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Daqu is a typical multi-enzyme and multi-microbes fermentation starter of traditional Chinese liquor. The culture-independent molecular method has become a general method for the study of the Daqu microbial community. To determine the most suitable DNA extraction method of Daqu samples, the effects of different DNA extraction methods on Daqu genomic DNA extraction and amplicon libraries were evaluated. In this study, four DNA extraction methods were selected for the extraction of microbial DNA from two kinds of Daqu. Combined with DNA extraction quality, qPCR quantitative results, Illumina Miseq sequencing results of bacterial 16S rRNA gene, and fungal ITS gene amplicon library, the effects of different extraction methods of Daqu genomic DNA were evaluated. The comprehensive analysis of DNA yield and microbial biomass showed that the DNA yield of the SDS-based extraction method was higher than that of the kit extraction method, and the DNA yield of the in-situ SDS-based extraction method was as high as 5.46 x 104 ng/g, but the DNA purity was low. The qPCR quantitative results of the SDS-based extraction method were 101 - 6 orders of magnitude higher than those of the kit extraction method, and the microbial biomass of the washing-pretreatment plus SDS-based extraction method was the highest, which was 101-3 orders of magnitude higher than that of the in-situ SDS-based extraction method. Whereas the microbial biomass of the DNA extraction kit was the lowest, with only 102-4of the Shannon diversity index among amplicon libraries showed that different DNA extraction methods had significant differences among fungal ITS amplicon libraries, but no significant differences among bacterial 16S rDNA amplicon libraries. The Shannon index of the fungal amplicon library of the washing-pretreated samples were higher than that of the in-situ treated samples. By comparing the operational taxonomic units (OTU) with significant differences among the amplicon libraries, it could be seen that most of the OTUs in the bacterial 16S rDNA amplicon library had differences in abundance, but most of them could be detected in different DNA extraction methods. However, among the fungal ITS amplicon libraries, most OTUs showed a similar trend between different DNA extraction methods, indicating that the DNA extraction method had a significant effect on the extraction of some fungal microbial genomes, and the washing-pretreatment was beneficial to the extraction of fungal genomic DNA. Compared with the four DNA extraction methods, the washing-pretreatment plus SDS-based extraction method was the most suitable for the quantitative and community structure analysis of Daqu microorganisms. [ABSTRACT FROM AUTHOR]

In this study, microcapsule beads‐0–3‐layers (M‐0–3 indicates microencapsulated beads with 0, 1, 2, and 3 layers) were prepared, their properties were measured and characterized, and the effects of M‐0–3 on solid‐state fermentation were investigated. The results showed that in a liquid environment, the releasing glucoamylase activities of M‐0–3 were 55.77%, 47.67%, 45.85%, and 42.87% in 360 h, respectively. In the solid environment, the reducing sugar production efficiency of M‐0–3 was 29.84%, 27.72%, 19.16%, and 15.93% in 15 days, respectively. Adding M‐0–3 improved the alcohol and reduced sugar content while decreasing the residual starch content of the Jiupei, indicating that adding M‐0–3 was beneficial to the solid‐state fermentation of Baijiu. Solid‐state fermentation simulation experiments illustrated that microcapsule beads play a positive role in the production of Baijiu, enhancing raw material utilization and yield of Baijiu production. [ABSTRACT FROM AUTHOR]

BACKGROUND: Baijiu brewing adopts the solid‐state fermentation method, using starchy raw materials, Jiuqu as saccharifying fermenting agent, and distilled spirits made by digestion, saccharification, fermentation and distillation. In the late stages of solid‐state fermentation of Baijiu, the reduced activity of glucoamylase leads to higher residual starch content in the Jiupei, which affects the liquor yield. The direct addition of exogenous glucoamylase leads to problems such as the temperature of the fermentation environment rising too quickly, seriously affecting the growth of microorganisms. RESULTS: To solve the problem of reduced activity of glucoamylase in the late stage of solid‐state fermentation of Baijiu, microcapsule beads (M‐B) based on microcapsule emulsion were prepared and the effect of M‐B on solid‐state fermentation of Baijiu was investigated. The results showed that the release of M‐B before and after drying was 53.27% and 25.77% in the liquid state (120 h) and 29.84% and 22.62% in the solid state (15 days), respectively. Adding M‐B improved the alcohol by 0.33 %vol and reducing sugar content by 0.51%, reduced the residual starch content by 1.21% of the Jiupei, and had an insignificant effect on the moisture and acidity of the Jiupei. CONCLUSION: M‐B have excellent sustained‐release properties. The addition of M‐B in solid‐state fermentation significantly increased the alcohol content, reduced the residual starch content of Jiupei, ultimately improving the starch utilization rate and liquor yield of Baijiu brewing. The preparation of M‐B provides methods and approaches for applying other active substances and microorganisms in the brewing of Baijiu. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background and Objectives: Mashing temperature is important during beer brewing processes. Qingke malt was a new material whose application in the beer industry holds significant importance for the beer industry and agriculture development in the Qinghai–Tibet Plateau. The objective of this study was to investigate the effects of mashing temperature on the physicochemical parameters, fermentation capacity, and antioxidant capacity of Qingke wort. Findings: Ethanol production and the real degree of fermentation decreased with increasing the temperature—S, while the real extract increased with increasing the temperature—S. A lower temperature—S proved to be more advantageous for the fermentation capacity of Qingke wort. In addition, a positive correlation between reducing power and the temperature—P and a negative correlation between the 2,2′‐azinobis‐(3‐ethylbenzothiazoline‐6‐sulfonate) free radical scavenging activity and the temperature—S were found. Conclusion: The fermentation capacity of Qingke wort was obtained the best when the temperature—P was 50°C and the temperature—S was 60°C. The antioxidant capacity of Qingke wort was satisfactory; the best was obtained when the temperature—P was 45°C and the temperature—S was 60°C. Significance and Novelty: This is the first study to investigate the mashing characteristics of Qingke wort under different mashing temperatures. The results show that β‐glucan content was abundant in Qingke wort and was positively correlative with the temperature—S. [ABSTRACT FROM AUTHOR]

The glucoamylase@ZIF‐8 was prepared using ZIF‐8 material as the carrier in this study. The preparation process was optimized by response surface methodology, and the stability of glucoamylase@ZIF‐8 was determined. The material was characterized by scanning electron microscopy, X‐ray diffraction, and Fourier transform infrared spectroscopy. The results showed that the optimum preparation process of glucoamylase@ZIF‐8 was 1.65 mol 2‐methylimidazole, 5.85 mL glucoamylase, 33°C stirring temperature, 90 min stirring time, and 84.0230% ± 0.6006% embedding rate. At 100°C, the free glucoamylase completely lost its activity, whereas the glucoamylase@ZIF‐8 still had a retained enzyme activity of 12.0123% ± 0.86158%; at pH 3–6, the highest activity of glucoamylase@ZIF‐8 was 95.9531% ± 0.96181%, and about 80% of glucoamylase activity could be retained under alkaline conditions. When the ethanol concentration was 13%, the retained enzyme activity was 7.9316% ± 0.19805%, significantly higher than free enzymes. The Km of glucoamylase@ZIF‐8 and free enzyme were 1235.6825 and 80.317 mg/mL, respectively. Vmax was 0.2453 and 0.149 mg/(mL min), respectively. The appearance, crystal strength, and thermal stability of glucoamylase@ZIF‐8 were improved after optimization, and they had high reusability. [ABSTRACT FROM AUTHOR]

Pit mud (PM) is the main component of Baijiu (traditional Chinese liquor), and its microorganisms are the primary sources of the aroma of Chinese strong-flavor Baijiu (SFB). Enrichment plays an important role in the selection of functional microorganisms in PM. Herein, the PM of SFB was submitted to six rounds of enrichment using clostridial growth medium (CGM), and changes in the metabolite accumulation and microbiota composition were evaluated. Based on the metabolite production and microbiota composition, the enrichment rounds were classified as the acclimation stage (round 2), main fermentation stage (rounds 3 and 4), and late fermentation stage (rounds 5 and 6). Species within the genus Clostridium dominated in the acclimation stage (65.84–74.51%). In the main fermentation stage, the dominant microbial groups were producers of butyric acid, acetic acid, and caproic acid, which included Clostridium (45.99–74.80%), Caproicibacter (1.45–17.02%), and potential new species within the order of Oscillataceae (14.26–29.10%). In the late stage of enrichment, Pediococcus dominated (45.96–79.44%). Thus, the main fermentation stage can be considered optimal for the isolation of acid-producing bacteria from PM. The findings discussed herein support the development and application of functional bacteria by bioaugmentation, and contribute to improving the quality of PM and SFB production. [ABSTRACT FROM AUTHOR]

Glucoamylase was often used in the brewing industry but was unstable to several environmental factors and reacted quickly to produce fermentable sugar, which limited its applications. Microencapsulation could effectively overcome the drawbacks. This study evaluated the feasibility of the preparation of glucoamylase microcapsules (GM) using W/O/W complex coacervation‐freeze‐drying method. The parameters of the microcapsules were optimized by the response surface optimization design: core‐wall ratio at 1:1, wall‐material concentration at 8%, and coagulation time for 20 min. Under current condition, the final microencapsulation efficiency reached 85.64 ± 1.60%. Glucoamylase could be slowly released for more than 96 h in the liquid state, and could react slowly for more than 336 h in the solid state. The optimized GM were incubated for 1 h, and the relative enzyme activity was better than that of free glucoamylase under high temperature conditions. The water capacity, solubility, morphology, differential scanning calorimetry, and Fourier transform infrared spectroscopy were conducted. Glucoamylase exhibited good sustained release characteristics. The microcapsules were more resistant to environmental stimuli and showed stronger robustness after optimization. Practical Application: Saccharification enzymes are often used in the winemaking industry, and direct addition will cause the fermentation process to heat up too quickly, resulting in the inactivation of microorganisms and saccharification enzymes, affecting the efficiency of saccharification enzymes. Therefore, microcapsules are used to encapsulate the saccharification enzyme, and its efficacy is slowly released for a long time during the fermentation process. [ABSTRACT FROM AUTHOR]

To explore the reuse of brewer's grains and develop novel Chinese fermented sausage with healthy characteristics, the influences of the addition of plant protein‐dietary fiber composite gel and Lactiplantibacillus plantarum XC‐3 on Chinese dry fermented sausages were studied. The results showed that the addition of Lactiplantibacillus plantarum XC‐3 reduced the pH, water activity, total volatile base nitrogen, residual nitrite, and thiobarbituric acid of fermented sausages while increasing the hardness, springiness, chewiness, and total volatile flavor substances of the fermented sausages (p < 0.05). In all, 69 volatile flavor substances were identified in the fermented sausages. The addition of plant protein‐dietary fiber composite gel resulted in a significant increase in the acids and esters content of fermented sausages (p < 0.05), but the increase in gel addition resulted in a decrease in the total content of volatile flavor substances in fermented sausages (p < 0.05) (still much higher than in the fermented sausage without gel addition). Novelty impact statement: The addition of plant protein‐dietary fiber gel and inoculation with Lactiplantibacillus plantarum XC‐3 effectively reduced harmful carcinogens in fermented sausages while promoting the production of flavor substances and adding some new ones. The novel fermented sausage developed in this study is delicious and healthy, which provides theoretical support for the development of healthy foods in the meat processing industry. [ABSTRACT FROM AUTHOR]

Moisture content (MC) is an important indicator to monitor the quality of Longjing tea during processing; therefore, it becomes more critical to develop digital moisture content detection methods for processing. In this study, based on a micro-near infrared (NIR) spectrometer and portable colorimeter, we used Longjing tea under the full processing process as the research object, and used competitive adaptive reweighted sampling (CARS) and a principal component analysis (PCA) to extract characteristic bands of spectral data as well as the principal component reduction processing of the color difference and glossiness data, respectively, combined with sensor data fusion technology to establish a quantitative prediction model of the partial least squares (PLS) for the moisture content of Longjing tea. The PLS quantitative moisture content prediction model, based on middle-level data fusion, obtained the best prediction accuracy and model robustness, with the correlation coefficient of the prediction set ( R p ) and the root mean square error of prediction (RMSEP) being 0.9823 and 0.0333, respectively, with a residual predictive deviation (RPD) of 6.5287. The results indicate that a data fusion of a micro NIR spectrometer and portable Colorimeter is feasible to establish a quantitative prediction model of the moisture content in Longjing tea processing, while multi-sensor data fusion can overcome the problem of a low prediction accuracy for the model established by single sensor data. More importantly, data fusion based on low-cost, fast, and portable detection sensors can provide new ideas and methods for real-time online detection in Longjing tea in actual production. [ABSTRACT FROM AUTHOR]

Changes in the content and morphology of residual starch in Zaopei during strong‐flavor Baijiu fermentation are investigated. The results show that the residual starch content increases through the Baijiu production and that the residual starch content of distiller's grains (DGS) is the highest (76.35%). The crystalline structure of starch changes from A‐type (raw grain starch) to B + V‐type (Zaopei, Hongzao, Mianzao, DGS). The upper Zaopei starch has the typical diffraction peaks of B + V‐type (7.4°, 12.8°, 14.9°, 19.7°, 19.6°, 26.6°) and retains the typical diffraction peaks of A‐type (17.0°, 22.2°). The intermediate and bottom Zaopei starch has the typical diffraction peaks of B + V‐type (7.4°, 12.8°, 16.9°, 19.7°, 20.7°, 26.6°) and loses the typical diffraction peaks of A‐type. With the progression of Baijiu production, the gelatinization temperature and enthalpy of starch increase, while the water‐holding capacity, freeze‐thaw stability, solubility, and swelling power decrease. The above results show that the starch complex is the primary form of residual starch in strong‐flavor Baijiu. [ABSTRACT FROM AUTHOR]

Glucoamylase is one of the most widely used enzymes in industry, but the development background and existing circumstances of industrial glucoamylase were not described by published articles. CiteSpace, a powerful tool for bibliometric, was used to analyze the past, existing circumstances, and trends of a professional field. In this study, 1820 Web‐of‐Science‐indexed articles from 1991 to 2021 were collected and analyzed by CiteSpace. The research hotspots of industrial glucoamylase, like glucoamylase strain directional improvement, Aspergillus niger glucoamylase, glucoamylase immobilization, application of glucoamylase in ethanol production, and "customized production" of porous starch, were found by analyzing countries, institutions, authors, keywords, and references of articles. Practical applications: The research progress of glucoamylase with industrial potential was analyzed by CiteSpace, and a significant research direction of glucoamylase with industrial potential was found. This is helpful for academic and corporate audiences to understand the current situation of glucoamylase with industrial potential and carry out follow‐up works. [ABSTRACT FROM AUTHOR]

Summary: Oxygen is contributing to the deterioration of the beer and shortening the shelf‐life of the packaged product. The effect of dissolved oxygen (DO) on oxidative and structural characteristics of protein in beer during forced ageing was examined. Results showed that increased DO decreased obviously protein content in beer, and further reduced antioxidant activities of beer and lipid transfer protein 1 (LTP1). Meanwhile, the increase of DO decreased significantly the free thiol groups content and enhanced the disulfide bonds level in beer and LTP1. Results from circular dichroism, surface hydrophobicity and zeta‐potential illustrated that the increase of DO dramatically changed the secondary and tertiary structure of LTP1 with the decrease in the surface hydrophobicity, α‐helix and β‐turn contents, and the increase in the random coil and negative zeta potential. These results indicated that increased DO could damage the structure of LTP1 and had a negative impact on oxidative stability of beer. [ABSTRACT FROM AUTHOR]

Abstract Very high-gravity (VHG) worts (24 °P) supplemented with wheat gluten hydrolysates (WGH) and their ultrafiltration fractions (Mw > 1 kDa and <1 kDa fractions) were used to evaluate their effects on physiological activity and ethanol fermentation of brewer's yeast. The results demonstrated that WGH and their ultrafiltration fractions supplementations could obviously improve the biomass and viability of yeast, and further enhance the sugar utilization and ethanol production under VHG fermentation. Supplementation with Mw < 1 kDa fraction exhibited the maximum biomass (6.90 g/L dry cell), sugar utilization (79.79%) and ethanol concentration (11.88%, v/v) during VHG fermentation. Meanwhile, the addition of Mw < 1 kDa fraction significantly decreased the plasma membrane permeability and intracellular reactive oxygen species (ROS) accumulation, and increased the mitochondrial membrane potential in cells during VHG fermentation. Moreover, Mw < 1 kDa fraction supplementation caused the highest accumulations of intracellular trehalose and glycerol, which were 12.10% and 31.22% higher than the control, respectively. These results illustrated that WGH (especially Mw < 1 kDa fraction) addition was an economic and efficient method to improve physiological activity and ethanol fermentation of brewer's yeast in VHG worts. Highlights • WGH and their ultrafiltration fractions were obtained as nitrogen sources of yeast. • WGH supplementation changed nitrogen metabolism of yeast during VHG fermentation. • Biomass and ethanol production were increased by WGH addition under VHG condition. • Physiological activity of yeast was improved by WGH addition under VHG condition. • Trehalose and glycerol in yeast accumulated by WGH addition under VHG condition. [ABSTRACT FROM AUTHOR]

Highlights • WGH supplementation improved the tolerance to osmotic and ethanol stress in yeast. • WGH supplementation improved ethanol production of yeast under VHG fermentation. • WGH addition caused the decrease in ROS and the increase in membrane integrity. • WGH addition increased the levels of intracellular glycerol and trehalose in yeast. • 40% ethanol fraction from WGH showed the best bioactivity for yeast cells. Abstract Wheat gluten hydrolysates (WGH) and their fractions (0%, 20% and 40% ethanol fractions) obtained on XAD-16 were used to examine their effects on multiple stress tolerance and ethanol fermentation performances of yeast during very high-gravity (VHG) fermentation. Results showed that WGH and their fractions supplementations increased significantly osmotic/ethanol stress tolerance, growth and vitality of yeast cells. Supplementation with 40% ethanol fraction resulted in 46.54% and 35.01% of increase in cell membrane integrity, and 42.59% and 21.79% of reduction in intracellular ROS level under osmotic and ethanol stress conditions, respectively. Moreover, WGH and their fractions supplementations also increased physiological activity and ethanol yield of yeast cells under VHG fermentation, and 40% ethanol fraction supplementation caused the maximum biomass and ethanol production during VHG fermentation. These results suggested that WGH supplementation was an efficient and convenient method for improvement of yeast cells with enhanced multiple stress tolerance and ethanol fermentation performances. [ABSTRACT FROM AUTHOR]

Summary: Three kinds of beers with different degrees of ageing were used to examine their nonvolatile small molecules by a metabonomics approach based on ultra performance liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry (UPLC‐Q‐ToF‐MS/MS). Results showed that a total of 2114 compounds were detected in forced‐aged beers with the positive mode of UPLC‐Q‐ToF‐MS/MS. There was a clear separation among three groups of beers with different degrees of ageing in principal component analysis (PCA) model. Sixteen potential metabolite markers related to beer oxidative stability were identified by orthogonal partial least‐squares discriminate analysis (OPLS‐DA). Results from the changes in the spectrum also indicated that some new compounds formed in beer during forced ageing. Thus, the proposed metabonomics approach is a powerful tool to give a fully understanding the ageing process of beer based on the identification of the markers related to oxidative stability. [ABSTRACT FROM AUTHOR]

Abstract: Lys and Leu were generally considered as the key amino acids for brewer's yeast during beer brewing. In the present study, peptide Lys–Leu and a free amino acid (FAA) mixture of Lys and Leu (Lys + Leu) were supplemented in 24 °P wort to examine their effects on physiological activity and fermentation performance of brewer's yeast during very high‐gravity (VHG) wort fermentation. Results showed that although both peptide Lys–Leu and their FAA mixture supplementations could increase the growth and viability, intracellular trehalose and glycerol content, wort fermentability, and ethanol content for brewer's yeast during VHG wort fermentation, and peptide was better than their FAA mixture at promoting growth and fermentation for brewer's yeast when the same dose was kept. Moreover, peptide Lys–Leu supplementation significantly increased the assimilation of Asp, but decreased the assimilation of Gly, Ala, Val, (Cys)2, Ile, Leu, Tyr, Phe, Lys, Arg, and Pro. However, the FAA mixture supplementation only promoted the assimilation of Lys and Leu, while reduced the absorption of total amino acids to a greater extent. Thus, the peptide Lys–Leu was more effective than their FAA mixture on the improvement of physiological activity, fermentation performance, and nitrogen metabolism of brewer's yeast during VHG wort fermentation. [ABSTRACT FROM AUTHOR]

As a promising adjunct material to beer brewing, Qingke (hulless barley) can provide sufficient hydrolyzable starch and rich nutrients for beer brewing. In this study, the effect of Qingke addition on the physicochemical properties, antioxidant capacity and flavor composition of beer was evaluated. The results showed that the addition of Qingke reduced the turbidity (25.03 NTU) and color (19.48 EBC) of the beer. The Qingke adjunct beer was enriched with more bioactive substances, which also made the Qingke adjunct beer exhibit better antioxidant capacity. The addition of Qingke resulted in elevated levels of higher alcohols (68.29 mg/L) and esters (76.71 mg/L). The addition of Qingke decreased the amount of volatile acid in the beer (5.84 mg/L). This study has guiding significance for the application of Qingke in beer industry. [Display omitted] • Proposal of a new adjunct material for beer brewing--Qingke. • Qingke can effectively boost the endogenous antioxidant power of beer. • The effect of Qingke on the composition of beer flavor substances was revealed. [ABSTRACT FROM AUTHOR]

Abstract: To increase use range of distillers’ hops, and to retain the original nutrients and characteristics of distillers’ hops, inlet temperature and outlet temperature and sample concentration has been studied of yield and rehydration rate with orthogonal design, quadratic polynomial stepwise regression, and response surfaces. The results showed that optimum conditions of spray drying is when inlet temperature is 162°C, outlet temperature is 84°C, sample concentration is 3.4g/200ml, feed temperature is 70 ∼ 80°C, fan power is 95%, fluid flow rate is 0.25L/h. In this condition, product yield is 56.432%, rehydration rate is 183.647%. [Copyright &y& Elsevier]

BACKGROUND RESULTS CONCLUSION Fern root starch has a high percentage of amylose and has great potential for application in the field of slow‐digesting foods. Clarifying the effect of treatment conditions on fern root starch is key to achieving industrialized production of fern root resistant starch. In the present study, fern root starch was treated by the autoclave‐enzymatic method with pullulanase, glucoamylase and mixed enzyme.The content of resistant starch in fern roots treated with mixed enzyme was the highest (24.07 ± 1.11%), which was approximately 320% times that of the native starch, had the best water‐holding capacity (151.08%), vital transparency and freeze–thaw stability. By contrast, the solubility, swelling and viscosity were lower than natural starch. In addition, mixed enzyme shows a denser structure, and the crystal form changes from C‐type to V‐type, with a high relative crystallinity and significantly enhanced thermal stability.After mixed enzyme combined with autoclave treatment, the content of resistant starch in fern root was greatly increased. The modified starch molecules did not produce new functional groups, which made the crystal structure of starch molecules more compact, and resistance to enzymatic hydrolysis and high temperature thermal stability were significantly enhanced. This provides a positive reference for further in‐depth study of fern root starch, improvement of utilization value, development and innovation of new food health products, and diabetes treatment. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Highlights • Wheat gluten hydrolysates (WGH) and soy protein hydrolysates (SPH) were prepared. • WGH and SPH exhibited significant yeast growth and fermentation promoting activity. • The bioactivity was not linear with the degree of hydrolysis and addition amount. • Bioactivity of hydrolysates was related to the molecular structure characteristics. • Glu, Leu, Lys and Arg in hydrolysates were responsible for their bioactivity. Abstract Wheat gluten hydrolysates (WGH) and soy protein hydrolysates (SPH) were used to examine their effects on the growth and fermentation performance of yeast during high-gravity fermentation. Results showed that both the kind and the addition amount of hydrolysates had significant impacts on the biomass, viability, fermentability and ethanol yield of yeast cells. Worts supplemented with WGH and SPH (with the hydrolysis time of 24 h and 12 h, and the addition amount of 1.0% and 0.1%, respectively) increased 5.5% and 12.6% of net cell growth, 0.3% and 1.1% of fermentability, and 19.3% (v/v) and 23.7% (v/v) of ethanol yields, respectively. All these results indicated that both hydrolysates were effective and preferential nitrogen sources for yeast growth and fermentation. The moderate molecular weight distribution, the complexity of nitrogen source and the higher hydrophilic and basic amino acids contents in hydrolysates might be responsible for their specific bioactivity. [ABSTRACT FROM AUTHOR]

The effects of wheat-gluten hydrolysates (WGH) and their ultrafiltration fractions on multiple-stress tolerance and ethanol production in yeast during very-high-gravity (VHG) fermentation were examined. The results showed that WGH and WHG-ultrafiltration-fraction supplementations could significantly enhance the growth and viability of yeast and further improve the tolerance of yeast to osmotic stress and ethanol stress. The addition of MW < 1 kDa fractions led to 51.08 and 21.70% enhancements in cell-membrane integrity, 30.74 and 10.43% decreases in intracellular ROS accumulation, and 34.18 and 26.16% increases in mitochondrial membrane potential (ΔΨ m ) in yeast under osmotic stress and ethanol stress, respectively. Moreover, WGH and WHG-ultrafiltration-fraction supplementations also improved the growth and ethanol production of yeast during VHG fermentation, and supplementation with the <1 kDa fraction resulted in a maximum biomass of 16.47 g/L dry cell and an ethanol content of 18.50% (v/v) after VHG fermentation.