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

Role of lipids in beef flavor development: A review of research from the past 20 years

This review systematically examined the effects of lipids on beef flavor, based on studies published over the past 20 years, focusing on the intrinsic factors that influence flavor. Research shows that enhancing beefy and roasted aromas can improve consumer preference, while undesirable oxidized and metallic aromas reduce acceptance. Key volatile organic compounds (VOCs) associated with flavor include several aldehydes (hexanal, nonanal, decanal, octanal, heptanal, pentanal, and (E,E)-2,4-decadienal), alcohols (1-octen-3-ol and 1-hexanol), 2-heptanone, 2-pentylfuran, and nitrogen- and sulfur-containing compounds (pyrazines and dimethyl sulfides). Fatty acids such as C18:1n9 and C18:2n6 and intramuscular fat significantly contribute to forming overall VOCs to develop the distinct beef flavor. Storage conditions such as high‑oxygen environments can facilitate lipid oxidation, resulting in off-flavors. Consequently, beef flavor develops through complex interactions between lipid properties and chemical reactions during storage and heating, with moderate oxidation playing a key role in developing desirable flavors.

L-cysteine modulates the Maillard reaction: Impacts on PhIP and pyrazine formation

L-Cysteine (L-Cys) serves as both an inhibitor of the carcinogen 1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and an enhancer of food flavor, supporting efforts to improve food safety and quality. Using a glucose/phenylalanine/creatinine model system, this study assessed the effects of varying L-Cys concentrations on PhIP inhibition and pyrazine flavor enhancement through UPLC-MS/MS and GC-MS analyses. The optimal PhIP reduction (82.8 %-83.1 %) was achieved with 20 mg and 100 mg of L-Cys, whereas the pyrazine enhancement peaked with 200 mg and 100 mg of L-Cys (50.54 %-99.16 % and 37.83 %-98.82 %, respectively). A partial least squares regression (PLS) model demonstrated strong predictive accuracy (R2c and R2p > 0.73), providing a robust framework for regulating PhIP and pyrazine levels. This study offers a theoretical basis for advancing food safety and flavor quality, contributing to the development of safer and more enjoyable food products while addressing health and sustainability considerations.

Uncovering quality changes in oysters (Crassostrea hongkongensis) during frozen storage based on lipidomics and proteomics

This study investigated quality changes in oysters during frozen storage through physicochemical analysis, quantitative lipidomics, and quantitative proteomics. Results showed that the quality of oysters progressively deteriorated with increasing freezing time and temperature, as evidenced by color darkening, texture softening, reduced water-holding capacity, and increased TVB-N levels. Simultaneously, protein oxidation and lipid oxidation were observed, resulting in increased carbonyl, disulfide bonds, dityrosine, TBARS, and Schiff base content, and decreased free sulfhydryl groups. Lipidomics analysis revealed oxidation and hydrolysis of polyunsaturated lipids in oysters during storage, with PC being preferentially oxidized. Proteomics analysis revealed extensive oxidation and degradation of structural proteins, particularly MHC and filamin-C. Correlation analysis further highlighted oxidative degradation of polyunsaturated lipids and structural proteins as major contributors to the quality decline of oysters during frozen storage. This study sheds light on the mechanisms of quality deterioration in frozen oysters and provides valuable guidance for enhancing their preservation quality.

Experimental evidence demonstrating how freeze-thaw patterns affect spoilage of perishable cached food

For the small number of temperate and boreal species that cache perishable food, previous research suggests that increasing freeze-thaw events can have a negative impact on fitness by degrading the quality of cached food. However, there is no experimental evidence that directly links freeze-thaw events to cache quality. To examine how the timing, frequency, duration, and intensity of freeze-thaw events influenced cached food mass loss, a proxy for caloric content, we conducted a series of month-long laboratory experiments by placing simulated caches (raw chicken placed between two pieces of black spruce Picea mariana bark) in programmable freezers. Freeze-thaw treatments were modelled after weather data from Algonquin Provincial Park, Ontario, where a population of Canada jays (Perisoreus canadensis), a species that caches perishable food for overwinter survival and to support late-winter breeding, has declined by >  70% since the 1980s. First, we found no evidence that an increased frequency of freeze-thaw events influenced mass loss, suggesting that microstructural damage caused by crystal reformation does not significantly influence cache quality. Instead, our experimental results demonstrated that mass loss was positively influenced by longer individual thaws, which likely reflects increased microbial growth, oxidation, and progressive drip loss. We also found that caches lost more weight when subjected to early freeze-thaw events compared to late freeze-thaw events. Finally, we show that milder freezes led to less mass loss and, unexpectedly, warmer than average thaws post-freeze also led to less mass loss. Our results suggest that longer thaw periods post-freezing and milder freezes cause or lead to significantly increased spoilage of perishable cached food. All of these temperature-related conditions are closely associated with long-term changes in climate and, thus, the effects on cache degradation reported in these experiments should be applicable to species caching perishable food in the wild.

Protein oxidation and its effect on functional properties of livestock products during the processing and storage: A review

Protein oxidation is a complex chemical process that pervades the entirety of the food domain. It is governed by two primary mechanisms: the direct oxidation by active entities and the indirect oxidation by secondary oxidation byproducts like lipid oxidation, influenced by many factors. The oxidation of proteins in livestock products readily occurs post-processing and storage through techniques such as freezing, cooking, ultrasonication, among others, leading to protein carbonylation and subsequent alterations in structure. Consequently, the purpose of this manuscript is to scrutinize the impacts of conventional processing and storage methodologies on protein oxidation in livestock products, delineating potential mechanisms, action sites, and influential factors implicated in this progression. Additionally, we delve into the ramifications of protein oxidation on the processing attributes of livestock products, while venturing into forthcoming trends and obstacles to set a groundwork for ensuring and regulating the caliber of these commodities.

Crosslinked protein-polysaccharide nanocomposite coating for pork preservation: Impact on physicochemical properties and microbial structure

Edible films are significant in prolonging the shelf life of meat products. Herein, we prepared some edible coatings (EW/TNPCSs) based on egg white/chitosan/pectin as polymer matrix, containing tannic acid-nisin composite nano-crosslinker with antibacterial-antioxidant activities. The results of preservation indicated that the prepared EW/TNPCSs reduced the water loss of chilled pork and delayed the changes of taste, texture and surface color. At the end of the 12-day storage period, the content of TVB-N and carbonyl as well as the pH of EW/TNPCS5 chilled pork decreased by 33.75 %, 96.61 % and 7.09 %, respectively, and colony count decreased by 17.71 % compared to the control. Additionally, EW/TNPCSs inhibited the richness and diversity of spoilage dominant bacteria (Myroides, Acinetobacter, etc.), which were positively regulated by physicochemical indicators such as saltiness and abundance of bacteriostatic materials-coated chilled pork. It will provide a practical basis for the application of EW/TNPCSs coatings in the preservation of chilled pork.

Evaluation of quality parameters of fried chicken chips containing different levels of roasted chickpea and corn flour

The effect of roasted chickpea and corn flour on the quality characteristics of chicken breast meat-based chips was evaluated in the present study. The chips are prepared in three formulations as follows: CC-1 (5 % corn-15 % roasted chickpea flour), CC-2 (10 % corn-10 % roasted chickpea flour), and CC-3 (15 % corn-5 % roasted chickpea flour). The chips dough was placed into a single screw extruder, and the extrudates were dried for 1.5 h at 50 °C to get final moisture content of 10 %. Afterward, the extrudate samples were deep-fat fried for 30 s at 180 °C using a deep fryer, cooled on a baking tray for 20 min at room temperature, manually coated with ready chip spices as a flavoring in each baking tray and performed with chemical analyses such as proximate composition, pH value, TBARS (Thiobarbituric Acid Reactive Substances) value, carbonyl content and hardness value. The results showed that CC-1, and CC-2 samples had similar moisture, protein, and ash contents, while CC-3 samples were statistically higher in fat, and carbohydrate content compared to other samples (P < 0.05). The amounts of roasted chickpea and corn flour significantly affected the pH value of the chips (P < 0.05). TBARS values, and carbonyl contents showed statistically increments (P < 0.05) up to 60 days at room temperature were observed for all samples. A decrease in hardness was observed in all samples with storage, but an increase was observed with increasing corn flour level. The meat-based chips provided both an alternative to new gluten-free products for celiacs, and an important source of protein for athletes.

Insight into the effect of GSH curing treatment on the flavor formation of chicken meat

Glutathione (GSH) is an important precursor of meat flavor. This study aimed to evaluate the effect of GSH-curing on the flavor of cooked chicken. GSH-cured chicken with different concentrations and uncured chicken (blank) were roasted separately and comprehensively analyzed in terms of flavors, odor-active compounds, free amino acids, and fatty acids profile. Volatile flavor compounds were analyzed using solid-phase micro-extraction (SPME) along with GC-MS, GC-O/AEDA, and odor activity value (OAV) calculations. The results showed that the contents of most flavors derived from the Maillard reaction increased due to GSH-curing treatment, such as 2-methylthiophene, 3-methylthiophene, 2-methylthiazole, and 5-methylthiazole, while the lipid degradation flavors reduced, like hexanal, heptanal, and (E,E)-2,4-decadienal. In particular, during sensory analysis, the cured sample with 1.6 mmol GSH had the greatest roasted meaty odor. In addition, GSH curing results in the increased formation of key odor-active substances (OAV ≥ 1), such as 2-acetylthiazole.

Ultrasound combined with Adenosine 5'-Monophosphate Treatment: A Strategic Approach for enhancing the tenderness of chicken wooden breast meat

This study aimed to evaluate the effects of ultrasound and adenosine 5'-monophosphate (AMP) treatments on the quality characteristics and tenderness of chicken wooden breast (CWB). Compared to normal breast, CWB exhibits distinct quality characteristics, including increased weight, higher pH, pale color, and a firmer texture. It was found that ultrasound, AMP, and their combined application significantly reduced the shear force of CWB (p < 0.05), effectively improving its tenderness. The combined treatment of ultrasound and AMP significantly decreased the filtering residues of myofibrillar proteins (MPs) and increased myofibrillar fragmentation index (p < 0.05). MPs structure analysis showed that the combined ultrasound and AMP treatment facilitated the degradation of tropomyosin, the transformation of α-helix into β-sheet, and decreased intensity of tryptophan fluorescence, promoting MPs degradation and improving CWB tenderness. Pathological analysis and scanning electron microscopy also observed muscle fiber damage and the loss of myofibrillar membrane integrity following the combined treatment. These findings highlight the potential of AMP and ultrasound treatments in the tenderization process of CWB.

Augmenting antioxidative capacity of myosin and cytoprotective potential of myosin digestion products through the integration of crocin and crocetin: A comprehensive analysis via quantum chemical computing and molecular dynamics

This study explores the binding properties of two important constituents from Crocus sativus L (crocin and crocetin) with myosin, examining their influence on antioxidant capacity in myosin and a grilled meat model. And their impact on cytoprotective potential of myosin digestion products was also assessed in Caco-2 cells. Crocin and crocetin exhibited discernible binding affinity to myosin via static quenching, which induced conformational alterations that bolstered the antioxidant capacity of myosin, preventing peroxidation, which also corroborated in a grilled meat model. Crocin resulted in greater enhancement of antioxidant capacity and binding affinity, as confirmed by quantum chemical calculations. Molecular dynamics simulations revealed the stable binding of crocin to GLU:272, GLU:606, GLN:628, and PHE:417 residues of myosin. In addition, crocin substantially enhanced the protective efficacy of myosin digestion products against H2O2-induced damage in Caco-2 cells by upregulating superoxide dismutase and GSH-Px and simultaneously downregulating reactive oxygen species and malondialdehyde levels.

Comparative analysis of quality and flavor profiles in raw and pre-cooked large yellow croaker (Larimichthys crocea) meat post freezing and reheating

To clarify the potential application of large yellow croaker (LYC) as a prefabricated dish, present study evaluated the quality and flavor differences between raw and pre-cooked LYC after freezing storage and reheating via steam, water bath, and microwave methods. Results showed that raw meat retained significantly higher moisture content and water-holding capacity (WHC) compared to pre-cooked meat (p < 0.05). At 0 weeks, moisture content in RA-W, RA-S, and RA-M was 1.25 %, 2.06 %, and 3.2 % higher than PC-W, PC-S, and PC-M, respectively. WHC of RA-W, RA-S, and RA-M was 1.85 %, 4.1 %, and 1.01 % higher than raw group. Pre-cooked samples had significantly higher lipid and protein oxidation, especially with microwave reheating, with TBARS 27.5 % higher than raw group. Sensory scores and color stability were better maintained in pre-cooked samples. GC-IMS indicated that volatile flavor peak intensities were highest in the microwave group. The study provides insights for developing prefabricated LYC dishes.

The Effects of Packaging Barrier Properties Coupled with Storage Temperatures on the Dominant Spoilage Bacteria Composition and Freshness Quality of Lamb

This study aims to establish a preservation method by coupling certain barrier packaging with storage temperatures suitable for extending the shelf of chilled lamb. Chilled lamb was packaged using three different oxygen permeability packaging materials of high-oxygen-barrier packaging (HORP), medium-oxygen-barrier packaging (MORP), and low-oxygen-barrier packaging (LORP) (1.70, 23.95, and 1631.44 cm3/(m2·24·h·0.1·MPa), respectively, then stored at temperatures of 4 °C and -1 °C for 28 days, respectively. The results of total viable count, pH, color, and volatile basic nitrogen indicate that HORP effectively inhibits the growth rate of surface microorganisms and the oxidation rate of proteins in lamb. The sulfhydryl content, carbonyl value, and electronic nose suggest that the oxidative decomposition rate of lamb during storage at -1 °C is lower compared to storage conditions at 4 °C. The microbial diversity suggests that HORP significantly hinders the growth and reproduction of Pseudomonas and Brochothrix aerobic spoilage bacteria, as well as diminishes the abundance of the dominant microbial community. Herein, utilizing high-barrier packaging with an oxygen permeability of lower than 1.70 cm3/(m2·24·h·0.1·MPa) in conjunction with ice temperature storage at -1 °C is a highly effective preservation method for prolonging the shelf life of chilled lamb to 28 days.

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.

Changes in basic composition and in vitro digestive characteristics of pork induced by frozen storage

Introduction

Frozen pork can reduce the quality of the meat and alter the digestibility and bioavailability of meat proteins in the human body. In this study, we investigated the changes in the basic composition during frozen storage and their effects on the structural properties of digestion products after protein digestion.

Methods

The impacts of frozen storage at different temperatures (-8, -18, -25, and -40°C) and for different times (1, 3, 6, 9, and 12 months) on the basic components and in vitro digestive characteristics of pork were evaluated.

Results

The moisture, crude fat, and protein contents decreased with extended storage and increased temperature, whereas muscle juice loss increased (p < 0.05). During in vitro digestion of samples frozen at -8°C for 12 months, trichloroacetic acid (TCA)-soluble peptides were decreased by 25.46% and 14.37% in the gastric and small intestinal phases, respectively, compared with fresh samples. Confocal laser scanning microscope (CLSM) showed that samples stored at -8°C had the largest particle size after digestion. Disruption of protein structure was confirmed by the decrease in α-helix, β-turn, and fluorescence intensity (all p < 0.05) and the increase in β-sheet, random coil, and maximum fluorescence wavelength of the digestion products of samples frozen at -8°C (all p < 0.05).

Discussion

Therefore, long-term high-temperature frozen storage brought about a significant decline in basic components of muscle and acceleration of loss of protein structural integrity after digestion.

Differences in bacterial community structure and volatile flavor substance of industrial-scale tiger skin chicken feet stored at air packaging and vacuum packaging

The aim of this study was to investigate the differences of quality indexes, bacterial community and volatile organic compounds (VOCs) of industrial-scale tiger skin chicken feet (TSCF) under air packaging (AP) and vacuum packaging (VP). The results showed that the pH, total volatile basic nitrogen, total number of bacterial colony, and sensory scores in VP group changed less than those in AP group during the storage period. Different packaging conditions also had significant effects on bacterial community at the genus levels. Weissella and Lactococcus was the dominant genus in AP group, while Lactiplantibacillus and Pediococcus also had the large proportions in addition to Weissella and Lactococcus in VP group, which also led to the differences in VOCs between the two groups. Several VOCs could be used as potential spoilage indicators, including 2-octanone, ethanol, ethyl acetate and acetic acid in AP-stored TSCF, and 2-octanone, ethanol, ethyl acetate, 2-butyl-1-octanol, (R)-2-butanol, (E)-3-hexenoic acid and 2-butanone in VP-stored TSCF. Correlation analysis showed that these predominance spoilage microorganisms were significantly correlated with these VOCs of TSCF during the storage period. This study can provide a theoretical basis for understanding of the spoilage process of TSCF.

Ultrasound-assisted immersion freezing improves the digestion properties of beef myofibrillar protein

This study focused on the effect of ultrasound-assisted immersion freezing (UIF) with different ultrasound power (200, 400, 600 W) on the physicochemical and in vitro digestive properties of beef myofibrillar proteins (BMP). The results showed that the solubility and thermal stability of BMP were significantly increased, when treated with 400 W ultrasound, and the α-helix, β-sheets, β-turns, and random-coil fractions structures content were higher and the fluorescence intensity was closest to that of the control group, demonstrating enhanced structural stability of BMP. The protein digestibility of the UIF-400 W group was significantly enhanced while the particle size of the digested product was reduced, which proved its enhanced in vitro digestion characteristics. Overall, UIF treatment with appropriate power can effectively delay the structural deterioration of proteins, and the loss of thermal stability, enhance the in vitro digestibility of proteins, and promote their digestion and utilization by consumers.

Influence of frozen storage and flavoring substances on the nonvolatile metabolite profile of raw beef: Correlation of lipids and lipid-like molecules with flavor profiles

This study aimed to explore the effects of frozen storage and flavoring substances (sugar and salt) on the metabolite profiles of nonflavored (BS1) and flavored (BS2) beef samples through UHPLC-MS/MS and an untargeted method and flavor profiles using GC-MS and targeted method. Analysis was conducted during 0, 3, and 6 months of frozen storage. A comprehensive analysis of biochemical databases yielded a total of 1791 metabolites: 1183 metabolites were identified in positive ion mode and 608 in negative ion mode. There were 3 categories of metabolites under superclass classification, accounting for 77.93 % of the total metabolites, including lipids and lipid-like compounds (502 species, 33.87 %), organic acids and derivatives (459 species, 30.97 %), and organoheterocyclic compounds (194, 13.09 %). Multivariate statistical analysis showed that after 0, 3, and 6 months of frozen storage, 120, 106, and 62 differential metabolites, respectively, were identified in the comparison between the BS1 and BS2 samples. The results indicated that frozen storage has a decreasing effect on the differential metabolites, while the flavoring substances mainly enhance the metabolite profiles. It can be concluded that flavoring substances and frozen storage primarily influence the metabolites. At 0 and 6 months of frozen storage, 27 volatiles were detected. The correlation analysis displayed a positive correlation between lipids and lipid-like molecules and flavor compounds.

Evaluation of the effect of dietary supplementation with Allium mongolicum regel bulb powder on the volatile compound and lipid profiles of the longissimus thoracis in Angus calves based on GC-IMS and lipidomic analysis

The effect of A. mongolicum Regel bulb powder (AMRP) supplementation on the flavour of beef from Angus calves has not been investigated thus far. We used GC-IMS and untargeted lipidomics techniques to examine the volatile compound and lipid metabolic profiles and reveal the effects of dietary AMRP supplementation on the flavour of beef. A total of 6 characteristic volatile compounds and 30 key lipid compounds were identified in the AMRP treatment group. AMRP promoted the release of triglycerides and phosphatidylinositols from beef and accelerated the production of volatile compounds such as ethyl acetate, 1-penten-3-one, and tetrahydrofurane, and the production of these three characteristic volatile compounds was significantly correlated with the UFAs in triglycerides according to correlation analysis. In summary, dietary AMRP supplementation had a positive effect on the flavour of beef, and these findings provide a theoretical basis for the development and utilisation of AMRP as a feed additive.

Comprehensive foodomics analysis reveals key lipids affect aroma generation in beef

Lipids are vital precursors to beef aroma compounds, but the exact lipid molecules influencing aroma generation remain unconfirmed. This study employs gas chromatography-olfactometry-mass spectrometry and absolute quantitative lipidomics to identify beef's aroma and lipid profiles and to examine lipid alterations post-thermal processing. The aim is to understand the role of lipids in aroma generation during beef's raw-to-cooked transition. Eighteen key aroma compounds were identified as significant contributors to the aroma of beef. 265 lipid molecules were quantified accurately, and we found that triglycerides containing C18:1 or C18:2 chains, such as TG(16:0_18:1_18:1), TG(16:0_18:1_18:2), TG(16:0_16:1_18:1), as well as phosphatidylcholine and phosphatidylethanolamine containing PC(16:1e_20:4), PC(16:0e_20:4), PC(18:2e_18:2), and PE(16:1e_20:4), played important roles in the generation of key aroma compounds in beef. C18:1, C18:2, C18:3, and C20:4 were key substrates for the formation of aroma compounds. In addition, lysophosphatidylcholine and lysophosphatidylethanolamine containing unsaturated fatty acid chains may serve as important aroma retainers.

Ultrasound effect on flavor profile of beef jerky produced with partial potassium salt substitute based on GC-IMS technology

Traditional beef jerky contains a high content of sodium salt while the reduction of sodium usage impairs the flavor of final product. Regarding above issues, this research innovatively applied ultrasound-assisted salts (NaCl and KCl) recombination in the pickling stage of low-sodium beef jerky, and further compared the flavor differences caused by ultrasound by sensory evaluation, E-nose and GC-IMS. Besides, the changes of physicochemical qualities were explored including salts content, color and shear force. Results showed that ultrasound had positive impacts on flavor quality. The 400 W treatment was chosen as an optimal group for flavor improvement which was mainly related with the increased level of 5 aldehydes (nonanal, 3-methylbutanal, heptanal, pentanal and octanal) and the decreased level of 3 ketones (2-butanone, 2-pentanone and 2,3-pentanedione). Simultaneously, ultrasound increased the redness and tenderness of final product. Thus, ultrasound is a promising approach for improving the flavor of low-sodium beef jerky.

Insight into the role of lipids in odor changes of frozen grass carp (Ctenopharyngodon idella) based on lipidomics and GC-MS analysis: Impact of freeze-thaw cycles and heat treatment

The role of lipids in changes of volatile organic compounds (VOCs) in grass carp during 1 month of frozen storage with different freeze-thaw cycles and subsequent heat treatment was investigated. Sixty VOCs were identified in all groups by SPME-GC-MS. Odor contents fluctuated along with the freeze-thaw cycles and heat treatment, and the highest odor content was observed in frozen sample without freeze-thaw cycles. Freeze-thaw and heat treatment significantly promoted the lipid oxidation and hydrolysis for all the groups(p<0.05). Lipid metabolites were analyzed using non-targeted lipidomics and could be well distinguished among different freeze-thaw groups and heat-treatment groups. A total of 10 key differential lipid molecules were annotated, involving 4 metabolic pathways related to lipid degradation and odor formation. Spearman correlation analysis showed that these key differential lipids were significantly related to the formation of key VOCs (p<0.05).

Impact of Frozen Storage on Sensory, Physicochemical, and Volatile Compounds Parameters of Different Extra Virgin Olive Oils

Storage is important for virgin olive oil, a product obtained only during the harvest period, which requires a year-round storage until its best-before date. Low temperatures slow undesirable reactions, though this method is not widely applied. The objective of this paper is to assess the impact of frozen storage on the volatile composition and sensory properties of virgin olive oils. The quality parameters, volatile composition, and sensory profiles were analyzed for samples stored under different conditions (time 0, sixth month supermarket and frozen storage, and long-term-frozen). The physicochemical parameters of the samples stored under supermarket conditions showed significant differences (p < 0.05), with the frozen-storage sample after three months of storage. Additionally, the samples stored under supermarket conditions showed higher volatile concentrations than frozen ones, with increased concentrations of aldehydes and acids producing sensory defects. Thirty-two samples, considered as the long-term-frozen, were divided into three groups depending on the frozen-storage time (1, 6 or 10 years). These long-term-frozen storage samples confirmed the suitability of the proposed oxidation markers (pentanal, hexanal, heptanal, nonanal, acetic, propanoic, butanoic, and hexanoic acids) for differentiating storage conditions and times. This work highlights the oxidation process under different storage conditions and suggests oxidation markers.

Effect of water migration on changes of quality and volatile compounds in frozen Penaeus monodon

The purpose of this study was to clarify effects of water changes on the quality and volatile compounds of Penaeus monodon during frozen storage. The content of immobilized water decreased significantly while the bound water and free water increased significantly. Total sulfhydryl content, and Ca2+-ATPase activity decreased significantly to 68.31 μmol/g and 0.127 U/mg, meantime, carbonyl content and MFI value increased significantly to 2.04 μmol/g prot and 55.10. Total of 50 volatile compounds were identified. Nonanal (M & D), 2-nonanone and octanal were only detected in fresh samples, while 3-hydroxy-2-butanone and 1-hydroxy-2-propanone were only found in the samples after 20 days of storage. Correlation analysis revealed that 6 of the volatile compounds were associated with the change of free water. Total of 28 and 17 volatile compounds showed significant correlations with the immobilized water and bound water, respectively. Four volatile compounds have the potential to be used as the flavor marker.

The improvement mechanism of volatile for cooked Tibetan pork assisted with ultrasound at low-temperature: Based on the differences in oxidation of lipid and protein

Low-temperature cooking causes flavor weakness while improving the texture and digestive properties of meat. To enhance the flavor of low-temperature cooked Tibetan pork, samples were cooked at low-temperature with or without ultrasound-assisted (UBTP, BTP) for different times (30 min, 90 min) and then analyzed using GC-MS and LC-MS. The results showed that ultrasound-assisted cooking caused a significant increase in lipid oxidation by 9.10% in the early stage of the treatment. Additionally, at the later stage of ultrasound-assisted processing, proteins were oxidized and degraded, which resulted in a remarkable rise in the protein carbonyl content by 6.84%. With prolonged effects of ultrasound and low-temperature cooking, the formation of phenylacetaldehyde in UBTP-90 sample originated from the degradation of phenylalanine through multivariate statistics and correlation analysis. Meanwhile, trans, cis-2,6-nonadienal and 1-octen-3-one originated from the degradation of linolenic acid and arachidonic acid. This study clarified the mechanism of ultrasound-assisted treatment improving the flavor of low-temperature-cooked Tibetan pork based on the perspective of lipids and proteins oxidation, providing theoretical supports for flavor enhancement in Tibetan pork-related products.

Interrelationship of lipid aldehydes (MDA, 4-HNE, and 4-ONE) mediated protein oxidation in muscle foods

Proteins and essential fatty acids are crucial components of the human diet. However, lipids and proteins are susceptible to oxidative modification during food processing resulting in changes to their structural characteristics and functional properties. Food products rich in polyunsaturated fatty acids are highly susceptible to lipid peroxidation and generate bifunctional reactive aldehydes. Bifunctional aldehydes such as malondialdehyde (MDA), 4-hydroxy-2-nonenal (4-HNE), and 4-oxo-2-nonenal (4-ONE) readily bind to protein nucleophiles and lead to intra- or intermolecular protein cross-linking. In comparison with lipid oxidation, the degradation of proteins by prooxidants appears to be more intricate and results in a greater diversity of oxidation products. Although individual oxidation processes involving lipids and proteins received increasing attention in the past decades, the interactions between those aldehydes and protein oxidation in food have not been extensively explored. Studies indicate that the reactions of lipid and protein oxidation may take place simultaneously or independently, but oxidation products that arose from one reaction may further interact with lipids or proteins. The present review presents a perspective on reactive aldehydes and the role of aldehydes in inducing protein oxidation in muscle foods. Emphasis is focused on the interaction mechanism of the lipid, protein, and myoglobin protein oxidations. In addition, the occurrence of aldehydes derived from lipid oxidation in food systems as well as the endogenous antioxidant peptides or amino acids in meat and plant proteins are also briefly described.

Taste-related and volatile organic compounds of fresh and frozen-thawed chicken breast meat

The effect of frozen storage (-18°C for 2 months) and thawing (4°C for 16 h) on the taste-related compounds and volatile organic compounds (VOCs) in chicken breast meat was studied. After freeze-thawing, inosine monophosphate levels in chicken meat decreased and inosine levels increased. Free amino acid content increased significantly, regardless of bitter, sweet, or umami amino acids. Increase in arachidonic, eicosapentaenoic, adrenic, and docosahexaenoic acids after freeze-thaw cycle was observed suggesting the impact of lipid oxidation during freezing and thawing. Total 95 VOCs were detected, and multivariate analysis discriminated the differences in aroma- and taste-related compounds. The variable importance in the projection score indicated that the total amounts of sweet and bitter amino acids, inosine monophosphate, ketones, oxetane, and 3,3-dimethyl-2-butanone were important in discriminating between fresh and frozen-thawed chicken meat. The freeze-thawing altered the flavor of fresh chicken meat, and these important compounds could be utilized as markers for characterizing fresh or frozen-thawed meat.

Effect of different processing steps in the production of beer fish on volatile flavor profile and their precursors determined by HS-GC-IMS, HPLC, E-nose, and E-tongue

Beer fish is characterized by its distinctive spicy flavor and strong beer aroma. Currently, there is a lack of comprehensive research analyzing the changes in taste and volatile compounds that occur during the processing of beer fish. Thus, this study used HS-GC-IMS, electronic tongue, and electronic nose to investigate the changes in flavor components during various processing stages of beer fish. The obtained results were subsequently analyzed using multivariate statistical analysis. The results showed that the final beer fish product (SF) had the greatest amount of free amino acids (888.28 mg/100 g), with alanine, glutamic acid, and glycine contributing to the taste of SF. The inosine monophosphate (IMP) content of beer fish meat varied noticeably depending on processing stages, with deep-fried fish (FF) having the greatest IMP content (61.93 mg/100 g), followed by the final product (SF) and ultrasonic-cured fish (UF). A total of 67 volatiles were detected by GC-IMS, mainly consisting of aldehydes, ketones, and alcohols, of which aldehydes accounted for >37%, which had a great influence on the volatile flavor of beer fish. The flavor components' composition varied noticeably depending on the stage of processing. PLS-DA model screened 35 volatile flavor components (VIP > 1) as markers; the most significant differences were 1-propanethiol, isoamyl alcohol, ethanol, and eucalyptol. Ultrasonic processing, frying, and soaking sauce can significantly improve the formation of flavor compounds, resulting in a notable enhancement of the final beer fish's umami taste and overall flavor quality.

Mechanism of low-voltage electrostatic field on flavor retention in refrigerated sturgeon caviar: Insights from phospholipids

This study investigated the effect of low-voltage electrostatic field on the flavor quality changes and generation pathways of refrigerated sturgeon caviar. Research has found that after storage for 3-6 weeks, the physicochemical properties of caviar in the LVEF treatment group are better than those in the control group. The results of two-dimensional gas chromatography-time-of-flight mass spectrometry showed that the contents of hexanal, nonanal, (E,Z)-2,6-nonadienal, (E)-2-octenal and 1-octene-3-one related to the characteristic flavor of caviar (sweet, fruity and green) increased significantly. The lipidomics results indicated that the effects of LVEF on caviar mainly involve glycerophospholipid metabolism, linoleic acid metabolism, and α-Linolenic acid metabolism. Methanophosphatidylcholine (15:0/18:1), phosphatidylcholine (18:0/20:5), and phosphatidylcholine (18,1e/22:6) were significantly correlated with odor formation. Therefore, low-voltage electrostatic field treatment preserved the quality and enhanced the flavor of sturgeon caviar. This study provided a new theoretical basis for the preservation of sturgeon caviar.

Insights into the molecular mechanisms of lipid transformation in sturgeon fillets: Interplay between specific spoilage and dominant bacteria

This study investigates spoilage bacteria's impact on lipid metabolism in sturgeon fillets using UHPLC-Q-Orbitrap-MS/MS-based untargeted lipidomic analysis. A total of 4041 lipid molecules across five classes and 42 subclasses were identified, including glycerophospholipids (GPs, 50.88%), glycerolipids (GLs, 36.08%), sphingolipids (SPs, 10.47%), fatty acyls (FAs, 2.45%), and sterol lipids (STs, 0.12%). Aeromonas sobria, a specific spoilage bacterium, reduced GPs and FAs while increasing GLs, SPs, and STs via extracellular lipases and esterases. Acinetobacter albensis, the dominant bacterium, mainly elevated SPs and FAs. Their interaction promoted lipid metabolism and oxidation while producing volatile organic compounds (VOCs). Ethyl isobutyrate, ethyl propionate, isobutyl formate, pentan-2-one, propan-2-one, 2-butanone, 3-methyl-3-buten-1-ol, and dimethyl sulfide were mainly associated with Acinetobacter albensis, while 1-hexanol, 1-pentanol, 1-penten-3-ol, 1-hydroxypropan-2-one, 3-methyl-1-butanol, 2-methylbutanal, 3-hydroxy-2-butanone, and propionaldehyde were mainly related to Aeromonas sobria. This work unveils the mechanism of lipid transformation in sturgeon fillets during refrigerated storage, offering insights for aquatic products quality control.

Characterization and Evaluation of Taihe Black-Boned Silky Fowl Eggs Based on Physical Properties, Nutritive Values, and Flavor Profiles

Taihe black-boned silky fowl (TS) is a native chicken breed in China with more than 2000 years of history. The present study aimed to characterize and evaluate the physical, nutritional, and flavor properties of TS eggs with a comparison to two other commercial breeds. Eggs from TS (n = 60) crossbred black-boned silky fowl (CB, n = 60) and Hy-line Brown (HL, n = 60) were used for physicochemical analysis. The evaluation system was divided into four parts based on nutrient and flavor profiles: protein and amino acids, lipids and fatty acids, mineral elements, and flavor-related amino acids and volatile compounds. Results showed that TS eggs were typically associated with the lowest egg weight and the highest yolk color, as compared with CB and HL eggs. No differences were found in crude protein, crude fat, triglycerides, and cholesterol content between eggs from the different breeds, but these eggs were distinct in terms of the amino acid, fatty acid, and volatile flavor compound profiles. Moreover, the differences in amino acid and fatty acid profiles might contribute to the specific flavor of TS eggs. Evaluation results indicated that TS egg whites may be suitable as a protein source for premature infants and young children under three years old and TS egg yolks could be considered a beneficial dietary lipid source due to their potential anti-cardiovascular properties. Additionally, TS whole eggs could serve as a valuable source of selenium (Se), molybdenum (Mo), zinc (Zn), and phosphorus (P) for adults aged 18 to 65. However, TS and CB eggs showed inferior Haugh units, eggshell quality, and essential amino acid compositions for older children, adolescents, and adults. These findings provide a better insight into the health benefits of TS eggs and contribute to the breeding and nutrition regulation of TS breeds.

Effects and mechanism of sub-freezing storage on water holding capacity and tenderness of beef

In order to explore the effect of sub-freezing storage on water holding capacity and tenderness of beef, four treatments were compared in this study: sub-freezing (-7 °C) fast sub-freezing (-38 °C until the core temperature achieved to -7 °C), superchilling (-1 °C) and fast frozen (-38 °C until the core temperature achieved to -18 °C) with the latter two treatments serving as the controls. The differences in muscle fiber structure, water distribution, protein oxidation and cytoskeletal protein degradation were studied. The results demonstrated that compared with other treatments, the fast sub-freezing treatment resulted in less structural damage to the muscle fibers and had better water holding capacity. Both sub-freezing and fast sub-freezing treatments inhibited protein oxidation compared with superchilling, but the former treatment's level of protein oxidation was higher than that in fast sub-freezing treatment during long-term storage (42 weeks). In addition, the structural proteins in the sub-freezing and fast sub-freezing treatments underwent faster degradation during long-term storage and therefore the meat was more tender compared with the fast frozen treatment. The results indicate that the fast sub-freezing treatment can be potentially applied in beef storage.

Revealing the spoilage characteristics of refrigerated prepared beef steak by advanced bioinformatics tools

BACKGROUND

Although microorganisms are the main cause of spoilage in prepared beef steaks, very few deep spoilage mechanisms have been reported so far. Aiming to unravel the mechanisms during 12 days of storage at 4 °C affecting the quality of prepared beef steak, the present study investigated the changes in microbial dynamic community using a combined high-throughput sequencing combined and bioinformatics. In addition, gas chromatography-mass spectrometry combined with multivariate statistical analysis was utilized to identify marker candidates for prepared steaks. Furthermore, cloud platform analysis was applied to determine prepared beef steak spoilage, including the relationship between microbiological and physicochemical indicators and volatile compounds.

RESULTS

The results showed that the dominant groups of Pseudomonas, Brochothrix thermosphacta, Lactobacillus and Lactococcus caused the spoilage of prepared beef steak, which are strongly associated with significant changes in physicochemical properties and volatile organic compounds (furan-2-pentyl-, pentanal, 1-octanol, 1-nonanol and dimethyl sulfide). Metabolic pathways were proposed, among which lipid metabolism and amino acid metabolism were most abundant.

CONCLUSION

The present study is helpful with respect to further understanding the relationship between spoilage microorganisms and the quality of prepared beef steak, and provides a reference for investigating the spoilage mechanism of dominant spoilage bacteria and how to extend the shelf life of meat products. © 2024 Society of Chemical Industry.

Molecular decoding a meat-like aroma generated from Laetiporus sulphureus-mediated fermentation of onion (Allium cepa L.)

The organoleptic properties of plant-based meat alternatives do not meet consumer expectations due to the lack of characteristic flavors resembling meat. To address this challenge, a fermentation system utilizing Laetiporussulphureus was developed to generate a meat-like and fatty flavor from a vegetable source, onion. By means of multiple stir bar sorptive extraction and gas chromatography-mass spectrometry-olfactometry, an unsaturated aldehyde, (E,Z)-2,4-decadienal, which imparts a tallow-like and fatty odor, and a sulfurous compound benzothiazole, with a broth-like odor were identified, which well contributed to the characteristic odor of the supernatant. (E,Z)-2,4-Decadienal as the most important odorant (odor activity value = 206) was biosynthesized by transformation of linoleic acid with L.sulphureus, as revealed by isotopic tracing experiments. For the first time in Basidiomycota, the biogenetic pathway of (E,Z)-2,4-decadienal from linoleic acid was proposed.

Dietary supplementation with quercetin: an ideal approach for improving meat quality and oxidative stability of broiler chickens

This study aimed to improve the eating quality of yellow-feathered broiler chicks by feeding them corn-soybean meal diets supplemented with 250, 500, and 1,000 mg/kg quercetin. we examined the impact of varying doses of dietary quercetin on the sensory quality of chicken breast meat as well as on the antioxidant enzymes, antioxidant-related signaling molecules, structure and thermal stability of myofibrillar protein (MPs), and microstructure of myogenic fibers in the meat during 24 h of postslaughter aging. Additionally, we investigated the potential correlations among antioxidant capacity, MP structure, and meat quality parameters. The results indicated that dietary supplementations with 500 and 1,000 mg/kg quercetin improved the physicochemical properties and eating quality of yellow-feathered broiler chicken breast meat during 12 to 24 h postslaughter. Additionally, quercetin improved the postslaughter oxidative stress status and reduced protein and lipid oxidation levels. It also increased hydrogen bonding interactions and α-helix content during 6 to 12 h postslaughter and decreased β-sheet content during 12 to 24 h postslaughter in chicken breast MP. This resulted in improved postslaughter MP structure and thermal stability. The correlation results indicated that the enhancement of antioxidant capacity and MP structure enhanced the physicochemical and edible qualities of yellow-feathered broiler chicken breast meat. In conclusion, the current findings suggest that dietary supplementation with quercetin is an ideal approach for improving the eating quality of chicken meat, thereby broadening our understanding of theoretical and technological applications for improving the quality of chicken.

The Potential Correlation between Bacterial Diversity and the Characteristic Volatile Flavor Compounds of Sichuan Sauce-Flavored Sausage

The distinctive taste of Sichuan sauce-flavored sausage comes from an intricate microbial metabolism. The correlation between microbial composition and distinct flavor components has not been researched. The study used headspace solid-phase microextraction action with gas chromatography mass spectrometry to find flavor components and high-throughput sequencing of 16S rRNA to look at the diversity and succession of microbial communities. The correlation network model forecasted the connection between essential bacteria and the development of flavors. The study revealed that the primary flavor compounds in Sichuan sauce-flavored sausages were alcohols, aldehydes, and esters. The closely related microbes were Leuconostoc, Pseudomonas, Psychrobacter, Flavobacterium, and Algoriella. The microbes aided in the production of various flavor compounds, such as 1-octen-3-ol, benzeneacetaldehyde, hexanal, (R,R)-2,3-butanediol, and ethyl caprylate. This work has enhanced our comprehension of the diverse functions that bacteria serve in flavor development during the fermentation of Sichuan sauce-flavored sausage.

Effects of improver on the quality of frozen Chinese sweet rice wine dough: Water status, protein structure and flavor properties

In the study, a sweet wine koji (YQ-5) was successfully selected to make frozen Chinese sweet rice wine dough (F-CD) for flavor enrichment. Subsequently, the effects of single improver (SI: xanthan gum, potassium carbonate, antifreeze protein, diacetyl tartaric esters of monoglycerides and composite improver (XPADG: Four improvers mixed in proportion) on the texture, rheological properties, microstructure, water status, protein secondary structure, volatile flavor substances and sensory properties of F-CD during frozen storage were investigated. The results indicated that XPADG slowed the increase in freezable water and water mobility in the dough, giving dough the most stable rheological properties and minimizing the damage of freezing to the secondary structure and microstructure of proteins. Besides, GC-QTOF/MS analysis showed that XPADG may facilitate the retention of flavoring substances in F-CD after storage for 6 days. Finally, the sensory evaluation showed that XPADG imparted good sensory properties to the product after freezing for 6 days.

Volatile Compounds for Discrimination between Beef, Pork, and Their Admixture Using Solid-Phase-Microextraction-Gas Chromatography-Mass Spectrometry (SPME-GC-MS) and Chemometrics Analysis

This study addresses the prevalent issue of meat species authentication and adulteration through a chemometrics-based approach, crucial for upholding public health and ensuring a fair marketplace. Volatile compounds were extracted and analyzed using headspace-solid-phase-microextraction-gas chromatography-mass spectrometry. Adulterated meat samples were effectively identified through principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA). Through variable importance in projection scores and a Random Forest test, 11 key compounds, including nonanal, octanal, hexadecanal, benzaldehyde, 1-octanol, hexanoic acid, heptanoic acid, octanoic acid, and 2-acetylpyrrole for beef, and hexanal and 1-octen-3-ol for pork, were robustly identified as biomarkers. These compounds exhibited a discernible trend in adulterated samples based on adulteration ratios, evident in a heatmap. Notably, lipid degradation compounds strongly influenced meat discrimination. PCA and PLS-DA yielded significant sample separation, with the first two components capturing 80% and 72.1% of total variance, respectively. This technique could be a reliable method for detecting meat adulteration in cooked meat.

Fluctuation of flavor quality in roasted duck: The consequences of raw duck preform's repetitive freeze-thawing

This study aimed to investigate the changes in flavor quality of roasted duck during repetitive freeze-thawing (FT, -20 ℃ for 24 h, then at 4 ℃ for 24 h for five cycles) of raw duck preforms. HS-SPME/GC-MS analysis showed that more than thirty volatile flavor compounds identified in roasted ducks fluctuated with freeze-thawing of raw duck preforms, while hexanal, nonanal, 1-octen-3-ol, and acetone could as potential flavor markers. Compared with the unfrozen raw duck preforms (FT-0), repetitive freeze-thawing increased the protein/lipid oxidation and cross-linking of raw duck preforms by maintaining the higher carbonyl contents (1.40 ∼ 3.30 nmol/mg), 2-thiobarbituric acid reactive substances (0.25 ∼ 0.51 mg/kg), schiff bases and disulfide bond (19.65 ∼ 30.65 μmol/g), but lower total sulfhydryl (73.37 ∼ 88.94 μmol/g) and tryptophan fluorescence intensity. Moreover, A lower protein band intensity and a transformation from α-helixes to β-sheets and random coils were observed in FT-3 ∼ FT-5. The obtained results indicated that multiple freeze-thawing (more than two cycles) of raw duck preforms could be detrimental to the flavor quality of the roasted duck due to excessive oxidation and degradation.

Evaluation of the flavor profiles of Yanbian-style sauced beef from differently treated raw beef samples

In this study, we investigated the volatile flavor compounds and sensory perceptions of Yanbian-style sauced beef prepared from raw meats subjected to different treatments (hot fresh, chilled, and frozen beef). The results indicated that the treatment of raw beef significantly impacted the quality and flavor of sauced beef. Sauced chilled beef (CRSB) exhibited the highest content of fatty acids and total amino acids. A total of 48 volatile compounds were identified. Moreover, a relative odor activity value analysis identified hexanal, nonanal, heptanal, 1-octen-3-ol, and 2,3-octanedione as the characteristic flavor compounds in Yanbian-style sauced beef. The sensory evaluation demonstrated that CRSB was the most palatable and flavorful. Additionally, correlation loading plot analysis indicated strong correlations between sensory evaluation, fatty acids, amino acids, and volatile flavor compounds. These results suggest that chilled beef meat is the best raw material for the production of Yanbian-style sauced beef.

Insight into the autochthonous bacterial strains as starter cultures for improving the flavor profiles of dry-cured duck: Changes in microbial diversity and metabolic profiles

The purpose of this study was to reveal the effect of inoculating autochthonous bacterial strains (Lactobacillus and Staphylococcus simulans) on the flavor profiles, microbial community, and metabolites, and to elucidate the potential mechanism of flavor formation in dry-cured duck. The results indicated that the inoculation of bacterial strains could improve the amount of lactic acid bacteria and Staphylococcus and reduce the counts of Enterobacteria. There was a significant difference in flavor profiles between samples inoculated with different strains. Hexanal-D, acetone, 3-methyl-1-butanol-D, thiophene, hexanal-M, propanal, pentanal, (Z)-2-penten-1-ol and ethanol-D were the potential biomarkers. A total of 70 differential metabolites were screened and identified. Amino acid metabolism and lipid metabolism were the key pathways for the production of flavor and metabolites in dry-cured duck. The results of this study will improve our understanding of the mechanism of flavor formation regarding the inoculation of autochthonous starter cultures.

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.

Effect of cinnamon powder on quality attributes and off-flavor in fried chicken drumsticks made from long-term thawed Korean native chicken

The effect of cinnamon powder on the quality and mitigation of off-flavor in fried chicken drumsticks made from long-term thawed Korean native chicken (Woorimatdag No. 1, WRMD1) was investigated. The WRMD1 drumsticks were categorized into 5 groups: conventional thawing (16 h, CT), long-term thawing (48 h, LT), cinnamon powder added into 'LT' as marinade (0.03%, CM) or incorporated into the batter (1.35%, CB), and long-term thawing with cinnamon powder incorporated both in the marinade and batter (0.03% + 1.35%, CMB). The crude fat content was significantly higher in the CT and CMB than that of the CB. The CM, CB, and CMB showed significantly lower levels of 2-thiobarbituric acid reactive substance compared with the CT and LT. The predominant fatty acids in all treatments were C18:1n9, C18:2n6, and C16:0. The LT displayed lower total unsaturated fatty acid content than the CT (P < 0.05). The CM effectively decreased lipid oxidative volatiles, such as 1-octanol, 1-octen-3-ol, and 2-octen-1-ol, (E), in the LT (P < 0.05). Both the CM and CB showed an inclination to increase specific pyrazines associated with pleasant notes compared with the LT, and showed higher levels of pyrazines, such as pyrazine, 2-ethyl-6-methyl-, and pyrazine, 3-ethyl-2,5-dimethyl-, than those of the CMB (P < 0.05). The CM contained higher levels of 2,3-butanedione when compared with the other groups (P < 0.05). Multivariate analysis demonstrated that cinnamon had an effect in discriminating the treatment groups with cinnamon addition from both the CT and LT, whereas the CM, CB, and CMB formed distinct clusters. The CM and CMB received significantly higher aroma scores from panelists in comparison to the other groups. These findings suggest that the CM (0.03% cinnamon powder) can be used to enhance the aroma in fried WRMD1 drumsticks by reducing or masking the off-flavor volatiles associated with long-term thawing.

Study on Ways to Improve the Quality of Black Goat Meat Jerky and Reduce Goaty Flavor through Various Spices

In this study, we analyzed the physicochemical and sensory properties of black goat jerky marinated with various spices (non-spice, control; rosemary, RO; basil, BA; ginger, GI; turmeric, TU; and garlic, GA). The physicochemical properties of black goat jerky analyzed were pH, water holding capacity, color, cooking yield, shear force, and fatty acid composition. The sensory characteristics were analyzed through the aroma profile (electronic nose), taste profile (electronic tongue), and sensory evaluation. The pH and water holding capacity of the GI showed higher values than the other samples. GI and GA showed similar values of CIE L* and CIE a* to that of the control. The shear force of the GI and TU was significantly lower than that of other samples (p<0.05). Regarding fatty acid composition, GI showed high unsaturated and low saturated fatty acid contents compared with that of the other samples except for RO (p<0.05). In the aroma profile, the peak area of hexanal, which is responsible for a faintly rancid odor, was lower in all treatment groups than in the control. In the taste profile, the umami of spice samples was higher than that of the control, and among the samples, GI had the highest score. In the sensory evaluation, the GI sample showed significantly higher scores than the control in terms of flavor, aroma, goaty flavor, and overall acceptability (p<0.05). Therefore, marinating black goat jerky with ginger powder enhanced the overall flavor and reduced the goat odor.

Emerging challenges and efficacy of polyphenols-proteins interaction in maintaining the meat safety during thermal processing

Polyphenols are well documented against the inhibition of foodborne toxicants in meat, such as heterocyclic amines, Maillard's reaction products, and protein oxidation, by means of their radical scavenging ability, metal chelation, antioxidant properties, and ability to form protein-polyphenol complexes (PPCs). However, their thermal stability, low polarity, degree of dispersion and polymerization, reactivity, solubility, gel forming properties, low bioaccessibility index during digestion, and negative impact on sensory properties are all questionable at oil-in-water interface. This paper aims to review the possibility and efficacy of polyphenols against the inhibition of mutagenic and carcinogenic oxidative products in thermally processed meat. The major findings revealed that structure of polyphenols, for example, molecular size, no of substituted carbons, hydroxyl groups and their position, sufficient size to occupy reacting sites, and ability to form quinones, are the main technical points that affect their reactivity in order to form PPCs. Following a discussion of the future of polyphenols in meat-based products, this paper offers intervention strategies, such as the combined use of food additives and hydrocolloids, processing techniques, precursors, and structure-binding relationships, which can react synergistically with polyphenols to improve their effectiveness during intensive thermal processing. This comprehensive review serves as a valuable source for food scientists, providing insights and recommendations for the appropriate use of polyphenols in meat-based products.

Identification and comparison of aroma and taste-related compounds from breast meat of three breeds of Korean native chickens

This study was aimed to identify and compare the taste-related compounds (nucleotide-related compounds, free amino acid contents, and fatty acid composition) and aroma (volatile organic compounds [VOC]) compounds in the chicken breast meat from 3 kinds of Korean native chicken (KNC), namely Hanhyup 3 (HH3), Woorimatdag 1 (WRMD1) and Woorimatdag 2 (WRMD2). Among the 3 breeds, WRMD1 had significantly higher IMP and AMP contents than HH3. WRMD2 exhibited higher levels of umami and sweet-taste amino acids and oleic acid composition compared to HH3 (P < 0.05). HH3 showed a higher composition of unsaturated fatty acids than WRMD2 (P < 0.05). On their discrimination by flavor composition, some compounds including aspartic acid were analyzed as important compounds. Regarding aroma compounds, unique aroma compounds were detected for each breed and some compounds such as isopropyl myristate, p-cresol, (S)-(+)-3-Methyl-1-pentanol, and cyclic octa-atomic sulfur were expected to be utilized as key compounds in discrimination of the 3 breeds. From the result of this study, the differences on the flavor compounds of three breeds were elucidated and key compounds for their discrimination were presented.

Natural-based edible nanocomposite coating for beef meat packaging

Researchers have made significant discoveries in addressing the limitations of essential oils (EOs) in food packaging using encapsulation systems combined with nanoparticles (NPs). This study aimed to develop a unique coating for beef preservation using nanostructured lipid carriers (NLCs). The optimal formulation of NLCs was determined based on size, zeta potential, and loading rate, achieving a content of 71.4% savory EO. A composite coating containing NPs was then created using different concentrations of NLCs (0, 0.85%, 1.7%, 2.55%, and 3.4%). The antimicrobial effectiveness of the coatings was assessed using well-diffusion assays to identify the best coating (17 mm). This optimized coating was applied to beef samples for 12 days, and extensive evaluation was conducted over time. The results demonstrated that the encapsulation percentage was higher than 98.7%. The optimal coating (CMC-OM-ZnO NPs-NLCs 3.4%) significantly reduced microbial growth (total count: over 1.6 log CFU/g), pH, thiobarbituric acid value (TBA), and total volatile nitrogen (TVN) compared with the control samples (P < 0.05). Overall, this novel bioactive packaging enriched with lipidic and inorganic nanomaterials represents an innovative way to improve meat products' oxidative and microbial stability.

Fava bean (Vicia faba L.) protein concentrate added to beef burgers improves the bioaccessibility of some free essential amino acids after in vitro oral and gastrointestinal digestion

The influence of partial replacement of animal protein by plant-based ingredients on the protein digestibility of beef burgers was investigated. Beef burgers were supplemented with fava bean protein concentrate (FB) or a mixture of FB and flaxseed flour (FBFS), both processed by extrusion, at different levels: 0 (control), 10, 15, and 20 % (w/w). A pilot sensory analysis was conducted to select the percentage of flour inclusion for further assays: control, 10 % FB, and 10 % FBFS. Protein digestibility, amino acid profile, and protein secondary structure of these burgers after in vitro oral and gastrointestinal digestion were studied. In vitro boluses were prepared with the AM2 masticator, simulating normal mastication, and static in vitro digestion of boluses was performed according to the INFOGEST method. Inclusion of 10 % FB in beef burgers did not alter their flavour or tenderness compared to the control, whereas tenderness and juiciness scored slightly higher for the 10 % FBFS burgers compared to 15 % and 20 % FBFS ones. Poor lipid oxidative stability during storage was observed with 10 % FBFS burgers. Total protein content was significantly higher (p < 0.05) in 10 % FB burgers than in control burgers after in vitro oral digestion. Additionally, 10 % FB burgers presented higher amounts of free essential amino acids like isoleucine, leucine, phenylalanine, and valine at the end of digestion, as well as methionine, tyrosine, and histidine. Partial substitution of meat protein by 10 % FB improves the nutritional profile of beef burgers, without altering their sensory qualities.

Efficient extraction based on a polydimethylsiloxane/bimetallic ZnCo-MOF carbonization sponge coupled with GC-MS for the rapid analysis of volatile compounds in cumin

A novel porous polydimethylsiloxane/bimetallic ZnCo-MOF carbonization (PDMS/ZnCo-MOF@C) sponge was successfully fabricated, followed by its utilization in GC-MS for the high efficiency extraction and determination of volatile compounds in cumin. The PDMS/ZnCo-MOF@C sponge exhibits outstanding properties with a considerable adsorption capacity, high surface area, and large pore volume and has shown potential as an ideal adsorbent for the separation and preconcentration of trace volatile compounds. The effect of different parameters on the extraction efficiency were investigated. Excellent analytical performances were achieved for the representative compounds (β-pinene, p-cymene, γ-terpinene, cuminaldehyde, and linalyl acetate), including wide linearity (2.31-440.1 ng) with high correlation coefficients (R2 ≥ 0.9979), low LODs (1.02-3.11 ng) and LOQs (2.45-7.08 ng), and satisfactory precision (intra-day RSDs ≤ 2.89% and inter-day RSDs ≤ 4.14%). The optimal method was applied for the analysis of cumin from different regions and 44 volatile compounds were identified. The correlation between the different regions of cumin and volatile compounds was explored using multivariate statistical analysis. These results demonstrated that PDMS/ZnCo-MOF@C is an efficient, simple and sensitive material for use in the pretreatment technique for the determination of the volatile compounds in aromatic plants.

Identification and biotransformation analysis of volatile markers during the early stage of Salmonella contamination in chicken

Salmonella is one of the most prevalent foodborne pathogens in poultry and its products. Its rapid detection based on volatile organic compounds (VOC) has been widely accepted. However, the variation in the VOCs of Salmonella-contaminated chicken during the early stage (48 h) remains uncertain. Headspace-SPME-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and headspace-gas chromatography-ion migration spectroscopy (HS-GC-IMS) were used to identify VOCs and their variations after the chicken meat was contaminated with Salmonella. Chemometric and KEGG enrichment analyses were performed to identify VOC markers and their potential metabolic pathways. A total of 64 volatile compounds were detected using HS-GC-IMS, which showed a better differentiation than HS-SPME-GC-MS (45 volatile compounds) based on principal component analysis (PCA) and orthogonal partial least squares-discriminant analysis (OPLS-DA). Fatty acid degradation was the main cause of VOC variation. 2-Propanol, hexadecane, 3-methylbutanol, acetic acid, propyl acetate, acetic acid methyl ester, and 3-butenenitrile were identified as VOC markers in the middle stage of decomposition, and 1-octen-3-ol was recognized as a VOC marker of Salmonella-contaminated chicken during the first 48 h of contamination. This provides a theoretical basis for the study of Salmonella contamination VOC markers in poultry meat.