Foods最新文献

Matcha is a very popular tea food around the world, being widely used in the food, beverage, health food, and cosmetic industries, among others. At present, matcha shade covering methods, matcha superfine powder processing technology, and digital evaluations of matcha flavor quality are receiving research attention. However, research on the differences in flavor and quality characteristics of matcha from the same tea tree variety from different typical regions in China is relatively weak and urgently required. Taking Japan Shizuoka matcha (R) as a reference, the differences in sensory quality characteristics and non-volatile substances of matcha processed with the same tea variety from different regions in China were analyzed. The samples were China Hangzhou matcha (Z1), China Wuyi matcha (Z2), China Enshi matcha (H), and China Tongren matcha (G), which represent the typical matcha of eastern, central, and western China. A total of 1131 differential metabolites were identified in the matcha samples, comprising 118 flavonoids, 14 tannins, 365 organic acids, 42 phenolic acids, 22 alkaloids, 39 saccharides, 208 amino acids and derivatives, 17 lignans and coumarins, seven quinones, 44 nucleotides and derivatives, 14 glycerophospholipids, two glycolipids, 15 alcohols and amines, 140 benzenes and substituted derivatives, 38 terpenoids, 30 heterocyclic compounds, and 15 lipids. Kaempferol-7-O-rhamnoside, 3,7-Di-O-methylquercetin, epigallocatechin gallate, epicatechin gallate, and epigallocatechin were detected in Z1, Z2, H, and G. A total of 1243 metabolites differed among Z1, Z2, and R. A total of 1617 metabolites differed among G, H, and R. The content of non-volatile difference metabolites of Z2 was higher than that of Z1. The content of non-volatile difference metabolites of G was higher than that of H. The 20 key differential non-volatile metabolites of Z1, Z2, G, and H were screened out separately. The types of non-volatile flavor differential metabolites of G and H were more numerous than those of Z1 and Z2. The metabolic pathways, biosynthesis of secondary metabolites, biosynthesis of co-factors, flavonoid biosynthesis, biosynthesis of amino acids, biosynthesis of various plant secondary metabolites, and purine metabolism of metabolic pathways were the main KEGG pathways. This study provides new insights into the differences in metabolite profiles among typical Chinese matcha geographic regions with the same tea variety.

The major components of tea leaves and their infusions were analyzed for various types of green tea available in Japan in 2022. Almost all the green teas used were from the first crop, known for their high amino acid content. The amino acids theanine and arginine in green tea have been shown to reduce stress. On the other hand, epigallocatechin gallate (EGCG) and caffeine, the major components of green tea, counteract the effects of theanine and arginine. We have shown that the CE/TA ratio, which is the ratio of the molar sum of caffeine (C) and EGCG (E) to the molar sum of theanine (T) and arginine (A), can be used to evaluate the stress-relieving effects of each green tea. Green tea with a CE/TA ratio smaller than 3 can be expected to have a stress-reducing effect. The CE/TA ratios of the tea leaves and infusions of Gyokuro, Sencha, and Tamaryokucha were less than 3, indicating that these teas are expected to have stress-relieving effects. In addition, when the same tea leaves were infused repeatedly, it was found that most of the amino acids were eluted by the first and second cups; therefore, no stress-relieving effect could be expected after the third cup.

Numerous reports have indicated that the type 3 resistant starch (RS3) derived from Canna edulis can regulate lipid metabolism. However, it remains unclear whether the type 5 resistant starch (RS5) exhibits similar effects. In this study, RS5 was prepared from Canna edulis native starch and lauric acid through a hydrothermal method for the first time, and its nutritional intervention effects on hyperlipidemia in mice were investigated. The Canna edulis type 5 resistant starch (Ce-RS5) prepared using Canna edulis native starch and lauric acid exhibited a high compound index and resistant starch content, along with decreased swelling power and enhanced starch granule stability. The crystallinity of Ce-RS5 was decreased, and its crystal structure displayed a B+V pattern. Microscopically, the surface appeared rough with deepened grooves, and the granules were loose. Feeding mice with 1.5 g/kg and 3 g/kg of Ce-RS5 significantly reduced their body weight, positively regulated their blood lipid levels, and improved liver damage and fat accumulation. Additionally, Ce-RS5 promoted the abundance of beneficial gut bacteria, such as norank_f_Muribaculaceae, and inhibited the abundance of harmful bacteria like Colidextribacter. This study provides the first evidence of the hypolipidemic and weight loss effects of Ce-RS5 in hyperlipidemia mice.

Alum, an essential additive in sweet potato vermicelli (SPV) production, is harmful to health. To eliminate the harm to the human body caused by alum in sweet potato vermicelli, and considering the different viscous properties of gliadin fractions, an experiment was performed to replace alum with gliadin fractions to enhance the boiling resistance of SPV in this study. The results showed that the longest boiling-resistant time of fresh SPV extended to 34.31 min when swelling the dough binder at 50 °C for 5 h, adding a 2% complex of ω-gliadin + αβγ-gliadin at a ratio of 1:1, and mixing at 70 °C for 20 min. The result was 95.7% higher than in the control. Starch swelling and freeze-thaw processes could partially replace the role of alum in preparing SPV. The results of FTIR and ¹³C solid-state NMR showed that the esterification reaction of ω-gliadin and αβγ-gliadin and hydrogen bonds between sweet potato starch and gliadin fractions reinforced the boiling resistance of vermicelli. There was no ordered area of starch in the new water-resistant vermicular. The gliadin fractions formed crystal with a diffraction angle of 17.38° (3.25 Å). Long-term cold storage could improve the boiling resistance of fresh sweet potato vermicelli. Additionally, the short-term retrogradation of sweet potato amylose significantly reduces its boiling resistance. The study provides new primary data and theoretical support for the industrial application of alum-free fresh sweet potato vermicelli.

Chicken with Armillaria mellea prepared via pressure cooking is a traditional Chinese delicacy with great potential for food development. Optimizing its cooking time is crucial. In this study, chicken and Armillaria mellea were pressure-cooked for different amounts of time (20 min, 25 min, 30 min, 35 min, and 40 min). In total, 101 and 81 volatile compounds were identified by GC-MS and GC-IMS, respectively. The results showed that the content of volatile compounds was the highest at 40 min. Nonanal, decanal, (E,E)-2,4-nonadienal, (E,E)-2,4-decadienal, and 1-octen-3-ol were identified as the most critical aroma compounds at this time, which brought unique fat, oil, and mushroom aroma to chicken with Armillaria mellea during the pressure-cooking process. The optimal time was determined to be 35 min through sensory properties. In summary, the optimal cooking time for chicken with Armillaria mellea prepared via pressure cooking is 35-40 min. Our research results not only preliminarily determined the optimal conditions for industrial processing of the prepared dish of with Armillaria mellea prepared via pressure cooking, laying a foundation for the later industrial production of prepared dishes and international sales, but also stimulated innovative composite food development and promoted people's exploration of the mechanism of heat treatment on composite food flavor and taste.

Legumes are an interesting matrix for food production. The aim of this study was to develop functional plant-based snacks using fermented red bean (RBB) seeds enriched with the following additives: marjoram-RBM (2%); carrot-RBC (30%); and red beetroot-RBRB (15%). In the process of constructing the snacks, the focus was on the maximum use of the raw material, including aquafaba, to improve nutritional properties, sensory acceptability, and biological activity. The chemical composition, protein digestibility, antioxidant activity, and phenolic content were analyzed. In addition, the effect of the in vitro digestion process on biologically active compounds and their interactions with intestinal microflora was analyzed. Sensory analysis and consumer evaluation were performed. It was found that fermentation with lactic acid bacteria increased the content of total protein (by 2%), reducing the presence of substances (by 8%) and phenolic compounds (by 13%) in red bean seeds. Snacks with marjoram (RBM) showed the highest antioxidant activity (increase by 42%) and content of polyphenolic compounds (increase by 25%) compared to the basic variant (RBB). During digestion, the content of phenolic compounds and antioxidant activity reached the highest values in the last section of the digestive tract, i.e., in the large intestine, with RBM achieving the best results (5.61 mg GAE/g and 28.82 mg TE/g). The snack variants with red beetroot (RBRB) and marjoram (RBM) were rated the best by consumers. The results obtained confirm that the obtained snacks can be innovative products with health-promoting properties, and marjoram turned out to improve their properties, including antibacterial ones.

Green peas, with their high moisture content, require effective drying techniques to extend shelf life while preserving quality. Traditional drying methods face challenges due to the dense structure of the seed coat and wax layer, which limits moisture migration. This study investigates cold plasma (CP) pretreatment as a novel approach to enhance drying kinetics and maintain the quality attributes of green peas. The results showed that CP treatment significantly improves drying efficiency by modifying the pea epidermis microstructure, reducing drying time by up to 18.18%. The moisture effective diffusivity coefficients (D_eff) for untreated and CP-pretreated green peas were calculated to range from 5.9629 to 9.9172 × 10^-10 m²·s^-1, with CP pretreatment increasing D_eff by up to 66.31% compared to the untreated group. Optimal CP parameters (90 s, 750 Hz frequency, 70% duty cycle) were found to improve the rehydration ratio, preserve color, and increase total phenolic content (TPC) by 24.06%, while enhancing antioxidant activity by 29.64%. Microstructural changes, including pore formation and increased surface roughness, as observed through scanning electron microscopy (SEM), partially explain the enhanced moisture diffusion, improved rehydration, and alterations in nutrient content. These findings underscore the potential of CP technology as a non-thermal, eco-friendly pretreatment for drying agricultural products, with broad applications in food preservation and quality enhancement.

Although eicosapentaenoic acid (EPA) as a functional fatty acid has shown significant benefits for human health, its susceptibility to oxidation significantly limits its application. In this study, we developed a nanoemulsion of the lactoferrin (LTF)-EPA complex and conducted a thorough investigation of its macro- and molecular properties. By characterizing the emulsion with different LTF concentrations, we found that 1.0% LTF formed the most stable complex with EPA, which benefited the formation and stability of the emulsion against storage and freezing/thawing treatment. As the foundation block of the emulsion structure, the binding mechanism and the entire dynamic reaction process of the complex have been fully revealed through various molecular simulations and theoretical calculations. This study establishes a comprehensive picture of the LTF-EPA complex across multiple length scales, providing new insights for further applications and productions of its emulsion.

The aroma of yak milk powder is a crucial sensory indicator for evaluating its quality and flavor. Yak milk powders collected from different lactation periods exhibit distinct flavors, but no studies have thoroughly investigated the aroma characteristics and variation patterns of yak milk powders across these periods. This study identified and analyzed the volatile compounds in freeze-dried colostrum powder (YCSP), freeze-dried mature milk powder (YMMP), and freeze-dried ending milk powder (YEMP) using headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) and multivariate statistical analysis. A total of 48 volatile compounds were identified, with significant differences in the types and contents of these compounds across the three samples. Compared to YCSP and YEMP, YMMP contained higher levels of acids and esters, while the levels of alkanes and alcohols were lower. Principal component analysis (PCA), orthogonal partial least squares discriminant analysis (OPLS-DA), and hierarchical clustering heatmap analysis revealed a high degree of differentiation and notable variation in volatile compounds between the samples from different lactation periods. Key compounds such as aldehydes, alcohols, and esters were found to distinguish the lactation stages, with certain compounds more prevalent in colostrum and others in mature and ending milk. These findings suggest that the methodologies employed-HS-SPME-GC-MS combined with multivariate analysis-can effectively distinguish flavor differences among yak milk powders from different lactation periods. This approach allows for the rapid and comprehensive analysis of volatile components in milk powders, aiding in the identification of collection periods and providing valuable insights for improving the flavor quality of dairy products. Furthermore, the results can benefit the dairy industry by enhancing product development, quality control, and flavor profiling of milk-based products across different stages of lactation.

Dextran is an exopolysaccharide (EPS) with multifunctional applications in the food and pharmaceutical industries, primarily synthesized from Leuconostoc mesenteroides. Dextran can be produced from dextrin through Gluconobacter oxydans fermentation, utilizing its dextran dextrinase activity. This study examined how jar fermentor conditions impact the growth and enzyme activity of G. oxydans, with a focus on the effects of pH on dextran synthesis via bioconversion (without pH control, pH 4.5, and pH 5.0; Jp-UC, Jp-4.5, and Jp-5.0). After 72 h, the cell density (O.D. at 600 nm) was 7.2 for Jp-4.5, 6.5 for Jp-5.0, and 3.7 for Jp-UC. Flow property analysis, indicating dextran production, showed that Jp-4.5 had the highest viscosity (30.99 mPa·s). ¹H-NMR analysis confirmed the formation of α-1,6 glycosidic bonds in bioconversion products, with bond ratios ranging from ~1:0.17 to ~1:2.84. The distribution of molecular weights varied from 1.3 × 10³ Da to 5.1 × 10⁴ Da depending on pH. The hydrolysis rates to glucose differed with pH, with the slowest rate at pH 4.5 (53.96%). These results suggest that the production of dextran by G. oxydans is significantly influenced by the pH conditions. This dextran could function as a slowly digestible carbohydrate, aiding in postprandial glycemic regulation and mitigating chronic metabolic diseases like diabetes.