Short-term frozen storage of raw chicken meat improves its flavor traits upon stewing

Identification and selection of volatile compounds derived from lipid oxidation as indicators for quality deterioration of frozen white meat and red meat using HS-SPME-GC-MS combined with OPLS-DA

This work aimed to investigate the effects of frozen storage on volatile compounds of white meats (chicken and duck) and red meats (pork, beef, and mutton). The samples were stored at -18 °C for 0, 2, 4, 10, 18 weeks, and volatile compounds were analyzed by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. Results indicated that the total amounts of volatile compounds increased with frozen storage duration of meats. The correlations were observed between frozen storage duration and levels of 2-ethyl-1-hexanol, tetradecane, nonanal, decanal, octanal, tridecanal, benzaldehyde, pentadecane, propanoic acid,2-methyl-,3-hydroxy-2,2,4-trimethylpentyl ester, heptadecane, and hexanal (r = 0.7456-0.9873). Levels of octanal and propanoic acid,2-methyl-,3-hydroxy-2,2,4-trimethylpentyl ester in white meat and benzaldehyde in red meat versus frozen storage duration fitted very well with zero-order reactions. Therefore, it was concluded that changes in volatile compounds derived from lipid oxidation may be used as indicators of quality deterioration during frozen storage of meat.

A review of taste-active compounds in meat: Identification, influencing factors, and taste transduction mechanism

Poultry and livestock meat are important parts of the human diet. As living standards have improved, food taste has become a major influence on consumer quality assessment and meat purchasing choices. There is increasing research interest in meat taste and meat taste-active compounds, which include free amino acids, flavor nucleotides, taste-active peptides, organic acids, soluble sugars, and inorganic ions. Taste component research is also an important part of sensory science. A deeper understanding of the meat taste perception mechanism and interactions among different taste compounds will promote the development of meat science and sensory evaluation. This article reviews the main taste compounds in meat, factors influencing their concentrations, and the identification and measurement of taste-active compounds, as well as summarizing the mechanisms of taste sensing and perception. Finally, the future of scientific taste component evaluation is discussed. This review provides a theoretical basis for research on meat taste and an important reference for the development of the meat industry.

Systematic evaluation of the meat qualities of free-range chicken (Xuan-Zhou) under different ages explored the optimal slaughter age

Meat qualities of free-range chicken (Xuan-Zhou) (XZ-FRC) are closely associated with slaughter age and directly influence the economic benefits of supplier and consumer's preference. Understanding of the relationship between meat qualities and ages will be of prime important to explore a better slaughter age of XZ-FRC. In this study, the quality traits of breast and thigh muscles from XZ-FRCs at 9 to 14 wk were analyzed to establish a relatively reliable method for selecting a better slaughter age. The results showed that the effects of slaughter ages on color (CIE L*, a* and b* values), shear force, centrifugal loss, and flavor of XZ-FRCs were significant (P < 0.05). There were greater differences in meat qualities, whatever breast or thigh muscles, between same or different ages. Eleven feature indexes used for colligation evaluation of slaughter age were selected by combining the quality characteristics and data analysis. The score of colligation evaluation for XZ-FRCs at 12 wk was higher than that at 9 and 14 wk, suggesting that the 12 wk was an optimal slaughter age. This work would provide a reference method that helps the producers of livestock and poultry to select a better slaughter age.

Changes in water-soluble taste compounds of tilapia (Oreochromis niloticus) fillets subjected to different thawing methods during long-term frozen storage

BACKGROUND

The taste of fish is highly dependent on the composition of free amino acids (FAAs) and nucleotides. The present study aimed to investigate the effect of long-term frozen storage periods (-18 °C, up to 6 months) and thawing methods [water thawing (WT, 25 °C), air thawing (AT, 25 °C), and chilled air thawing (CAT, 4 °C)] on the taste quality of tilapia (Oreochromis niloticus) fillets.

RESULTS

The results showed that increase in bitter FAAs of CAT samples was 150.57% at 6 months of storage, which was lower than that of AT and WT. Glycine was the most abundant FAA and CAT maintained the highest sweet FAAs (249.90 mg/100 g). Additionally, the inosine monophosphate (IMP) of CAT samples were 1.18 and 1.09 times higher than that of WT and AT, respectively, at a frozen period of 6 months. In particular, the increase in equivalent umami concentration (EUC) values ranged from 24.25% to 103.16% in the three groups during the first 2 months. Data from principal component analysis (PCA) and orthogonal partial least-squares discrimination analysis (OPLS-DA) indicated that the taste quality was highly correlated with high levels of FAAs, hypoxanthine inosine (HxR) and hypoxanthine (Hx) as the storage time progressed.

CONCLUSION

In general, CAT is beneficial in maintaining the taste quality of tilapia fillets during frozen storage, and frozen durations for 2 months enhances the umami flavor. This study provides useful information for the preservation of frozen aquatic products during the storage and thawing, and enrich the theoretical knowledge of the flavor chemistry of fish products. © 2024 Society of Chemical Industry.

Unraveling the flavor profiles of chicken meat: Classes, biosynthesis, influencing factors in flavor development, and sensory evaluation

Chicken is renowned as the most affordable meat option, prized by consumers worldwide for its unique flavor, and universally recognized for its essential savory flavor. Current research endeavors are increasingly dedicated to exploring the flavor profile of chicken meat. However, there is a noticeable gap in comprehensive reviews dedicated specifically to the flavor quality of chicken meat, although existing reviews cover meat flavor profiles of various animal species. This review aims to fill this gap by synthesizing knowledge from published literature to describe the compounds, chemistry reaction, influencing factors, and sensory evaluation associated with chicken meat flavor. The flavor compounds in chicken meat mainly included water-soluble low-molecular-weight substances and lipids, as well as volatile compounds such as aldehydes, ketones, alcohols, acids, esters, hydrocarbons, furans, nitrogen, and sulfur-containing compounds. The significant synthesis pathways of flavor components were Maillard reaction, Strecker degradation, lipid oxidation, lipid-Maillard interaction, and thiamine degradation. Preslaughter factors, including age, breed/strain, rearing management, muscle type, and sex of chicken, as well as postmortem conditions such as aging, cooking conditions, and low-temperature storage, were closely linked to flavor development and accounted for the significant differences observed in flavor components. Moreover, the sensory methods used to evaluate the chicken meat flavor were elaborated. This review contributes to a more comprehensive understanding of the flavor profile of chicken meat. It can serve as a guide for enhancing chicken meat flavor quality and provide a foundation for developing customized chicken products.

The Effects of Assisted Freezing with Different Ultrasound Power Rates on the Quality and Flavor of Braised Beef

This study investigated the effects of ultrasound-assisted immersion freezing (UIF) at different power rates (0, 200, 400, and 600 W) on the changes in beef quality and flavor after braising. The results demonstrated that UIF treatment at 400 W significantly reduced the juice loss (cooking loss decreased from 49.04% to 39.74%) and fat oxidation (TBARS value decreased from 0.32 mg/kg to 0.20 mg/kg) of braised beef. In addition, the tenderness (hardness value decreased from 5601.50 g to 2849.46 g) and color stability of braised beef were improved after UIF treatment. The flavor characteristics of braised beef were characterized using an electronic nose and an electronic tongue. The PCA analysis data showed that the cumulative contribution rates of the first and second principal components were 85% and 93.2%, respectively, with the first principal component accounting for a higher proportion. The UIF-400 W group had the highest concentration for the first principal component, and the differentiation was not significant compared to the control group. The total amino acid values of different power UIF treatment groups were improved compared to the AF treatment group, indicating that UIF can effectively reduce the losses caused by freezing. The results demonstrate that ultrasound-assisted freezing treatment is beneficial in enhancing the tenderness and flavor attributes of beef after braising, providing new insights into the processing of meat products with desirable quality characteristics.

Evaluation of the aroma and taste contributions of star anise (I. Verum hook. f.) in braised duck leg via flavor omics combined with multivariate statistics

To promote the rationalized and standardized application of star anise in braised poultry products, the effects of different concentrations of star anise (0 %, 0.1 %, 0.2 %, 0.3 %, and 0.4 %) on the aroma and taste compounds intensities of braised duck legs from the perspective of flavor were evaluated by using flavor omics approach combined with multivariate statistics. The volatile flavor results showed that there were 17 key aroma compounds with odor activity values (OAVs) > 1, including aldehydes, alcohols, ketones, furans, hydrocarbons, and ethers. Most of the aroma compounds related to lipid oxidation were significantly inhibited when the concentration of star anise reached 0.2 %, especially inhibited the concentrations of the unpleasant off-odorants containing hexanal, heptanal, 1-octen-3-ol, and 2-pentyl-furan by 30.27 %, 15.08 %, 30.30 %, and 41.63 %, respectively. And the flavor intensities of these compounds were negatively correlated with the concentration of star anise. Additionally, star anise gave braised duck legs characteristic aroma such as floral and herbal notes. The taste results revealed that the maximum umami value (4.36 g MSG/100 g) of braised duck legs was observed when the concentration of star anise reached 0.2 %. Six flavor markers were obtained via PLS-DA model, and the flavors of braised duck legs with different concentrations of star anise were distinguished. This study provided a vital theoretical basis for the rational application and flavor control of star anise in braised poultry products.

Umami Characteristics and Taste Improvement Mechanism of Meat

Taste is one of the five senses that detect vital information about what we are eating. Comprehending taste is crucial for enhancing the flavor of foodstuffs and high-protein foods like meat. Umami has global recognition as the fifth elementary taste, alongside sweetness, sourness, saltiness, and bitterness. Umami compounds are known to enhance the sensation of recognized flavors such as salty, sweet, bitter, and others. This could end up in greater food consumption by consumption by consumers. With the rising global population, meat consumption is rising and is projected to double by 2025. It is crucial to comprehend the umami mechanism of meat and meat products, identify novel compounds, and employ laboratory methodologies to gather varied information. This knowledge will aid in the development of new consumer products. Although very limited information is available on umami taste and compounds in meat through research data. This article discusses recent advancements in umami compounds in other foodstuff as well as meat to aid in designing future research and meat product development. Moreover, another objective of this review is to learn present techniques in foodstuffs to enhance umami taste and utilize that knowledge in meat products.

Coexisting with Ice Crystals: Cryogenic Preservation of Muscle Food─Mechanisms, Challenges, and Cutting-Edge Strategies

Cryopreservation, one of the most effective preservation methods, is essential for maintaining the safety and quality of food. However, there is no denying the fact that the quality of muscle food deteriorates as a result of the unavoidable production of ice. Advancements in cryoregulatory materials and techniques have effectively mitigated the adverse impacts of ice, thereby enhancing the standard of freezing preservation. The first part of this overview explains how ice forms, including the theoretical foundations of nucleation, growth, and recrystallization as well as the key influencing factors that affect each process. Subsequently, the impact of ice formation on the eating quality and nutritional value of muscle food is delineated. A systematic explanation of cutting-edge strategies based on nucleation intervention, growth control, and recrystallization inhibition is offered. These methods include antifreeze proteins, ice-nucleating proteins, antifreeze peptides, natural deep eutectic solvents, polysaccharides, amino acids, and their derivatives. Furthermore, advanced physical techniques such as electrostatic fields, magnetic fields, acoustic fields, liquid nitrogen, and supercooling preservation techniques are expounded upon, which effectively hinder the formation of ice crystals during cryopreservation. The paper outlines the difficulties and potential directions in ice inhibition for effective cryopreservation.

Pork organs as a potential source of flavour-related substances

The increase in world population has generated a higher demand for quality proteins, increasing the production in meat industry but also the generation of thousands of tons of by-products, with a negative economic and environmental impact. The valorisation of slaughterhouse by-products by giving by-products a new use as food ingredient is one of the best strategies to add value while reducing environmental damage. Flavour is one of the most influential parameters in the purchasing decision of consumers, and in meat products it is mostly influenced by the content in free amino acids and nucleotides. In this study, the potential of 4 pork organs (liver, kidney, lung, and brain) as a source of flavour-related substances was investigated. Liver proved to be the organ showing the highest content of free and total amino acids related to taste, while kidney was the organ with the highest content of umami nucleotides. The results of the Taste Activity Value indicated that umami, sweet, and bittersweet amino acids are main responsible for the taste of the organs. On the other hand, the synergy between amino acids and nucleotides in relation with umami taste was determined, showing liver and kidney the best values in Equivalent Umami Content. In addition, the antioxidant activity of the organs was determined, and liver and kidney showed the highest antioxidant activity in all assays (p < 0.05). In conclusion, pork organs, especially liver and kidney, may be good candidates to be used as raw materials to produce functional flavouring ingredients.

Effects of replacement partial sodium chloride on characteristic flavor substances of bacon during storage based on GC×GC-MS and non-targeted metabolomics analyses

Comprehensive 2D gas chromatography-mass spectrometry (GC × GC-MS) and non-targeted metabolomics were employed to investigate the differences in key volatile flavor substances between bacon salted with alternative salt and traditional bacon during storage. The GC × GC-MS analysis revealed that among 146 volatile compounds in both types of bacon, alcohol, aldehydes, ketones, phenols, and alkenes were the most abundant. Additionally, non-targeted metabolomics indicated that the changes in amino acids and the oxidation degradation of lipids could be the main reasons for the flavor differences among the two kinds of bacon. Furthermore, the acceptability scores of both bacon types showed a general upward trend as the storage time increased, indicating that the metabolic of substances occurring during bacon storage significantly impact its overall quality. By partially substituting sodium chloride with 22% potassium chloride and 11% calcium ascorbate, coupled with appropriate storage conditions, the quality of bacon can be improved.

Effects of temperature fluctuations on non-volatile taste compounds in tilapia fillets (Oreochromis niloticus)

In this study, the effect of temperature fluctuations on the taste quality of tilapia fillets during frozen storage was investigated. Major temperature-responsive factors included free amino acids (FAAs) and flavor nucleotides in fish fillets, which were identified using multidimensional infrared spectroscopy (MM-IR). The main FAA in tilapia fillets is a sweet amino acid (glycine). Compared with the control group, the umami FAAs and sweetness FAAs were significantly increased, and the total FAAs content increased to 1.30 times after the ninth fluctuation, reaching the highest level (611.16 ± 73.60 mg/100 g). Considering the equivalent umami intensity values, adenosine monophosphate and inosine monophosphate were retained during the first and second temperature fluctuations. In addition, the content of Na⁺, K⁺, and Ca²⁺ decreased (P < 0.05). Therefore, MM-IR is an effective method to identify taste components. With regard to taste quality, temperature fluctuations in the twofold range have an umami-enhancing effect.

Effects of kojic acid on changes in the microstructure and myofibrillar protein of duck meat during superchilled storage

This study investigated the effect of 0.8% (m/v) kojic acid treatment on changes in the microstructure and myofibrillar protein of duck meat covered with oxygen-permeable polyvinylchloride (PVC) film (9 ± 0.5 µM) during superchilled storage (-1.65 ± 0.5°C). The superchilled samples exhibited wider gaps between muscle fibers at 5 weeks storage compared with kojic acid-treated groups. Based on the variation of water status, the water-holding capacity decreased significantly (p < 0.05), and bound water and immobilized water were gradually converted into free water during superchilled storage. For kojic acid-treated samples, however, no major changes were observed with respect to muscle structure, water status, and protein degradation at 6 weeks. The 0.8% (m/v) kojic acid treatment increased the water-holding capacity, reduced carbonyl content and protein degradation, and decreased the α-helix contents loss of myofibrillar proteins. Kojic acid treatment effectively protected myofibrillar protein structure from being destroyed during superchilled storage, suggesting that this method was a good way to reduce protein oxidation and prolonged its shelf life.

Correlation of Taste Components with Consumer Preferences and Emotions in Chinese Mitten Crabs (Eriocheir sinensis): The Use of Artificial Neural Network Model

This study took a consumer sensory perspective to investigate the relationship between taste components and consumers’ preferences and emotions. Abdomen meat (M), hepatopancreas (H), and gonads (G) of Chinese mitten crabs, one from Chongming, the Jianghai 21 variety (C-JH), and two from Taixing, the Jianghai 21 (T-JH) and Yangtze II varieties (T-CJ), were used to evaluate flavor quality. The results indicated that in the abdomen meat, differences in taste components were mainly shown in the content of sweet amino acids, bitter amino acids, K+, and Ca2+; M-C-JH had the highest EUC value of 9.01 g/100 g. In the hepatopancreas, bitter amino acids were all significantly higher in H-C-JH (569.52 mg/100 g) than in the other groups (p < 0.05). In the gonads, the umami amino acid content was significantly higher in G-T-JH than in the other groups (p < 0.05) (EUC values: G-T-JH > G-C-JH > G-T-CJ). Consumer sensory responses showed that different edible parts of the crab evoked different emotions, with crab meat being closely associated with positive emotions and more complex emotional expressions for the hepatopancreas and gonads. In comparison, consumers were more emotionally positive when consuming Yangtze II crab. H-C-JH evoked negative emotions due to high bitter taste intensities. Multifactor analysis (MFA) showed arginine, alanine, glycine, proline, K+, and Ca2+ were found to have a positive correlation with consumer preference; an artificial neural network model with three neurons was built with good correlation (R2 = 0.98). This study can provide a theoretical foundation for the breeding of Chinese mitten crabs, new insights into the river crab industry, and the consumer market.

Effects of Drying Methods on Taste Components and Flavor Characterization of Cordyceps militaris

The influences of four drying methods (hot air drying (HAD), vacuum freeze drying (VFD), vacuum drying (VD) and intermittent microwave combined with hot air drying (MW-HAD)) on the taste profile and flavor characteristic of Cordyceps militaris were investigated. MW-HAD samples had the highest levels of umami taste 5'-nucleotides, bitter taste amino acids, and equivalent umami concentration (EUC) value. The aroma fingerprints and differences of dried Cordyceps militaris were established by GC-MS with odor activity values (OAVs) and GC-IMS with principal component analysis (PCA). GC-MS data showed that the predominant volatiles of dried samples were aldehydes, alcohols, and ketones. VFD samples had the highest amount of total aroma compounds and C8 compounds. Moreover, 21 aroma-active components (OAVs ≥ 1) were the main contributors to the flavor of dried Cordyceps militaris. The OAVs of 1-octen-3-one and 3-octanone associated with mushroom-like odor in VFD were significantly higher than other samples. Furthermore, a significant difference in flavor compounds of four dried samples was also clearly demonstrated by GC-IMS analysis with PCA. GC-IMS analysis revealed that VFD samples had the most abundant flavor compounds. Overall, MW-HAD was an effective drying method to promote umami taste, and VFD could superiorly preserve volatiles and characteristic aroma compounds in dried Cordyceps militaris.

Effect of cooking modes on quality and flavor characteristic in Clitocybe squamulose chicken soup

The effects of cooking modes [cooking in stainless-steel pot (SS), ceramic pot (CP), and electrical ceramic stewpot (EC) with different stewing time] on chemical compositions, whiteness, 5'-nucleotides, fatty acids (FAs), sensory quality and flavor substances in chicken soup added Clitocybe squamulose (Pers.) Kumm (a natural edible fungus) were investigated. The results showed that CP chicken soup had higher soluble solid matter (5.83 g/100 mL), total sugar (2.38 mg/mL), crude protein (7.58 g/100 g), and 5'-nucleotides (325.53 mg/mL) than EC and SS chicken soups. 48 volatile flavor compounds, mainly aldehydes and alkanes, were found by gas chromatography-mass spectrometry (GC-MS), and the characteristic flavor substances were identified by Principal component analysis (PCA) and orthogonal partial least squares discrimination analysis (OPLS-DA). Hexanal, (E,E)-2,4-decadienal and 3-methyl-hexadecane were the most abundant differential volatile compounds in the CP chicken soup. Additionally, the results of sensory evaluation showed that the chicken soup cooked in CP had the higher values of aroma, taste, and overall acceptability. Our results indicate that CP mode might be the best option for cooking chicken soup. This study provides a new perspective in the improvement of the quality and flavor of chicken soup by using an appropriate cooking mode. Theoretical support for the use of various cooking modes is also discussed to improve the quality of chicken soup at home and in the industry.

Oxidative stability of chicken burgers using organic coffee husk extract

The antioxidant capacity of organic coffee husk extract (Coffee arabica L.) added to chicken burgers was evaluated. Two formulations were prepared: with addition of the extract (100 and 200 ppm CAE/kg), in addition to control formulations without the addition of antioxidant, and with the addition of synthetic antioxidant. The products were characterized by physical and chemical analysis and analyzed for oxidative stability during 45 days of storage under freezing. The addition of extract in the proportion of 200 ppm CAE/kg of hamburger revealed efficacy against lipid oxidation equivalent to treatment with a synthetic antioxidant. As for protein oxidation, there was no pro or antioxidant influence in the treatments. The addition of organic coffee husk extract to chicken hamburgers is thus indicated, being considered as a potential natural additive. In addition, the use of coffee husks helps to minimize the lager amounts of agro-industrial by-products generated by the coffee industry.

Physicochemical Characteristics and Flavor-Related Compounds of Fresh and Frozen-Thawed Thigh Meats from Chickens

The physicochemical characteristics and flavor-related compounds of thigh meat derived from diverse Korean native chickens (KNC), namely Hanhyup No. 3 (HH3), Woorimatdag No 1 (WRMD 1), and Woorimatdag No 2 (WRMD 2), under fresh and frozen-thawed conditions were studied and compared with those of commercial broilers (CB). Regardless of the breed, KNC showed a higher (p < 0.05) percentage of linoleic and arachidonic acid. The highest proportion of docosahexaenoic acid was observed in WRMD 2. Despite having a higher collagen content, thigh meat derived from KNC maintained a similar texture profile in comparison to that of CB. The concentrations of most free amino acids (FAA), except for taurine, tryptophan, and carnosine, were higher in frozen-thawed meat than in fresh meat. Regarding volatile organic compounds (VOC), following freezing, the concentration of favorable VOCs increased in CB, but decreased in WRMD 1, suggesting a loss of pleasant flavor in frozen-thawed meat. This study indicated that changes in VOCs, including hydrocarbons (d-limonene, heptadecane, hexadecane, naphthalene, pentadecane, 3-methyl-, tridecane), esters (arsenous acid, tris(trimethylsilyl) ester, decanoic acid, ethyl ester, hexadecanoic acid, ethyl ester), alcohol (1-hexanol, 2-ethyl-), ketones (5,9-undecadien-2-one, 6,10-dimethyl-), and aldehydes (pentadecanal-, tetradecanal, tridecanal), may be a promising marker for distinguishing between fresh and frozen-thawed chicken thigh meat. These findings are of critical importance as preliminary data for developing high-quality chicken meat products.

Role of Lipids in Food Flavor Generation

Lipids in food are a source of essential fatty acids and also play a crucial role in flavor and off-flavor development. Lipids contribute to food flavor generation due to their degradation to volatile compounds during food processing, heating/cooking, and storage and/or interactions with other constituents developed from the Maillard reaction and Strecker degradation, among others. The degradation of lipids mainly occurs via autoxidation, photooxidation, and enzymatic oxidation, which produce a myriad of volatile compounds. The oxidation of unsaturated fatty acids generates hydroperoxides that then further break down to odor-active volatile secondary lipid oxidation products including aldehydes, alcohols, and ketones. In this contribution, a summary of the most relevant and recent findings on the production of volatile compounds from lipid degradation and Maillard reactions and their interaction has been compiled and discussed. In particular, the effects of processing such as cooking, drying, and fermentation as well as the storage of lipid-based foods on flavor generation are briefly discussed.

Progress of Research on the Application of Nanoelectronic Smelling in the Field of Food

In the past 20 years, the development of an artificial olfactory system has made great progress and improvements. In recent years, as a new type of sensor, nanoelectronic smelling has been widely used in the food and drug industry because of its advantages of accurate sensitivity and good selectivity. This paper reviews the latest applications and progress of nanoelectronic smelling in animal-, plant-, and microbial-based foods. This includes an analysis of the status of nanoelectronic smelling in animal-based foods, an analysis of its harmful composition in plant-based foods, and an analysis of the microorganism quantity in microbial-based foods. We also conduct a flavor component analysis and an assessment of the advantages of nanoelectronic smelling. On this basis, the principles and structures of nanoelectronic smelling are also analyzed. Finally, the limitations and challenges of nanoelectronic smelling are summarized, and the future development of nanoelectronic smelling is proposed.

Enrichment of taste and aroma perceptions in chicken meat stewed in braised soup used repeatedly

Flavor enrichment of sauce-braised chicken creates a popular umami taste and aroma. In order to preliminarily reveal the enrichment of taste and aroma compounds of sauce-braised meat products processed with braised soup used repeatedly, the system containing only chicken and chicken soup was designed to simulate the process of repeated stewing. Free amino acids, 5-nucleotides, fatty acids, and volatile compounds in stewed chicken were determined, and taste and aroma profiles were evaluated using an electronic tongue (E-tongue) and an electronic nose (E-nose), respectively. As repeated stewing times increased, the total free amino acid content increased from 514.37 mg/100 g to 721.33 mg/100 g, and the contents of 5'-inosine monophosphate, 5'-guanosine monophosphate, and 5'-adenosine monophosphate increased by approximately 20%. Meanwhile, the relative content of saturated fatty acids increased, and the relative content of monounsaturated fatty acids decreased significantly. Oleic acid, linoleic acid, and palmitoleic acid accounted for more than 80% of the total fatty acid content. A total of 15 aroma-active compounds were identified during repeated stewing, and their concentrations increased by more than 40%, especially for monounsaturated alkenals. Within 10 times of repeated stewing, the taste and aroma compounds were enriched because of a decrease in the concentration difference of taste substances and an increase in the flavor-adsorption capacity of fat, which was also consistent with the results from the E-nose and E-tongue. The taste and aroma of stewed chicken tended to remain constant after 10 times of repeated stewing of braised soup. The obtained information can provide guidelines for regulating the aroma and taste of sauce-braised chicken. PRACTICAL APPLICATION: The fat level of stewed chicken and the difference in concentration between stewed meat and braised soup were important potential factors that could be employed to enhance the flavor of stewed meat.

Fatty acid profiles and flavour-related compounds of the retorted Korean ginseng chicken soup (Samgyetang) affected by pre-treated black garlic extract

Objective

This study aimed to characterize the effect of pre-treated black garlic (BG) extracts addition into retorted Korean ginseng chicken soup (Samgyetang) on the fatty acid composition and flavour-related indexes.

Methods

Four different treatments; Samgyetang made with a 5% (w/w) addition of garlic (G), fresh BG (FBG), oven-dried BG (DBG), or encapsulated BG (EBG) extracts were developed and compared to negative control (NC) without any extract addition. Prepared samples were cooked via retorting at 121.1°C, 1.5 kgf/cm² for 1 h.

Results

The BG treated samples were higher in C18:3n3 and C18:2n6 fatty acids, with thrombogenic index was 18% to 20% lower than the NC. EBG yielded the highest umami-related nucleotides (5′-guanosine monophosphate and 5′-inosine monophosphate) and modified some free amino acid (alyne, phenylalanine and leucine) thus possessed the highest equivalent umami concentration among samples. Some individual aldehydes (pentanal, hexanal, and heptanal) were lower, while furans and volatile sulfur compounds were higher than the NC and G treatment group, indicating a potential suppression of unpleasant flavour alongwith the intensificiation of favourable flavour from the addition of BG extracts into retorted Samgyetang.

Conclusion

Taken together, the synergistic results of this study indicate that incorportating suitable pre-treatment of BG extract could be of critical importance for the development of the retorted Samgyetang with improved flavour and functionalities.

Insight into the effect of frozen storage on the changes in volatile aldehydes and alcohols of marinated roasted beef meat: Potential mechanisms of their formation

This study aimed to evaluate the effect of frozen storage on the changes in volatile aldehydes (VAs), volatile alcohols (VCs), lipid oxidation, and fatty acid composition of marinated roasted beef meat. Thirty VAs and VCs were identified in all meat samples by using headspace solid-phase microextraction-gas chromatography-mass spectrometry. The total concentrations of VAs increased with storage periods up to four months and gradually decreased. Whereas the total concentrations of VCs decreased with prolonged storage periods. The contents of thiobarbituric acid reactive substances and hexanal increased with prolonged storage periods in all samples until four months and then gradually decreased except the hexanal contents in the control sample (BS1), which showed an increase up to six months. Saturated and monounsaturated fatty acids decreased after storage in all samples except the control. By contrast, polyunsaturated fatty acids increased with prolonged storage in all samples. The correlation analysis showed the positive correlation of flavor compounds with fatty acids, E-nose, and sensory notes.

Characteristic Aroma Compound in Cinnamon Bark Extract Using Soybean Oil and/or Water

The effects of soybean oil (20%, v/w) and extraction time (30, 60, or 90 min) on volatile compounds in cinnamon bark extract were investigated. The relative content and odor activity values (OAVs) of volatile compounds were measured by Gas Chromatography-Mass Spectrometer (GC-MS). The results showed that a total of 26 and 27 volatile compounds were detected in the water extract and the aqueous phase of the water/oil extraction, respectively. Hexanal, nonanal, cinnamaldehyde, D-limonene, 1-octen-3-ol, linalool, and anethole were the major aroma-active compounds, accounting for 85% of the total substance content. Cinnamaldehyde had the highest contribution rate to the aroma of the water extract (26%), whereas anethole has the highest contribution rate to the aroma of the oil/water extract (30%). Whether or not the extraction medium contained soybean oil, the relative content of aroma-active compounds in the aqueous phase decreased with increased extraction time, and the relative content of these compounds in the aqueous phase further decreased when soybean oil was present. This should be due to the high hydrophobicity of these compounds, which were prone to dissolving in the oil layer during the extraction process, resulting in a decrease in the relative content of aroma-active compounds in the aqueous phase.

Effect of short-term frozen storage on taste of gonads of female Eriocheir sinensis and the classification of taste quality combined with sensory evaluation and fuzzy logic model

To investigate the taste quality of gonads of Eriocheir sinensis during frozen storage, the difference in overall taste profile was determined by electronic tongue, and the contents of free amino acids and 5'-Nucleotides were measure. The results showed that the overall taste profile of samples during frozen storage could be effectively distinguished. The contents of free amino acids and 5'-Nucleotides increased with the extension of frozen storage time. The content of water-soluble substances stored at -20 ℃ was higher than those of stored at -40 and -80 ℃. In addition, taste was evaluated by equivalent umami concentrention (EUC) and taste active value (TAV). The sensory evaluation results indicated that with the extension of frozen storage time, umami, sweetness and saltiness decreased, while bitterness increased, which was inconsistent with the previous experimental results. Sensory verification experiments were carried out to prove that bitterness could inhibit umami, sweetness and saltiness. Fuzzy logic model was used to classify the taste of gonads during frozen storage, with Hypoxanthine (Hx), Lysine (Lys) and Histidine (His) as input variables and twelve flavor grades as output variables. Finally, taste was evaluated using the designed model. When the gonads were stored at -20, -40 and -80 °C, the Pearson correlation coefficients between storage time and the taste grade of gonads were 0.98, 0.99 and 0.99, respectively.

Effect of frozen storage on the lipid oxidation, protein oxidation, and flavor profile of marinated raw beef meat

This study aimed to evaluate the effects of long-term frozen storage on the lipid oxidation, protein oxidation, and flavor profile of marinated raw beef meat. Twenty-eight volatiles were identified in all the samples during different times of frozen storage using HS-SPME-GC-MS. Frozen storage affected the contents of flavor compounds, in which their concentrations fluctuated along with the frozen storage. Partial least squares-discriminant analysis screened six flavors as markers, indicating the effect of frozen storage in all the beef samples. They included octanal, 2-ethyl-1-hexanol, benzeneacetaldehyde, 1-heptanol, isoeugenol, and hexanal. Most of the screened markers belonged to aldehydes and alcohols, indicating that these components were derived from lipid oxidation. Thiobarbituric acid reactive substances significantly increased in the first two months of frozen storage and then decreased slightly. Carbonyl content was increased linearly in all the samples during frozen storage.