Association of lipidome evolution with the corresponding volatile characteristics of postmortem lamb during chilled storage

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.

Insight into the aged braised broth on braised chicken: Antioxidant activity, physicochemical properties, and flavor characteristics

The aged braised broth (ABB) is crucial in determining the superior quality of braised chicken by enriching meat-derived flavor compounds. However, its effects on antioxidant activity and sensory attributes remain poorly understood. This study examined the impact of ABB on both antioxidant activity and sensory qualities of braised chicken. The chicken meat sample, compared to chicken broth, ABB increased total phenolic and flavonoid contents by 72.79 % and 206.04 %, respectively. Additionally, ABB boosted antioxidant activity and significantly reduced lipid oxidation (from 0.95 to 0.13 mg MDA/kg). ABB also improved moisture distribution, reduced cooking and centrifugal losses, and had minimal effects on color and texture. The flavor profile was analyzed using an electronic nose, GC-IMS, and GC-MS, confirming that ABB enhanced flavor characteristics. Chemometric analysis identified eugenol, estragole, anethole, 1-octen-3-ol, and hexanal as key aroma compounds. These findings highlight the effectiveness of ABB in improving the eating quality of braised chicken.

Correlation of lipid hydrolysis, oxidation, and molecular transformation with volatile compound revolution in pork during postmortem wet-aging process

Lipid hydrolysis and oxidation properties, lipid metabolites, and volatile flavors were investigated to elucidate the wet-aging process (1 h to 10 d) on lipid molecule transformation and volatile flavor evolution in pork. Phospholipase A2 (PLA2) activity increased at 12 h, with lipoxygenase (LOX) increasing from 1 h to 7 d (P < 0.05). A total of 546 differential lipids from 997 lipids and 19 aroma-active compounds out of 43 volatiles were identified, with most fatty aldehydes reaching the highest at 10 d. Acyl carnitine (18:2) and hexadecanal are potential markers to predict the wet-aging progress of pork. Correlation analysis indicated that phospholipid molecule hydrolysis by PLA2 and lipid enzymatic oxidation mediated by LOX rather than reactive oxygen species contributed to volatile aldehyde evolution, while phosphatidylcholine (16:2e/22:6) may be the key lipid molecule. These results offer insights into the lipid transformation and aroma evolution in pork during the wet-aging process.

Effect of Antifreeze Glycopeptides on the Quality and Microstructure of Frozen Lamb Meatballs

This study explored the protective effects of antifreeze glycopeptide and alginate on the quality of -18 °C frozen lamb meatballs across various storage periods.

METHODS

Measurements of volatile salt nitrogen (TVB-N), thiobarbituric acid (TBARS), water retention, water distribution, microstructure, and metabolite changes were taken in the lamb meatballs.

RESULTS

The results showed that the addition of antifreeze glycopeptides (AFGs) significantly preserved the quality characteristics of lamb meatballs. In particular, the 0.30% antifreeze glycopeptide demonstrated the strongest protective effect on water retention and metabolites during freezing. The ice crystal area within the microstructure of lamb meatballs with added antifreeze glycopeptides was markedly reduced compared to the others after 14 days of freezing (p < 0.05). Additionally, AFGs lessened the lipid oxidation reaction and prolonged the oxidation time of lamb after 28 days of freezing.

CONCLUSION

In summary, AFGs beneficially affected the quality of frozen lamb meatballs and are a potential, safe, and efficient cryoprotectant.

Changes in meat quality of Esox Lucius during postmortem storage: Based on the lysosomal-mitochondrial apoptotic pathway

In this study, we explored the correlation between the lysosome-mitochondrial apoptosis pathway and fish softening, as well as the correlation between ferritin degradation and lysosomal iron changes. The results indicated that ferritin levels gradually decreased, lysosomal iron first increased and then decreased and tended to stabilize, and lysosomal membrane stability significantly decreased (p < 0.05). Spearman's analysis suggested that an increase in lysosomal iron was associated with ferritin degradation. Lysosomal instability promoted the release of cathepsin D, thereby increasing the release of Bid and Bax, and inhibiting the expression of Bcl-2. Subsequently, caspase-9/-3 was activated. In addition, transmission electron microscopy revealed ultrastructural damage to mitochondria and cell nuclei, which are morphological features of apoptosis during post-mortem storage. Moreover, TUNEL staining confirmed the occurrence of apoptosis. We concluded that the lysosome- mitochondrial apoptosis pathway was active during the storage of Esox Lucius, in which ferritin degradation and increased lysosomal iron were key factors inducing lysosomal damage, and cathepsin D released by lysosomes was a key factor connecting lysosomes and mitochondria.

Integrated electronic nose and multi-omics reveal changes in flavour characterization of cashmere goats and tan sheep meat

This study aimed to employ a multi-omics method to identify key compounds contributing to the sensory flavour of mutton and to investigate the internal correlation between volatile metabolites and lipids in Cashmere goats and Tan sheep. The results demonstrate that the electronic nose can effectively and quickly distinguish goats and sheep meat. A total of 18 volatile metabolites and 314 lipids were identified as significant contributors to the flavour difference between goats and sheep meat, as determined by HS-SPME-GC-MS and lipidomic respectively. Specifically, TG(18:1/20:4/20:4), TG(18:1/18:2/20:4), TG(18:1/18:1/20:4), DG(18:0/20:4), and dodecanoic acid influence flavour by participating in key KEGG pathways such as the "fat digestion and absorption", "cholesterol metabolism" and "lipid and atherosclerosis". This study lays the groundwork for understanding the sources and mechanisms of mutton flavour compounds, providing valuable insights to support the growth and development of the mutton industry.

Exploring the freshness biomarker and volatiles formation in stored pork by means of lipidomics and volatilomics

Raw pork is prone to oxidation and rancidity as it contains a high level of unsaturated lipid molecules. Reliable biomarkers to benchmark pork freshness and their formation have not been systematically investigated. The results indicated that the peroxide values, TVB-N and rancid volatiles dramatically increased in pork during the storage period (4 °C, 0-9 d). Concentrations of most volatile compounds with carbonyl groups were increased markedly in pork during storing, including hexanal, acetic acid, and hexadecanoic acid methyl ester. Lipidomics, volatilomics and chemometrics methods were used to discriminate the freshness of pork, among which acetic acid and PC O-20:3 emerged as the most reliable freshness biomarkers. Phospholipids and neutral lipids, including phosphatidylcholines (PC), triglycerides (TG), and phosphatidylethanolamine (PE), played a crucial role in the formation of rancid volatiles and the decreased freshness. This work will provide technical supports for the efficient storage and preservation of raw meat.

Effects of intramuscular fat on the flavor of fresh sheep and goat meat: Recent insights into pre-mortem and post-mortem factors

Sheep and goat meat products are becoming increasingly popular among consumers due to their unique flavor derived from intramuscular fat (IMF), which contributes to formation of the distinctive odor. However, there is currently a dearth of reviews on the impact of IMF on the flavor of sheep and goat meat. The present review aims to discuss the relationships between IMF and flavor through lipid composition and fatty acid (FA) distribution, provide an overview of characteristic flavor compounds affecting the flavor of sheep and goat meat, and shed light on the impacts of pre-mortem and post-mortem factors on meat flavor attributed to changes in FAs and flavor compounds. Controlling pre-mortem practices and adjusting post-mortem harvesting methods are key factors in shaping and/or driving the flavor of sheep and goat meat products. This review enhances the comprehensive understanding of the impact of IMF on the flavor of sheep and goat meat.

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.

The authentication of Yanchi tan lamb based on lipidomic combined with particle swarm optimization-back propagation neural network

This study successfully combined widely targeted lipidomic with a back propagation (BP) neural network optimized based on a particle swarm algorithm to identify the authenticity of Yanchi Tan lamb. An electronic nose and gas chromatography-olfactometry-mass spectrometry (GC-O-MS) were used to explore the flavor differences in Tan lamb from various regions. Among the 17 identified volatile compounds, 16 showed significant regional differences (p < 0.05). Lipidomic identified 1080 molecules across 41 lipid classes, with 11 lipids, including Carnitine 15:0, Carnitine 17:1, and Carnitine C8:1-OH, serving as potential markers for Yanchi Tan lamb. In addition, a stepwise linear discriminant model and three types of BP neural networks were used to identify the origin of Tan lamb. The results showed that particle swarm optimization-back propagation (PSO-BP) neural network had the best prediction effect, with 100 % prediction accuracy in both the training and test sets. The established PSO-BP model was able to achieve effective discrimination between Yanchi and non-Yanchi Tan lamb. These results provide a comprehensive perspective on the discrimination of Yanchi Tan lambs and improve the understanding of Tan lamb flavor and lipid composition in relation to origin.

Revealing the mechanism of flavor improvement of fermented goat milk based on lipid changes

The mechanism of goat milk (GM) flavor improvement based on lipid changes requires understanding. According to sensory evaluation results, the texture, taste, appearance, aroma, and overall acceptability score of Guishan fermented goat milk (GMF) were higher than those of GM. In total, 779 lipid molecules and 121 volatile compounds were formed from the metabolite-lipid level in the GM and GMF, as determined through lipidomics and gas chromatography-mass spectrometry. The key volatile flavor compounds in the GMF were (E,E)-2,4-decadienal, ethyl acetate, acetoin, 2,3-pentanedione, acetic acid, and 2,3-butanedione. Of them, 60 lipids significantly contributed to the flavor profiles of the GMF, based on the correlation analysis. The triacylglycerides (TAGs) 12:0_14:0_16:0 and 13:0_13:0_18:2 contributed to aroma retention, while TAG and phosphatidylethanolamine were identified as key substrates for flavor compound formation during fermentation. Lipids associated with glycerophospholipid and linoleic acid metabolism pathways significantly affected volatile compound formation in the GMF. This study provides an in-depth understanding of the lipids and flavors of the GMF, and this information will be useful for the development of specific GMF products.

Influence of phospholipid structures on volatile organic compounds generation in model systems

To investigate the regularities and differences in oxidation products of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) by gas chromatography-mass spectrometry (GC-MS), and examine the influence of variations in fatty acid compositions and head groups on the kinds and contents of volatile organic compounds (VOCs) generated. A total of 42 VOCs were identified from PE (16:0-18:2), PC (16:0-18:2), and PC (16:0-18:1), with aldehydes and ketones being the main VOCs in three phospholipids (PLs). The content of most VOCs produced by PE (16:0-18:2), PC (16:0-18:2), and PC (16:0-18:1) increases with the increase of oxidation temperature and time. Reached peak at 175 °C for 60 min. The total VOCs contents generated by PE (16:0-18:2) and PC (16:0-18:2) were higher than those produced by PC (16:0-18:1), with PC (16:0-18:2) showing the highest total VOCs contents. PLs exhibited three mass loss processes with increasing temperature, namely stability, reduction, and stabilization. PC (16:0-18:2) experienced the highest mass loss, followed by PE (16:0-18:2), while PC (16:0-18:1) showed the least mass loss. These findings showed that polyunsaturated fatty acids were more susceptible to oxidation and degradation during oxidation, and the presence of choline groups in the form of PE may enhance the oxidative stability of fatty acyl groups compared to PC.

Comprehensive analysis of key aroma compounds enhanced by Tamarix ramosissima Ledeb in mutton roasted by air-frying roast technology by means of SAFE-GC-O-MS and lipidomics

Little information is known about the increased aroma compounds and possible mechanism in Tamarix ramosissima Ledeb roasted mutton (TRM). A comprehensive analysis of aroma compounds and lipids were firstly performed by lipidomics and sensomics approach. The results indicated that 9 out of 53 aroma compounds were considered as key odorants, including 5-methyl-2,3-diethylpyrazine. The roasted mutton contained highest levels of phosphatidylcholine (PC, 13.95%), triglyceride (TG, 13.50%), and phosphatidylethanolamine (PE, 12.25%). TG 18:0_18:0_18:1 and nine odorants were the potential biomarkers for discriminating differential samples due to variable importance in projection (VIP) > 1 and p < 0.05. PCs and TGs, including PC 21:0_13:1 and TG 16:0_18:1_18:1, might be predominantly responsible for the formation and retention of aroma compounds, respectively. This will clarify the enhanced effect of Tamarix ramosissima Ledeb on the presence of aroma compounds via lipid pathways in roasted mutton.

Ultrasound-induced modifications of beef flavor characteristics during postmortem aging

To investigate the effect of ultrasound treatment on the flavor profile of beef during postmortem aging, a comprehensive analysis of beef flavor was conducted at 0, 7, and 12 d of aging using sensory evaluation and electronic nose. Furthermore, the key volatile flavor compounds were identified using gas chromatography-mass spectrometry (GC-MS), and the odor activity value (OAV) was further evaluated. In addition, the primary pathway involved in flavor formation during beef aging after ultrasound treatment was explored. The results indicated that ultrasound enhanced the flavor profile of beef during postmortem aging by modifying the OAV of hexanal, heptanal, octanal, nonanal, decanal, (Z)-2-nonenal, dodecanal, pentanal, 1-octen-3-ol, octanoic acid, and 2-pentylfuran. Lipid oxidation was a crucial pathway through which ultrasound promoted the generation of volatile flavor compounds in beef, confirmed by the improved oxidation level of fatty acids, particularly monounsaturated ones. The study indicates that ultrasound technology can be regarded as an effective method for enhancing the beef flavor profile during postmortem aging.

Insights into flavor formation of braised chicken: Based on E-nose, GC-MS, GC-IMS, and UPLC-Q-Exactive-MS/MS

Effects of braising duration on volatile organic compounds (VOCs) and lipids in chicken were investigated. Aroma profiles identified by an electronic nose were effective in differentiating braising stages. During braising process, a total of 25 key VOCs were detected in braised chicken, and sample braised for 210 min exhibited the highest level of key VOCs. Additionally, a gas chromatography mass spectrometry fingerprint was established to evaluate the distribution of VOCs throughout the braising process. Partial least square discriminant analysis indicated that 2-heptanone, 3-methyl-2-butanone, octanal, nonanal, butanal, (E)-2-pentenal, 1-octen-3-ol, 1-hexanol, pentanal, hexanal, and 1-pentanol significantly affected flavor characteristics of braised chicken. Furthermore, 88 differential lipids were screened, and glycerolipids metabolic was found to be main metabolic pathway during braising process. Triglycerides (TG) and phosphatidyl ethanolamine (PE), such as TG (16:0/18:1/18:2), TG (18:0/18:1/18:2), TG (18:1/18:2/18:3), TG (18:1/18:1/18:2), PE (O-18:2/18:2), PE(O-18:2/18:1), and TG (16:0/16:1/18:2), played a vital role in the generation of VOCs.

Depth of Interbreed Difference in Postmortem Bovine Muscle Determined by CE-FT/MS and LC-FT/MS Metabolomics

Japanese Brown (JBR) cattle have moderately marbled beef compared to the highly marbled beef of Japanese Black (JBL) cattle; however, their skeletal muscle properties remain poorly characterized. To unveil interbreed metabolic differences over the previous results, we explored the metabolome network changes before and after postmortem 7-day aging in the trapezius muscle of the two cattle breeds by employing a deep and high-coverage metabolomics approach. Using both capillary electrophoresis (CE) and ultra-high-performance liquid chromatography (UHPLC)-Fourier transform mass spectrometry (FT/MS), we detected 522 and 384 annotated peaks, respectively, across all muscle samples. The CE-based results showed that the cattle were clearly separated by breed and postmortem age in multivariate analyses. The metabolism related to glutathione, glycolysis, vitamin K, taurine, and arachidonic acid was enriched with differentially abundant metabolites in aged muscles, in addition to amino acid (AA) metabolisms. The LC-based results showed that the levels of bile-acid-related metabolites, such as tauroursodeoxycholic acid (TUDCA), were high in fresh JBR muscle and that acylcarnitines were enriched in aged JBR muscle, compared to JBL muscle. Postmortem aging resulted in an increase in fatty acids and a decrease in acylcarnitine in the muscles of both cattle breeds. In addition, metabolite set enrichment analysis revealed that JBR muscle was distinctive in metabolisms related to pyruvate, glycerolipid, cardiolipin, and mitochondrial energy production, whereas the metabolisms related to phosphatidylethanolamine, nucleotide triphosphate, and AAs were characteristic of JBL. This suggests that the interbreed differences in postmortem trapezius muscle are associated with carnitine/acylcarnitine transport, β-oxidation, tricarboxylic acid cycle, and mitochondrial membrane stability, in addition to energy substrate and AA metabolisms. These interbreed differences may characterize beef quality traits such as the flavor intensity and oxidative stability.

A Role of Multi-Omics Technologies in Sheep and Goat Meats: Progress and Way Ahead

Sheep and goat meats are increasingly popular worldwide due to their superior nutritional properties and distinctive flavor profiles. In recent decades, substantial progress in meat science has facilitated in-depth examinations of ovine and caprine muscle development during the antemortem phase, as well as post-mortem changes influencing meat attributes. To elucidate the intrinsic molecular mechanisms and identify potential biomarkers associated with meat quality, the methodologies employed have evolved from traditional physicochemical parameters (such as color, tenderness, water holding capacity, flavor, and pH) to some cutting-edge omics technologies, including transcriptomics, proteomics, and metabolomics approaches. This review provides a comprehensive analysis of multi-omics techniques and their applications in unraveling sheep and goat meat quality attributes. In addition, the challenges and future perspectives associated with implementing multi-omics technologies in this area of study are discussed. Multi-omics tools can contribute to deciphering the molecular mechanism responsible for the altered the meat quality of sheep and goats across transcriptomic, proteomic, and metabolomic dimensions. The application of multi-omics technologies holds great potential in exploring and identifying biomarkers for meat quality and quality control, thereby promoting the optimization of production processes in the sheep and goat meat industry.

Multi-Omics Approaches to Improve Meat Quality and Taste Characteristics

With rapid advances in meat science in recent decades, changes in meat quality during the pre-slaughter phase of muscle growth and the post-slaughter process from muscle to meat have been investigated. Commonly used techniques have evolved from early physicochemical indicators such as meat color, tenderness, water holding capacity, flavor, and pH to various omic tools such as genomics, transcriptomics, proteomics, and metabolomics to explore fundamental molecular mechanisms and screen biomarkers related to meat quality and taste characteristics. This review highlights the application of omics and integrated multi-omics in meat quality and taste characteristics studies. It also discusses challenges and future perspectives of multi-omics technology to improve meat quality and taste. Consequently, multi-omics techniques can elucidate the molecular mechanisms responsible for changes of meat quality at transcriptome, proteome, and metabolome levels. In addition, the application of multi-omics technology has great potential for exploring and identifying biomarkers for meat quality and quality control that can make it easier to optimize production processes in the meat industry.