Food Chemistry: X最新文献

α-Tocopherol and γ-oryzanol affect physicochemical properties of oils, while their role in frying oil uptake remains unclear. Thus, the influence of various concentrations of 0-1000 mg α-tocopherol/kg oil and 0-15,000 mg γ-oryzanol/kg oil on the oil absorption of French fries and possible mechanisms were investigated. The results demonstrated that α-tocopherol and γ-oryzanol reduced surface oil by 29.83% and surface-penetrated oil by 28.19% in the fries, compared with control sample. Furthermore, α-tocopherol and γ-oryzanol inhibited the formation of total polar materials and diglycerides, delayed the increase in oil viscosity, and influenced the porosity of French fries. Additionally, α-tocopherol and γ-oryzanol decreased the rate constants for water loss and oil absorption at the French fry-oil interface. The most significant reduction in total oil content was observed with 1000 mg α-tocopherol/kg oil and 10,000 mg γ-oryzanol/kg oil. This study provides new insights for developing low-oil fried foods.

Frozen pears undergo complex internal quality changes during frozen storage, while conventional evaluation methods are destructive and time-consuming, limiting rapid or continuous monitoring. This study employed hyperspectral reflectance imaging combined with spectral preprocessing, feature wavelength selection, and machine learning algorithms to model key quality indicators of frozen pears, including soluble solids content (SSC), titratable acidity (TA), and total sugar content (TSC). The results revealed distinct optimal modeling strategies for different quality attributes. Stable predictions of TSC were achieved using full-spectrum data or weak wavelength screening, whereas SSC and TA required targeted wavelength optimization to improve prediction robustness. The optimal models exhibited high coefficients of determination, low prediction errors, and acceptable RPD values across prediction sets. Further validation using the guidance method confirmed stable error distributions without evident overfitting. Overall, this study demonstrates that hyperspectral imaging can provide a reliable alternative for non-destructive quality assessment of Lanzhou frozen pears.

This study aims to investigate how endogenous walnut pellicle polyphenols (WPP) alter the structural and functional properties of walnut protein isolate (WalPI). WPP influence was assessed by adjusting polyphenol content in walnut meal (WM) through treatments that peeled and dephenolized the pellicle. Results showed that WPP decreased the β-sheet content of unpeeled walnut protein isolate (UWalPI), increased random coil structures, and induced structural unfolding. These structural changes raised the water-holding capacity of UWalPI from 1.72 to 2.48 g/g and enhanced foaming capacity and foam stability by 31.12% and 46.44%, respectively. Conversely, surface hydrophobicity declined by 62.9%, oil-holding capacity reduced to 2.44 g/g, and emulsifying capacity, solubility, and thermal stability were compromised. Scanning electron microscopy indicated WPP-induced rearrangement and aggregation, molecular docking simulations predicted interactions between WPP and WalPI. The results clarify the mechanisms of WPP-WalPI interactions and provide strategies for the application of WM and WalPI in food processing.

Walnut pellicle is rich in polyphenols that enhance antioxidant capacity and health benefits, including anti-inflammatory and neuroprotective effects. Profiling these compounds has been hindered by their structural diversity, regional variability, and the limitations of traditional metabolomics approaches. This study employed a pseudotargeted metabolomics strategy, integrating ultra-high-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) for untargeted profiling and multiple reaction monitoring (MRM) on a QTRAP system for semi-quantification. We analyzed 21 walnut pellicle samples from Xinjiang, Yunnan and the Taihang Mountains, identifying 406 polyphenols, including flavonoids, hydrolysable tannins, phenolic acids, coumarins, lignans and minor constituents. Multivariate analyses (PCA, PLS-DA, OPLS-DA) revealed region-specific metabolic fingerprints. KEGG pathway enrichment highlighted significant variations in flavonoid and phenylpropanoid biosynthesis across regions, with origin-specific markers like casuarinin, prunin, and ε-viniferin supporting provenance authentication. This research bridges the methodological gap in walnut polyphenol analysis and informs quality assurance, targeted breeding, and functional product development in sustainable food systems.

Pumpkin (Cucurbita moschata and Cucurbita maxima) is a nutrient-rich vegetable, yet cooking-induced changes in comprehensive quality attributes across cultivars remain poorly understood. Here, the effects of steaming, boiling, and baking on taste components, texture, nutritional quality, and volatile profiles were systematically evaluated in three pumpkin cultivars. Sugar and starch contents were largely unaffected by cooking, whereas textural properties were significantly altered, with baking causing the least structural disruption. Steaming and boiling increased organic acid and vitamin C contents as well as antioxidant activity. Boiling enhanced carotenoid extractability, with Tian Mi highest at 3.13 mg/g DW. Cultivar-dependent differences were observed: Dan Hong showed higher hardness, chewiness, and gumminess, while Zhen Mi exhibited greater total volatile content. Volatile analysis revealed that cooking, particularly boiling, reduced green and earthy odorants while increasing key aroma-active compounds, including furfural and 4-vinylguaiacol. Overall, boiling provided the most favorable balance between nutritional enhancement and aroma improvement.