Analysis of metabolic differences between Jiaosu fermented from dendrobium flowers and stems based on untargeted metabolomics.

Dendrobium officinale is an important traditional Chinese medicinal herb containing bioactive polysaccharides and alkaloids. This study characterized metabolite differences between jiaosu (fermented plant product) from Dendrobium flowers versus stems using untargeted metabolomics. The jiaosu was fermented by mixed fermentation of Saccharomyces cerevisiae, Lactobacillus bulgaricus and Streptococcus thermophilus. Liquid chromatography-mass spectrometry analysis identified 476 differentially expressed metabolites between the two Jiaosu products. Key results showed downregulation of flavonoid metabolism in Dendrobium Stems Edible Plant Jiaosu (SEP) but increased flavonoid synthesis in Dendrobium Flowers Edible Plant Jiaosu (FEP), likely an antioxidant response. SEP displayed upregulation of lignin metabolites with potential antioxidant properties. The findings demonstrate significant metabolite profile differences between SEP and FEP, providing the basis for developing functional jiaosu products targeting specific health benefits.

Antifungal mechanism of rose, mustard, and their blended essential oils against Cladosporium allicinum isolated from Xinjiang naan and its storage application.

AIMS: To reveal the inhibition mechanism of rose, mustard, and blended essential oils against Cladosporium allicinum isolated from Xinjiang naan, and investigate the effect of the three essential oils on oxidative damage and energy metabolism. METHODS AND RESULTS: Rose and mustard essential oils significantly inhibited mycelial growth and spore viability in a dose-dependent relationship. After essential oil treatment, the cell membrane permeability was altered, and significant leakage of intracellular proteins and nucleic acids occurred. SEM observations further confirmed the disruption of cell structure. ROS, MDA, and SOD measurements indicated that essential oil treatment induced a redox imbalance in C. allicinum, leading to cell death. As for energy metabolism, essential oil treatment significantly reduced Na+K+-ATPase, Ca2+Mg2+-ATPase, MDH activity, and CA content, impairing metabolic functions. Finally, storage experiments showed that all three essential oils ensured better preservation of naan, with mustard essential oil having the best antifungal effect. CONCLUSIONS: Rose and mustard essential oils and their blends can inhibit C. allicinum at multiple targets and pathways, destroying cell morphological structure and disrupting metabolic processes.

Active colorimetric bilayer polycaprolactone-eucalyptus oil@silk fibroin-bayberry anthocyanins (PCL-EO@SF-BAs) membrane with directional water transport (DWT) for food packaging.

Currently, designing smart membranes with multifunctional effectiveness is crucial to food freshness monitoring and retention. Herein, an active colorimetric Janus bilayer membrane with directional water transport (DWT) performance is constructed by electrospinning, which comprises a hydrophilic layer of silk fibroin-bayberry anthocyanins (SF-BAs) and a hydrophobic layer of polycaprolactone-eucalyptus oil (PCL-EO). The entities of BAs and EO are well dispersed in the fiber matrix by hydrogen bonds and physical interactions, respectively. BAs endow the membrane colorimetric response and antioxidant activity, and EO contributes to the antibacterial activity while DWT performance is generated from the asymmetric wettability of the two layers. The bilayer membrane has an accumulative one-way transport index of 1077%, an overall moisture management capacity of 0.76 and a water evaporation rate of 0.48 g h-1. Moreover, the release of BAs and EO was predominantly controlled by Fickian diffusion. As a pH-sensing indicator, PCL-EO@SF-BAs is highly sensitive to external pH stimuli and the response is reversible. In addition to freshness monitoring, PCL-EO@SF-BAs can extend the shelf-life of pork beyond 100% at 4 °C. Also, it can extend the shelf life of shrimp by approximately 70% at 25 °C with the synergistic effect of antibacterial activity and the DWT performance.

Ethylene-vinyl Alcohol Copolymer-Montmorillonite Multilayer Barrier Film Coated with Mulberry Anthocyanin for Freshness Monitoring.

Colorimetric films incorporated with anthocyanins as an indicator for freshness monitoring have aroused growing interest recently. However, the application of the films is limited by the easily oxidizable nature of anthocyanins. In this work, we developed a novel colorimetric film with a barrier by coating mulberry anthocyanin (MBA) on the internal side of an ethylene-vinyl alcohol copolymer-montmorillonite (EVOH-MMT) multilayer film. A facile layer-by-layer (LBL) assembly was employed under a parallel electric field to build the EVOH-MMT multilayer structure, in which the exfoliated MMT nanosheets were well-oriented and assembled on the EVOH matrix to form a tightly stacked layer between two EVOH layers. The interlayer of MMT significantly enhanced the barrier and mechanical properties of the films (below 40 layers). The interactions between EVOH and MMT and between EVOH and MBA were confirmed to be intermolecular hydrogen bonds. The colorimetric response of (EVOH-MMT)40-MBA3 to volatile ammonia and pH was sensitive, and the color change could be easily distinguished by the naked eye. The successful application of (EVOH-MMT)40-MBA3 to shrimp-freshness monitoring confirms its high potential for the freshness monitoring of packaged food.