Process Optimization for Production of Persimmon Wine with Lower Methanol

Persimmon wine has various nutritional elements and high commercial potential. However, the high content of methanol, which is derived from the fruit's pectin, always hinders persimmon wine production. To reduce the methanol level in the wine, the effects of persimmon cultivar, starter, pectinase, and pretreatment methods were investigated via single-factor and orthogonal experiments. The persimmon cultivar 'MaoKui' was finally used throughout the study owing to its lowest pectin concentration (24.5 g/kg). The best treatment conditions against the persimmon pulp were pectinase (0.04 g/kg) at 30 °C for 4 h, then boiled at 115 °C for 15 min before fermentation started. The optimized fermentation conditions for wine production were pectinase (0.03 g/kg), 250 mg/kg starter (BO213 and SPARK with equal amounts), at 28 °C for 6 d. The obtained wine had 77.7 mg/L methanol and a 68.4% raw juice yield. The fruit wine had 111.4 mg/L methanol and a 90.6 sensory evaluation score. Forty-nine volatile aromas were identified. Ethyl acetate content was the highest, followed by 3-methyl-1-butanol, 2,3-butanediol, and lactate ethyl ester. The persimmon wine had a unique style with transparent color, elegant aroma, and pure taste.

Bioactive Components of Lycium barbarum and Deep-Processing Fermentation Products

Lycium barbarum, a homology of medicine and food, contains many active ingredients including polysaccharides, polyphenol, betaine, and carotenoids, which has health benefits and economic value. The bioactive components in Lycium barbarum exhibit the effects of antioxidation, immune regulation, hypoglycemic effects, and vision improvement. Recently, the development of nutrition and health products of Lycium barbarum has been paid more and more attention with the increase in health awareness. A variety of nutrients and bioactive components in wolfberry can be retained or increased using modern fermentation technology. Through fermentation, the products have better flavor and health function, which better meet the needs of market diversification. The main products related to wolfberry fermentation include wolfberry fruit wine, wolfberry fruit vinegar, and lactic acid fermented beverage. In this review, the mainly bioactive components of Lycium barbarum and its deep-processing products of fermentation were summarized and compared. It will provide reference for the research and development of fermented and healthy products of Lycium barbarum.

Enhancement of Human Epidermal Cell Defense against UVB Damage by Fermentation of Passiflora edulis Sims Peel with Saccharomyces cerevisiae

The processing of Passiflora edulis Sims results in large amounts of wasted peel resources and environmental pollution. In order to improve the utilisation of natural plant resources and economic benefits, this study uses Saccharomyces cerevisiae to ferment Passiflora edulis Sims peel to obtain Passiflora edulis Sims peel fermentation broth (PF). The content of active substances in unfermented Passiflora edulis Sims peel water extract (PW) and PF is then determined, as well as their in vitro antioxidant capacity. The protective effects of PF and PW on UVB-induced skin inflammation and skin barrier damage in human immortalised epidermal keratinocytes (HaCaT) cells (including cell viability, ROS, HO-1, NQO1, IL-1β, IL-8, TNF-α, KLK-7, FLG, AQP3 and Caspase 14 levels) are investigated. Studies have shown that PF enhances the content of active substances more effectively compared to PW, showing a superior ability to scavenge free radical scavenging and antioxidants. PW and PF can effectively scavenge excess intracellular ROS, reduce the cellular secretion of pro-inflammatory factors, regulate the content of skin barrier-related proteins and possibly respond to UVB-induced cell damage by inhibiting the activation of the PI3K/AKT/mTOR signalling pathway. Studies have shown that both PW and PF are safe and non-irritating, with PF exploiting the efficacy of Passiflora edulis Sims peel more significantly, providing a superior process for the utilisation of Passiflora edulis Sims waste. At the same time, PF can be developed and used as a functional protective agent against ultraviolet damage to the skin, thereby increasing the value of the use of Passiflora edulis Sims waste.

Effect of Hop Varieties and Forms in the Hopping Process on Non-Alcoholic Beer Quality

The aim of this study was to determine how the hopping technique affects the quality of non-alcoholic beer (NAB). A series of NABs were brewed and tested for basic physicochemical characteristics, profiles of selected volatile compounds, and microbial contamination. The brewing process yielded 13 experimental groups of beers, all of which had an ethanol content of <0.5%v/v. Among the batches brewed with ‘Marynka’ hops, the pellet form was found to provide the highest concentrations of hop-derived volatile compounds, whereas in the ‘Magnum’ groups, the extracts and whole hops proved superior. Humulene and caryophyllene were the primary volatiles in terms of quantity. All the brews were contamination-free—no microbes other than yeast cells were detected. Their microbiological purity was also supported by an assay of beer-defect indicators (volatile compounds), which only showed low levels of acetaldehyde, 1-propanol, 2-methylbutanol, and 3-methylbutanol. The hopping technique deployed was found not to affect the physicochemical parameters of NABs, but did have a significant impact on their volatile compound profile.

Two Laminaria japonica Fermentation Broths Alleviate Oxidative Stress and Inflammatory Response Caused by UVB Damage: Photoprotective and Reparative Effects

UVB radiation can induce oxidative stress and inflammatory response in human epidermal cells. We establish a UVB-induced damage model of human immortalized epidermal keratinocytes (HaCaT) to explore the protective and reparative effects of Laminaria japonica on UVB-damaged epidermal inflammation after fermentation by white Ganoderma lucidum (Curtis) P. Karst and Saccharomyces cerevisiae. Compared with unfermented Laminaria japonica, fermented Laminaria japonica possesses stronger in vitro free radical scavenging ability. Laminaria japonica white Ganoderma lucidum fermentation broth (LJ-G) and Laminaria japonica rice wine yeast fermentation broth (LJ-Y) can more effectively remove excess reactive oxygen species (ROS) in cells and increase the content of the intracellular antioxidant enzymes heme oxygenase-1 (HO-1) and NAD(P)H quinone oxidoreductase 1 (NQO-1). In addition, fermented Laminaria japonica effectively reduces the content of pro-inflammatory factors ILs, TNF-α and MMP-9 secreted by cells. The molecular research results show that fermented Laminaria japonica activates the Nrf2 signaling pathway, increases the synthesis of antioxidant enzymes, inhibits the gene expression levels of pro-inflammatory factors, and alleviates cellular oxidative stress and inflammatory response caused by UVB radiation. Based on the above results, we conclude that fermented Laminaria japonica has stronger antioxidant and anti-inflammatory activity than unfermented Laminaria japonica, possesses good safety, and can be developed and used as a functional inflammation reliever. Fermented Laminaria japonica polysaccharide has a more slender morphological structure and more rockulose, with better moisturizing and rheological properties.

Flavor Formation in Chinese Rice Wine (Huangjiu): Impacts of the Flavor-Active Microorganisms, Raw Materials, and Fermentation Technology

Huangjiu (Chinese rice wine) has been consumed for centuries in Asian countries and is known for its unique flavor and subtle taste. The flavor compounds of Huangjiu are derived from a wide range of sources, such as raw materials, microbial metabolic activities during fermentation, and chemical reactions that occur during aging. Of these sources, microorganisms have the greatest effect on the flavor quality of Huangjiu. To enrich the microbial diversity, Huangjiu is generally fermented under an open environment, as this increases the complexity of its microbial community and flavor compounds. Thus, understanding the formation of flavor compounds in Huangjiu will be beneficial for producing a superior flavored product. In this paper, a critical review of aspects that may affect the formation of Huangjiu flavor compounds is presented. The selection of appropriate raw materials and the improvement of fermentation technologies to promote the flavor quality of Huangjiu are discussed. In addition, the effects of microbial community composition, metabolic function of predominant microorganisms, and dynamics of microbial community on the flavor quality of Huangjiu are examined. This review thus provides a theoretical basis for manipulating the fermentation process by using selected microorganisms to improve the overall flavor quality of Huangjiu.

Changes in the Concentration of Carbonyl Compounds during the Alcoholic Fermentation Process Carried out with Saccharomyces cerevisiae Yeast

The aim of the study was to determine the influence of the source material and the applied S. cerevisiae strain on the concentrations of carbonyl fractions in raw spirits. Acetaldehyde was the most common aldehyde found, as it accounted for 88-92% of the total amount of aldehydes. The concentration of acetaldehyde in maize, rye and amaranth mashes was highly correlated with fermentation productivity at a given phase of the process, and reached its highest value of 193.5 mg/l EtOH in the first hours of the fermentation, regardless of the yeast strain applied. The acetaldehyde concentration decreased over the time with the decreasing productivity, reaching its lowest value at the 72nd hour of the process. The final concentration of acetaldehyde depended on the raw material used (ca 28.0 mg/l EtOH for maize mashes, 40.3 mg/l EtOH for rye mashes, and 74.4 mg/l EtOH for amaranth mashes). The effect of the used yeast strain was negligible. The overall concentration of the analyzed aldehydes was only slightly higher: ca 30.3 mg/l EtOH for maize mashes, 47.8 mg/l EtOH for rye mashes, and 83.1 mg/l EtOH for amaranth mashes.

Systematic Engineering of Escherichia coli for d-Lactate Production from Crude Glycerol

Crude glycerol resulting from biodiesel production is an abundant and renewable resource. However, the impurities in crude glycerol usually make microbial fermentation problematic. This issue was addressed by systematic engineering of Escherichia coli for the production of d-lactate from crude glycerol. First, mgsA and the synthetic pathways of undesired products were eliminated in E. coli, rendering the strain capable of homofermentative production of optically pure d-lactate. To direct carbon flux toward d-lactate, the resulting strain was endowed with an enhanced expression of glpD-glpK in the glycerol catabolism and of a heterologous gene encoding d-lactate dehydrogenase. Moreover, the strain was evolved to improve its utilization of cruder glycerol and subsequently equipped with the FocA channel to export intracellular d-lactate. Finally, the fed-batch fermentation with two-phase culturing was carried out with a bioreactor. As a result, the engineered strain enabled production of 105 g/L d-lactate (99.9% optical purity) from 121 g/L crude glycerol at 40 h. The result indicates the feasibility of our approach to engineering E. coli for the crude glycerol-based fermentation.