2 '-Fucosyllactose (2 '-FL), a human milk oligosaccharide with prebiotic properties, has been incorporated into infant formula. alpha-Lactalbumin (alpha-LA), a key milk protein, may undergo the Maillard reaction with 2 '-FL upon heating and extended storage. However, the impact of this reaction on the prebiotic activity of 2 '-FL remains unclear. This study confirmed the formation of Maillard reaction products (MRPs) through the measurement of furosine and free 2 '-FL levels. Mass spectrometry analysis identified that alpha-LA can conjugate with seven 2 '-FL molecules, resulting in high-molecular-weight MRPs. In vitro assays revealed that alpha-LA-2 '-FL complexes significantly reduced the growth and metabolism of Bifidobacterium, as evidenced by a 47 % decrease in Bifidobacterium density and a 62 % decrease in the production of short-chain fatty acids. These findings highlight for the first time the reduced prebiotic properties of 2 '-FL upon interaction with alpha-LA, providing valuable insights for preserving the functional properties of infant formula during formulation and storage.
Aging is an indispensable process for developing the unique flavor of Baijiu, yet systematic analyses of aged flavor profiles remain limited. This study systematically elucidated the chemical and sensory evolution of Jiangxiangxing Baijiu (JXB) over 4 to 18 years of aging by integrating sensory evaluation and GC × GC-TOFMS. Sensory analyses demonstrated that aging significantly increased the intensity of aged aroma, sweetness, softness, richness, and harmony. A total of 897 volatile flavor compounds were identified by GC × GC-TOFMS, with 25 compounds subsequently selected as age markers. Further quantitative and OAV analyses identified eight aroma-active compounds as age markers. In aged JXB samples, esters, aldehydes, acids, heterocyclic, and pyrazine compounds collectively contributed to the aromatic character of aged JXB. The results of this study establish foundational data and a comprehensive framework for further research into aged JXB flavor.
The aim of this work was to elucidate the specificity of the cellar mud odor compounds in strong aroma base Baijiu using gas chromatography-olfactometry-mass spectrometry analysis based on chemical and sensory profiles. Fifty-three aroma compounds in both base and commercial Baijiu were identified and quantified by comparing their MS, retention indices with those of pure standards. Odor activity values and principal component analysis were used to account for the variation in the sensory attributes of these aroma compounds. The results demonstrate that high acid and phenol contents contribute to the cellar mud aroma profiles in base strong aroma Baijiu. This approach may provide valuable information for product quality control of strong aroma Baijiu products.
Saccharomyces cerevisiae spores exposing (3-glucan layers exhibit notable immunomodulatory properties, suggesting their potential as a natural and efficient source of (3-glucans. However, studies on the application of spore wall (3-glucans are limited, and their precise structural characteristics and immunological mechanisms remain poorly understood. This study aimed to investigate the structural characteristics and immunomodulatory properties of (3-glucan extracted from the yeast spores (YSG) and compare them with those of (3-glucan derived from vegetative cells (YG). Similar to YG, YSG consists of a backbone chain of (3-(1,3) glucan and side chains of (3-(1,6) glucan with a natural triplex structure. However, there are differences in the branching ratio and helical structure between YSG and YG. YSG has fewer branches and a less pronounced triple helix structure than YG. The particle size (222.4 nm) and molecular weight (Mw: 1392.27 kDa) of YSG were found to be significantly smaller than those of YG. Additionally, YSG can bind to the Dectin-1 receptor protein on the surface of macrophages, activating the Syk/CARD9/NF-KB pathway to promote the expression of iNOS and cytokine mRNAs, thereby facilitating the release of NO and related cytokines for increased immunostimulatory effects. Collectively, our results provide foundational insights into the potential of yeast spore wall (3-glucan as a functional immunostimulatory agent.
This study investigated the impact of low, medium, and high molecular weight β-glucans on physicochemical properties and in vitro digestibility of normal (NHBS) and waxy highland barley starches (WHBS). Results indicated that β-glucans with different molecular weights had varying effects on HBS properties. High molecular weight β-glucan (HBG) significantly increased the pasting temperature and gelatinization enthalpy of two HBS, and reduced the apparent viscosities. The firmness of NHBS was decreased after adding β-glucans, while the opposite result was observed in WHBS. Structural analysis showed HBG formed stronger interactions with two HBS, resulting in a more ordered structure. LF-NMR analysis revealed that β-glucans had water-binding capacities, and their interaction with water limited water access to HBS and reduced water mobility. In vitro digestion indicated that HBG significantly decreased the digestibility of NHBS and WHBS to 67.87 % and 73.85 %, respectively. HBG improved the HBS properties through its interaction with HBS and water.
