The dynamic changes of flavors and UPLC-Q-Exactive-Orbitrap-MS based lipidomics in mackerel (Scomberomorus niphonius) during dry-cured processing

Effects of 'bask in sunlight and dewed at night' on the formation of fermented flavor in shrimp paste after maturation

The purpose of the study was to illustrate the roles of three primary indexes, namely sunlight, ventilation and stirring, in the 'bask in sunlight and dewed at night' technique on the quality of shrimp paste, through a laboratory-scale design. The results showed that changes in the post-ripening fermentation conditions, especially sunlight, was instrumental in the physicochemical properties of the shrimp paste. E-nose and SPME-GC-MS were employed to assess the volatile flavor of post-ripening fermentation. A total of 29 key volatile aroma components played a crucial role in the development of post-ripening flavor in shrimp paste with or without sunlight. Lipidomic analysis revealed that sunlight promoted the oxidative degradation of FA, resulting in the production of a diverse range of flavor compounds that imparted the unique aroma of shrimp paste. The findings of this study will establish a theoretical basic for better control of the post-ripening fermentation of traditional shrimp paste.

Combined of plasma-activated water and dielectric barrier discharge atmospheric cold plasma treatment improves the characteristic flavor of Asian sea bass (Lates calcarifer) through facilitating lipid oxidation

To explore the combination effects of plasma-activated water and dielectric barrier discharge (PAW-DBD) cold plasma treatment on the formation of volatile flavor and lipid oxidation in Asian sea bass (ASB), the volatile flavor compounds and lipid profiles were characterized by gas chromatography-ion mobility spectrometry and LC-MS-based lipidomics analyses. In total, 38 volatile flavor compound types were identified, and the PAW-DBD group showed the most kinds of volatile components with a significant (p < 0.05) higher content in aldehydes, ketones, and alcohols. A total of 1500 lipids was detected in lipidomics analysis, phosphatidylcholine was the most followed by triglyceride. The total saturated fatty acids content in PAW-DBD group increased by 105.02 μg/g, while the total content of unsaturated fatty acids decreased by 275.36 μg/g. It can be concluded that the PAW-DBD processing increased both the types and amounts of the volatile flavor in ASB and promoted lipid oxidation by altering lipid profiles.

Multi-omics Analysis of Volatile Flavor Components in Pacific Chub and Spanish Mackerel during Freezing using GC-MS-O

This study employed gas chromatography-mass spectrometry with olfactory (GC-MS-O) and multi-omics methods to investigate the changes in volatile flavor compounds during the freezing process of Pacific chub mackerel (Scomber japonicus) from Japan and China, and Spanish mackerel (Scomberomorus niphonius). A total of 18 volatile flavor compounds were identified, and significant differences in volatile flavor components were observed among samples frozen for 1 week, 1 year, and 2 years. The results of the Partial least squares regression (PLSR) indicated that the fishy odor was correlated with independent variables such as fatty acids (FA 22:4, FA 28:6, FA 24:4), differentially expressed genes (Gene.2425 (NDUFA5), Gene.38 (GPX1), and Gene.2844 (DAD1)). Classification and regression tree (CART) analysis revealed that the peak area values of fatty acids (FA 22:5, FA 20:4) and fatty acid esters of hydroxy fatty acids (FAHFA 18:0/22:3) were the main differentiating factors for fishy odor perception.

Lc-ms-based lipidomics analyses revealed changes in lipid profiles in Asian sea bass (Lates calcarifer) with dielectric barrier discharge (DBD) atmospheric plasma treatment

A comprehensive LC-MS-based lipidomics analysis of Asian sea bass (Lates calcarifer) muscle after dielectric barrier discharge (DBD) atmospheric plasma treatment was performed. Through the analysis, 1500 lipid species were detected, phosphatidylcholine (PC, 27.80%) was the most abundant lipid, followed by triglyceride (TG, 20.50%) and phosphatidylethanolamine (PE, 17.10%). Among them, 125 lipid species were detected and identified as differentially abundant lipids in Asian sea bass (ASB). PCA and OPLS-DA showed that ASB lipids changed significantly after DBD treatment. Moreover, glycerophospholipid metabolism was key metabolic pathways, as PC, PE, and lysophosphatidylcholine (LPC) were key lipid metabolites. The findings concerning fatty acids revealed that the saturated fatty acids (SFA) content of ASB after DBD treatment increased by 8.54%, while the content of monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) decreased by 13.77% and 9.16%, respectively. Our study establishes a foundation for the lipid oxidation mechanism of ASB following DBD treatment.

Exploring potential lipid precursors for aroma formation in non-smoked bacon during hot air drying via untargeted lipidomics and oxidation model

The effect of drying on the lipid profiles of the lean (LN) and fat (FT) portions of non-smoked bacon was investigated based on a lipidomic approach. The study identified 989 lipids belonging to 26 subclasses in bacon, with triglyceride and phosphatidylethanolamine being the most abundant. Triglycerides, phosphatidylcholines, and phosphatidylethanolamines were significantly decreased, whereas diglycerides, free fatty acids, and lysophospholipids were increased after drying. TG (16:1/18:1/18:2) and TG (16:0/18:1/18:1) were the primary lipids responsible for the binding of volatiles. Based on VIP > 1 and P < 0.05, 355 and 444 differential lipids were observed in the FT and LN portions, respectively. In total, 26 lipids were screened as key precursors for the production of key aroma compounds of bacon in the FT portion, while 127 were screened in the LN portion. PE (18:0/18:2) is believed to be the primary lipid molecule precursors responsible for the development of aroma in both lean and fat portions. This research has enhanced the comprehension of the generation of key aroma compounds derived from lipid oxidation.

LC-MS-based lipidomics analyses of alterations in lipid profiles of Asian sea bass (Lates calcarifer) induced by plasma-activated water treatment

A lipidomics approach based on liquid chromatography-mass spectrometry was employed to investigate alterations in lipid profiles within the muscles of Asian sea bass (ASB) (Lates calcarifer) post-treatment with plasms-activated water (PAW). Lipidomics studies detected 1500 diverse lipid types in ASB muscles; the phosphatidylcholine (PC) lipid subclass constituted the highest number of lipids (21.07 %), followed by triglycerides (TGs, 20.53 %) and phosphatidylethanolamine (PE, 12.73 %). Comparative analysis between PAW-treated ASB and raw ASB revealed the presence of differentially abundant lipids, with 48 lipids accumulating at high levels and 92 at low levels. Pathway enrichment analysis identified a total of seven lipid-related metabolic pathways; glycerophospholipid metabolism emerged as the predominant pathway. Furthermore, the content of saturated fatty acids in PAW-treated ASB increased from 1059.81 μg/g (raw ASB) to 1099.77 μg/g. Conversely, the content of monounsaturated and polyunsaturated fatty acids decreased from 645.81 μg/g and 875.02 μg/g to 640.80 μg/g and 825.25 μg/g, respectively. Collectively, these results indicate significant alterations in ASB lipid profiles following PAW treatment, establishing a theoretical foundation for understanding the mechanism involved in promoting lipid oxidation.

Integrative deep learning framework predicts lipidomics-based investigation of preservatives on meat nutritional biomarkers and metabolic pathways

Preservatives are added as antimicrobial agents to extend the shelf life of meat. Adding preservatives to meat products can affect their flavor and nutrition. This review clarifies the effects of preservatives on metabolic pathways and network molecular transformations in meat products based on lipidomics, metabolomics and proteomics analyses. Preservatives change the nutrient content of meat products via altering ionic strength and pH to influence enzyme activity. Ionic strength in salt triggers muscle triglyceride hydrolysis by causing phosphorylation and lipid droplet splitting in adipose tissue hormone-sensitive lipase and triglyceride lipase. DisoLipPred exploiting deep recurrent networks and transfer learning can predict the lipid binding trend of each amino acid in the disordered region of input protein sequences, which could provide omics analyses of biomarkers metabolic pathways in meat products. While conventional meat quality assessment tools are unable to elucidate the intrinsic mechanisms and pathways of variables in the influences of preservatives on the quality of meat products, the promising application of omics techniques in food analysis and discovery through multimodal learning prediction algorithms of neural networks (e.g., deep neural network, convolutional neural network, artificial neural network) will drive the meat industry to develop new strategies for food spoilage prevention and control.

Lipidomics reveals the relationship between lipid oxidation and flavor formation of basic amnio acids participated Low-Sodium cured large yellow croaker

The effects of basic amino acids on lipid oxidation and the formation of volatile compound in low-sodium cured large yellow croaker were investigated. Basic amino acids contribute a lot in inhibiting the degradation of phospholipids, especially l-lysine. Lipid oxidation was also inhibited by basic amino acids, and the total oxidation of groups could be sorted as low-sodium (LS) > control (C) > l-Histidine participated LS group (LS-His) > l-Arginine participated LS group (LS-Arg) > l-lysine participated LS group (LS-Lys). PC 18:1/20:5, PC 16:0/18:1, triacylglycerol (TG) 16:1/20:5/22:6, etc., were found to be key differential lipid metabolites, and 1-propanol, 2-methyl, gamma-hexalactone, etc. were recognized as key differential volatile compounds. The results of correlation analysis showed that alcohols and esters were positively correlated with TG molecules composed of saturated fatty acids and monounsaturated fatty acids. These findings provided new insights into the relationship between flavor formation and the degradation and oxidation of lipids.

Natural antioxidants as strategy to minimize the presence of lipid oxidation products in canned fish: Research progress, current trends and future perspectives

Canned fish is one of the most popular forms of fish consumption due to its high nutritional value, availability, and practicality. However, canning may induce lipid oxidation. Thus, this study provides in-depth information on the impact of high temperatures applied during canning on fish lipids. The thermo-oxidation is evidenced, for example, by the high levels of both primary and secondary oxidation products determined in fish after canning, as well as the presence of harmful compounds such as cholesterol oxides. Given the role of lipid oxidation in canned fish, this study also presents a comprehensive review on using natural antioxidants to control it. The antioxidant properties of common liquid mediums (vegetable oils and sauces) are highlighted. Moreover, adding algae extracts, spices, and condiments to the liquid medium to enhance its antioxidant potential has been considered, while the exploitation of by-products and wastes from the food industry also emerges as a suitable strategy. Besides the promising results, these practices may promote positive impacts on other quality parameters (e.g. water and oil holding capacities, texture, microbiological growth). However, further studies are needed, including research on aspects related to safety, effective concentrations and application methods, without ignoring consumers' sensory acceptance.