Food Chemistry: X最新文献

Four famous freshwater fish in China are renowned for their high production among freshwater species and are much-prized as sought-after delicacies. However, the distinct taste profiles and the specific associated taste substance of these carps remain poorly understood. This study primarily investigated the taste profiles and associated taste compounds, along with non- volatile metabolites of these four species using ultra performance liquid chromatography-mass spectrometry (UPLC-MS) combined with electronic tongue technology. Results revealed that Mylopharyngodon piceus (MP) exhibited significantly higher levels of total free amino acids and adenosine triphosphate (ATP) compared to the other three fish species (p < 0.05), with contents reaching approximately 388.90 mg/100 g and 140.88 mg/100 g, respectively. Ctenopharyngodon idella (CI) and MP possessed richer tastes compared to Aristichthys nobilis (AN) and Hypophthalmichthys molitrix (HM) based on the electronic tongue analysis. Furthermore, UPLC-MS metabolomics analysis identified 49 key metabolites, highlighting major metabolic pathways including lipid, amino acid, and organic acid metabolism. The findings suggested that variations in taste-related compounds and metabolites within metabolic pathways contribute to the distinct flavor profiles observed among the four famous fish species. This research offers essential insights for aquaculture professionals and researchers focused on enhancing the flavor quality of these key fish species, especially in understanding the regulatory mechanisms involved in flavor development.

Aroma profiles of tomato flesh from 16 tomato varieties with 4 different fruit colors were characterized by headspace-solid phase microextraction coupled with gas chromatography-triple quadrupole mass spectrometry (HS-SPME-GC-MS/MS) and electronic nose (E-nose). A total of 154 volatile organic compounds (VOCs) were qualitatively and semi-quantitatively identified, including 29 aldehydes, 22 hydrocarbons, 21 alcohols, 32 unknown compounds, and others, with aldehydes being the most abundant. Twenty-six characteristic VOCs might be major contributors to tomato flavor by relative odor activity value analysis. The correlation between E-nose sensor responses and GC-MS/MS volatile profiles was also examined. The machine learning models were constructed to show potential for distinguishing the fruit colors of the tomato. Finally, 16 fruit color-indicating VOCs were selected via multivariate data analysis. The present study will contribute to flavor evaluation and provide a chemical basis for future tomato flavor improvement, to be accompanied by sensory validation.

Fermented cowpeas, a traditional Chinese pickle, are valued for their characteristic taste and nutrition. This study examined flavor evolution and microbial dynamics during fermentation and storage via physicochemical analysis, volatile and nonvolatile compounds profiling, and microbial community assessment. 21 and 18 key discriminatory volatiles (VIP > 1) were identified via GC-MS and GC-IMS in cowpea samples, respectively. Multivariate analysis indicated that changes in flavor quality resulted from the combined effects of lactic acid, umami, and sweet amino acids, and 12 key aroma-active compounds (VIP > 1 and OAV > 1). Five core functional microorganisms (Debaryomyces, Companilactobacillus, Levilactobacillus, Chromohalobacter, and Microbacterium) were identified. Pearson correlation analysis revealed positive associations among these microorganisms and lactic acid, amino acids (Glu, Asp, Ala), and several key aroma-active compounds but negative associations with spermidine, tartaric acid, and Asn. These findings link microbial metabolism to flavor development in fermented cowpeas, revealing insights into fermentation-driven flavor modulation.

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.

To overcome the subjectivity of traditional bacon authentication, this study developed an objective discrimination framework integrating LC-MS/MS-based metabolomics with machine learning. Metabolomic profiling of bacon samples from pork belly (LRW) and pork rump (LRT) identified 100 differential metabolites common to both groups. The Kruskal-Wallis H test (p < 0.05) identified 75 significant features, which were further reduced to 22 key metabolites through random forest-based feature selection and low-variance filtering. Subsequently, a multidimensional evaluation of these 22 key metabolites (VIF < 75, label correlation >85%, and information gain = 1) highlighted four candidate discriminatory metabolites, including 6-hydroxyoctanoylcarnitine characterizing LRT, and dimethylethanolamine, xanthine, and ethyl hydrogen fumarate associated with LRW. Bidirectional validation using RF, KNN, SVM, and FNN models demonstrated robust discriminatory performance. This framework provides a basis for optimizing bacon production and offers a generalizable paradigm for data-driven biomarker discovery in meat products.

Poria cocos is a commonly utilized traditional Chinese dietary ingredient for tea, soup, porridge, baking, and herbal formulas. To compare the effects of different processing techniques on triterpenoids, six representative Poria cocos decoction pieces were selected through market analysis, and a novel analysis method was established based on the SIRIUS-MCnebula in combination with UPLC-QTOF-MS/MS. 211 triterpenoids were summarized by classyfireR, and 56 were identified. The results showed significant differences in the frequency of occurrence of different types of parent nuclei and side chains, among which Lanoster-8-ene triterpenoid and m-type are the highest. The shade drying group contained richer triterpenoid components and higher content compared to the non-heat-treated groups (sun-dried, fresh-cut, sweat-treated) and the heat-treated groups (steam-treated, sweat and steam-treated). This research enhances how processing techniques influence the triterpenoid components of Poria cocos and provides scientific evidence for optimizing Poria cocos processing techniques, emphasizing the potential of AI technology in food research.

Bacillus licheniformis, as a major food spoilage organism, can cause serious deterioration of food quality and safety. In this work, Sichuan pepper seed essential oil (SPSEO) was extracted from pepper seed, the by-product of pepper pericarp production, as a novel biological antibacterial agent. It exhibited a prominent inhibitory effect on Bacillus licheniformis. Furthermore, the in-depth study of inhibitory mechanisms was conducted by metabolomics combined with multiple biochemical analysis. The results showed that the cell wall/membrane integrity and surface properties of the bacteria were heavily altered after SPSEO treatment. SPSEO depolarized membrane potential, limited DNA synthesis, and induced ROS accumulation of bacteria. SPSEO was found to disrupt the carbohydrate, amino acid, lipid, and nucleotide metabolism of bacteria, which further revealed the inhibitory mechanisms and their intrinsic relation from metabolism perspective. Additionally, SPSEO effectively controlled the growth of Bacillus licheniformis in milk at a high sensory acceptable dose, demonstrating its practical applicability.

Plant-based milk analogues are suitable substitutes for animal milk, more environmentally friendly, and sustainable. The microbiological stability, quality, anti-nutritional elements, and techno-functional properties of plant analogues and their proteins need to be considered. The type and concentration of reactive plasma species are influenced by parameters such as frequency, voltage, electrode spacing, treatment time, and gas composition. These factors regulate the efficacy of cold plasma in microbial disinfection and enzyme inactivation. The results indicate that cold plasma enhances the solubility, emulsifying properties, hydrophilicity, and foaming characteristics of plant-based analogues and proteins. In this study, the most potential sources of cold plasma and their impact on the functional characteristics of plant milk and proteins are thoroughly discussed. The work presents current insights into cold plasma for plant-based milk analogues and highlights their prospective applications, recent research, and developments in the field.

Metal-phenolic networks (MPNs) are widely used to improve the structure, mechanical properties and stability of gels. In this study, tannic acid (TA) was coordinated with metal ions (Mn²⁺ and Zn²⁺) under pH conditions of 2.0, 5.5, and 8.0 to form MPNs, which subsequently induced soy protein hydrolysate nanofibrils (SPHN) to produce gels (SPHN-MPNs gels). As the pH increased, the coordination interactions between TA and Mn²⁺/Zn²⁺ became progressively stronger, as reflected by the emergence of new charge-transfer-related absorption features. Spectral analysis confirmed that MPNs could promote gel cross-linking via hydrogen bonds and metal ions coordination interactions between MPNs and SPHN. Gels induced by MPNs displayed a denser gel structure as the pH increased, resulting in higher storage modulus and elevated thermal transition temperature. MPNs formed between TA and Zn²⁺ at pH 8.0 imparted higher G' values and a faster recovery rate to the gels after four shear-stress cycles. These findings will expand the potential applications of SPHN-MPNs gels in the food industry.