Differentiating Huangjiu with Varying Sugar Contents from Different Regions Based on Targeted Metabolomics Analyses of Volatile Carbonyl Compounds

Unraveling key non-volatiles responsible for taste differences of Pixian broad bean paste based on sensory analysis and untargeted metabolomics

Besides aroma, the tastes of Pixian Broad Bean Paste (PBBP) are also important, however, they have not yet been thoroughly elucidated. Therefore, this study employed sensory and untargeted metabolomics approaches to investigate taste characteristics, molecular basis and their metabolic pathways of PBBP from three different manufacturers and two grades. Results showed PBBP was predominantly characterized by strong sour, umami and salty tastes, and significant differences were observed in samples from different manufacturers and grades (p < 0.05), especially higher sourness, saltiness and umami in premium PBBP. Based on non-volatiles, 55 key differential metabolites were identified through orthogonal partial least square discriminant analysis (OPLS-DA, P value<0.05, VIP value>1.0) and Pearson correlation analysis (|ρ| > 0.7). These key differential metabolites responsible for taste differences were metabolized by 36 crucial KEGG pathways (P value<0.05, impact value>0.05). These results could expand our understandings of PBBP taste compounds and their metabolisms, and provide theoretical evidences for further quality improvement.

The Microbial Diversity and Flavor Metabolism Regulation of Xiangzao During Different Natural Fermentation Time Periods

Xiangzao brine is a special flavored food produced by the natural fermentation of Huangjiu lees. To clarify fermentation time on its quality, this study integrated flavoromics analysis, macro-genomics, and polypeptide omics to analyze the volatile flavor components, microbial species, and flavor peptide distributions of four groups of samples (XZ-1Y, XZ-2Y, XZ-3Y, and XZ-4Y) fermented for 1-4 years. The results showed that the samples fermented for 1 year had the highest contents of umami amino acids and umami peptides, and the samples fermented for 4 years had the highest contents of organic acids and fruity components. In addition, 42 volatile flavor components and 532 peptides were identified, including 393 umami taste peptides and only 37 bitter taste peptides. Correlation analysis showed that ethyl lactate and furfural were positively correlated with the abundance of Nocardioides and Stenotrophomonas, respectively. The abundance of Pseudomonas was positively correlated with four previously unreported umami peptides (FATPR, RELER, FNLERP, and RSSFLGQ) screened by molecular docking. This study provides a reference for the flavor metabolism regulation of Xiangzao brine.

Green infant formula analysis: Optimizing headspace solid-phase microextraction of carbonyl compounds associated with lipid peroxidation using GC-MS and pentafluorophenylhydrazine derivatization

The refinement and optimization of a method combining headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS) was successfully performed for the first time to determine seven carbonyl and dicarbonyl compounds, including glyoxal, methylglyoxal, dimethylglyoxal, and malondialdehyde in infant formulae, related to lipid peroxidation. HS-SPME was utilized for simultaneous extraction and derivatization with pentafluorophenylhydrazine (PFPH). Critical parameters such as temperature, pH, extractive phase, and salting-out were meticulously investigated and fine-tuned by an asymmetrical 2232//9 screening design to ensure the method's efficacy and reliability. Optimal conditions included a PFPH concentration of 5 g/L, pH 5.0, head-space extraction at 60 °C within 10 min, utilizing a DVB/CAR/PDMS coating, and a 20% w/w salting-out. The analytical validation of this method, compliant with FDA guidelines, demonstrated exceptional linearity, sensitivity, specificity, precision (RSD ≤13.8%), and accuracy (84.8% ≤ recovery ≤111.5%). The metric approach AGREEprep confirms its eco-friendliness, marking a significant step towards an environmentally conscious approach in infant formula analysis. An occurrence study conducted on 25 infant formula samples revealed widespread carbonyl and dicarbonyl compounds in both powdered and liquid variants. ANOVA results exhibited variations in compound concentrations among different sample groups. Clustering analyses delineated distinct groups based on carbonyl content, indicating the potential of these compounds as markers for lipid peroxidation and food quality assessment. This method serves as a valuable tool for evaluating infant formula quality, stability towards oxidation, and safety.

Therapeutic Potential of Fucoidan in Alleviating Histamine-Induced Liver Injury: Insights from Mice Studies

Histamine, a bioactive component in certain foods such as Huangjiu has been associated with liver injury and disrupted intestinal balance. This study explored the potential therapeutic effects of fucoidan (FCD) in mitigating histamine-induced imbalances in mice. We found that FCD mitigated liver injury, reducing transaminases, oxidative stress, and inflammation. Histological improvements included decreased cell infiltration and necrosis. FCD restored tight junction proteins and suppressed inflammation-related genes. Western blot analysis revealed FCD's impact on TGF-β1, p-AKT, AKT, CYP2E1, Grp78, NLRP3, Cas-1, and GSDMD. Gut LPS levels decreased with FCD. Gut microbiota analysis showed FCD's modulation effect, reducing Firmicutes and increasing Bacteroides. FCD demonstrates potential in alleviating histamine-induced liver injury, regulating inflammation, and influencing gut microbiota. Further research exploring higher dosages and additional parameters is warranted.