Mechanism and Clinical Observation of Effect of Growgx Yeast Fermentation Product Extract on Photo-aged HFF-1 Cells

[Objectives]To explore the effect of the extract of Growgx yeast fermentation product on ultraviolet A(UVA)-induced photo-aging of human skin fibroblasts(HFF-1)and its specific mechanisms from the level of cell biology,and discussed the application of the Growgx yeast fermentation product extract for skin aging.[Methods]A photo-aging model of HFF-1 cells was induced by UVA radiation meter,and it was given different concentrations of Growgx for intervention.The proliferation activity of the HFF-1 cells was detected with MTT method,and their migration and invasion ability was measured by scratch test.The SOD,HYP and MDA levels were detected with corresponding kits.After oxygen infusion apparatus assisted facial skin administration,the repair of the skin was observed through the VISIA skin tester.[Results]The survival rate of HFF-1 cells was reduced significantly by UVA with an irradiation dose of 10.8 J/cm2(P<0.05),while Growgx significantly increased their survival rate(P<0.001)and sped up the repair of damaged cells.Growgx promoted the production of SOD(P<0.05),reduced the level of MDA(P<0.05),and increased the level of HYP(P<0.05).Growgx effectively inhibited UVA-induced photo-aging of HFF-1 cells.The mechanism may be related to accelerating cell damage repair,up-regulating SOD and HYP expression levels,and reducing MDA expression level.The clinical observation showed that Growgx effectively improved skin spots and pores,making the skin smoother and more delicate.[Conclusions]Growgx can effectively fight against photo-aging caused by ultraviolet rays,and can significantly improve skin wrinkles.

Isolation and identification of Starmerella davenportii strain Do18 and its application in black tea beverage fermentation

The objective of this study was to isolate and identify a yeast strain from the kombucha beverage and evaluate its potential as a novel starter in beverage fermentation in vitro.Starmerella davenportii Do18 was characterized for its cholesterol reduction;growth at different conditions such as temperatures(25,30,37 and 42◦C),low pH(1.2,1.5,2.03.0,and 7.0),bile salts(0%,0.25%,0.5%,1%and 2%)high-sucrose stress(2%,10%,20%,40%and 60%);and in-vitro survival in gastric and intestinal environments.Results showed that the yeast strain has a cholesterol-lowering capacity of 45%±2%,grew at temperature of 37◦C and is resistant to pH 1.5,2%bile and 40%sucrose solution,could survive in simulated gastric and intestinal environments.The physicochemical characteristics of the fermented beverages were also evaluated,which indicated that the yeast has pH reduction capacity and can produce organic acids and volatile compound such as 2-phenylethanol.Furthermore,the fermented beverage also has high total phenolics and flavonoids content and showed great antioxidant and antimicrobial activities.Therefore,the findings of this research provide strong evidence that S.davenportii Do18 has good fermentation properties,can be a potential starter in food and beverage fermentation.

面包防腐剂对酵母发酵力的影响研究

面包防腐剂丙酸钙、山梨酸钾、脱氢乙酸钠及其复合防腐剂对面包防腐效果明显,被广泛应用到面包工业中。采用浮水法研究单一和复合面包防腐剂对酵母发酵力的影响。研究结果发现,面包防腐剂对酵母的发酵力有不同程度的抑制作用,防腐剂添加量越大,抑制作用越大,部分复合防腐剂对酵母的发酵力抑制作用也比单一防腐剂大。由于防腐剂影响酵母发酵力和面团的发酵体积,对面包的烘焙品质有很大的副作用,在面包工业中,在保证防腐剂对面包防腐效果的同时,应适量添加防腐剂,以降低防腐剂对酵母发酵力的影响,提高面包烘焙品质。

Fermented Spirulina products with Saccharomyces and non- Saccharomyces yeasts:Special reference to their microbial,physico-chemical and sensory characterizations

Innovative products produced from various sources through fermentation processes have been a resurgence of interest.This study was designed to determine the performance of fermented Spirulina (FS) products by three different yeast species including Debaryomyces hansenii ,Kluyveromyces marxianus and Saccharomyces cerevisiae and investigate the microbial,physicochemical and sensory characteristics of products.The results showed that the increase in yeast cell number was around 3 log after 48 h fermentation in Spirulina medium without additional carbon source.Protein bands with a molecular weight of ∼51 kDa seemed less visible and bands 14–22 kDa disappeared after 48 h fermentation by K.marxianus showed strong hydrolysis of proteins during fermentation.The amino acid compositions of the three kinds of FS were different also compared to unfermented Spirulina (unFS).Glutamic acid,methionine,lysine,isoleucine and valine became more dominant in FS samples.According to GC–MS analysis,there was a decrease in the concentration of pyrazine,ketone and aldehyde compounds of FS compared to unFS.The flavor notes of “seaweed”,“cardboard”,“earthy/muddy” and “cereal/straw” were found to be the highest in unFS than in FS detected by panelists during sensory evaluations.FS by K.marxianus is highly characterized as having the lowest “seaweed” and “umami” flavor attributes and higher “fermented” and “rose” attributes.Finally,the current study revealed that the potential of Spirulina biomass to be a suitable substrate for yeasts and fermentation of Spirulina with different yeast species led to different kinds of products.