Maillard reaction of food-derived peptides as a potential route to generate meat flavor compounds: A review

Flavor effect, application status, and research trend of umami peptides based on microbial fermentation in food

Umami peptides are important non-volatile compounds produced by protein degradation, contributing to food umami flavor and enhancing product quality. Microbial fermentation promotes the production of taste peptides, including umami peptides, which act as key flavor substances and precursors. Microbial-derived umami peptides are cost-effective, easy to produce, and a major source of umami peptide production. Although microbial fermentation of umami peptides has been extensively studied in preparation, screening, and evaluation, a systematic review of microbial fermentation is still lacking. Therefore, this paper aims to address the following aspects: (1) umami peptide taste characteristics, influencing factors, and preparation methods; (2) microbial sources of umami peptides; (3) the current application status of microbial fermentation-derived umami peptides in various foods; and (4) future directions for microbial fermentation of umami peptides. Consequently, this literature review seeks to offer insights for advancing microbial fermentation in umami peptide production.

Effect of different natural antioxidants on the quality promotion of pork chip snacks during storage as revealed by lipid profiles and volatile flavor compounds

This study primarily investigated the effects of different natural antioxidants (ascorbic acid, rosemary extract, PostbioYDFF-3®, and NatuProtec®) on changes in the lipid profiles and volatile flavors of pork chip snacks (PCS) during storage via lipidomic techniques and SPME-GC-MS. Compared with the control, the PCS containing different natural antioxidants exhibited obvious reductions in TBARS, peroxide, and acid values after 90-day storage (P < 0.05). At the initial (0 d), middle (45 d), and final (90 d) stage, 30, 32, and 50 volatile compounds and 692, 937, and 1095 lipid molecules were detected, respectively, mainly enriched in the sphingolipid pathway. The lipid hydrolysis of PCS occurred obvious with storage. Correlation analysis revealed that the rosemary extract exhibited the most optimal prevention of oxidative rancidity and maintained the superior quality profiles of the PCS during long-term storage. The present work provided a theoretical basis for the retardation of lipid oxidation during PCS storage.

Enhancing beef flavor profiles via Maillard reaction of γ-Glutamylated beef protein hydrolysates and xylose

Beef protein hydrolysates (BH) and their γ-glutamylated products (γ-BH and γ-GBH, 0 and 7 % L-Gln extra-addition) were prepared, followed by xylose-induced Maillard reaction. Maillard reaction products (MRPs) of γ-glutamylated products (γ-BH-MRP and γ-GBH-MRP) showed a higher degree of Maillard reaction and improved sensory characteristics (p < 0.05). Specifically, UV absorbances and fluorescence intensity of MRPs significantly increased (p < 0.05), and there were significant increases in kokumi, umami, saltiness, roast, and meaty flavors, and a reduction in bitterness (p < 0.05) after γ-glutamylation. In γ-BH-MRP and γ-GBH-MRP, the relative content of most flavor compounds increased significantly (p < 0.05), especially pyrazines and furans, and 8 and 10 new flavor compounds were also detected. 7 and 25 new γ-glutamyl peptides were identified, with their contents ranging 2.26-8.38 μM and 1.93-71.90 μM, respectively. These data illustrate that γ-glutamylation can promote the formation of MRPs, thereby improving the flavor characteristics of beef flavorings.

Cost-effective production of meaty aroma from porcine cells for hybrid cultivated meat

Cultivated meats are typically hybrids of animal cells and plant proteins, but their high production costs limit their scalability. This study explores a cost-effective alternative by hypothesizing that controlling the Maillard and lipid thermal degradation reactions in pure cells can create a meaty aroma that could be extracted from minimal cell quantities. Using spontaneously immortalized porcine myoblasts and fibroblasts adapted to suspension culture with a 1 % serum concentration, we developed a method to isolate flavor precursors via freeze-thawing. Thermal reaction conditions were optimized to enhance aroma compound production. Chemical profiling demonstrates that myoblasts produce an aroma profile closer to pork meat than fibroblasts, although serum reduction decreased aroma yield. Sensory analysis supported these findings. Incorporating the optimized aroma extract - derived from just 1.2 % (w/w) cells - into plant proteins resulted in a hybrid cultivated meat with 78.5 % sensory similarity to pork meat, but with a significant 80 % reduction in production costs.

Integrated transcriptomics and metabolomics reveal the molecular characteristics and metabolic regulatory mechanisms among different muscles in Minxian black fur sheep

BACKGROUND

Mammalian skeletal muscle is comprised of heterogeneous fibers with various contractile and metabolic properties that affect muscle flavor. Thus, it is of great significance to identify and characterize the potential molecular characteristics and metabolic regulatory mechanisms associated with muscle fiber properties.

RESULTS

In this study, the muscle samples (Biceps femoris; longissimus dorsi; and infraspinatus) from Minxian black fur sheep were used to perform transcriptome and metabolome analyses. Then, the key genes regulating the metabolism of important flavor precursors (amino acids and lipids) were explored by integrating transcriptome and metabolome. Consequently, we identified 432 differentially expressed genes, which were mainly involved in muscle development and function maintenance (e.g., myofibril, myocyte differentiation, etc.), metabolism (e.g., fatty acid metabolism, arachidonic acid metabolism, PPAR signaling pathway, and PI3K-Akt signaling pathway, etc.), and homeostasis (e.g., regulation of actin cytoskeleton, ECM-receptor interaction, calcium signaling pathway, etc.). A total of 58 key genes affecting muscle fiber properties, including MYL2, HOXA/C/D, MYBPH8, MYH8, etc., were screened, which characterized the molecular differences in muscle fiber metabolic properties between oxidative and glycolytic muscle. Meanwhile, we identified 463 differentially accumulated metabolites. Except for glycerophospholipids, most flavor metabolites were higher in oxidative muscle. Subsequently, key genes highly related to flavor amino acids were identified by weighted gene co-expression network analysis, such as ALDH6A1, BCKDHB, SLC16A7, LDHB, etc. Based on KEGG enrichment analysis, a regulatory network with both lipid metabolism and its crosstalk with other metabolic pathways was constructed.

CONCLUSIONS

In conclusion, this study provides an in-depth understanding of the molecular mechanism of differences in muscle fiber properties among different muscles of Minxian black fur sheep, and also lays a foundation for further exploration of the regulatory mechanism of key genes on flavor metabolites.

Effect of Boiling Time on the Color, Water, Protein Secondary Structure, and Volatile Compounds of Beef

The influence of boiling time on the persistent changes in the surface color, water content and distribution, protein secondary structure, and the concentration of volatile compounds in beef were studied, in order to obtain quality short-term boiled beef slices. The results show that the water content of beef samples significantly decreased and migration occurred between the high-freedom water and the low-freedom water. On average, boiling for 1 min was a key point in the changes of color parameters (L*, a*, b*, w, ΔE, and BI) and partial protein secondary structure because of the change in the ambient temperature around beef. In six samples, 29 volatile compounds were confirmed by GC-MS, and 13 compounds were regarded as the potential key volatile compounds, including 1-heptanol, 1-octen-3-ol, octanal, hexanal, decanal, heptanal, nonanal, (E, E)-2,4-decadienal, (E, E)-2,4-nonadienal, dodecanal, (E)-2-undecenal, 2,3-octanedione, and 2-pentylfuran. The color, water, and protein secondary structure were closely correlated with some potential key volatile compounds. The results could be used to guide the consumers to better grasp the quality of hot-pot meat during gatherings and have a comfortable consumer experience.

Analysis of volatile and odor-active compounds in charcoal-grilled marinated beef using gas chromatography-mass spectrometry and gas chromatography-olfactometry

Charcoal-grilled marinated beef (CMB) is a popular Korean food that has garnered worldwide attention. In this study, volatile and odor-active compounds generated in CMB were analyzed using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Solvent-assisted flavor extraction and solid-phase micro extraction were employed to extract the volatile compounds before GC-MS and GC-O analyses. In total, 196 compounds were identified in CMB. Certain heterocyclic compounds, such as pyrazines and thiazoles, could be produced by grilling at high temperatures. The formation of benzene derivatives and phenols could be attributed to charcoal grilling and marinade used. In the GC-O results, 3-methylsulfanylpropanal, 2-methoxyphenol, 1,3-benzothiazole, furaneol, 3-methylphenol, prop-2-ene-1-thiol, 2-ethyl-3,5-dimethylpyrazine, and 2,5-dimethylpyrazine exhibited relatively high flavor dilution factors. Based on these findings, sulfur-containing compounds, pyrazines, phenols, and aldehydes primarily influence the characteristic flavor of CMB.

Dynamic effects of ultrasonic treatment on flavor and metabolic pathway of pumpkin juice during storage based on GC-MS and GC-IMS

In this study, the dynamic effects of ultrasonic treatment (0-400 W) on the volatile flavor compounds of pumpkin juice under different storage periods were investigated systematically using a combination of headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS) and gas chromatography-ion mobility spectrometry (GC-IMS) techniques. A total of 139 and 46 volatile organic compounds (VOCs) were identified by GC-MS and GC-IMS, respectively. The results indicated that complex changes in volatile components occurred during storage. It was found that the content of key volatile components, such as 2-ethylhexan-1-ol and 1-pentanol, decreased significantly, whereas the content of 1-nonanol and menthol increased in the early stage of storage, resulting in the gradual change of the aroma of pumpkin juice from an initial aromatic fruity aroma to an alcoholic and rancid aroma. In particular, it was noted that the 200 W ultrasonic treatment not only effectively promoted the release of volatile components, but also significantly slowed down the generation of undesirable flavor substances during storage, which had a positive effect on the retention of pumpkin juice flavor. Through multivariate statistical analysis and KEGG enrichment analysis, phenylalanine metabolism was found to play a key role in regulating the formation of volatile flavor compounds, further confirming the potential value of ultrasonic treatment in the preservation and processing of pumpkin juice. This provides important theoretical support and practical guidance for the commercial production and processing technology of pumpkin juice and other fruit and vegetable juices.

An Overview of Recent Progress in Cultured Meat: Focusing on Technology, Quality Properties, Safety, Industrialization, and Public Acceptance

BACKGROUND

Cultured meat technology represents an innovative food production approach that enables the large-scale cultivation of animal cells to obtain muscle, fat, and other tissues, which are then processed into meat products. Compared with traditional meat production methods, cell-cultured meat may significantly reduce energy consumption by 7%-45%, greenhouse gas emissions by 78%-96%, land use by 99%, and water use by 82%-96%. This technology offers several advantages, including a shorter production cycle and enhanced environmental sustainability, resource efficiency, and overall sustainability. However, numerous technical challenges remain.

OBJECTIVES

The latest advancements in cultured meat research were reviewed such as the development of serum-free media, maintenance of seed cell functionality, large-scale cell culture techniques, 3-dimensional culture methods, and innovations in scaffold materials.

METHODS

Recent publications on cultured meat were examined.

RESULTS

These hurdles were addressed to achieve low-cost, high-efficiency industrial production in the cultivated meat sector. Furthermore, as a supplement or substitute for traditional meat, cultured meat products must possess similar sensory characteristics and nutritional value, ensure high food safety standards, and maintain low production costs to enhance market competitiveness.

CONCLUSIONS

Achieving the industrialization of cultured meat necessitates careful consideration of several additional challenges related to sensory attributes, nutritional quality, food safety, and consumer acceptance. This review systematically examines these aspects to provide a theoretical and practical foundation for the sustainable biomanufacturing of cultured meat.

Evaluating the effect of different recycling frequencies on marinade quality, characteristics, and volatile constituents

The quality of marinade is closely related to its recycling frequency, and affects the flavor and quality of leisure dried tofu. The changes in physicochemical parameters, oxidation indicators, and volatile constituents of marinade under different recycling frequencies (0, 3, 6, 9, 12, 15) were systematically investigated in this work. The results showed that the levels of amino acid nitrogen, viscosity, soluble solids, and salinity in the marinade were significantly increased with recycling frequency. The increase in marinade recycling frequency led also to a rise in the peroxide value and thiobarbituric acid reactive substances from 2.13 meq/kg and 0.17 mg/kg to 4.02 meq/kg and 0.94 mg/kg, respectively, suggesting slight oxidation. Marination yielded 101 volatile constituents, mainly including 35 alcohols, 21 hydrocarbons, 15 aldehydes, 9 aromatics. Pearson correlation analysis revealed that the levels of cedrene, cineole, and myrcene were closely related to the quality and flavor of marinade under different recycling times.

Formation of key aroma compounds in Agrocybe aegerita during hot air drying: Amino acids and reducing sugars identified as flavor precursors

Agrocybe aegerita is a type of mushroom widely popular among consumers for its unique flavor. In this study, aroma properties and key aroma-active compounds (AACs) in fresh and dried A. aegerita were identified by molecular sensory science. The flavor characteristics are more abundant in A. aegerita submitted to hot air drying (HAD), especially nutty, roasted, smoky and meaty, while raw mushroom and earthy were significantly reduced, which can be attributed to the shift of key AACs from aldehydes and ketones to heterocyclic and sulfur-containing compounds during HAD. Pearson correlation analysis and validation experiments showed that the Maillard reaction between methionine (Met) and ribose was the main pathway for producing "meaty" compounds like dimethyl trisulfide and 3-methylthiopropanal. Moreover, dimethyl trisulfide and 3-methylthiopropanal production showed a nonlinear fit with increasing Met and ribose contents. The study provides a theoretical basis for A. aegerita as a novel meat flavor condiment.

Effects of sterilization intensity on the flavor profile of canned Antarctic krill (Euphausia superba): Moderate vs. excessive

Selecting the appropriate sterilization intensity is crucial for the canning of Antarctic krill (Euphausia superba). This study investigated the effects of different sterilization intensities on volatile organic compounds (VOCs) of canned krill. Using gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS), which identified 45 and 36 VOCs, respectively. As the sterilization intensity was increased, the flavor profile became more stabilized; however, excessive sterilization led to the generation of off-flavor compounds. Eight key flavor markers were identified at different sterilization intensities. Cluster analysis could distinguish between samples obtained from low (F = 6, 9) and high (F = 12, 15) sterilization intensities. Odor Activity Value (OAV) analysis revealed that higher sterilization intensities led to the generation of fishy, fatty, and earthy notes. The findings suggest that sterilization at F = 9 can best maintain the desired flavor characteristics. Overall, this work provides valuable insights into the optimization of the canning process of Antarctic krill.

Combining Sensory Analysis and Flavoromics to Determine How the Maillard Reaction Affects the Flavors of Golden Pomfret Hydrolysates

Enzymatic hydrolysis can enhance the flavor of aquatic products. Nevertheless, the strong fishy odor restricts its utilization in culinary applications. This study is centered on enhancing the flavor of golden pomfret samples by promoting the Maillard reaction (MR) between golden pomfret hydrolysate (GHES) and reducing sugars. The research results demonstrate that the Maillard reaction significantly improves the sensory characteristics of GHES. It prompts the formation of diverse volatile compounds, such as aldehydes, esters, and furans. Simultaneously, it reduces the relative amounts of substances associated with fishy odor, such as 1-Octen-3-ol and Hexanal. Moreover, the Maillard reaction increases the contents of amino acids contributing to umami and sweetness, as well as 5'-nucleotides in the samples, thus enriching their umami flavor profiles. After undergoing the Maillard reaction treatment, the antioxidant capacity of the samples is also significantly enhanced (p < 0.05). This research highlights the potential of the Maillard reaction in improving both the flavor and antioxidant properties of GHES, establishing a theoretical basis for elevating the quality of golden pomfret products.

Research Progress in Saltiness Perception and Salty Substitutes

Salty taste in foods is a key sensory attribute for appetite enhancement, however, consumption of a high salt diet is associated with a high risk of hypertension, stroke, and heart diseases. To address this issue, the World Health Organization (WHO) has recommended reducing the global per capita salt consumption by 30% by 2025, with adults optimally consuming less than 5 g/day of salt. Therefore, the search for new salty substitutes to reduce salt intake in foods has become a research hotspot. Despite the ongoing endeavors of global research, multiple studies have focused on the application of a single category of salty alternatives or food processing quality (such as preservative effects and process characteristics), and there is still little comprehensive evaluation of these alternatives in terms of nutritional value, health impact, and consumer acceptance in the literature. This review will first outline the urgency of global salt reduction, followed by thorough discussion of salty substitutes and associated mechanisms from the perspective of human salty taste perception. Second, the present review will explore the potential application of salty substitutes and highlight the interaction between taste and odor in foods. Additionally, the potential impacts of salty substitutes on human health will be discussed. The present review will provide a scientific basis for the development of low salt products by food industry.

Investigation on the pro-aroma generation effects of fatty acids in beef via thermal oxidative models

Fatty acids (FAs) in lipids are important precursors for the formation of meat aroma compounds. However, the specific roles of individual FAs and related reactions in beef aroma formation remain unclear. This study established thermal oxidation models to investigate the impact of different FAs on the formation of beef aroma compounds. The results revealed that thermal oxidation of seven FAs with different saturation produced 42 aroma compounds. Among them, unsaturated fatty acids (UFAs) participating in thermal oxidation degradation is the primary pathway for aroma compound formation, and the types of aroma compounds produced by C18:2n6 and C20:4n6 are similar. The addition of UFAs to lipid-free beef induces lipid oxidation-Maillard reaction interactions, producing more thiophenes, thiazoles, and pyridines, such as 2-acetyl-3-methylthiophene and 2-pentylpyridine, etc. The key aroma compounds in beef with odor characteristics such as fruity, green, fatty or milky are mainly produced by C18:1n9, C18:2n6 and C20:4n6.

Evaluation of edible quality and processing suitability of segmented products from silver carp under different thermal processing methods

This study investigated the edible quality differences in muscle segments of silver carp (Hypophthalmichthys molitrix) and established an evaluation model for processing suitability. The results showed that steamed dorsal meat had the highest levels of total free amino acids, umami amino acids, and total volatile compounds. Fried tail meat exhibited the highest content of sweet amino acids and equivalent umami concentration (EUC) values, which were superior in all fried meat parts compared to those that were steamed. Key quality indicators for steaming included L*, crude protein, 5'-inosine monophosphate (IMP), (E)-2-Nonenal, and lysine, while IMP, moisture, 2-acetyl-1-pyrroline, and proline were key quality indicators for frying. The established processing suitability evaluation model accurately predicted overall sensory acceptability. Dorsal and belly portions of H. molitrix were best suited for steaming, whereas the tail was more suitable for frying.

Effect of protease reaction conditions on volatile compounds generated in Maillard reaction products from soy protein hydrolysates

Maillard reaction products (MRPs) produced by heating protease-catalyzed soy protein hydrolysates (SPHs) with cysteine and ribose can generate meat-like flavors. However, the impact of protease reaction conditions on the volatile compound composition of MRPs has not been thoroughly investigated. In this study, seven SPHs were prepared using two proteases, flavourzyme and trypsin, over reaction times of 10, 120, and 1440 min. The volatile compound compositions, including sulfur-containing compounds, aldehydes, pyrazines, and furans, of the seven SPHs and the corresponding seven MRPs varied according to the protease reaction conditions and the Maillard reaction. Differences in pH, free amino acid composition, and peptide composition were responsible for these variations. Notably, soy-derived peptides containing unique cysteine sequences, such as PGCPST, DETICT, ECQIQK, and HCQR, were significantly reduced during the Maillard reaction, suggesting that these sequences may serve as precursors to volatile compounds.

Sensorial flavor characteristics and volatile Maillard reaction products of Tenebrio molitor mealworm based-reaction flavors with beef broth-like flavor

This study analyzed the sensorial flavor characteristics and volatile Maillard reaction products of Tenebrio molitor mealworm based-reaction flavors (M-RFs) optimized in our previous study; it also explored the main contributors to M-RFs with a desirable beef broth-like flavor. Seven flavor characteristics (i.e., sweet, sour, meaty, sulfur-like, boiled soy sauce-like, baked potato-like, and dried shrimp-like flavors) were profiled in the M-RFs by sensory evaluation; when the baked potato-like, boiled soy sauce-like, sweet, and meaty flavor attributes were intensified, the M-RFs had beef broth-like flavor. Also, pyrazines, pyrroles, and pyrans were strongly associated with them in the partial least-squares regression plot. Those M-RFs were reacted with a small amount of cysteine and a large amount of methionine compared to other M-RFs and it was revealed that cysteine and methionine significantly influenced the desirable beef broth-like flavor characteristics of M-RFs.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-024-01681-2.

Maillard reaction products of soybean protein hydrolysates and reducing sugar: Structure and flavor insights

Maillard reaction products (MRPs) were prepared at high temperatures using soybean protein hydrolysates (SPH) and reducing pentose (xylose and arabinose), hexose (galactose and glucose), and disaccharide (maltose), and their potential as flavoring in plant protein foods was evaluated. The results indicated that, after sugar was involved in the reaction, the unfolding of proteins enabled aromatic amino acid residues to enter a more hydrophobic environment, contributing to the reduction of bitterness in MRPs and formation of caramelization. This effect was partially attributed to the interaction forces, hydrogen bonds and van der Waals forces, that existed between the sugars and SPH involved in Maillard reaction. More basic amino acid residues interacted with pentose during the reaction, which exhibited faster reaction rate and promoted the formation of pyrazines and oxygen containing compounds, thereby contributing to meaty, roasted and caramelized flavors. Trimethyl pyrazine, 3-ethyl-2,5-dimethylpyrazine, 2-methylpyrazine, and 2-heptanone were the most abundant in pentose MRPs, and these volatile compounds were positively correlated with umami and richness. Overall, MRPs prepared with arabinose may serve as a potential meaty flavoring with notable umami, and hexose contributed to the enrichment of nutty flavor profiles, while the MRPs formed by disaccharide exhibited the characteristics of superior fruity aromas. MRPs from different reducing sugar may be used to develop different food ingredients.

Antioxidant Maillard Reaction Products from Milk Whey: A Food By-Product Valorisation

The Maillard reaction (MR) is a key process in food science, producing bioactive compounds with antioxidant properties. This study evaluates the antioxidant potential of MR products (MRPs) from different dairy byproducts-cow cheese whey, goat cheese whey, and cow yoghurt whey-highlighting their applicability in food preservation and waste valorisation. Whey samples were subjected to the MR at 140 °C for 90 min, showing significant amino acid and sugar consumption, particularly arginine, histidine, and lactose. Using a library of potential antioxidant MRPs (molecular weight < 250 Da), 28 key compounds, including 2-pyrrolecarboxaldehyde and maltol isomer, were identified, primarily in cow cheese whey. A complementary high-molecular-weight MRP library (≥250 Da) identified 72 additional antioxidant compounds, with distinct production patterns linked to whey type. Multivariate analyses confirmed that whey type strongly influences MRP profiles. These results highlight the potential of MR to transform whey by-products into valuable sources of natural antioxidants. This approach offers sustainable strategies for enhancing food preservation, reducing food waste, and supporting the targeted use of MRPs in the food industry.

Optimization of the Meat Flavoring Production Process for Plant-Based Products Using the Taguchi Method

The development of plant-based meat substitutes is imperative for reducing animal fat intake and promoting dietary diversification. However, the flavor profiles of these products frequently fall short of consumer expectations. This study sought to optimize the production process of meat flavorings for plant-based products using the Taguchi method. The study investigated the effects of sugar type, concentration, and reaction temperature on the Maillard reaction products, sensory characteristics, and volatile organic compounds. The thermal process flavors were obtained from the flavor precursor by heating in a laboratory microwave station at 30 bar for 15 min. The variable factors were the type of sugar (fructose, glucose, xylose), its concentration (25, 50, and 100 mM), and the temperature of the reaction (140, 150, and 160 °C). The study's findings indicated that temperature emerged as the predominant factor influencing the formation of Maillard reaction products and the sensory characteristics of the flavorings. Specifically, 25 mM xylose-based flavorings prepared at 140 °C demonstrated the most notable meat flavor and the highest level of acceptability. Moreover, the analysis of volatile organic compounds revealed the presence of a diverse array of substances, including aldehydes, ketones, and alcohols, that are characteristic of meat flavor. A heat map of the volatile content was constructed to facilitate a comparison of the samples. The study demonstrates the effectiveness of the Taguchi method in optimizing the production process of meat flavorings for plant-based products and provides valuable insights for the development of more balanced odor profiles.

Impact of Slaughter Weight on Flavor Metabolites in Longissimus Dorsi Muscle of Tianfu Finishing Pigs

In order to investigate the flavor compounds in the muscles of Tianfu finishing (TF) pigs with different slaughter weight (SW), 12 TF pigs were selected for the experiment. The volatile metabolic profiles of meat specimens from the longissimus dorsi (LD) muscle of TF pigs with different SW were studied by untargeted liquid chromatography-mass spectrometry. Our data revealed that the three types of TF pork showed significantly different profiles of hydrocarbons, alcohols, esters, heterocyclic compounds, and others, which could underpin the nuances of their flavors. A total of 118 differentially expressed metabolites (DEMs) were identified (2 upregulated DEMs and 116 downregulated DEMs). Among the volatile flavor compounds, hydrocarbons, alcohols, ester, and heterocyclic compound in the three groups accounted for 26.71%, 13.01%, 13.01%, and 13.70%, respectively, and their contents decreased with increasing SW. The contents of alcohols, aldehydes, and hydrocarbons in the 150-kg group was significantly higher than those in the 125-kg and 100-kg groups (p < 0.05). Taken together, raising SW to 125 kg, or more, decreased the flavor of TF pork and had no benefits to pork quality attributes. Our results provided insights into the molecular basis for sensory variations among different SW of TF pork.

Effective Strategies for Understanding Meat Flavor: A Review

This review provides an effective strategy for understanding meat flavor. Understanding the taste of meat is essential for improving meat quality, and the taste should be analyzed based on complex chemical research to identify various factors that impact the composition, formation, and development of meat. To address flavor chemistry in meat, the discussion focuses on the major compounds responsible for the characteristic flavors of different meats, such as lipids, proteins, and Maillard reaction products. Meat flavor is largely based on heat-induced chemical reactions that convert flavor precursors, such as sugars, proteins, and lipids, into volatile compounds. The flavor of meat is influenced by animal species, sex, age, feed, and processing, and in this respect, flavor is one of the representative quality indicators of meat. Research on meat flavor uses omics technology to study the molecular mechanisms that affect meat quality, including flavor, tenderness, and fat composition. Therefore, this review provides a comprehensive understanding of the complex processes governing meat flavor and provides avenues for further research and industrial applications to advance the meat industry.

Application of Animal Resources into the Maillard Reaction Model System to Improve Meat Flavor

Simulating meat flavor via Maillard reaction model systems that contain a mixture of amino acids and reducing sugars is an effective approach to understanding the reaction mechanism of the flavor precursors. Notably, animal resources such as fish, beef, chicken, pork hydrolysates, and fats are excellent precursors in promoting favorable meaty and roasted flavors and umami tastes of Maillard reaction products. The experimental conditions and related factors of the model systems for sensory enhancements, debittering, and off-flavor reduction with meat and by-products are summarized in this review. The review also highlights the flavor precursors in the animal resources and their participation in the Maillard reaction. This review provides a basis for a better understanding of the model systems, especially those prepared with animal resources.

Towards healthier low-sugar and low-fat beverages: Design, production, and characterization

Many consumers are adopting low-sugar and low-fat beverages to avoid excessive calories and the negative impact of high trans- and/or saturated fat on health and wellbeing. This article reviews strategies to reduce sugar, fat, and high trans- and/or saturated fat content in beverages while maintaining their desirable physicochemical and sensory attributes. It assesses the impact of various sugar and fat replacers on the aroma, taste, texture, appearance, and nutritional profile of beverages. Combinations of natural sugar replacers and protein or polysaccharide-based fat replacers have shown partial success in mimicking the qualities of sucrose and fat. Future strategies for designing low-sugar and low-fat beverages include developing novel replacers and using odorants to enhance sensory profiles. The article also highlights methods for flavor detection and oral tribology methods, emphasizing their role in development of low-sugar and low-fat beverages. The information presented in this review article is intended to stimulate research into the design of healthier low-sugar and low-fat beverages in the future.

Structural and sensory characteristics of ultrasonic assisted wet-heating Maillard reaction products of Giant salamander protein hydrolysates

BACKGROUND

Chinese giant salamander protein hydrolysates (CGSPH) are beneficial to human health as a result of their high content of amino acids and peptides. However, the formation of bitter peptides in protein hydrolysates (PHs) would hinder their application in food industry. The ultrasound assisted wet-heating Maillard reaction (MR) is an effective way to improve the flavor of PHs. Thus, the effect of ultrasonic assisted wet-heating MR on the structure and flavor of CGSPH was investigated in the present study.

RESULTS

The results indicated that the ultrasound assisted wet-heating MR products (MRPs) exhibited a higher degree of graft and more significant changes in the secondary and tertiary structures of CGSPH compared to traditional wet-heating MRPs. Moreover, ultrasound assisted wet-heating MR could significantly increase the content of small molecule peptides and reduce the content of free amino acids of CGSPH, which resulted in more significant changes in flavor characteristics. The changed in flavor properties after MR (especially ultrasound assisted wet-heating MRPs) were mainly manifested by a significant reduction in bitterness, as well as a significant increase in the content of aromatic aldehyde ester compounds such as furan-2-carbaldehyde, butanal, benzaldehyde, furfural, etc. CONCLUSIONS: Ultrasound assisted wet-heating MR between CGSPH and xylose could be a promising way to improve the sensory characteristics of CGSPH. © 2024 Society of Chemical Industry.

Diversity analysis, nutrition, and flavor evaluation of amino acids in Chinese native geese germplasms

Background and Aim

As living standards improve and consumption patterns shift, the market for goose meat continues to grow because of its exceptional dietary quality and distinctive flavor. The composition and content of amino acids are critical for determining the nutritional value and flavor of meat. This study aimed to evaluate the nutritional value and flavor of 10 Chinese native geese germplasms based on their amino acid content and composition.

Materials and Methods

A total of 568 geese from 10 Chinese native geese germplasms reared under identical conditions were slaughtered at 10 weeks of age. The pectoralis and thigh muscles (thighs) were collected to determine the amino acid content using an amino acid analyzer. Subsequently, diversity, variance, cluster, and principal component analyses were performed to identify superior germplasm with improved nutrition and flavor.

Results

The results revealed 17 amino acids in goose meat, with Glutamate and Aspartate being the most abundant. The amino acid scores of goose meat exceeded the values recommended by the Food and Agriculture Organization/World Health Organization. The Shannon-Wiener Diversity Index (1.72-2.07) indicated a high degree of diversity in amino acid content among geese germplasms. The pectoralis exhibited significantly higher amino acid content (p < 0.05 or p < 0.01) than the thigh, except for the essential amino acids to total amino acids ratio (p < 0.05 or p < 0.01). The 10 germplasms were categorized into four clusters, with Wanxi (WX) and Taizhou (TZ) geese grouped in Cluster I, displaying significantly higher nutritional value and flavor (p < 0.05 or p < 0.01) than other germplasms.

Conclusion

Germplasms with superior nutritional value and flavor (WX and TZ) were identified among 10 Chinese native geese germplasms, providing valuable insights for the conservation of existing germplasms and the cultivation of new goose breeds with improved meat quality.

Transforming plant proteins into plant-based meat alternatives: challenges and future scope

The global transition towards sustainable living has led to a growing demand for innovative food products that enhance environmental sustainability. Traditional meat production is known for its high energy consumption and significant carbon emissions, necessitating alternative approaches. Plant-based meat (PBM) offers a promising solution to reduce the ecological footprint of animal agriculture. This paper examines various challenges in PBM development, including nutritional equivalence, industrial scalability, organoleptic properties, and digestibility. Addressing these challenges requires interdisciplinary collaboration to ensure consumer acceptance, regulatory compliance, and environmental stewardship. Advanced technologies like nanotechnology, fermentation, and enzymatic hydrolysis, along with automation and repurposing cattle farms, offer solutions to enhance PBM's quality and production efficiency. By integrating these innovations, PBM has the potential to revolutionize the food industry, offering sustainable and nutritious alternatives that meet global dietary needs while significantly reducing environmental impact.

Graphical abstract

A rich-nutritious cultured meat via bovine myocytes and adipocytes co-culture: Novel Prospect for cultured meat production techniques

Cultured meat, an emerging meat production technology, has reduced environmental burden as well as provide healthier and more sustainable method of meat culture. Fat in cultured meat is essential for enhancing texture, taste, and tenderness. However, current cultured meat production method is limited to single-cell type. To meet the consumer demands for cultured meat products, it is crucial to develop new methods for producing cultured meat products that contain both muscle and fat. In this study, cell viability and differentiation were promoted by controlling the ratio and cultivation conditions of myocytes and adipocytes. The total digestibility of cultured meat exceeded 37%, higher than that of beef (34.7%). Additionally, the texture, appearance, and taste of the co-cultured meat were improved. Collectively, this research has great promise for preparing rich-nutritious and digestion cultured meat.

Multi-frequency power ultrasound (MFPU) pretreatment of crayfish (Procambarus clarkii): Effect on the enzymatic hydrolysis process and subsequent Maillard reaction

Crayfish, as a new consumer trend, has become one of the most popular freshwater aquatic foods in China, and its processed product output has been increasing year by year. In this study, the effect of multi-frequency power ultrasound (MFPU) pretreatment in various working modes including mono-, dual- and tri-frequency on the enzymatic hydrolysis and Maillard reaction of crayfish was investigated. Additionally, the underlying mechanism was also explored. Results showed that the degree of hydrolysis (DH) of crayfish was 23.89 %, while it increased to 40.78 % after MFPU pretreatment at 20/40 kHz dual-frequency, indicating that MFPU pretreatment significantly (p < 0.05) enhanced the enzymatic hydrolysis of crayfish. The crayfish protein after MFPU pretreatment exhibited a decrease in α-helix and increase in β-fold content, and the occurrence in the unfolding of the protein structure and alteration of tertiary structure. According to scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses, the MFPU pretreatment resulted in the fragmentation of crayfish protein. During the analyses of subsequent Maillard reaction, the composition and quantity of volatiles detected by the electronic nose and GC-MS indicated that MFPU pretreatment enhanced flavor of the Maillard reaction products. In conclusion, MFPU pretreatment is a promising technology for improving the degree of hydrolysis of crayfish protein and enhancing the flavor of Maillard reaction products.

Amelioration of myofibrillar protein emulsion gel properties by mildly oxidized sunflower oil

Different oxidation states of oil affect the emulsion stablility and gel properties of emulsified meat products. Emulsified chicken gels were prepared using sunflower oil (SFO) with different oxidation levels (0, 20, 40, and 60 min, 120 °C). The pre-oxidation treatment of oils was investigated for emulsification and gelation of myofibrillar protein (MP). The results showed that MP emulsion gels with mildly oxidized (20 min) SFO had higher elastic modulus (G') and more homogeneous water distribution, which were due to increased hydrophobic interactions between MP and lipids, and improved emulsification stability. However, the addition of highly oxidized (60 min) SFO resulted in aggregation of proteins, increased emulsion particle size, significantly reduced hardness and chewiness (P > 0.05), and exhibited large pores in the network microstructure. The results suggested that mildly oxidized SFO has an ameliorating effect on MP emulsion gelation, which facilitates better comprehension of the protein oxidation process in oil-loaded meat systems.

Characterization of flavour components and identification of lipid flavour precursors in different cuts of pork by phospholipidomics

The lipids and volatile compounds in pork from different parts, including the loin, belly, shoulder and hind leg were analyzed by triple quadrupole tandem time-of-flight mass spectrometer (Q-TOF/MS) and gas chromatography-olfactometry-mass spectrometry (GC-O-MS), respectively. Partial least squares regression (PLSR) and Pearson correlation analysis were utilized to establish the relationship between the lipids and volatile compounds. A total of 8 main flavour substances, 38 main phospholipids, and 32 main fatty acids were identified. The results showed that the key flavour compounds were mainly derived from unsaturated fatty acids and phospholipids containing unsaturated fatty acids, including oleic acid (C18:2n6c), α-Linolenic acid (C18:3n3), arachidonic acid (C20:4n6), PE O (18:1/20:4), PE O (18:2/20:4), and PE O (18:2/18:2), etc. Understanding the relationship between flavour compounds and lipids of pork will be helpful to control the quality of pork.

Effects of Flavonoids in Fructus Aurantii Immaturus on Carcass Traits, Meat Quality and Antioxidant Capacity in Finishing Pigs

This experiment aimed to explore the effects of flavonoids in Fructus Aurantii Immaturus (FFAI) on carcass traits, meat quality, and the antioxidant capacity of finishing pigs. The results indicated that the addition of an appropriate amount of FFAI into their diet could significantly reduce the backfat thickness and perirenal fat percentage of finishing pigs, as well as the drip loss, water-holding capacity, shear force, and the levels of lactate, glucose-6-phosphate, glucose, ATP, phosphofructokinase, and pyruvate in the longissimus dorsi (LD) muscle. It also elevated the levels of flavor amino acids such as glutamate, serine, and threonine, and enriched the composition of flavor substances, including benzene and octanal, which significantly contributed to the enhancement of pork flavor. Furthermore, it enhanced the expression levels of MyHC I and MyHC IIa. In summary, the appropriate addition of FFAI to the diet could improve the carcass traits, meat quality, and antioxidant capacity of finishing pigs. The optimal level of FFAI supplementation is 0.12%.

Comprehensive characterization of the differences in metabolites, lipids, and volatile flavor compounds between Ningxiang and Berkshire pigs using multi-omics techniques

This study was conducted to comprehensively characterize, metabolites, lipids, and volatile flavor compounds of NingXiang (NX) pigs, Berkshire (BKS) pigs, and their crossbred (Berkshire × Ningxiang, BN) pigs using multi-omics technique. The results showed that NX had high intramuscular fat (IMF) content and meat redness. The metabolite and lipid compositions were varied greatly among three pig breeds. The NX pigs exhibited distinctive sweet, fruity, and floral aroma while BN pigs have inherited this flavor profile. 2-pentylfuran, pentanal, 2-(E)-octenal, and acetic acid were the key volatile flavor compounds (VOC) of NX and BKS pork. The VOCs were influenced by the composition and content of metabolites and lipids. The NX pigs have excellent meat quality traits, unique flavor profiles, and high degree of genetic stability regarding flavor. The study deepens our understanding of the flavor of Chinese indigenous pigs, providing theoretical basis to understand the meat flavor regulation under different feeding conditions.

Effects of cricket powder on structural and mechanical properties of soy protein isolate extrudates

This study investigated the impact of cricket powder (CP) incorporation on the structural and mechanical properties of soy protein isolate (SPI) extrudates. The physicochemical properties of CP, rheological properties of SPI-CP blends and their potential structuring properties were evaluated. The results showed that CP had a high protein content (72.10 ± 0.61%) and a notable amount of dietary fiber. Rheological analysis revealed that the complex modulus (G∗) of SPI-CP blends decreased over time at 140 °C, with the rate of decrease accelerating with higher CP content. Structural and mechanical analysis indicated that the addition of CP enhanced anisotropic structure formation, with optimal anisotropy observed at 10% CP, while higher concentrations reduced mechanical strength and coherence due to the presence of insoluble components and the formation of large cracks. Flavor analysis showed that CP contributed pyrazines and ethers, imparting a desirable burnt and baked flavor to the extrudates. These findings suggested that CP can be effectively used to improve the textural properties and flavor of SPI-based extrudates at optimal concentrations. However, excessive CP incorporation can compromise structural integrity.

Yeast extract as a more sustainable food ingredient: Insights into flavor and bioactivity

Yeast extract (YE), a nutritious and sustainable food ingredient, primarily functions as a food flavor enhancer and bioactive ingredient in the food industry. Currently, there is a dearth of systematic reviews on the taste-active and bioactive activities of YE. This review provides a comprehensive review of preparation methods, taste-active and bioactive activities of YE as well as their applications in the food sector. Furthermore, the challenges and future perspectives of YE are discussed. YE can be obtained through the degradation and removal of yeast cell walls. Its extraction can be achieved through various methods, including physical, autolytic, enzymatic, and cell wall disruption techniques. YE comprises a range of components, including glucan, mannan, proteins, phospholipids, minerals, vitamins, and various functional factors. These components collectively contribute to its diverse bioactivities, such as antioxidant, ACE-inhibitory, antibacterial, immunomodulatory, diuretic and sedative effects. Furthermore, YE contains taste-active substances and aroma-active compounds, making it promising as a flavor enhancer. It is potent bioactivity also makes it applicable in the food and nutraceutical industries.

Screening of Antioxidant Maillard Reaction Products Using HPLC-HRMS and Study of Reaction Conditions for Their Production as Food Preservatives

The Maillard reaction (MR) involves interactions between reducing sugars and amino acids or proteins during heating, producing Maillard reaction products (MRPs) that influence food flavour, aroma, and colour. Some MRPs exhibit antioxidant properties, prompting interest in their potential as natural food preservatives. This study aimed to develop a method for detecting and identifying antioxidant MRPs using high-pressure liquid chromatography (HPLC) coupled with high-resolution mass spectrometry (HRMS). By improving chromatographic conditions, the separation of antioxidant MRPs was optimised using known antioxidant MRPs as reference signals. This work also examined the effects of pH, reaction time, and different sugar-amino acid combinations on the production and composition of antioxidant MRPs. Results indicated that neutral to basic pH facilitated faster reactions, with pH 7 selected as optimal. A library of 50 m/z signals for potential antioxidant MRPs was created, and the best combinations of amino acids and sugars for their production were identified. These findings pave the way for more precise analyses of antioxidant MRPs, with future research focusing on isolating and characterising specific MRPs to understand their structures and mechanisms, ultimately contributing to the development of functional foods with natural antioxidant properties.

Alternative proteins; A path to sustainable diets and environment

With a growing global population and the resulting pressure on natural resources, the supply of high-value protein has become increasingly limited. The rise of environmental and ethical concerns has led to the emergence of meat analogues as a credible alternative to traditional animal-derived meat. Growing demand for plant-based protein sources has gained attention as viable alternatives to conventional animal proteins. This article reviews commercially available plant proteins for meat replacement and evaluates recent research on producing meat analogues, highlighting their advantages and limitations. Beyond production, an examination of the physicochemical, textural, and structural attributes of the meat alternatives is conducted, highlighting the improvements made in achieving sensory and nutritional parallels with animal-derived meat. Furthermore, this article explores the current commercial applications of meat alternatives, highlighting the challenges faced in their widespread adoption and suggesting future research directions. The comparison of the environmental impacts of plant proteins and animal proteins is also presented. The ultimate goal is to develop meat substitutes that closely mimic the sensory, nutritional, and aesthetic qualities of real meat. Despite promising innovations in processing technologies, challenges remain that researchers are actively addressing to close the gap between plant-based meat analogues and animal-derived counterparts.

Metabolome and Transcriptome Profiling Reveals Age-Associated Variations in Meat Quality and Molecular Mechanisms of Taihe Black-Bone Silky Fowls

To explore the changes in meat quality and molecular mechanisms during the growth and development of Taihe black-bone silky fowl, this study employed liquid chromatography-mass spectrometry (LC-MS/MS) metabolomics to elucidate the dynamic changes of key differential metabolites (DMs) affecting meat quality, indicating that chicken at D120 had higher levels of ω-3 polyunsaturated fatty acids (PUFAs), creatine, anserine, and homocarnosine, while D150 had the most stachydrine and D210 had the most acylcarnitines. Additionally, D120 and D180 had more umami and sweet compounds. Furthermore, key metabolic pathways influenced by age included purine metabolism, the pentose phosphate pathway, nicotinate and nicotinamide metabolism, and taurine and hypotaurine metabolism. Transcriptomic identified differential expression genes (DEGs) are predominantly enriched in focal adhesion, the TGF-β signaling pathway, and the MAPK signaling pathway. Integrated metabolomics and transcriptomics revealed complex regulatory networks of DEGs and DMs in key metabolic pathways. This research enhanced our understanding of the biology of Taihe black-bone silky fowl meat quality, revealing possible biomarkers.

Sensory improvement and antioxidant enhancement in silver carp hydrolysate using prebiotic oligosaccharides: insights from the Maillard reaction

Our previous studies have highlighted the potential of silver carp hydrolysate (SCH) in managing chronic diseases. Unfortunately, its fishy smell and bitter taste limited consumer acceptance. Prebiotic oligosaccharides are often used as dietary supplements, ignoring their role as carbonyl ligands in the Maillard reaction to enhance food's sensory and antioxidant properties. This study aimed to improve SCH's sensory attributes and investigate its physicochemical properties and antioxidant activities using prebiotic oligosaccharides via the Maillard reaction. The results showed that xylo-oligosaccharide (XOS) had the highest reactivity among the oligosaccharides tested, and it greatly enhanced the taste and flavor of SCH, as well as its antioxidant activities (0.45 to 16.5 times). Specifically, XOS effectively reduced the fishy smell and bitter taste, imparting a caramel-like flavor and overall acceptability to SCH. The improved flavor profile was attributed to the increased presence of sulfur-containing and nitrogen oxide volatile flavor compounds, such as benzothiazole, methional, and furans, which also contributed to antioxidant effects. Sensory evaluation results indicated that SCH obtained from papain exhibited a stronger bitter taste than that obtained from alcalase. Additionally, XOS imparted a reddish-brown color to SCH due to the higher browning intensity. This study is the first to demonstrate that XOS in the Maillard reaction can effectively improve the undesirable flavor and taste of SCH while enhancing its antioxidant activities, providing a theoretical basis for developing SCH as a market-acceptable functional food ingredient.

Mechanochemistry in Glycation Research

Mechanochemistry by milling has recently attracted considerable interest for its ability to drive solvent-free chemical transformations exclusively through mechanical energy and at ambient temperatures. Despite its popularity and expanding applications in different fields of chemistry, its impact on Food Science remains limited. This review aims to demonstrate the specific benefits that mechanochemistry can provide in performing controlled glycation, and in "activating" sugar and amino acid mixtures, thereby allowing for continued generation of colors and aromas even after termination of milling. The generated mechanical energy can be tuned under specific conditions either to form only the corresponding Schiff bases and Amadori compounds or to generate their degradation products, as a function of the frequency of the oscillations in combination with the reactivity of the selected substrates. Similarly, its ability to initiate the Strecker degradation and generate pyrazines and Strecker aldehydes was also demonstrated when proteogenic amino acids were milled with glyoxal.

Myofibrillar protein hydrolysis under hydroxyl radical oxidative stress: Structural changes and their impacts on binding to selected aldehydes

In this study, a hydroxyl radical oxidation system was established to simulate the oxidation process in fermented meat products. This system was employed to examine the structural changes in myofibrillar proteins (MPs) resulting from tryptic hydrolysis after a hydroxyl radical oxidative regime. The effect of these changes on the ability of MPs to bind selected aldehydes (3-methyl butanal, pentanal, hexanal, and heptanal) was also investigated. Moderate oxidation (H2O2 ≤ 1.0 mM) unfolded the structure of MPs, facilitating trypsin-mediated hydrolysis and increasing their binding capacity for the four selected aldehydes. However, excessive oxidation (H2O2 ≥ 2.5 mM) led to cross-linking and aggregation of MPs, inhibiting trypsin-mediated hydrolysis. The oxidised MPs had the best binding capacity for heptanal. The interaction of the oxidised trypsin-hydrolysed MPs with heptanal was driven by hydrophobic interactions. The binding of heptanal affected the structure of the oxidised trypsin-hydrolysed MPs and reduced their α-helix content.

The volatile organic compounds generated from the Maillard reaction between l-ascorbic acid and l-cysteine in hot compressed water

BACKGROUND

Hot compressed water (HCW), also known as subcritical water (SCW), refers to high-temperature compressed water in a special physical and chemical state. It is an emerging technology for natural product extraction. The volatile organic compounds (VOCs) generated from the Maillard reaction between l-ascorbic acid (ASA) and l-cysteine (Cys) have attracted significant interest in the flavor and fragrance industry. This study aimed to explore the formation mechanism of VOCs from ASA and Cys and examine the effects of reaction parameters such as temperature, time, and pH in HCW.

RESULTS

The identified VOCs were predominantly thiophene derivatives, polysulfides, and pyrazine derivatives in HCW. The findings indicated that thiophene derivatives were formed under various pH conditions, with polysulfide formation favored under acidic conditions and pyrazine derivative formation preferred under weak alkaline conditions, specifically at pH 8.0.

CONCLUSION

The Maillard reaction between ASA and Cys mainly produced thiophene derivatives, polysulfides, and pyrazine derivatives in HCW. The generation mechanism was significantly dependent on the surrounding pH conditions. © 2024 Society of Chemical Industry.

Characteristics of meat flavoring prepared using hydrolyzed plant protein mix by three different heating processes

Meat flavoring was prepared using mainly enzymatic hydrolysate of plant protein mix, VB1, cysteine, and glucose by three heating processes, including A (80 °C-140 min), B (two-stage, 80 °C-30 min/120 °C-30 min), and C (120 °C-40 min). The A-, B-, and C-heated samples exhibited the strongest fatty and weakest meaty, the strongest meaty and kokumi, and the strongest roasted and bitterness characteristics, respectively. PLS-DA for free amino acids with TAVs and that for SPME/GC-MS results with GC-O and OAVs, suggested three amino acids and eight flavor compounds contributed significantly in differentiating taste or aroma attributes of the three heated samples. Molecular weight distribution and degree of amino substitution suggested 1-5 kDa peptides contributed to kokumi taste. Overall, C- and A-heating exhibited the highest rates in Maillard reaction and lipid oxidation, respectively, while those of B heating were between these two heating processes and responsible for better flavor of meat flavoring.

Flavor-switchable scaffold for cultured meat with enhanced aromatic properties

Cultured meat is emerging as a new type of food that can provide animal protein in a sustainable way. Many previous studies employed various types of scaffolds to develop cultured meat with similar properties to slaughtered meat. However, important properties such as flavor were not discussed, even though they determine the quality of food. Flavor characteristics vary dramatically depending on the amount and types of amino acids and sugars that produce volatile compounds through the Maillard reaction upon cooking. In this study, a flavor-switchable scaffold is developed to release meaty flavor compounds only upon cooking temperature mimicking the Maillard reaction of slaughtered meat. By introducing a switchable flavor compound (SFC) into a gelatin-based hydrogel, we fabricate a functional scaffold that can enhance the aromatic properties of cultured meat. The temperature-responsive SFC stably remains in the scaffold during the cell culture period and can be released at the cooking temperature. Surprisingly, cultured meat fabricated with this flavor-switchable scaffold exhibits a flavor pattern similar to that of beef. This research suggests a strategy to develop cultured meat with enhanced sensorial characteristics by developing a functional scaffold which can mimic the natural cooking flavors of conventional meat.

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 potential meat flavoring derived from Maillard reaction products of rice protein isolate hydrolysate-xylose via the regulation of temperature and cysteine

Maillard reaction products (MRPs) derived from rice protein isolate hydrolysate and D-xylose, with or without L-cysteine, were developed as a potential meat flavoring. The combined impact of temperature (80-140 °C) and cysteine on fundamental physicochemical characteristics, antioxidant activity, and flavor of MRPs were investigated through assessments of pH, color, UV-visible spectra, fluorescence spectra, free amino acids, volatile compounds, E-nose, E-tongue, and sensory evaluation. Results suggested that increasing temperature would reduce pH, deepen color, promote volatile compounds formation, and reduce the overall umami and bitterness. Cysteine addition contributed to the color inhibition, enhancement of DPPH radical-scavenging activity and reducing power, improvement in mouthfulness and continuity, reduction of bitterness, and the formation of sulfur compounds responsible for meaty flavor. Overall, MRPs prepared at 120 °C with cysteine addition could be utilized as a potential meat flavoring with the highest antioxidant activity and relatively high mouthfulness, continuity, umami, meaty aroma, and relatively low bitterness.

Structural and functional properties of Maillard-reacted casein phosphopeptides with different carbohydrates

This study used glucose, fructose, maltose and dextran to explore the effects of different carbohydrates on the Maillard reaction of casein phosphopeptides (CPP). The color parameter results showed that heating time from 1 to 5 h led to brown color, which was consistent with the observed increased in browning intensity. Fourier transform infrared spectroscopy results verified that four carbohydrates reacted with CPP to produce Maillard conjugates. Fluorescence spectroscopy showed that the Maillard reaction changed the tertiary structure of CPP by decreasing the intrinsic fluorescence intensity and surface hydrophobicity compared with the CPP-carbohydrate mixture. At the same time, the Maillard reaction effectively improved the emulsifying properties, reducing power and DPPH radical scavenging activity of CPP. Furthermore, this study also found that glucose and fructose improved CPP more than maltose and dextran. Therefore, monosaccharides have good potential in modifying CPP via the Maillard reaction.

Graphical Abstract

Technological challenges and future perspectives of plant-based meat analogues: From the viewpoint of proteins

The global demand for high-quality animal protein faces challenges, prompting a surge in interest in plant-based meat analogues (PBMA). PBMA have emerged as a promising solution, although they encounter technological obstacles. This review discusses the technological challenges faced by PBMA from the viewpoint of plant proteins, emphasizing textural, flavor, color, and nutritional aspects. Texturally, PBMA confront issues, such as deficient fibrous structure, chewiness, and juiciness. Addressing meat flavor and mitigating beany flavor in plant protein are imperative. Furthermore, achieving a distinctive red or pink meat color remains a challenge. Plant proteins exhibit a lower content of essential amino acids. Future research directions encompass (1) shaping myofibril fibrous structures through innovative processing; (2) effectively eliminating the beany flavor; (3) developing biotechnological methodologies for leghemoglobin and plant-derived pigments; (4) optimizing amino acid composition to augment the nutritional profiles. These advancements are crucial for utilization of plant proteins in development of high-quality PBMA.

Characterization and emulsifying ability evaluation of whey protein-pectin conjugates formed by glycosylation

Glycosylation is a method that enhances the functional properties of proteins by covalently attaching sugars to them. This study aimed at preparing three conjugates (WP-HG, WP-SBP, and WP-RGI) by dry heating method to research the influence of different pectin structures on the functional properties of WP and characterize properties and structures of these conjugates. The research results manifested that the degree of glycosylation (DG) of HG, SBP and RGI were 13.13 % ± 0.07 %, 23.27 % ± 0.3 % and 36.39 % ± 0.3 % respectively, suggesting that the increase of the number of branch chains promoted the glycosylation reaction. The formation of the conjugate was identified by the FT-IR spectroscopy technique. And SEM showed that WP could covalently bind to pectin, resulting in a smoother and denser surface of the conjugates. The circular dichroism analysis exhibited that the glycosylation reaction altered the secondary structure of WP and decreased the α-Helix content. This structural change in the protein spatial conformation led to a decrease in the hydrophobicity of protein surface. But the addition of pectin further regulated the hydrophilic-hydrophobic ratio on the surface of the protein, thus improving the emulsification properties of WP. In addition, the glycosylation could improve the stability of the emulsion, giving it a smaller droplet size, higher Zeta-potential and more stable properties. In a word, this study pointed out the direction for the application of different pectin structures in the development of functional properties of glycosylation products in food ingredients.