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The study aimed to determine the in vitro digestive properties of wolfberry multigrain meal replacement powders with a low glycemic index (GI). The basic components, water absorption and swelling rate, starch components, starch hydrolysis rate, and estimated glycemic index (eGI) of each raw material powder and meal replacement powder were measured. The changes in protein hydrolysis rate, total phenolic content, flavonoid content and antioxidant activity in each raw material powder and meal replacement powder were comparatively analyzed by in vitro simulation of gastrointestinal digestive methods. The results showed that the contents of fat and crude fiber in the meal replacement powder were lower than the raw material powders. The water absorption rate of each raw material powder and meal replacement powder at a high temperature was approximately two times of that at room temperature, among which the meal replacement powder had the lowest water absorption rate (0.27%±0.05% at room temperature and 0.59%±0.05% at a high temperature). The rapidly digestion starch content (40.4%±0.003%) and eGI value (23.4) of the meal replacement powder were the lowest among all the ingredient powders, while the slowly digestion starch and resistant starch contents were both relatively high. In the in vitro simulated gastrointestinal digestion experiment, the protein hydrolysis rate of each raw material powder and meal replacement powder gradually increased and the hydrolysis was mainly in the stomach, in which the protein hydrolysis rate of the meal replacement powder was relatively high. The total phenol content tended to increase during gastrointestinal digestion, and the meal replacement powder reached the highest content at the end of digestion (7.26 mg/g). The flavonoid content increased significantly during simulated gastric digestion and decreased in simulated intestinal digestion. DPPH and ABTS+ radical scavenging rates increased significantly (P

Chinese Artichoke (Stachys sieboldii Miq.), an indigenous vegetable in China, is renowned for its rich nutritional content and medicinal properties. With a significant cultivation history and promising prospects, this vegetable holds great potential for further development. In this study, we investigated changes in gene expression levels and metabolite content within relevant metabolic pathways during the development of Chinese Artichoke tubers. Tubers from three different periods—S1 (6 Aug), S2 (2 Sep), and S3 (1 Oct)—served as materials for the analysis. The results revealed that differentially expressed genes and differentially accumulated metabolites were predominantly enriched in pathways associated with secondary metabolite synthesis, carbohydrate metabolism, amino acid metabolism, and lipid metabolism. These pathways are known to play significant regulatory roles in the development of Chinese Artichoke tubers. Two crucial metabolic pathways identified through a comprehensive analysis of transcriptomics and metabolomics were further investigated. The genes GOLS, STS, AGAL, and INV potentially play crucial roles in stachyose accumulation. Additionally, the genes trpB (Cluster-5100.0), GOT2 (Cluster-7051.0), and TYRAAT (Cluster-4023.14777) potentially influence the aromatic amino acid content at different developmental stages. However, the regulatory mechanisms of these genes and their relationship with metabolites require further investigation. The study findings provide a theoretical foundation for understanding the key pathways that influence the growth of Chinese Artichoke tubers, metabolic mechanisms of stachyose and amino acids, verification of gene functions, and genetic enhancement of Chinese Artichoke cultivars.

With the growing production of raw milk, interest has been increasing in its quality control. CO2, as a cold processing additive, has been studied to extend the cold storage period and improve the quality of raw milk. However, it is yet uncertain how representative microbial species and biomarkers can succeed one another at distinct critical periods during refrigeration. Therefore, the effects of CO2 treatment on the succession footprint of the microbial community and changes in quality during the period of raw milk chilling were examined by 16S rRNA analysis combined with electronic nose, and electronic tongue techniques. The results indicated that, the refrigeration time was shown to be prolonged by CO2 in a concentration-dependent way. And CO2 treatment was linked to substantial variations in beta and alpha diversity as well as the relative abundances of various microbial taxa (p < 0.01). The dominant bacterial phylum Proteobacteria was replaced with Firmicutes, while the major bacterial genera Acinetobacter and Pseudomonas were replaced with lactic acid bacteria (LAB), including Leuconostoc, Lactococcus, and Lactobacillus. From the perspective of biomarkers enriched in CO2-treated sample, almost all of them belong to LAB, no introduction of harmful toxins has been found. The assessment of the quality of raw milk revealed that CO2 improved the quality of raw milk by lowering the acidity and the rate of protein and fat breakdown, and improved the flavor by reducing the generation of volatiles, and increasing umami, richness, milk flavor and sweetness, but reducing sourness. These findings offer a new theoretical foundation for the industrial use of CO2 in raw milk.

The study aimed to assess differences in proteomic and metabolite profiles in ageing (1, 2, 4, and 6 days at 4 °C) beef exudates and determine their relationship with beef muscle iron metabolism and oxidation. Proteomic and metabolomic analyses identified 877 metabolites and 1957 proteins. The joint analysis identified 24 differential metabolites (DMs) and 56 differentially expressed proteins (DEPs) involved in 15 shared pathways. Ferroptosis was identified as the only iron metabolic pathway, and 4 DMs (l-glutamic acid, arachidonic acid, glutathione and gamma-glutamylcysteine) and 5 DEPs (ferritin, phospholipid hydroperoxide glutathione peroxidase, heme oxygenase 1, major prion protein, and acyl-CoA synthetase long chain family member 4) were involved in iron metabolism by regulating heme and ferritin degradation, Fe2+ and Fe3+ conversion, arachidonic acid oxidation and inactivation of glutathione peroxidase (GPX) 4, leading to increased levels of free iron, ROS, protein and lipid oxidation (P

Oligosaccharides are important functional active components of Lycium barbarum L. (LBL, “Goji”) fruits, but their metabolic mechanisms are not yet clear. In this study, we firstly investigated the changes in the content of oligosaccharides in LBL at different stages (S1–S5), and found that it mainly accumulated at S3 and S4. Secondly, the structural characteristics of LBL oligosaccharide (LBO) were studied by GC-MS and FT-IR. Thirdly, using iTRAQ proteomics analysis, we identified 135 differentially expressed proteins associated with oligosaccharide metabolism, which is mainly accomplished through the collaboration of a range of key enzymes. At S1 and S2, oligosaccharide synthesis was achieved mainly through photosynthesis, and changes in anabolism were mainly associated with the expression of sucrose synthase, sucrose phosphate synthase and hexokinase. Oligosaccharide accumulation was achieved through starch and polysaccharide metabolism and cellulose catabolism at S3 and S4, where the enzymes associated with changes in oligosaccharide anabolism included glycosylase, β-fructosidase and glucan endonuclease. This report will provide a theoretical basis for further elucidating the mechanisms of oligosaccharide anabolism during the growth and development of LBL.

Microbial community succession in raw milk determines its quality and storage period. In this study, carbon dioxide (CO2) at 2000 ppm was used to treat raw milk to investigate the mechanism of extending the shelf life of raw milk by CO2 treatment from the viewpoint of microbial colonies and metabolites. The results showed that the shelf life of CO2-treated raw milk was extended to 16 days at 4 °C, while that of the control raw milk was only 6 days. Microbiomics analysis identified 221 amplicon sequence variants (ASVs) in raw milk, and the alpha diversity of microbial communities increased (p < 0.05) with the extension of storage time. Among them, Pseudomonas, Actinobacteria and Serratia were the major microbial genera responsible for the deterioration of raw milk, with a percentage of 85.7%. A combined metagenomics and metabolomics analysis revealed that microorganisms altered the levels of metabolites, such as pyruvic acid, glutamic acid, 5′-cmp, arginine, 2-propenoic acid and phenylalanine, in the raw milk through metabolic activities, such as ABC transporters, pyrimidine metabolism, arginine and proline metabolism and phenylalanine metabolism, and reduced the shelf life of raw milk. CO2 treatment prolonged the shelf life of raw milk by inhibiting the growth of Gram-negative aerobic bacteria, such as Acinetobacter guillouiae, Pseudomonas fluorescens, Serratia liquefaciens and Pseudomonas simiae.

Chilled Tan mutton is currently the mainstream of Tan mutton production and consumption in China, but the reports on chilled meat quality evaluation and shelf-life discrimination by volatiles are limited. This study aimed to investigate the changes of volatile compounds in chilled Tan mutton at four storage stages (1d, 3d, 5d, 7d) in order to differentiate the various storage stages. An analysis protocol was established for the characterization and discrimination of the volatiles in chilled Tan mutton based on high capacity sorptive extraction-thermal desorption-gas coupled with chromatography-mass spectrometry (HiSorb-TD-GC-MS), electronic nose (E-nose), and multivariate statistical analysis. A total of 96 volatile compounds were identified by HiSorb-TD-GC-MS, in which six compounds with relative odor activity value >1 were screened as the key characteristic volatiles in chilled Tan mutton. Four storage stages were discriminated by partial least squares discriminant analysis, and nine differential volatile compounds showed a variable importance for the projection score >1, including octanoic acid, methyl ester, decanoic acid, methyl ester, acetic acid, heptanoic acid, methyl ester, propanoic acid, 2-hydroxy-, methyl ester, (ñ)-, hexanoic acid, propanoic acid, butanoic acid, and nonanoic acid. With the volcano plot analysis, hexadecanoic acid, methyl ester, was the common volatile marker candidate to discriminate chilled stages of Tan mutton. Meanwhile, E-nose could discriminate chilled Tan mutton at different storage stages rapidly and efficiently using linear discriminant analysis. Furthermore, E-nose sensors could obtain comprehensive volatile profile information, especially in esters, acids, and alcohols, which could confirm the potential of E-nose for meat odor recognition. Thus, this analysis protocol could characterize and discriminate the volatiles in chilled Tan mutton during storage.

Excessive softening of Lycium barbarum L. (LBL) fruit can limit the storage and transportation of fresh fruit. To better understand the underlying molecular mechanisms of fruit softening in LBL, changes in the pre-climacteric (S1) and post-climacteric (S2) proteomes were investigated by iTRAQ methods. The 14-fold reduction in S2 fruit firmness compared to S1 was accompanied by increased espiratory intensity and degradation of cell wall components. A total of 258 differentially expressed proteins (DEPs) were identified, which were mainly associated with photosynthesis, carbohydrate, amino acids and fatty acids metabolism. From the functional proteomic analysis, enhanced energy metabolisms, such as glycolysis/gluconeogenesis and citrate cycle (TCA cycle) contributed to cell wall degradation and conversion to substrates for respiratory metabolism, leading to fruit softening. These findings have provided new insights into the molecular pathways associated with fruit softening in LBL and the bioinformatics analyses provided insightful information for further transcriptional studies.

This study evaluated the physio-chemical properties of a structural lipid (SL) obtained by the enzymatical incorporation of flaxseed oil into mutton tallow (MT). By measuring the melting point, colour, safety, fatty acids, apparent viscosity, shear stress and volatile compounds of the samples, the results showed that compared to MT, SL exhibited lower L∗(lightness) value, melting point, apparent viscosity and shear stress (p < 0.05). Noteworthy, the Saturated fatty acids (SFA)content of MT was reduced from 61.46% to 25.49% (p < 0.05), although SL was found to be more prone to oxidation during storage. The clearest discrepancy in volatile compounds was the increase of heterocyclic compounds in SL. In summary, improving the edible properties of animal fats by adding vegetable oils is an effective solution, and SL may have a great potential to be developed into a high-quality product with improved nutritional composition of animal fat.

Haem is considered to be a potential producer of meat oxidation and the effect of its mediated oxidation on the water holding capacity (WHC) of beef is not yet clear. This work investigated the interrelationships between haem, protein and lipid oxidation, and WHC in beef during refrigerated storage. The increase in juice loss during storage (p

Goji berry (Lycium barbarum L., LBL) is a good source of carotenoids, while the bioaccessibility of various types of LBL carotenoids has not been explored. In the study, eight carotenoids, three carotenoid esters and two carotenoid glycosylated derivatives were identified by a non−targeted metabolomics approach. The dried LBL (DRI), LBL in water (WAT), and LBL in “Baijiu” (WIN) were used to recreate the three regularly chosen types of utilization, and the in vitro digestion model showed that the bioaccessibility of the carotenoids increased significantly from the oral to the gastric and intestinal phase (p < 0.05). The bioaccessibility of LBL carotenoids was the most elevated for DRI (at 28.2%), followed by WIN and WAT (at 24.9% and 20.3%, respectively). Among the three carotenoids, zeaxanthin dipalmitate showed the highest bioaccessibility (51.8–57.1%), followed by β−carotene (51.1–55.6%) and zeaxanthin (45.2–56.3%). However, the zeaxanthin from DRI exhibited significantly higher bioaccessibility (up to 58.3%) than WAT and WIN in both the gastric and intestinal phases (p < 0.05). Results of antioxidant activity tests based on DPPH, FRAP, and ABTS showed that the addition of lipids improved the bioaccessibility of the carotenoids. (p < 0.05).

Abnormal iron metabolism can cause oxidative stress in broilers, and transport stress (TS) may potentially influence iron metabolism. However, the mechanisms by which TS affects iron metabolism are unclear. This study used quantitative proteome analysis based on tandem mass tag (TMT) to investigate the effects of TS on liver iron metabolism in broilers. Broilers (n = 24) reared under the same conditions were selected randomly into the transported group for 4 h (T2) and non-transported group (T1). Results showed that the serum iron level and total iron-binding capacity of broilers in the T2 were significantly higher than those in the T1 (p < 0.05). The liver iron content of broilers in the T2 (0.498 ± 0.058 mg·gprot−1) was significantly higher than that in the T1 (0.357 ± 0.035 mg·gprot−1), and the iron-stained sections showed that TS caused the enrichment of iron in the liver. We identified 1139 differentially expressed proteins (DEPs). Twelve DEPs associated with iron metabolism were identified, of which eight were up-regulated, and four were down-regulated in T2 compared with T1. Prediction of the protein interaction network for DEPs showed that FTH1, IREB2, and HEPH play vital roles in this network. The results provide new insights into the effects of TS on broilers’ liver iron metabolism.