The present study investigated the covalent binding behavior of the flavonoids, catechin, eriodictyol, luteolin and quercetin with β-lactoglobulin (βlg). Since the four flavonoids possess the identical A- and B-ring structures, effects of the C-rings on the properties of flavonoids and the corresponding semiquinones are revealed. Experimental methods including DLS and CD spectra indicated that with quercetin at room temperature did not induce aggregation of βlg, whilst binding with the other three flavonoids resulted in aggregation of βlg.
View Article and Find Full Text PDFThis study aimed to simulate frozen instant soup rice noodles (FISRN) and investigate the effects of long-term frozen storage (-18 °C, 180 days) on the quality characteristics, moisture status, and starch retrogradation of FISRN. The findings indicated that the extent of starch retrogradation gradually increased over 90 days, which elevated the RS rate and inhibited starch digestibility. However, recrystallization resulted in a gradual increase in ice crystal size after 90 days, which disrupted the ordered structure formed by starch retrogradation, reduced the degree of starch order, and accelerated the rate of starch digestion.
View Article and Find Full Text PDFThis study investigated the effects of high-hydrostatic-pressure (HHP) treatment of varying intensity (100-600 MPa) and duration (10-30 min) on polyphenols and volatile aromatic compounds in Marselan red wine. The types and concentrations of polyphenols and volatile aromatic compounds were compared before and after HHP treatment; the results indicated that HHP treatment at 300 MPa for 20 min significantly increased the total polyphenol content to 369.70 mg/L, a rise of 35.
View Article and Find Full Text PDFThe study evaluated the effect of freezing rate on the quality of water-added quick-frozen rice noodles and water-free quick-frozen rice noodles. Results indicated that the retrogradation enthalpy, relative crystallinity, freezable water content, and cooking loss of water-added quick-frozen rice noodles were higher than those of water-free quick-frozen rice noodles with increasing storage time. Furthermore, ice recrystallization accelerated the deterioration of the quality of the rice noodles, resulting in the enlargement of the pores within the rice noodles and the formation of many pores on the surface.
View Article and Find Full Text PDFBlack rice wine (BRW) is a traditional Chinese rice wine with unique flavors; however, the formation pathways of flavor compounds driven by microbiota remain unclear. This study employed HPLC and GC-MS to reveal that during BRW fermentation, free amino acids increased sevenfold, volatile compounds doubled, and 28 key characteristic flavor compounds were identified. Metatranscriptomic analysis indicated that during fermentation, driven by physicochemical factors and microbial interactions, Saccharomyces gradually became the dominant active microorganism (relative abundance 87.
View Article and Find Full Text PDFThis study aimed to explore the immunomodulatory effects and mechanism of a sodium hyaluronate health drink in immunosuppressed mice. The results showed that the sodium hyaluronate health drink could improve thymus atrophy, repair spleen cell damage, promote the release of IL-2, IL-6 and TNF-α in serum, restore immune deficiency, and enhance immune function. In addition, 16s rRNA sequencing results of intestinal flora showed that different doses of health drink had different effects on the intestinal flora of mice.
View Article and Find Full Text PDFGlobal warming has increased the contamination of mycotoxins. Patulin (PAT) is a harmful contaminant that poses a serious threat to food safety and human health. Saccharomyces cerevisiae biodegrades PAT by its enzymes during fermentation, which is a safe and efficient method of detoxification.
View Article and Find Full Text PDFThe flavor of black rice wine (BRW) can be diversified by the Xiaoqus, from different regions; however, the functional microbiota that contributes to its flavor remains unclear. Accordingly, this study selected three regional Xiaoqus from Sichuan Dazhu (Q1), Jiangxi Yingtan (Q2), and Hubei Fangxian (Q3) as starters to investigate flavor compounds and microbial communities during BRW brewing. Results indicated that altogether 61 flavor substances were identified, 16 of which were common characteristic flavor compounds (odor activity value > 0.
View Article and Find Full Text PDFPatulin poses a potential risk to human health, and current methods for removing it have certain limits. Thus, the effective and secure technique for degrading patulin in juice is critical. In this study, a nitrogen-doped chitosan-TiO nanocomposite (N-TiO Nps) as a photocatalyst was employed to decompose patulin.
View Article and Find Full Text PDFAmino acid metabolic pathways can have profound impacts on the activities of key enzymes in the biosynthesis of specific aroma compounds during yeast fermentation. Aroma compounds, pyruvic acid and glucose were monitored in relation to the key enzymes of leucine aminotransferase (LTR), phenylalanine aminotransferase (PAL), pyruvate kinase (PK) and acetyl-CoA in the amino acid metabolic pathways during the fermentation of simulated juice systems with added amino acids in order to explore the formation of characteristic aroma compounds. The addition of L-phenylalanine or L-leucine to the simulated juice systems significantly improved the activities of PK, PAL and LTR, and the content of acetyl-CoA, and significantly increased the concentrations of phenylethyl alcohol, octanoic acid, isoamyl acetate, phenylethyl acetate, ethyl hexanoate and ethyl caprylate during fermentation.
View Article and Find Full Text PDFTo promote the normal metabolism of human uric acid, high-performance hyaluronic acid-black rice anthocyanins (HAA) nanocomposite particles were successfully prepared by a simple crosslinking method as a novel xanthine oxidase inhibitor. Its structure and properties were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectrometry (FT-IR), and X-ray diffraction (XRD). SEM and TEM electron microscopy showed an obvious double-layer spherical structure with a particle size of ~298 nm.
View Article and Find Full Text PDFPatulin (PAT), a mycotoxin mainly produced by various species of fungi, is frequently detected in moldy fruit- and vegetable-based products, which pose a health risk to the consumer. Over the past decades, a few studies reported that PAT content could be significantly decreased by microbial fermentation process. However, the physical adsorption mechanism between PAT and yeast during fermentation is still unclear.
View Article and Find Full Text PDFThe objective of this paper is to explore the effects of high hydrostatic pressure (HHP) treatments on the structural and physical properties of nisin-soy-protein-isolate (SPI) films by scanning electron microscopy (SEM), Fourier transformed infrared (FTIR) spectroscopy, circular dichroism (CD) spectroscopy, UV-Vis spectrophotometry, texture analyzer and rotational rheometer. It was found that the nisin-SPI based films treated by high HHP had uniform and smooth appearance and compact internal structures. Moreover, HHP treatment significantly improved the barrier and mechanical properties of the composite films.
View Article and Find Full Text PDFThis work aims to investigate the potential of fiber-optic Fourier transform-near-infrared (FT-NIR) spectrometry associated with chemometric analysis, which will be applied to monitor time-related changes in residual sugar and alcohol strength during kiwi wine fermentation. NIR calibration models for residual sugar and alcohol strength during kiwi wine fermentation were established on the FT-NIR spectra of 98 samples scanned in a fiber-optic FT-NIR spectrometer, and partial least squares regression method. The results showed that R and root mean square error of cross-validation could achieve 0.
View Article and Find Full Text PDFFermentation temperature strongly affects yeast metabolism during apple wine making and thus aromatic and quality profiles. In this study, the temperature effect during apple wine making on both the key aroma compounds and sensory properties of apple wine were investigated. The concentration of nine key aroma compounds (ethyl acetate, isobutyl acetate, isopentylacetate, ethyl caprylate, ethyl 4-hydroxybutanoate, isobutylalcohol, isopentylalcohol, 3-methylthio-1-propanol, and benzeneethanol) in apple wine significantly increased with the increase of fermentation temperature from 17 to 20 °C, and then eight out of the nine key aroma compounds with an exception of ethyl 4-hydroxybutanoate, decreased when the temperature goes up 20 to 26 °C.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
March 2009
The sugar content and the matrix always are being changed during cider-making fermentation. In order to measure and monitor sugar content accurately and rapidly, it is necessary for the spectra to be sorted. Calibration models were established at different fermentation stages based on near infrared spectroscopy with artificial neural network.
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