Quantitative Proteomics Reveals the Relationship between Protein Changes and Volatile Flavor Formation in Hunan Bacon during Low-Temperature Smoking.

This study aimed to investigate the changes in proteins and volatile flavor compounds that occur in bacon during low-temperature smoking (LTS) and identify potential correlations between these changes. To achieve this, a combination of gas chromatography-mass spectrometry and proteomics was employed. A total of 42 volatile flavor compounds were identified in the bacon samples, and, during LTS, 11 key volatile flavor compounds with variable importance were found at a projection value of >1, including 2',4'-dihydroxyacetophenone, 4-methyl-2H-furan-5-one, Nonanal, etc. In total, 2017 proteins were quantified at different stages of LTS; correlation coefficients and KEGG analyses identified 27 down-regulated flavor-related proteins. Of these, seven were involved in the tricarboxylic acid (TCA) cycle, metabolic pathways, or amino acid metabolism, and they may be associated with the process of flavor formation. Furthermore, correlation coefficient analysis indicated that certain chemical parameters, such as the contents of free amino acids, carbonyl compounds, and TCA cycle components, were closely and positively correlated with the formation of key volatile flavor compounds. Combined with bioinformatic analysis, the results of this study provide insights into the proteins present in bacon at various stages of LTS. This study demonstrates the changes in proteins and the formation of volatile flavor compounds in bacon during LTS, along with their potential correlations, providing a theoretical basis for the development of green processing methods for Hunan bacon.

[Ecological implication and behavior mechanism of food selection of mammalian herbivores].

This paper is aimed to review the research progress in the behavior mechanism of food selection of mammalian herbivore. The study of food preference of mammalian herbivores is a prominent field of research in foraging ecology. It was put forth that nutritious hypotheses, plant secondary compounds hypotheses, nutrient balance hypotheses, optimal foraging theory, and conditioned flavor aversion hypotheses could explain the food preference of mammalian herbivores. Animals learn about foods through affective system and cognitive system. Social learning is a form of phenotype plasticity, and enable individuals to acquire adaptive behavior patterns suitable for local habitats. Early experience by the offspring mediated by social learning through the mother may play an important role in determination of food preference in the life. Where the environment is relatively stable, offspring may copy the food choices of older individuals, whereas in highly fluctuating environments, those individuals that select food on a trial and error basis are likely to obtain a more nutritious diet that those imitating the older adults.