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Microbial enzymes: the bridge between Daqu flavor and microbial communities Full text
2024
Zelong Zhong | Tianyi Liu | Kaiping He | Min Zhong | Xiaoxue Chen | Yansong Xue | Beizhong Han | Diqiang Wang | Jun Liu
Baijiu Daqu, a traditional component in the Baijiu brewing process, serves as both a 'saccharifying fermenting agent' and an 'aroma-producing catalyst', embodying a rich historical legacy. Daqu offers a diverse microorganism environment that is crucial for the fermentation of Baijiu. The distinctive flavor profile, a key attribute of Baijiu, is intricately linked to the microflora present in Daqu. To date, research on Daqu has primarily concentrated on the diversity of microbial communities, microbial interactions, flavor characteristics, and biochemical properties. The functional enzyme system in Daqu serves as a crucial link connecting the flavor of Baijiu with the microbial community of Daqu. However, reviews that particularly focus on the role of enzymes in determining the quality of Daqu have not yet been reported. Thus, here the types and production processes of Daqu are initially summarized. Then, the pathways involved in the production of the major flavor substances in Daqu are elucidated, as well as the role and contribution of different functional enzymes in the formation of Daqu flavor. Finally, the current technologies for improving Daqu flavor through microbial inoculation aree discussed, including the advantages, shortcomings, and bottlenecks of microbial inoculation. The findings gained in this study provide valuable information for the efficient production of high-quality Daqu for the brewing of Baijiu.
Show more [+] Less [-]The effect of static magnetic field on inducing the binding of bovine serum albumin and cyanidin-3-O-glucoside Full text
2024
Zongrui Zhang | Yixiao Shen | Guang Xin | Wei Deng | Hui Tan | Ahmed Adel Ashour | Dongnan Li
Serum albumin can bind with a diverse range of small molecules. It could therefore serve a protective or carrier function, and effectively address the issue of anthocyanins' susceptibility to decomposition. The anisotropic effect of the magnetic field (MF) can influence their interaction, thereby playing a distinct role in molecular bonding. In this study, bovine serum albumin (BSA) and cyanidin-3-O-glucoside (C3G) were used as raw materials. The mechanism underlying the formation of BSA-C3G complexes induced by static magnetic field (SMF) was investigated through analyses of secondary structure, functional groups, dipole moment, crystal cell dimensions, and microstructural characteristics. BSA and C3G were treated with 50, 100, 150, and 200 mT, respectively. As the magnetic intensity increased, the secondary structure of the complex changed, the α-spiral content, β-corner content, and irregular curl content decreased, while, the β-folding content increased. The average grain size of the BSA-C3G composite was observed to decrease. Furthermore, alterations in the crystal cell dimensions of the BSA-C3G complex were noted, accompanied by a tendency for the microstructure to become more flattened. This study offers valuable insights into the influence of SMF on the assembly behavior and structural characteristics of proteins and anthocyanins.
Show more [+] Less [-]Appropriate sodium nitroprusside dose contributes to the quality maintenance of fresh walnuts Full text
2024
Liping Qiao | XiuLi Deng | Xiaoli Yu | Min Feng | Yuzhen Jiao | Yansheng Wang | Laifeng Lu | Xia Liu
Fresh walnuts (Juglans regia L.) are challenging to store due to their high water content and delicate green appearance. It has been reported that sodium nitroprusside (SNP, a nitric oxide donor) can promote stress tolerance. However, whether SNP affects the postharvest quality of fresh walnuts remains unknown. This research showed that appropriate SNP treatment contributed to walnut preservation; in particular, 0.5 mmol/L SNP treatment resulted in a better appearance and less decay (59.7%). Compared with the control, this treatment not only increased the levels of proteases related to fresh walnut disease (chitinase and β-1,3-glucanase) but also increased the overall antioxidant level and reduced oxidant damage. Moreover, respiratory metabolism and ethylene release were greatly suppressed (9.5%), and the overall sensory evaluation did not reveal any adverse effects associated with a lower acid or peroxide content. Thus, it was inferred that the optimal SNP dose activated disease-related enzymes, mediated the physiological metabolism rate, regulated the ROS-redox balance and therefore reduced decay and maintained the walnut quality. This is the first report of SNP (NO) application for the preservation of fresh walnuts and may provide information to facilitate practical application of this potential innovation.
Show more [+] Less [-]The powerful function of Saccharomyces cerevisiae in food science and other fields: a critical review Full text
2024
Zhiluo Que | Shengnan Wang | Mengyuan Wei | Yulin Fang | Tingting Ma | Xiaoyu Wang | Xiangyu Sun
Saccharomyces cerevisiae is the earliest domesticated fungus, researched deeply and widely used fungus. When used in food fermentation, Saccharomyces cerevisiae has an important influence on the quality, flavor, and aroma of products. Future developments will focus on enhancing flavor diversity, increasing production efficiency, sustainability, and product consistency, as well as improving the fermentation characteristics by using advanced technologies. Saccharomyces cerevisiae is an ideal substrate for synthetic biology research, usually used in the production of lactic acid, terpenes, steroids, vaccines, etc., which helps to reduce production cost, shorten the production cycle, improve production capacity, and has a very broad application prospect. In addition, in the field of environmental protection, biofuel ethanol is one of the promising and popular fuels with potential for energy and environmental security. However, there are major challenges for Saccharomyces cerevisiae that use lignocellulosic biomass as feedstock to produce biofuel ethanol.
Show more [+] Less [-]Drivers behind consumers' intent to purchase deodorized soy milk Full text
2024
Jingyi Zhou | Yeon Ho Shin | Seung Eun Jung | Lingyan Kong
Soy milk, rich in vitamin D and calcium, is a common alternative to dairy milk. However, its distinct 'beany off-flavor' has limited its acceptance, particularly in Western countries. A new technique employing preformed 'empty' V-type starch has been introduced to scavenge this off-flavor, aiming to promote soy milk consumption. The purpose of this study was to identify predictors of consumers' purchase intention of 'empty' V-type starch deodorized soy milk, particularly among college students. In this cross-sectional study, 105 college students were surveyed by a validated survey instrument that measures their perceptions of sensory quality, healthiness, price, environmental friendliness, food safety, and purchase intention of a novel product – 'empty' V-type starch deodorized soy milk. Additionally, demographic data were gathered to understand any correlations between these factors and the students' willingness-to-purchase of the deodorized soy milk. From the results, more than 80% of the participants expressed a positive attitude toward the 'empty' V-type starch-deodorized soy milk. The two dominant drivers behind their purchasing decision were Sensory Quality and Environmental Concern. Accordingly, it is crucial to highlight the improved sensory profile and the environmental friendliness of this soy milk product in order to achieve marketing success.
Show more [+] Less [-]Controlled atmosphere effects on postharvest quality and antioxidant capacity of blue honeysuckle (Lonicera caerulea L.) Full text
2024
Jinli Qiao | Liangchuan Guo | Junwei Huo | Dejian Huang | Yan Zhang
Changes in the quality of blue honeysuckle fruit following exposure to air or controlled atmospheres (CA1: 20% O2 and 20% CO2; CA2: 5% O2 and 20% CO2; CA3: 5% O2 and 10% CO2) were investigated. The 'Lanjingling’ blue honeysuckle was stored at a temperature of −1 °C for a duration of 28 d. An elevated concentration of CO2 led to a reduction in fruit weight loss, ethanol content, and respiration rate, while simultaneously increasing the epicuticular wax coverage index, firmness, TSS, ascorbic acid, polyphenols, and antioxidant capacity. Notably, treatment with high levels of carbon dioxide (20% CO2) led to an approximately 150% increase in total anthocyanin content compared to control conditions. Additionally, it was observed that reducing the oxygen content from 20% to 5% had a detrimental effect on the antioxidant capacity of blue honeysuckle during storage. Specifically, there were decreases of 10.4%, 16.8%, and 6.7% in DPPH, ABTS, and FRAP, respectively. The respiration rate is increased by treatment with 5% O2 and 5% CO2, which may result in accelerated senescence of blue honeysuckle. After 28 d, the treatment resulted in a respiration rate that was 1.49 times higher than the control. Hence, it can be deduced that maintaining a controlled atmosphere containing 20% O2 and 20% CO2 can be deemed an effective method of blue honeysuckle for prolonging storage life and safeguarding its bioactive components.
Show more [+] Less [-]Gastrointestinal digestion fate of Tremella fuciformis polysaccharide and its effect on intestinal flora: an in vitro digestion and fecal fermentation study Full text
2024
Xiangyang Zhu | Jing Su | Lan Zhang | Fan Si | Dapeng Li | Yang Jiang | Chen Zhang
In this work, the gastrointestinal digestive outcome of Tremella fuciformis polysaccharide (TFP) was examined using in vitro simulated experiments, together with its effect on the intestinal microbiota. TFP did not significantly alter during the stage of oral digestion, according to an in vitro digestion investigation. Nevertheless, glycosidic connections of TFP were broken throughout the intestinal and stomach digesting phases, which resulted in the dissociation of macromolecular aggregates, a marked rise in decreasing sugar content (CR), as well as a drop in molecular weight (Mw). Additionally, microbial community analysis following fecal fermentation in vitro indicated that TFP might control the alpha and beta diversity of gut microbiota and change the genus- and phylum-level community composition. It increased the abundance of beneficial bacteria including Megasphaera, Phascolarctobacterium, and Bacteroides, and suppressed the growth of harmful bacteria like Escherichia-shigella and Fusobacterium, thus contributing to maintaining gut homeostasis. These results suggested that TFP could have a positive impact on health through enhancing the gut microbiota environment, giving a theoretical basis for its use as a prebiotic.
Show more [+] Less [-]Microfluidization of tender coconut water and its impact on spoilage enzymes and physicochemical properties Full text
2024
P. S. Sruthi | A. Vanmathi Mugasundari | Shubham Nimbkar | Jeyan Arthur Moses | Vadakeppulpara Ramachandran Sinija
In this study, microfluidization was explored to inactivate autolytic spoilage enzymes (polyphenol oxidase, PPO, and peroxidase, POD) that significantly impact the nutritional and sensory qualities of tender coconut water (TCW). TCW was treated at three different pressure levels (70, 140, and 210 MPa) and five different number of passes/cycles (3, 5, 7, 9, and 11). The highest percentage reduction was obtained in the case of PPO (~61% in the 11th pass, at 210 MPa), while for POD, ~45% reduction was achieved in the 9th pass, at 70 MPa. The impact of different treatment conditions on the physicochemical properties of TCW, such as color, turbidity, total soluble solids (TSS), pH, titratable acidity, total phenolic content (TPC), and protein content was assessed. The pH and TSS remained unaffected; whereas, turbidity showed an increase with treatment intensity from 2.59% ± 0.14% (untreated) to 8.62% ± 0.39% (30,000 psi, 11 passes), and the highest color difference was observed for this sample (ΔE = 4.61 ± 0.018). Furthermore, TPC and antioxidant activity showed minimal changes upon treatment. Overall, the findings of this research provide new insights into the application of microfluidization for the processing of thermally sensitive products such as TCW, extending their shelf life without any additives and providing a clean label solution.
Show more [+] Less [-]Gut microbiota-associated metabolites in metabolic diseases and their impact from food processing Full text
2024
Aohuan Huang | Qingping Wu | Pongpol Thanuphol | Larissa Leandro da Cruz | Zhiqing Xie | Mengfei Chen | Fen Zhang | Zhenjun Zhu | Yu Ding
Gut microbiota-associated metabolites can be synthesized endogenously or derived from dietary nutrients and host compounds. Among them, alkaloids, terpenes, and flavones originating from edible and medicinal foods have attracted remarkable interest recently and play crucial roles in metabolic diseases. The efficacy of these metabolites is susceptible to dietary intervention, especially after food processing. Therefore, this review comprehensively summarizes the different sources of common gut microbial metabolites, including microbial self-synthesis, biodegradation of exogenous substances (mainly dietary nutrients), and participation in host metabolism. In addition, the latest studies on novel metabolites such as alkaloids, terpenoids, and flavonoids are discussed, and their action mechanisms on metabolic diseases are elaborated. How food processing impacts dietary nutrients and their metabolites is carefully examined, as well as their effects on disease modification. These insights could contribute to a deeper understanding of the mechanisms by which diet efficacy helps prevent metabolic diseases, particularly through gut microbial metabolites.
Show more [+] Less [-]Changes in the physicochemical and volatile profiles during the winemaking of Marselan in the Eastern Foot of Helan Mountain, China Full text
2024
Lei Fang | Ningli Qi | Yajun Li | Tinghui Chen | Xiao Gong
Marselan wine, one of the most important wines in the Ningxia Hui Autonomous Region of China, has attracted much attention due to its unique quality. This study focused on determining and analyzing the changes in volatile flavor compounds and antioxidant activity during different stages of Marselan winemaking. A total of 40 volatile aroma compounds were identified by headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS). Among these compounds, ethyl hexanoate, isoamyl acetate, ethyl formate, ethyl acetate, ethyl butanoate, ethyl octanoate, 3-methyl-1-butanol, ethanol, and 2-methyl-1-propanol showed significant increases after fermentation. Flavonoid and phenol contents in Marselan wine samples also significantly increased after fermentation, demonstrating high antioxidant capacity. Principal component analysis (PCA) successfully distinguished the fruit juice processing stage, alcohol fermentation stage, and malolactic fermentation stage, while the malolactic fermentation stage and wine stable stage could not be distinguished, This indicates that the formation of aroma profiles primarily occurs during the malolactic fermentation stage. The study successfully established flavor fingerprints of samples from different stages of Marselan wine production based on the detected volatile compounds.
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