming to balance the tartness from a new fruit extract with the sweetness from a sugar substitute. The core concept here is the interaction and perception of taste profiles. The calculation, while not strictly mathematical in a numerical sense, involves a conceptual balancing act. Let’s consider the perceived sweetness intensity of the sugar substitute as \(S\) and the perceived tartness intensity of the fruit extract as \(T\). The developer aims for a specific target taste profile, let’s call it \(P_{target}\). The formulation involves adjusting the concentration of the sugar substitute and the fruit extract. If the initial formulation has a sweetness of \(S_1\) and a tartness of \(T_1\), and the target profile is \(P_{target}\), the developer needs to adjust concentrations. A common approach in sensory science is to consider the interaction of tastes. For instance, high acidity can suppress perceived sweetness, and high sweetness can sometimes mask subtle tartness. The developer is trying to find a balance where neither taste completely overwhelms the other, and the overall sensory experience is pleasant and characteristic of the intended product. The question asks about the primary sensory attribute that needs careful management to achieve this balance. While texture and aroma are important, the direct conflict and interaction described (tartness vs. sweetness) points to the **flavor profile**. Flavor is the integrated perception of taste, aroma, and mouthfeel. In this specific context, the interplay between the sweet and tart components is paramount. The developer is not just adding ingredients; they are engineering a specific sensory experience. The correct answer focuses on the holistic perception of taste and its interaction with other sensory inputs. The other options represent important but secondary considerations in this particular balancing act. Texture relates to mouthfeel, which is influenced by viscosity and other factors, not directly by the sweet-tart ratio itself, though it contributes to the overall flavor. Aroma is crucial for the overall perception but the core challenge described is the taste balance. Color is a visual attribute and while it can influence taste perception, it’s not the direct attribute being manipulated to balance sweetness and tartness. Therefore, managing the overall flavor profile, which encompasses the interplay of taste, is the most direct and critical aspect.

The question probes the understanding of the principles of food preservation, specifically focusing on the role of water activity (\(a_w\)) in microbial growth and spoilage. Water activity is a measure of the unbound water available for microbial metabolism and chemical reactions. Lowering \(a_w\) significantly inhibits or prevents the growth of most bacteria, yeasts, and molds. For instance, bacteria generally require an \(a_w\) of at least 0.90, yeasts around 0.85, and molds can tolerate lower levels, often down to 0.70 or even 0.60 for xerophilic molds. The scenario describes a product with a water activity of 0.75. This value is below the threshold typically required for the growth of most spoilage bacteria and many yeasts. However, it is still within the range where certain osmophilic yeasts and xerophilic molds can proliferate. Therefore, while the product is significantly more shelf-stable than a product with a higher \(a_w\), it is not completely sterile or immune to all microbial spoilage. The presence of these specific microorganisms means that the product is susceptible to spoilage, albeit at a slower rate and by a narrower spectrum of microbes compared to products with higher water activity. This understanding is crucial in food science and technology, particularly at institutions like the Ho Chi Minh City University of Food Industry, where optimizing shelf-life and ensuring food safety through controlled water activity is a core principle. The ability to predict microbial behavior based on \(a_w\) is fundamental to developing stable food products.

The question probes the understanding of sensory evaluation principles in food science, specifically concerning the impact of processing on perceived flavor profiles. The scenario describes a comparative study of two batches of a popular Vietnamese fermented fish product (mắm nêm) at the Ho Chi Minh City University of Food Industry. Batch A underwent a traditional, extended fermentation process, while Batch B was subjected to a novel accelerated fermentation technique using specific microbial cultures and controlled temperature. The core concept being tested is how different processing methods influence the development of key flavor compounds (e.g., esters, aldehydes, sulfur compounds) and how these changes are perceived by trained sensory panels. The accelerated fermentation in Batch B, while aiming for efficiency, might lead to a less complex or even unbalanced flavor profile compared to the traditional method. Traditional fermentation, often characterized by a longer, slower microbial action, typically results in a richer, more nuanced array of volatile compounds that contribute to the characteristic umami and pungent notes of mắm nêm. Accelerated methods, if not perfectly optimized, can sometimes favor the production of undesirable byproducts or fail to develop the full spectrum of desirable flavor precursors. Therefore, a sensory panel trained in evaluating traditional Vietnamese fermented foods would likely identify a difference in the depth and complexity of flavor. The question requires inferring the most probable outcome based on general principles of food fermentation and sensory science, as applied to a specific product relevant to the university’s focus. The correct answer reflects the understanding that while accelerated methods can achieve faster results, they may not fully replicate the intricate flavor development of traditional, time-intensive processes, leading to a less complex sensory experience.

The question probes the understanding of sensory evaluation principles, specifically focusing on the concept of sensory fatigue and its implications in food product testing. Sensory fatigue occurs when prolonged exposure to a specific taste or aroma diminishes an individual’s ability to perceive that stimulus accurately. In the context of a food science program at the Ho Chi Minh City University of Food Industry, understanding how to mitigate such effects is crucial for reliable product development and quality control. For instance, if a panelist is evaluating the sweetness of a new beverage, repeated tasting without palate cleansing can lead to a reduced perception of sweetness, potentially skewing results. Therefore, implementing strategies like offering water, unsalted crackers, or neutral-flavored foods between samples is essential to reset the palate. This allows for a more objective and accurate assessment of each product’s sensory attributes. The correct answer emphasizes the proactive management of sensory fatigue, a core competency in applied sensory science, which is a significant area of study within food technology and related disciplines at the university.

The question probes the understanding of fermentation processes, specifically focusing on the role of yeast in producing ethanol and carbon dioxide from sugars. In the context of food industry applications, particularly in baking and brewing, controlling the rate and byproducts of fermentation is crucial. The scenario describes a controlled environment where temperature, pH, and nutrient availability are optimized for yeast activity. The key concept is that under anaerobic conditions, yeast primarily undergoes alcoholic fermentation. This process converts glucose (a common sugar substrate) into ethanol and carbon dioxide. The balanced chemical equation for this process is \(C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2\). This equation illustrates that for every molecule of glucose consumed, two molecules of ethanol and two molecules of carbon dioxide are produced. Therefore, if a batch of dough is undergoing fermentation, the primary gaseous byproduct responsible for leavening is carbon dioxide. While other metabolic pathways exist for yeast, alcoholic fermentation is dominant under the described conditions and is the intended focus for a food industry context like baking. Understanding the stoichiometry of this reaction is fundamental for predicting yield and process efficiency. The question requires identifying the most significant gaseous product that contributes to the desired outcome (leavening in baking or carbonation in brewing).

The question probes the understanding of sensory evaluation principles within the context of food product development, a core area for students at Ho Chi Minh City University of Food Industry. The scenario involves a new beverage formulation. The goal is to assess consumer preference for sweetness and acidity, crucial for market acceptance. A key consideration in sensory evaluation is the potential for carry-over effects between samples, where the taste or sensation from one sample influences the perception of the next. This is particularly relevant when evaluating multiple attributes or different formulations. To mitigate such effects and ensure accurate data, a specific experimental design is employed. In this case, the panelists are instructed to rinse their mouths with water between tasting each sample. This practice serves to neutralize residual tastes and aromas, resetting the palate for the subsequent evaluation. This technique is fundamental in sensory science to isolate the perceived characteristics of each individual sample. Without this intervention, a highly sweet sample might make a moderately sweet sample appear less sweet by comparison, or an acidic sample could enhance the perception of sweetness in a subsequent sample. Therefore, the mouth rinse is a critical step in maintaining the independence of each data point collected during the sensory panel.

The scenario describes a food processing plant at the Ho Chi Minh City University of Food Industry HCM that is experiencing a significant increase in microbial contamination in its packaged fruit juices. The primary goal is to identify the most probable root cause based on the provided observations. The plant uses pasteurization as its primary microbial control method. The observation that the contamination is primarily found in *packaged* juices, and that the spoilage is characterized by gas production and cloudiness, strongly suggests that the pasteurization process itself is not achieving the desired microbial inactivation or that post-pasteurization contamination is occurring. Let’s analyze the options: 1. **Inadequate pasteurization temperature or time:** If the pasteurization parameters (temperature and duration) are not sufficient to eliminate heat-resistant microorganisms (like certain bacterial spores or thermophilic bacteria), these microbes can survive and proliferate in the packaged product, leading to spoilage. This aligns with the observed gas production and cloudiness. 2. **Post-pasteurization contamination:** Even if pasteurization is effective, contamination can occur during the packaging process if equipment is not sterile, packaging materials are compromised, or aseptic handling procedures are not followed. This would also lead to spoilage in the final packaged product. 3. **Raw material spoilage:** While raw material quality is important, if the spoilage was primarily due to raw material issues, it would likely manifest earlier in the process or in a broader range of products, not specifically and predominantly in the *packaged* juices after pasteurization. 4. **Improper storage conditions:** Storage conditions can affect the rate of microbial growth, but they are less likely to be the *primary* cause of spoilage if the product was adequately pasteurized and packaged aseptically. Improper storage might accelerate spoilage of already compromised products but wouldn’t typically initiate it from a sterile state. Considering the specific observation of spoilage in *packaged* juices and the nature of the spoilage (gas production, cloudiness), both inadequate pasteurization and post-pasteurization contamination are strong contenders. However, the question asks for the *most probable* root cause. In a university food processing plant setting, rigorous quality control checks are expected. If the contamination is widespread and consistent across batches, it points to a systemic issue. Inadequate pasteurization is a direct failure of the primary microbial control step. Post-pasteurization contamination is also a critical failure, but often, initial pasteurization effectiveness is a prerequisite. Without further data distinguishing between these two, both are highly plausible. However, the prompt asks for a single best answer. The most direct explanation for surviving microbes causing spoilage in a heat-treated product is that the heat treatment itself was insufficient. If the pasteurization was truly effective, post-pasteurization contamination would be less likely to cause such widespread issues unless there were significant, systemic breaches in aseptic packaging. Therefore, focusing on the efficacy of the core preservation method is often the first line of investigation for such spoilage. Let’s refine the reasoning to pinpoint the most probable cause. The spoilage is characterized by gas production and cloudiness. This is indicative of active microbial metabolism. If pasteurization was insufficient, heat-resistant spores or vegetative cells would survive. If post-pasteurization contamination occurred, it would be from environmental microbes. Both can lead to gas and cloudiness. However, the university’s focus on food science principles would emphasize the critical role of the thermal process in achieving microbial lethality. A failure in this core step is a fundamental issue. If the pasteurization process is consistently failing to achieve the required reduction in microbial load, even minor post-pasteurization contamination could lead to significant spoilage. Conversely, if pasteurization is robust, even minor post-pasteurization contamination might not lead to such rapid and widespread spoilage. Therefore, the most fundamental and probable root cause, given the information, is a failure in the pasteurization process itself. Final Answer Calculation: The question requires identifying the most probable root cause of spoilage in packaged fruit juices after pasteurization. The spoilage is characterized by gas production and cloudiness. This indicates the presence and metabolic activity of microorganisms. The primary preservation method is pasteurization. 1. **Inadequate Pasteurization:** If the pasteurization temperature or time is insufficient, heat-resistant microorganisms (e.g., bacterial spores, thermophilic bacteria) can survive. These survivors can then multiply in the packaged product, leading to spoilage symptoms like gas production and cloudiness. This is a direct failure of the core preservation step. 2. **Post-Pasteurization Contamination:** If pasteurization is effective, contamination can occur during the filling and packaging stages if aseptic conditions are not maintained. This introduces viable microorganisms into the product, which can then spoil it. 3. **Raw Material Spoilage:** If raw materials were heavily contaminated with spoilage organisms, and these were not adequately inactivated during processing, it could lead to spoilage. However, the spoilage is specifically noted in *packaged* juices, suggesting the issue is either with the process after raw material handling or the raw material itself was not sufficiently handled. 4. **Improper Storage:** Storage conditions affect the rate of microbial growth but are unlikely to be the primary cause of spoilage in a properly processed and packaged product. Given that the spoilage occurs in *packaged* juices and is characterized by active microbial growth (gas, cloudiness), the most direct and probable cause is that the pasteurization process itself did not achieve the necessary microbial inactivation. This could be due to incorrect temperature, insufficient holding time, or improper equipment calibration. While post-pasteurization contamination is also a possibility, a failure in the primary thermal processing step is often the most fundamental reason for such widespread spoilage in a heat-treated product. Therefore, inadequate pasteurization is the most probable root cause. The final answer is \( \text{Inadequate pasteurization temperature or time} \).

The question probes the understanding of fermentation processes, specifically focusing on the role of microorganisms in food production, a core area for the Ho Chi Minh City University of Food Industry. The scenario describes the production of a fermented beverage, likely a type of rice wine or similar traditional Vietnamese drink, where yeast is crucial for converting sugars into ethanol and carbon dioxide. The key concept here is the metabolic pathway of alcoholic fermentation. Yeast, under anaerobic or semi-anaerobic conditions, utilizes enzymes like zymase to break down glucose (a sugar) into ethanol and carbon dioxide. This process is fundamental to the production of many fermented foods and beverages, aligning with the university’s focus on food technology and processing. Understanding the specific byproducts and the role of the primary fermenting agent is essential. The question requires identifying the most accurate description of yeast’s primary metabolic contribution in this context. The other options represent either incomplete processes, different types of microbial activity, or byproducts not directly generated by yeast in alcoholic fermentation. For instance, lactic acid fermentation is carried out by lactic acid bacteria, not yeast, and produces lactic acid. Acetic acid is produced by acetic acid bacteria through the oxidation of ethanol, a secondary process. The production of carbon dioxide is a direct byproduct of alcoholic fermentation, alongside ethanol. Therefore, the most comprehensive and accurate description of yeast’s primary role in this scenario is the conversion of sugars into ethanol and carbon dioxide.

The question probes the understanding of the principles of food preservation, specifically focusing on the role of water activity (\(a_w\)) in microbial growth and spoilage. Water activity is a measure of the unbound water available for microbial metabolism and chemical reactions. Lowering \(a_w\) is a fundamental strategy in food preservation because most bacteria require a minimum \(a_w\) of approximately 0.85 to grow, while yeasts and molds can tolerate lower levels, typically down to 0.60 and 0.70 respectively. Consider a scenario where a food product is being developed for extended shelf life without refrigeration. To inhibit bacterial growth, the water activity must be reduced below 0.85. However, to also prevent spoilage by yeasts and molds, a further reduction is necessary. Yeasts generally cease growth below an \(a_w\) of 0.85, but some can grow down to 0.60. Molds, being more xerophilic (dry-loving), can grow at even lower water activities, with the most resistant species capable of growth down to 0.60 or even slightly lower in specific conditions. Therefore, to ensure comprehensive microbial stability against the majority of spoilage organisms, including yeasts and molds, the water activity should ideally be lowered to a level that inhibits the most tolerant of these microorganisms. While 0.70 would inhibit most yeasts and many molds, a target of 0.60 provides a more robust safety margin against a wider spectrum of spoilage microorganisms, including the most xerophilic molds. This aligns with the principles taught in food science programs at institutions like the Ho Chi Minh City University of Food Industry, emphasizing the critical role of controlling water activity for food safety and quality.

The question probes the understanding of sensory evaluation principles in food science, a core area for the Ho Chi Minh City University of Food Industry. Specifically, it addresses the concept of sensory fatigue and its impact on product assessment. Sensory fatigue occurs when prolonged exposure to a stimulus diminishes the ability to perceive it. In the context of a tasting panel evaluating multiple food products, continuous exposure to a dominant flavor profile, such as intense sweetness or spiciness, can desensitize the panelists’ taste receptors. This desensitization leads to an inaccurate perception of subsequent samples, potentially causing them to underestimate the sweetness or spiciness of later products. To mitigate this, a palate cleanser is used to reset the sensory receptors. Water is a common and effective palate cleanser because it is neutral and helps wash away residual tastes without introducing new flavors that could interfere with the evaluation. Therefore, providing water between samples is a standard practice to minimize sensory fatigue and ensure more reliable and objective sensory data collection, which is crucial for product development and quality control in the food industry, aligning with the university’s focus on applied food science.

The question probes the understanding of sensory evaluation principles in food science, a core area for the Ho Chi Minh City University of Food Industry. Specifically, it tests the ability to discern the most appropriate method for assessing a subtle textural difference in a food product, such as the crispness of a rice cracker, a common product in Vietnamese cuisine and relevant to the university’s curriculum. The scenario involves two batches of rice crackers produced by the university’s food technology department, where one batch exhibits a slightly altered texture. The goal is to determine which sensory evaluation technique would best capture this nuanced difference. A descriptive analysis panel, trained to identify and quantify specific sensory attributes, is the most suitable method here. This technique involves a group of trained individuals who systematically evaluate and rate various sensory characteristics of a food product, including texture, flavor, and aroma. For a subtle textural variation like crispness, a trained panel can provide detailed, objective, and reproducible data by using a standardized vocabulary and rating scales. This allows for the differentiation between slight variations that might be missed by untrained consumers. Triangle testing, while useful for detecting *if* a difference exists, doesn’t quantify the nature or magnitude of that difference. Hedonic testing, which measures consumer liking, is focused on overall preference and is less effective for pinpointing specific textural attributes. A simple preference test would also not provide the detailed textural information needed to understand the nature of the change. Therefore, a trained descriptive analysis panel is the most rigorous and informative approach for characterizing subtle textural differences in food products, aligning with the advanced scientific inquiry expected at the Ho Chi Minh City University of Food Industry.

The question probes the understanding of the principles of food preservation, specifically focusing on the impact of different processing methods on microbial inactivation and enzyme activity. The scenario describes a hypothetical food product developed at the Ho Chi Minh City University of Food Industry, aiming for extended shelf life. The core concept being tested is the efficacy of various preservation techniques in achieving this goal while maintaining product quality. The primary goal of food preservation is to inhibit or destroy microorganisms and enzymes that cause spoilage and disease. Different methods achieve this through various mechanisms. Thermal processing (like pasteurization or sterilization) uses heat to denature proteins and inactivate enzymes and microorganisms. High-pressure processing (HPP) uses mechanical pressure to disrupt cell membranes and inactivate enzymes and microbes, often with less impact on sensory qualities than heat. Chemical preservatives, such as sorbates or benzoates, work by interfering with microbial metabolism or cell structure. Modified atmosphere packaging (MAP) alters the gaseous environment around the food, typically by reducing oxygen and increasing carbon dioxide or nitrogen, to slow down microbial growth and oxidative reactions. Considering the objective of extended shelf life and maintaining quality, a combination of methods is often most effective. However, the question asks which *single* approach, when implemented effectively, would offer the most comprehensive benefit for a novel food product at the Ho Chi Minh City University of Food Industry. Thermal processing, while highly effective at microbial inactivation, can significantly alter the sensory and nutritional profile of food, especially for delicate products. Chemical preservatives can be effective but may raise consumer concerns regarding additives. Modified atmosphere packaging is primarily a barrier and a means to slow down spoilage, not a direct inactivation method. High-pressure processing (HPP) is known for its ability to inactivate a broad spectrum of microorganisms and enzymes with minimal impact on flavor, color, and nutritional value, making it a strong candidate for extending shelf life while preserving product integrity. Therefore, effective implementation of HPP would likely provide the most significant and balanced benefit for a novel food product aiming for extended shelf life and quality retention, aligning with advanced food science research often conducted at institutions like the Ho Chi Minh City University of Food Industry.

The question probes the understanding of sensory evaluation principles, specifically focusing on the impact of cross-contamination in a food product tasting context at the Ho Chi Minh City University of Food Industry. The scenario describes a panel evaluating different varieties of Vietnamese coffee. The key issue is the potential for residual flavors from one sample to influence the perception of the next. To mitigate this, a palate cleanser is essential. Water is a common and effective palate cleanser because it is neutral and can rinse away lingering tastes without introducing new ones. Other options, like milk, would introduce their own flavor profile, potentially masking or altering the taste of subsequent coffee samples. A strong herbal tea could also impart its own distinct flavor. Even a simple cracker, while intended to cleanse, might leave a subtle starchy or salty residue. Therefore, plain water is the most scientifically sound choice for maintaining the integrity of the sensory evaluation and ensuring that each coffee sample is judged on its own merits, a critical principle in food science and sensory analysis taught at institutions like the Ho Chi Minh City University of Food Industry.

The question probes the understanding of sensory evaluation principles, specifically focusing on the impact of cross-contamination in taste panels. In a scenario where a panelist consumes a highly pungent food item immediately before evaluating a delicate dessert, the primary concern is the lingering taste and aroma of the pungent item interfering with the perception of the dessert’s subtle flavors and textures. This interference is a form of sensory adaptation or fatigue, where the olfactory and gustatory receptors become less sensitive to new stimuli after prolonged exposure to a strong one. To mitigate this, a palate cleanser is used. Common palate cleansers are neutral in flavor and texture, designed to rinse away residual tastes and aromas without introducing their own strong sensory input. Water is a basic cleanser, but for more persistent flavors, a mild, unsalted cracker or a small sip of unsweetened, unflavored carbonated water can be more effective. The goal is to reset the sensory receptors to a baseline state, allowing for accurate and unbiased evaluation of the subsequent sample. Therefore, the most appropriate action to prevent the pungent item from influencing the dessert evaluation is to ensure the panelist uses an effective palate cleanser.

The question probes the understanding of sensory evaluation principles within the context of food product development, a core area for the Ho Chi Minh City University of Food Industry. Specifically, it addresses the critical distinction between descriptive analysis and hedonic testing. Descriptive analysis aims to characterize the sensory attributes of a product (e.g., sweetness, bitterness, texture, aroma intensity) using trained panelists who provide quantitative data on these specific characteristics. This method is crucial for understanding product profiles, identifying areas for improvement, and ensuring consistency. Hedonic testing, conversely, focuses on consumer preference and acceptance, measuring how much consumers like or dislike a product, often on a scale (e.g., “like very much” to “dislike very much”). It answers the “what” of consumer opinion rather than the “how” of product characteristics. Therefore, a scenario requiring the identification of specific flavor notes and textural components, and their intensity, would necessitate a descriptive analysis approach. For instance, if a food technologist at the Ho Chi Minh City University of Food Industry is developing a new Vietnamese coffee beverage and needs to quantify the perceived bitterness, acidity, and body, they would employ descriptive analysis. This allows for precise adjustments to the formulation to achieve a desired sensory profile, which is fundamental to product innovation and quality control in the food industry, aligning with the university’s practical and research-oriented curriculum.

The question probes the understanding of the principles of food preservation, specifically focusing on the impact of water activity (\(a_w\)) on microbial growth and its relevance to the curriculum at Ho Chi Minh City University of Food Industry. Water activity is a measure of the unbound water available for microbial metabolism and chemical reactions. Lowering \(a_w\) is a primary strategy in food preservation because most bacteria, yeasts, and molds require relatively high water activity to grow. For instance, most bacteria require \(a_w > 0.90\), many yeasts require \(a_w > 0.85\), and molds can grow at \(a_w\) as low as 0.70, with some xerophilic molds growing down to \(a_w \approx 0.60\). Therefore, reducing the water activity of a food product below these thresholds inhibits or prevents microbial spoilage. Methods like drying, adding solutes (sugar, salt), or using humectants (glycerol) are employed to lower \(a_w\). The scenario describes a food product with a high initial \(a_w\) that is then processed to reduce it. The goal is to select the preservation method that most directly targets and significantly lowers the water activity to inhibit a broad spectrum of microbial contaminants. Drying removes free water, thereby directly reducing \(a_w\). Adding a high concentration of salt or sugar also lowers \(a_w\) by binding water molecules through osmosis and solvation, making them less available for microbial use. Pasteurization, while a heat treatment, primarily inactivates existing microorganisms but does not fundamentally alter the water activity of the food. Therefore, while pasteurization can extend shelf life, it is not the primary method for *reducing* water activity to inhibit microbial growth. The question asks for the method that *most effectively reduces* water activity. Both drying and adding solutes achieve this. However, drying is a direct physical removal of water, a fundamental way to lower \(a_w\). Adding solutes is also effective. Considering the options, the most direct and universally applicable method for significantly lowering \(a_w\) across a wide range of food products, and a core concept taught in food science programs like those at Ho Chi Minh City University of Food Industry, is the reduction of available water. Among the choices, drying is the most direct method of achieving this.

The question probes the understanding of critical quality attributes (CQAs) in food product development, specifically focusing on the sensory and textural properties that are paramount for consumer acceptance, a core tenet at the Ho Chi Minh City University of Food Industry. The scenario describes a new formulation for a Vietnamese rice noodle product, aiming for a specific “chewy yet tender” mouthfeel. This requires identifying the CQA that most directly relates to this desired texture. Texture is a complex sensory attribute influenced by various factors, including ingredient composition, processing parameters, and the interaction of macromolecules like starch and proteins. In the context of rice noodles, the gelatinization of rice starch is a primary determinant of texture. The degree of gelatinization, influenced by factors such as water content, temperature, and shear, directly impacts the noodle’s firmness, elasticity, and tendency to become mushy or brittle. Therefore, the “gelatinization degree of rice starch” is the most precise CQA that encapsulates the desired “chewy yet tender” characteristic. Other options, while related to food science, are less direct in their impact on the specific textural profile described. “Moisture content” is a significant factor, but it’s a consequence of processing and ingredient interactions that lead to the final gelatinization state. “Acidity of the processing water” can influence starch behavior, but its primary effect is often on enzyme activity or protein denaturation, not directly on the intrinsic textural outcome of starch gelatinization itself. “Presence of emulsifiers” is relevant for improving texture and stability, but the fundamental textural property being targeted is the result of starch hydration and structure formation, which is best represented by the gelatinization degree. Thus, understanding the fundamental changes in the rice starch during processing is key to achieving the desired sensory outcome, making the gelatinization degree the most appropriate CQA.

The question probes the understanding of sensory evaluation principles in food science, a core area for students at Ho Chi Minh City University of Food Industry. The scenario describes a product development team at the university aiming to assess the texture of a new rice noodle formulation. They are considering different sensory testing methodologies. The goal is to identify the most appropriate method for a preliminary, broad assessment of textural differences among several prototype formulations, focusing on identifying which prototypes are perceived as significantly different by a diverse group of untrained individuals. Method A, descriptive analysis, involves trained panelists to identify and quantify specific textural attributes. While rigorous, it requires extensive training and is more suited for detailed characterization rather than initial screening. Method B, hedonic testing, focuses on consumer preference and acceptance, which is not the primary objective here; the team wants to understand textural differences, not necessarily liking. Method C, paired comparison, asks consumers to choose between two samples based on a specific attribute. This is effective for direct comparison but can be time-consuming if many prototypes are involved and doesn’t easily provide a broad overview of textural profiles. Method D, category scaling, where panelists rate attributes on a defined scale (e.g., from “very soft” to “very firm”), allows for a quantitative assessment of perceived intensity of various textural attributes by a larger group of untrained consumers. This method is efficient for initial screening, can capture a range of perceptions, and provides data that can be statistically analyzed to identify significant textural differences among the prototypes, making it the most suitable for the team’s stated objective.

The question probes the understanding of sensory evaluation principles in food science, specifically concerning the impact of processing on perceived flavor profiles. The scenario describes a comparative analysis of two batches of pho broth produced by the Ho Chi Minh City University of Food Industry’s culinary science program. Batch A underwent a traditional simmering process for 8 hours, while Batch B was subjected to a high-pressure thermal processing (HPTP) method for 2 hours, aiming for similar flavor development. The core concept being tested is how different processing techniques affect the release and perception of volatile aromatic compounds and the Maillard reaction products, which are crucial for the complex flavor of pho. Traditional simmering allows for gradual extraction and interaction of ingredients, leading to a well-rounded, nuanced flavor. HPTP, while efficient, can sometimes lead to the degradation of certain delicate aroma compounds or the formation of different, potentially less desirable, flavor notes due to the intense conditions. Therefore, a panel trained in sensory analysis, using descriptive profiling, would likely identify differences in the aromatic intensity, mouthfeel, and overall flavor complexity. Specifically, the HPTP method might result in a less complex aroma profile, a potentially “cooked” or “metallic” off-flavor due to rapid thermal degradation, and a less integrated mouthfeel compared to the slow-simmered broth. The question requires inferring the most probable outcome based on established food processing principles and sensory science. The correct answer focuses on the potential for HPTP to alter the characteristic flavor profile by affecting the balance of volatile compounds and the extent of non-enzymatic browning reactions, leading to a perceived difference in complexity and potentially introducing subtle off-notes.

The question probes the understanding of sensory evaluation principles in food science, specifically focusing on the role of trained panelists versus untrained consumers in product development and quality control at institutions like the Ho Chi Minh City University of Food Industry. Trained panelists undergo rigorous selection and training to develop sensitivity to specific attributes and reduce personal bias. They are taught to identify and quantify sensory characteristics (e.g., bitterness, sweetness, texture variations) with greater precision and consistency. This precision is crucial for tasks such as identifying subtle off-flavors caused by processing deviations, comparing the sensory profiles of different formulations during product development, or establishing objective quality standards. Untrained consumers, while valuable for market acceptance testing, are more susceptible to individual preferences, cultural backgrounds, and external factors, making their feedback less reliable for fine-tuning product specifications or diagnosing specific quality issues. Therefore, for tasks requiring detailed attribute analysis and the establishment of precise quality benchmarks, as would be expected in advanced food science research at the Ho Chi Minh City University of Food Industry, the systematic calibration and controlled responses of trained panelists are indispensable. This allows for the identification of minute differences that might be missed by a general consumer panel, thereby supporting the development of superior food products that meet stringent quality and sensory targets.

The question assesses understanding of food processing principles, specifically the impact of processing parameters on product quality and safety, a core area for students at Ho Chi Minh City University of Food Industry. The scenario involves optimizing a pasteurization process for a dairy beverage. Pasteurization aims to reduce microbial load while minimizing detrimental effects on sensory attributes and nutritional value. Thermal processing, like pasteurization, involves balancing time and temperature. Higher temperatures achieve faster microbial inactivation but can also lead to greater degradation of heat-sensitive vitamins (e.g., Vitamin C, B vitamins) and undesirable changes in flavor and texture (e.g., Maillard reactions, protein denaturation). Lower temperatures require longer holding times, which can also impact quality. The concept of “thermal death time” (TDT) curves and “decimal reduction time” (D-value) is relevant here, illustrating the relationship between temperature and the time required to reduce a specific microbial population by 90%. For a given D-value, as temperature increases, the time required decreases. Conversely, as temperature decreases, the time required increases. The goal is to achieve a specific level of microbial inactivation (e.g., a 5-log reduction) with the least impact on quality. Therefore, a process that utilizes a slightly higher temperature for a shorter duration, while still achieving the required microbial kill, would generally be preferred over a lower temperature for a significantly longer duration, assuming both achieve the target safety level. This is because the cumulative thermal exposure, often measured in “pasteurization units” (PU), is a better indicator of quality degradation than just the total time or temperature alone. A higher temperature/shorter time combination can result in a similar or even lower PU value compared to a lower temperature/longer time combination for the same microbial inactivation, thus preserving more of the product’s desirable characteristics. This principle is fundamental to designing efficient and high-quality food processing operations, aligning with the practical and scientific focus of the Ho Chi Minh City University of Food Industry.

The question probes the understanding of sensory evaluation principles in food science, specifically focusing on the role of trained panelists versus untrained consumers in product development at the Ho Chi Minh City University of Food Industry. The scenario describes a situation where a new formulation of a traditional Vietnamese beverage, “nuoc mia” (sugarcane juice), is being developed. The goal is to assess consumer acceptance and identify subtle flavor profile improvements. Trained panelists are crucial for identifying specific sensory attributes and their intensity, allowing for precise feedback on formulation changes. They undergo rigorous training to develop a standardized vocabulary and sensitivity to detect nuances in taste, aroma, texture, and appearance. This precision is vital for product refinement, where even minor adjustments can impact the overall quality. For instance, if the new “nuoc mia” formulation has a slightly different sweetness level or a less pronounced sugarcane aroma, trained panelists can quantify this difference and attribute it to specific ingredients or processing steps. This detailed feedback enables food scientists and product developers to make targeted adjustments, ensuring the final product meets desired quality standards and is distinct from competitors. Untrained consumers, on the other hand, provide insights into overall liking and purchase intent. While valuable for market research, their feedback is often more subjective and less granular. They might express general preference or dislike without being able to articulate the specific reasons behind it. In the context of product development at the Ho Chi Minh City University of Food Industry, where innovation in traditional food products is a key focus, the ability to dissect sensory profiles is paramount. Therefore, for the initial stages of refining a complex flavor profile like that of “nuoc mia,” relying solely on untrained consumers would likely yield less actionable data for precise formulation adjustments. The question, therefore, hinges on identifying the most appropriate methodology for detailed sensory analysis in a product development setting.

The question probes the understanding of sensory evaluation principles in food science, a core area for students at Ho Chi Minh City University of Food Industry. The scenario involves a panel of trained tasters evaluating a new formulation of a traditional Vietnamese beverage, *nuoc mia* (sugarcane juice), for its sweetness, acidity, and mouthfeel. The goal is to identify the most appropriate statistical method for analyzing the resulting ordinal data, which represents subjective judgments on a Likert-type scale (e.g., “Slightly Sweet” to “Very Sweet”). Ordinal data, by definition, has ordered categories but the intervals between categories are not necessarily equal or quantifiable. Therefore, parametric tests that assume interval or ratio data and normal distribution, such as a standard t-test or ANOVA, are generally inappropriate. Non-parametric tests are designed for data that does not meet these assumptions. The Kruskal-Wallis H-test is a non-parametric statistical test used to determine if there are statistically significant differences between two or more independent groups on a continuous or ordinal dependent variable. In this context, the “groups” are the different formulations of *nuoc mia*, and the “dependent variable” is the sensory attribute (sweetness, acidity, mouthfeel) as rated by the trained tasters on an ordinal scale. This test is a direct analogue to the one-way ANOVA but for ordinal data. The Wilcoxon signed-rank test is used for comparing two related samples, typically for paired data or repeated measures on the same subjects, which is not the case here as different formulations are being compared by independent tasters. Friedman’s test is another non-parametric test for ordinal data, but it is used for related samples (e.g., when the same panel evaluates multiple treatments). Since the question implies independent evaluations of different formulations, the Kruskal-Wallis H-test is the most fitting choice for comparing multiple independent groups on ordinal sensory data. Chi-square tests are typically used for categorical data, not ordered categorical data where the order is significant. Therefore, the Kruskal-Wallis H-test is the most suitable statistical method for analyzing the sensory evaluation data from the trained tasters at Ho Chi Minh City University of Food Industry, as it correctly handles ordinal data and compares multiple independent groups.