Food Chemistry: X最新文献

In the context of coexisting traditional and intensive yak production systems, clarifying the effects of different fattening strategies is crucial for optimizing meat quality and meeting consumer demands. This study compared three feeding regimes: traditional grazing (TG), low-concentrate (LC), and high-concentrate (HC) stall-feeding, in 18 yaks. The HC regimen enhanced carcass traits, average daily gain, dressing percentage, and marbling score, while also increasing myofiber size and drip loss. Shear force of meat from TG yak was greater than the two stall-fed groups and from LC yaks was greater than the HC yaks. Nutritionally, TG and HC meat had a higher polyunsaturated fatty acid (PUFA) content and PUFA:SFA ratio than LC meat. Importantly, grazing enriched n-3 PUFAs and improved oxidative stability, indicated by higher superoxide dismutase activity and lower malondialdehyde. The HC diet, however, increased n-6 PUFA and intramuscular fat. In conclusion, while feedlot finishing improves production efficiency and tenderness, grazing yields superior nutritional benefits and oxidative stability in yak meat.

The analysis of isomers in Citrus remains challenging due to chemical diversity and structural similarity under conventional 70 eV electron ionisation (EI) conditions. This study investigated electron energies down to 5 eV and evaluated the impact of manual tune on molecular ion (M^+•) repeatability using gas chromatography-quadrupole time-of-flight mass spectrometry (GC-QTOF/MS). Thirty-one representative Citrus isomers were used to optimise EI source parameters: emission current, electron energy, and ion source temperature. Manual tune improved M^+• repeatability, reducing RSD from 15.4-18.5% to 1.8%. The optimised low energy EI method (typically 11-12 eV, 175-195 °C) achieved favourable M^+• intensities with RSD below 5.5%. Comparisons across structurally related compounds revealed that conjugation and trans-configuration enhance M^+• stability, whereas allylic hydroxyl groups reduce it. This low energy EI approach improves M^+• preservation and repeatability, providing a promising option for isomer differentiation in complex Citrus volatile profiles.

To explore variations in the volatile components of milk originating from various species and to explain the material basis of their odor differences, electronic nose analysis coupled with headspace gas chromatography-mass spectrometry (HS-GC-MS) was employed to analyze the characteristics of human, sheep, goat, and cow milk. It was found that human milk exhibited larger response values to the broadrange and sulfur-chlor sensors, while sheep milk exhibited a large response value to the broad-methane sensor. The concentrations of dodecanoic acid, n-decanoic acid, and octanoic acid were significantly higher in human milk than in the sheep, cow, and goat milk. Moreover, it was deduced that a range of the detected volatile organic compounds were involved in the fatty acid biosynthesis pathway. These results allow identification of the different odor components related to human milk and other ruminant milk, providing a scientific basis for development of the dairy industry.

This study comprehensively evaluated the phytochemical and organoleptic evolution of Aronia melanocarpa wines aged for 12 months in glass bottles and oak barrels. Integrated analytical approaches-including CIELab color space, phenolic profiling, antioxidant capacity assays, headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS), electronic tongue, and Check-All-That-Apply (CATA) consumer testing-revealed distinct aging dynamics. Barrel aging caused 96.2% anthocyanin loss, shifting wine color to reddish-brown, while bottle aging preserved greater color stability (retaining 42.6% of anthocyanins). HS-GC-IMS identified 65 volatile compounds; barrel aging increased oxidative markers (e.g., 3-penten-2-one and 4-hydroxy-4-methyl-2-pentanone) and oak-derived notes (e.g., cocoa and coconut), whereas bottle aging enhanced tertiary aromas characterized by spicy, tobacco, and leather nuances. Electronic tongue and CATA analyses confirmed both aging methods improved taste profiles by reducing sourness and mitigating astringency/bitterness aftertastes. Bottle-aged wine demonstrated superior consumer preference (54.24% first-choice ranking) due to its fruity aroma, deeper color, and balanced taste.

This study aimed to compare the nutritional characteristics, antioxidant activity, and flavor differences of traditional fermented glutinous rice from four regions of China, and to elucidate the underlying metabolic mechanisms using metabolomics. Physicochemical assays, HPLC, GC-MS, and LC-MS analyzed five samples (HB_MPP, SC, JS, GZ_LYM, SWJD). Significant differences in antioxidant capacity and amino acids were found, with lysine as the first limiting amino acid. Dominant organic acids were lactic, malic, and fumaric acids. Forty volatile compounds (mainly esters, alcohols, acids) were detected, with phenylethanol, ethyl hexadecanoate, and ethyl decanoate as key flavor markers (VIP ≥ 1). Metabolomics identified 3027 metabolites, dominated by lipids (27.59%) and organic acids (26.99%). Key pathways included plant secondary metabolite biosynthesis and amino acid metabolism. This first multi-omics comparison highlights regional characteristic bases, aiding traditional fermented food quality evaluation and industrial application.

This study investigates the impact of cabbage outer leaf powder (COLP) on the quality attributes of a set-type yogurt. COLP is rich in vitamin C (156.62 mg/100 g), total phenolic content (TPC, 217 mg GAE/100 g), minerals, total dietary fiber (TDF, 64.41 g/100 g), and insoluble dietary fiber (IDF, 52.91 g/100 g) and exhibited high DPPH radical scavenging activity (82.81% inhibition). COLP supplementation significantly (p < 0.05) increased the ash, total solids, vitamin C, TDF, IDF, soluble dietary fiber (SDF), Fe, K, Mg, Ca, Mn, Na, TPC and DPPH antiradical activity of yogurt. It significantly increased (p < 0.05) the acidity, water holding capacity (WHC), hardness, adhesiveness, springiness, cohesiveness, redness (a*), yellowness (b*), color, flavor, taste, and overall acceptability and significantly (p < 0.05) decreased the pH, syneresis, and lightness (L*) of yogurt. Overall, COLP improved yogurt's nutritional, bioactive, and physical quality attributes and can be considered a natural additive to produce a functional yogurt without negative effect on sensory attributes.

Rice starch-protein interactions significantly influence techno-functional properties and phenolic binding. This study elucidated the molecular mechanisms governing cyanidin-3-O-glucoside (C3G) interactions with rice starch-protein matrices containing varying protein levels (0-15% w/w). Protein contents of 5% and 10% significantly enhanced C3G binding by 14.8% and 10.7%, respectively, whereas C3G bioaccessibility remained statistically unchanged upon starch digestion. Increasing protein levels reduced particle size, altered granule morphology, and reduced iodine affinity. FTIR analysis revealed strengthened hydrogen bonding, amide-I shifts, and modified starch chain organization, whereas XRD showed reduced crystallinity with attenuated V-type peaks. At 10% protein, C3G produced fine, uniform, pigment-loaded particles, whereas 15% protein induced reaggregation. These structural changes increased resistant starch, decreased slowly digestible starch, and shifted color from red-blue to red-yellow. Molecular docking confirmed that C3G intensified hydrogen bonding and hydrophobic interactions at the starch-protein interfaces. Overall, protein content can be tuned to engineer functional foods with targeted nutritional properties.