Undesirable Flavor Research Articles

Undesirable volatile compound analysis in infant formula based on nutritional analysis, GC-MS, and recombination/omission experiments methods

Infant formula (IF), rich in essential nutrients such as polyunsaturated fatty acids crucial for infant growth, is susceptible to quality deterioration due to fatty acid oxidation. This study aimed to analyze nutritional changes and off-flavors in commercially available one-stage IFs. Specifically, the study assessed the content of protein, lipid, and lactose. Headspace solid-phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS) was then used to analyze volatile compounds. Using Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA), the four samples can be distinctly separated. Odor activity values (OAVs) and variable importance in projection (VIP) were calculated to identify key odorant components. Subsequent recombinant/omission experiments confirmed pentanal, (E,E)-2,4-decadienal, hexanal, (E)-2-nonenal, and 1-penten-3-one as key contributors to off-flavors in IF. These findings provide a scientific basis for preventing the formation of undesirable flavors and preserving the nutritional integrity of one-stage IF during commercialization.

Glycation modification of protein hydrolysate from channel catfish (Ictalurus Punetaus) viscera to mitigate undesirable flavor: Unraveling structure and flavor characteristics

To investigate the impacts of glycation modification on the structure and flavor of fish viscera-derived protein hydrolysates, channel catfish viscera was utilized and hydrolyzed by Flavourzyme, followed by glycation with glucosamine, xylose, ribose and glucose, respectively. The structural characteristics, taste and odor of glycated products were evaluated. The results revealed that glycation led to an increase in peptides (<1 kDa) and a decrease in peptide fraction (>5 kDa). UV and fluorescence spectra indicated a gradual rise in absorbance and fluorescence intensity. Glucosamine-induced glycation significantly mitigated bitterness, while enhancing saltiness and umami. GC–MS/MS analysis revealed that glycation led to reduced undesirable odor, and formation of aromatic compounds. LC-MS/MS identified Arg and Lys as the main modification sites. Interestingly, aldehydes were found to modify peptides via carbonyl-amine reaction, leading to decreased fishy odor. The present study contributes to flavor improvement of fish viscera-derived peptides through glycation and high-value utilization of fish viscera.

Effect of myosin-kappa carrageenan pickering emulsions on the quality of bighead carp surimi gels

Emulsions could be utilized to improve surimi gels. How myosin-kappa carrageenan (κC) Pickering emulsions to affect the quality of bighead carp surimi is still unclear. The particle distribution of myosin-κC Pickering emulsion was characterized as uniform and stable through particle size potential and microstructure observations. The impact of oil substitution rate on the gel quality of bighead carp (Aristichthys nobilis) surimi was investigated by incorporating substitution oil into the surimi. The results indicated that the gel strength and hardness of bighead carp surimi increased significantly with higher oil substitution rates. When the myosin-κC Pickering emulsion completely replaced the oil, the gel hardness of surimi reached its highest level, and the L∗ value and whiteness significantly increased (P < 0.05). Additionally, the water-holding capacity (WHC) of the surimi gel improved with increasing oil substitution rates. Myosin-κC Pickering emulsions were evenly distributed within the gel matrix as small oil droplets, filling the pores of the surimi and effectively enhancing the gel network structure. Sensory evaluation and gas phase ion migration spectrometry demonstrated that the myosin-κC Pickering emulsion improved sensory properties and reduced undesirable flavors when it completely replaced the oil. These results suggest that myosin-κC Pickering emulsion is beneficial for enhancing the properties and flavor of surimi gels.

The Commercial Application of Insect Protein in Food Products: A Product Audit Based on Online Resources.

Insect protein has received considerable attention as an alternative to conventional animal proteins with its high nutritional contents and eco-friendly credentials. Exploring commercially available insect-protein-enhanced foods, this study aims to profile and compare such products in the ultra-processed category with products protein-enhanced with dairy (e.g., milk and whey) and plants (e.g., pea and rice). A global product audit was conducted drawing from English-language online retail portals to determine the product formats and statistically compare their nutritional contents with products fortified with non-insect proteins. The results show that four categories-flour/powder, pasta/noodle, starch-based snacks (e.g., chips, crackers, and cookies), and energy bars-are involved with food enhanced with insect protein. Flour/powder and pasta/noodles with insects demonstrated comparable protein contents to non-insect equivalents, highlighting insects' potential as effective protein sources. However, insect protein's performances in snacks and energy bars were less favourable, with significantly lower protein contents compared to products enhanced with non-insect sources. This may be attributed to the high fat content of insects, which may also contribute to undesirable flavours in complex foods, limiting their usage. The study highlights the need for industry innovation and scientific collaboration to overcome the challenges to widely applying insects as food ingredients, offering benefits for both the industry and consumers.

Unraveling the key cooked off-flavor compounds in thermally sterilized green tea beverages, and masking effect of tea raw material baking

The occurrence of the cooked off-flavor during the thermal sterilization of green tea beverages negatively impacts their quality. This study aimed to identify the key cooked off-flavor compounds by molecular sensory science. The increase of 12 compounds, including malty (e.g., 3-methylbutanal), floral (e.g., linalool), sweet (e.g., methional), and smoky (2-methoxy-4-vinylphenol) compounds, contributed to the development of the cooked off-flavor. Additionally, the loss of five aroma compounds—dimethyl sulfide, (E)-β-ionone, 2-methylbutanal, 1-penten-3-one, and (E,Z)-2,6-nonadienal—also caused the emergence this undesirable flavor. One potential solution to reduce the cooked off-flavor was the baking of tea raw materials. While baking did not significantly reduce the concentration of off-flavor compounds, it led to an increase in eight roasty aroma compounds, such as pyrazines and pyrroles, which helped partially mask the cooked off-flavor in green tea beverages.

Enhancing nutritional composition and aroma characteristics of kiwifruit wines through indigenous non-Saccharomyces yeast extracellular extract treatment

To unlock the potential of strains for further enhancing the aromatic complexity of kiwifruit wines while avoiding undesirable flavors, indigenous non-Saccharomyces yeast extracellular extract treatment for fermentation was established. The extracellular extract from Zygosaccharomyces rouxii, Pichia kudriavzevii, and Meyerozyma guilliermondii were prepared and supplemented individually or in pairs to the kiwifruit wine fermentation system. Subsequently, the changes in physicochemical properties, antioxidants, and volatile characteristics of kiwifruit wines produced by different protocols were comprehensively evaluated, and the major aroma descriptors affecting sensory acceptability were analyzed by sensory evaluation and partial least squares regression. The results showed that extracellular extract treatment significantly improved the organic acids and monomeric phenols content, antioxidant capacity, and volatiles of kiwifruit wines. Compared to Sc, the increase in esters and alcohols, along with the decrease in aldehydes and acids in Pk-Zr and Mg-Zr, enhanced the aromatic complexity while reduce grassy and fungal flavors, resulting in higher sensory acceptability.

Current Updates on Lactic Acid Production and Control during Baijiu Brewing

Lactic acid is closely linked to the safety and quality of baijiu, the traditional Chinese fermented alcoholic beverage. Produced by lactic acid bacteria during fermentation, it creates an acidic environment that inhibits the growth of spoilage organisms and harmful microbes, thereby enhancing the safety and stability of the final product. Additionally, lactic acid is a key contributor to baijiu’s flavor profile, providing a smooth and rounded taste. Its levels can significantly impact consumer experience. An excess of lactic acid can result in a sour, undesirable flavor, while insufficient levels may lead to a flat and less appealing taste. Maintaining balanced lactic acid levels is crucial for ensuring that baijiu is both safe and enjoyable to drink, ultimately contributing to the product’s success and marketability. This paper reviews the mechanisms of lactic acid production in baijiu, examines its effects on flavor and the potential causes of imbalances, explores regulatory measures for controlling lactic acid during brewing, and discusses the impact of these measures on baijiu’s quality, taste, and yield, along with practical applications by various distilleries. The goal of this paper is to provide a reference for regulating lactic acid in the baijiu production processes.

Growth and Depuration of Off‐Flavors in Rainbow Trout Oncorhynchus Mykiss in a Partial Recirculating Aquaculture System (PRAS)

ABSTRACTIn recirculating aquaculture systems (RAS), off‐flavours accumulated in fish muscle tissue can be problematic in terms of consumer acceptance and the reputation of farmed fish products. Off‐flavours often give fish earthy, muddy, or other undesirable flavours. Typically, off‐flavours are removed during a depuration period in which fish are fasted and held in clean water. Unfortunately, this causes additional costs and delayed sales, while fish lose weight and show a decrease in lipid content. First, we studied fish growth in a partial RAS (PRAS) where the conditions are very similar to those in depuration with a water exchange rate of 4000 L kg−1 feed, compared to RAS with a 650‐L water kg−1 feed. Rainbow trout (Oncorhynchus mykiss) was reared in both systems. Our aim was to combine the benefits of a higher water exchange rate: the lack of need for biofilters and a lower accumulation of off‐flavours while obtaining stable rearing conditions. Additionally, we studied the effects of moderate feeding and H2O2 addition during depuration. The fish grew faster in a PRAS than in a RAS when fed ad libitum. Thirteen off‐flavour compounds were found in the fish flesh and 11 in the circulating water. The H2O2 addition led to decreased levels of off‐flavours in the tank water and in fish muscle. The results showed no significant differences in off‐flavours between the fed and not‐fed systems, showing that moderate feeding did not prevent a good depuration result. However, the lipid content and the overall fish weight were higher in the fed systems, which suggests more effective depuration. Increased depuration efficiency can be an important tool when considering ways to improve the profitability of production.

Application of Nanomaterials in Food Packaging: A Review Study

Nanotechnology is one of the unused innovations which has opened its way to different businesses, and is broadly utilized in several areas. One of these industries which play a crucial role in wellbeing of the community is bundling industry. This is a review study conducted on nanotechnology in food packaging. Data collection was based on study features, nanotechnology, nano-composites, and food packaging. The results of research studies have revealed that nanotechnology-based packaging was able to repair packages and prevent food spoilage. Advantages of nanotechnology in food industry, including the ability to enrich as well as encapsulate and preserve useful compounds for their controlled delivery to the target cell, the ability to cover undesirable flavors, the utilization of dynamic, and shrewdly packaging and its application in food quality and security diagnostics have encouraged using this technology. Using these packages will protect food against exchange of oxygen and moisture from the external. Furthermore, nano-materials can be used to protect food from spoilage. Natural polymers such as sugars and proteins are able to form green nano-composites in combination with nano-materials and biomaterials such as cellulose nanofibers, which are non-toxic, biodegradable, and biocompatible, and are transformed into the environment by decomposing organisms. Knowing the capabilities of nanotechnology, it is hoped that the current food packaging systems can be modified and products can be introduced to the community in accordance with the culture of proper nutrition.

Karakteristik Velva Labu Kuning LA3 (Cucurbita moschata) Dari Campuran Labu Kuning-Air Dan Jenis Bahan Penstabil

Diversified fruit processing technology offers an alternative to improve undesirable flavors, adding value and extending shelf life. The LA3 pumpkin (Cucurbita moschata) has a pleasant taste and significant potential for processing into fruit velva. Yellow pumpkin velva is known for its smooth texture and resistance to melting. The choice of stabilizer significantly affects its consistency. This research aims to determine the most suitable stabilizer for producing LA3 pumpkin velva, with desirable melting resistance and favorable panelist preferences. A Completely Randomized Design (CRD)was employed, with factor A being the ratio of pumpkin: water (200 g: 40 mL; 200 g: 80 mL; 200 g: 120 mL; and 200 g: 160 mL), and factor B being the type of stabilizer (CMC and gum arabic). The objective was to determine the optimal formulation and stabilizer for LA3 pumpkin velva production. The research results showed that the best treatment LA3 pumpkin velva involved the ratio of 200 g pumpkin to 80 mL water with the CMC stabilizer, yielding an overrun of 21.23%, a melting speed of 18.57%, a lightness value (L*) of 46.09, and a β carotene content of 0.46 mg/100g of material. The organoleptic evaluation showed preference scores for taste at 4.08, color at 4.16, aroma at 4.16, texture at 4.16, and overall acceptance at 4.20.

Effect of Corynebacterium glutamicum Fermentation on the Volatile Flavors of the Enzymatic Hydrolysate of Soybean Protein Isolate.

This study focused on improving the flavor quality of seasonings, and enzymatic hydrolysis of soybean protein isolate (SPI) seasoning via traditional technology may lead to undesirable flavors. Herein, we aimed to develop a new type of SPI seasoning through microbial fermentation to improve its flavor quality. The effect of Corynebacterium glutamicum fermentation on the flavoring compounds of seasonings in SPI enzymatic hydrolysate was examined. Sensory evaluation showed that the SPI seasoning had mainly aromatic and roasted flavor, and the response signals of S18 (aromatic compounds), S24 (alcohols and aldehydes), and S25 (esters and ketones) sensors of the electronic nose differed significantly. Overall, 91 volatile compounds were identified via gas chromatography-mass spectrometry. SPI seasonings contained a higher number of alcohols, ketones, aromatics, and heterocyclic compounds than traditional seasonings, which had stronger cheese, fatty, and roasted aromas. According to the relative odor activity value (ROAV) analysis, n-pentylpyrzine, 2,6-dimethylpyrazine, and tetramethylpyrazine are the key flavoring compounds (ROAV ≥ 1) of SPI seasoning, which may impart a unique roasted and meaty aroma. Therefore, the fermentation of SPI enzymatic hydrolysate with C. glutamicum may improve the flavor quality of its products, providing a new method for the development and production of new seasoning products.

Comparative analysis of physical traits, mineral compositions, antioxidant contents, and metabolite profiles in five cherry tomato cultivars

Cherry tomatoes (Solanum lycopersicum var. cerasiforme) are cultivated and consumed worldwide. While numerous cultivars have been bred to enhance fruit quality, few studies have comprehensively evaluated the fruit quality of cherry tomato cultivars. In this study, we assessed fruits of five cherry tomato cultivars (Qianxi, Fengjingling, Fushan88, Yanyu, and Qiyu) at the red ripe stage through detailed analysis of their physical traits, mineral compositions, antioxidant contents, and metabolite profiles. Significant variations were observed among the cultivars in terms of fruit size, shape, firmness, weight, glossiness, and sepal length, with each cultivar displaying unique attributes. Mineral analysis revealed distinct patterns of essential and trace element accumulation, with notable differences in calcium, sodium, manganese, and selenium concentrations. Fenjingling was identified as a selenium enriched cultivar. Analysis of antioxidant contents highlighted Yanyu as particularly rich in vitamin C and Fenjingling as having elevated antioxidant enzyme activities. Metabolomics analysis identified a total number of 3,396 annotated metabolites, and the five cultivars showed distinct metabolomics profiles. Amino acid analysis showed Fushan88 to possess a superior profile, while sweetness and tartness assessments indicated that Yanyu exhibited higher total soluble solids (TSS) and acidity. Notably, red cherry tomato cultivars (Fushan88, Yanyu, and Qiyu) accumulated significantly higher levels of eugenol and α-tomatine, compounds associated with undesirable flavors, compared to pink cultivars (Qianxi and Fengjingling). Taken together, our results provide novel insights into the physical traits, nutritional value, and flavor-associated metabolites of cherry tomatoes, offering knowledge that could be implemented for the breeding, cultivation, and marketing of cherry tomato cultivars.

Proteomic Analysis of the Characteristic Flavor Components in Bacillus subtilis BSNK-5-Fermented Soymilk.

Fermentation with Bacillus subtilis significantly enhances the physiological activity and bioavailability of soymilk, but the resulting characteristic flavor seriously affects its industrial promotion. The objective of this study was to identify key proteins associated with characteristic flavors in B. subtilis BSNK-5-fermented soymilk using tandem mass tag (TMT) proteomics. The results showed that a total of 765 differentially expressed proteins were identified. Seventy differentially expressed proteins related to characteristic flavor were screened through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. After integrating metabolomics data, fifteen key proteases of characteristic flavor components in BSNK-5-fermented soymilk were further identified, and free ammonia was added. In addition, there were five main formation mechanisms, including the decomposition of urea to produce ammonia; the degradation of glutamate by glutamate dehydrogenase to produce ammonia; the degradation of threonine and non-enzymatic changes to form the derivative 2,5-dimethylpyrazine; the degradation of valine, leucine, and isoleucine to synthesize isovalerate and 2-methylbutyrate; and the metabolism of pyruvate and lactate to synthesize acetate. These results provide a theoretical foundation for the improvement of undesirable flavor in B. subtilis BSNK-5-fermented soy foods.

The hotspot of consumers complaints on infant formula: Exploring the relationship among volatile components, sensory evaluation, and aroma recombination and omission experiment

Two-stage infant formula (IF) is rich in polyunsaturated fatty acids (PUFAs), However, PUFAs are susceptible to oxidation, thus affecting the flavor profile of the product. This study aimed to evaluate 4 samples with the participation of 60 consumers. Among these, three samples with the lowest consumer preference and one with the highest preference were selected as controls to explain the causes of off-flavors in two-stage infant formulas. Through qualitative and quantitative analysis of 28 flavor-active compounds in two-stage infant formulas using GC-MS, E-nose, GC-O, odor activity values (OAVs), and variable importance in projection (VIP) values, hexanal, heptanal, pentanal, octanal, and 1-penten-3-one were identified as the important compounds affecting the flavor of two-stage infant formulas. Further, recombination/deficiency experiments confirmed hexanal and heptanal as the key undesirable flavor components in two-stage infant formulas.

Application of ATR-FTIR for Green Arabica Bean Shelf-Life Determination in Accelerated Storage.

Coffee bean oxidation is associated with enzymatic and non-enzymatic browning, the degradation of desirable aromatic compounds, the development of undesirable flavors, increased susceptibility to microbial spoilage, and volatile compound losses. This study investigated natural dry process (DP) and honey process (HP) green coffee beans stored in GrainPro® bags for 0, 5, 10, and 20 days under accelerated storage conditions at 30 °C, 40 °C, and 50 °C with relative humidity of 50%. A kinetic model was used to estimate the shelf life of the green coffee beans. DP recorded durability of 45.67, 29.9, and 24.92 days at 30 °C, 40 °C, and 50 °C, respectively, with HP 60.34, 38.07, and 19.22 days. Partial least squares (PLS) analysis was performed to build the models in order to predict the shelf life of coffee based on peroxide (PV) and thiobarbituric acid reactive substances (TBARS) values. In terms of prediction with leave-one-out cross-validation (LOOCV), PLS provided a higher accuracy for TBARS (R2 = 0.801), while PV was lower (R2 = 0.469). However, the auto-prediction showed good agreement among the observed and predicted values in both PV (R2 = 0.802) and TBARS (R2 = 0.932). Based on the variable importance of projection (VIP) scores, the ATR-FTIR peaks as 3000-2825, 2154-2150, 1780-1712, 1487-2483, 1186-1126, 1107-1097, and 1012-949 cm-1 were identified to be the most related to PV and TBARS on green coffee beans shelf life. ATR-FITR showed potential as a fast and accurate technique to evaluate the oxidation reaction that related to the loss of coffee quality during storage.

Efficacy of Clustering Algorithms for Young ‘Nam-Hom’ Coconut Gene Expression Data in Unveiling the Specific Genes Determining the Flavor: A Comparative Analysis of K-means and Fuzzy C-means

This study explores the application of K-means and Fuzzy C-means clustering techniques to analyze gene expression data related to the flavor of young ‘Nam-Hom’ coconuts. By comparing these clustering methods, the research aims to identify gene clusters that significantly influence the aromatic and off-flavor profiles of young ‘Nam-Hom’ coconuts stored at different temperatures (4°C and 25°C). Specifically, our findings highlight clusters involved in lipid metabolism and cold stress response which are crucial for developing desirable and undesirable flavors, such as LOX1 and ADH2 genes. The study advances our understanding of coconut genetics demonstrates the utility of clustering techniques in agricultural genomics, offering valuable pathways for future genetic enhancement and storage optimization strategies aimed at improving coconut aroma.

Reduction of antinutrients and off-flavour in kidney bean flour by acidic and alkaline reactive extrusion

The presence of antinutrients and undesirable flavours in kidney bean flour poses challenges to consumer acceptance. Although extrusion can mitigate antinutrients to some extent, its impact on reducing beany flavour in bean flour remains underexplored. This study investigated the effects of injecting acetic acid or sodium carbonate solutions at three concentration levels (0.05, 0.1, 0.15 mol/L), in conjunction with three temperature profiles (40/60/80/80/90, 40/60/80/90/110, 50/70/90/110/130 °C) and two feed moisture levels (25, 30 %), on the removal of antinutrients (condensed tannins, trypsin inhibitor activity, phytic acid, raffinose family oligosaccharides) and reduction of volatile compounds that contribute to beany flavour in whole kidney bean flour. The results showed that all concentrations of acetic acid and sodium carbonate solutions effectively reduced condensed tannins compared to water, especially at 130 °C extrusion temperature. Introducing acetic acid and sodium carbonate solutions at a concentration of 0.15 mol/L led to 72 and 90 % reduction of total raffinose family oligosaccharide content, respectively, in contrast to the 17 % reduction observed with water alone. The incorporation of sodium carbonate solution reduced the total volatile compounds by 45–58 % as compared with water (23–33 %) and acetic acid (11–27 %). This reduction was primarily due to the reduction of aldehydes, alcohols, and aromatic hydrocarbons. These results indicate that injecting sodium carbonate solution during extrusion can effectively reduce antinutrients and beany flavour compounds in kidney bean flour.

Exploring off‐flavour compounds in soy‐based meats: Mechanisms and removal methods

AbstractPlant‐based meat is projected to address world‐wide meat shortage and supply–demand imbalances, potentially promoting the growth of sustainable diet choices. Soybean is a key ingredient to produce this alternative food, but the off‐flavours that naturally occur in soy can hinder its widespread acceptance among consumers. This review extensively elaborates on the primary compounds responsible for off‐flavours, their formation mechanisms, and removal techniques. Lipoxygenase oxidation–reduction, oleosins removal, adjustment extrusion conditions, and β‐cyclodextrin treatment were discussed. Fermentation mechanisms, solvent extraction, enzymes hydrolysis, flavouring, and controlling storage conditions were summarised. The most crucial, safe, and effective techniques were enzyme restriction, β‐cyclodextrin treatment in conjugation with phospholipase A2, and modification of the extrusion condition. The reviews provide a systematic summary of the development and prevention methods for the undesirable flavour of soy protein isolate and soy‐based meat products.

Cultivar Differentiation and Quality Changes Monitoring of Strawberry during Storage using Electronic Nose

Strawberry, Fragaria x ananassa Duchesne, is a popular fruit with unique aromas and a sour-to-sweet taste. Aroma is an important aspect of identifying the quality of Strawberry during storage after harvesting. In this study, an electronic nose was used to identify the characteristics of volatile organic compounds produced in the Strawberry during storage and compare differences in characteristics of volatile organic compounds according to the cultivar of Strawberry. The results indicate no difference between quality indexes in Strawberry except for the weight loss (WL) and volatile organic compounds (VOCs) production during storage. The WL of Seolhyang (ST1) and Geumsil (ST2) increased from 0 to 10 d. VOCs in ST1 correlated to 1-Propanol, 2-methyl-, methyl hexanoate, propyl nonanoate, methyl formate, (Z)-3-Hexen-1-ol, and (E)-2-hexenal during the storage period at 5 ℃. VOCs in ST2 were identified as 5-ethyl-3-hydroxy-4-methyl-2(5H)-furanone, 2-ethyl-3-methylpyrazine, methyl butanoate, (Z)-3-Hexen-1-ol, and methyl hexanoate. These VOCs can be used as biomarkers in the early detection of undesirable flavor production in the food industry and crucial factors in the shelf-life determination of Strawberry during storage.

Quality characteristics and volatile compounds of plant-based patties supplemented with biji powder

Biji (okara or soybean curd residue), a by-product of soybean processing, contains proteins. In this study, control plant-based patties were compared with patties supplemented with biji powder (5, 10, 15, and 20 g). Increasing the amount of biji added to patties was found to be favorably associated with increased water-holding capacity, decreased cooking loss, and reduced diameter and thickness. Texture profile analysis revealed trends of increased hardness, springiness, cohesiveness, and chewiness which were proportional to the inclusion of biji powder. The volatile compounds in plant-based patties supplemented with biji were analyzed using HS-SPME-Arrow-GC/MS. Notably, benzaldehyde, nonanal, and 2-heptanone, which are undesirable flavors, were detected at significantly lower levels in patties supplemented with biji. Therefore, biji can serve as a supplementary ingredient to enhance the texture and flavor of plant-based patties.