Using Kombucha fermentation liquid as main raw material, and it was mixed with Dendrobium officinale, wolfberry and chrysanthemum extract to prepare Kombucha beverage. Some physicochemical indexes of the three Kombucha beverage were determined and sensory evaluation was conducted, and the antioxidant, hypoglycemic and hypolipidemic activities in vitro were studied. The results showed that the highest sensory score of D. officinale Kombucha beverage was 82.20, and its p H, sugar and acidity were 3.34, 6.67 °Bx and 1.69 g/L, respectively. The contents of total phenol,total flavonoids and total polysaccharide were 145.76 mg（gallic acid equivalent, GAE）/ml, 11.34 mg（rutin equivalent, RE）/ml and 1 622.13 mg/ml,respectively. In vitro biological activity of D. officinale Kombucha beverage was the optimal. The scavenging rates of 2,2’-diazide（3-ethylbenzothiazolin-6-sulfonic acid） diamiammonium salt（ABTS）, 1,1-diphenyl-2-trinitrophenylhydrazine（DPPH） and hydroxyl radical were 97.85%, 95.26% and75.06%, respectively. The maximum absorbance value of iron reduction capacity was 0.784. The inhibition rate of α-glucosidase activity was98.17%. The binding rates of sodium glycholate and sodium taurocholate were 59.23% and 58.15%, respectively. D. officinale Kombucha had good taste and functionality, which provided ideas for the development of Kombucha series products.

Kombucha is a sweet-sour beverage made with tea and sucrose as fermentation substrates and symbiotic culture of bacteria and yeasts（SCOBY） as fermentation agent by static fermentation. This article reviews the research progress of Kombucha, including its fermentation microorganisms and production technology. The characteristics of Kombucha traditional fermentation technology and new fermentation technology are summarized in this review. Meanwhile,the paper suggests that sugar-acid ratio can be used as an important physicochemical parameter to determine the end point of fermentation. This article aims to provide ideas for the large scale production of Kombucha and the development of series products.

本研究采用气质联用技术(Gas Chromatograph-Mass Spectrometer,GC-MS)解析黑青稞超临界CO2萃取物中的脂肪酸组分,共鉴定出8种脂肪酸,其中棕榈油酸占27.42％,亚油酸占60.73％,不饱和脂肪酸占比超过90％.通过超临界CO2萃取制备的黑青稞全谷粒油脂品质优良,具备开发成功能性脂肪酸产品的潜力.

黄酒是我国传统发酵食品,具有健康保健功效.该文综述了黄酒健康功效和生物活性物质解析及有关配料和工艺优化等方面的进展,提出了深入发掘黄酒中功效成分及其作用机理、强化黄酒健康功效的策略与路径,以期为提升黄酒品质和研发新品种提供依据.

以青海柴达木黑枸杞为研究材料,对其超临界CO2萃取物,采用超高效液相色谱-质谱联用技术和PeakView色谱工作站拟合进行分析,并通过二级质谱解析和紫外光谱及质谱数据比对,阐明其中的黄酮组分及其结构.共鉴定出黑果枸杞果的超临界CO2萃取物中含有13种黄酮类化合物(7种黄酮醇苷元及黄酮醇苷,3种二氢黄酮醇苷元,2种黄酮苷元和1种二氢黄酮苷元),包括芦丁、槲皮素-3-β-葡萄糖醛酸苷、金丝桃苷即槲皮素-3-O-吡喃半乳糖苷、二氢槲皮素、二氢异鼠李素、二氢山柰酚、槲皮素、芹菜素、橙皮素、苜蓿素、山柰酚、异鼠李素和山柰素,其中橙皮素和苜蓿素在黑果枸杞成分研究中未被发现过.

采用超临界CO2萃取技术获得沙棘果油,通过超高效液相色谱-质谱联用技术和Peakview色谱工作站拟合、二级质谱解析和紫外光谱及质谱数据比对,确定有关化合物的组成和分子结构.共鉴定出沙棘果超临界CO2萃取物中含有18种黄酮类化合物,其中包括8种黄酮醇苷元及黄酮醇苷,3种二氢黄酮醇苷元及二氢黄酮醇苷,5种黄酮苷元及黄酮苷,1种二氢黄酮苷元和1种黄烷醇苷,其中芹菜素-6-C-葡萄糖苷-8-C-木糖苷、儿茶素-7-吡喃葡萄糖苷、苜蓿素、紫罗兰素、刺槐黄素这5种黄酮首次被发现存在于沙棘中.

In the field of probiotic properties,tolerance to high temperature,bile salt and gastric acid,antibacterial activities to harmful bacteria and resistance to different antibiotics were chosen to research on Bacillus coagulaus 13002.The results showed that the survival rate of strain was 72.3％ after 10 minutes under 80 ℃.Under the conditions of bile salt for 12 h and gastric acid of pH2.0 for 4 h,the survival rate were 69.8％ and 40.0％ respectively.The strain had certain antibacterial activities to Staphylococcus aureus and Escherichia coli,with the inhibition zone of 13.650 and 14.367 mm respectively.It also resisted penicilin,streptomycin and achromycin in different MIC which were 0.781 mg/mL,0.391 mg/mL and 0.039 mg/mL Bacillus coagulans 13002 possessed great probiotic properties.

内生菌普遍存在于植物类食品资源中,不仅对宿主植物的生长、代谢、抗逆等起着重要调节作用,而且对植物食品中功效成分合成产生重要影响.将功效性的植物内生菌开发成制剂,用于提升食品资源品质、提高农产品产量、改良土壤、保障食品安全等,并通过调控植物内生菌菌相以丰富或提升植物资源中功效成分,具有广阔的应用前景.

黄酒是中国传统保健养生佳品,具有丰富的生物活性.深入发掘黄酒中功效成分,在传统黄酒的基础上进一步强化黄酒产品的功效性,是今后黄酒产业发展的一个重要趋势.

The reproduction characteristics of 343 sows in six different breeding groups were analyzed to estimate the crossbreeding parameters. The results indicated that the ovulation rate and the weights of uterus and ovary are mainly determined by the additive genetic effects while the nonadditive genetic effects play an important role in embryonal traits and litter performance. The heterosis effects in the first litter are larger than those in the second litter because of heterosis x environment interaction. The results also showed the existence of a highly significant maternal heterosis effect on the fertility traits of sows.

研究了雪莲菌来源酵母的益生特性.鉴定了分离自雪莲菌的7株优势酵母菌,分别是酿酒酵母K11,发酵毕赤酵母K14,汉逊德巴利酵母H2,涎沫假丝酵母D3,近平滑假丝酵母菌D4,马克斯克鲁维酵母Z17,单孢酿酒酵母K21.经过模拟胃液的耐酸性,模拟肠液和耐胆盐试验,筛选出K11、K14、H2和Z17为潜在益生特性的酵母菌株.试验结果表明:4株酵母菌株显示较好的耐酸性和胃肠转运耐受性以及耐受胆盐的能力,其中Z17能耐受2.0％的胆盐,K11和K14能耐受1.8％的胆盐浓度,H2能耐受1.5％的胆盐;4株酵母菌株在培养条件下以及非生长的静息细胞状态都表现出降解胆固醇活性,其中菌株K11降解活性最好,培养48h和静息细胞12h胆固醇的降解率这65％和57％.4株酵母均具有DPPH自由基和羟自由基清除能力.

Aroma of Chinese steamed bread (CSB) is one of the important parameters that determines the overall quality attributes and consumer acceptance. However, the aroma profile of CSB still remains poorly understood, mainly because of relying on only a single method for aroma extraction in previous studies. Therefore, the objective of this study was to determine the volatile aroma compounds of five different samples of CSB using three different aroma extraction methods, namely solid-phase microextraction (SPME), simultaneous distillation-extraction (SDE), and purge and trap (P&T). All samples showed a unique aroma profile, which could be attributed to their unique microbial consortia. (E)-2-Nonenal and (E,E)-2,4-decadienal were the most prevalent aromatic compounds revealed by SDE, which have not been reported previously, while ethanol and acetic acid proved to be the most dominant compounds by both SPME and P&T. Our approach of combining three different aroma extraction methods provided better insights into the aroma profile of CSB, which had remained largely unknown in previous studies.

我国是蔬菜生产大国,蔬菜产业是农业的重要组成成分.本文阐述蔬菜发酵加工的意义,分析泡菜、腌菜、酱菜和发酵蔬菜汁饮料4种蔬菜发酵加工制品的研究现状,并展望蔬菜发酵加工的未来发展方向.

Aroma of Chinese steamed bread (CSB) is one of the important parameters that determines the overall quality attributes and consumer acceptance. However, the aroma profile of CSB still remains poorly understood, mainly because of relying on only a single method for aroma extraction in previous studies. Therefore, the objective of this study was to determine the volatile aroma compounds of five different samples of CSB using three different aroma extraction methods, namely solid-phase microextraction (SPME), simultaneous distillation-extraction (SDE), and purge and trap (P&T). All samples showed a unique aroma profile, which could be attributed to their unique microbial consortia. (E)-2-Nonenal and (E,E)-2,4-decadienal were the most prevalent aromatic compounds revealed by SDE, which have not been reported previously, while ethanol and acetic acid proved to be the most dominant compounds by both SPME and P&T. Our approach of combining three different aroma extraction methods provided better insights into the aroma profile of CSB, which had remained largely unknown in previous studies.

Biodiesel has attracted considerable attention as an environmentally friendly alternative fuel. Lipase is the most popular enzyme for biodiesel production and immobilization has been deployed to improve enzyme stability and reusability. Exploitation of high activity lipase is the key point for biodiesel production. Whole-cell biocatalysts have been applied in the biosynthesis of biodiesel and bioimprinting is a promising approach for enzyme performances improvement. In this study, based on the S. cerevisiae cell-surface display system with α-agglutinin as anchor, a whole-cell biocatalyst of codon-optimized Rhizopus oryzae lipase was constructed and bioimprinted with oleic acid, gaining 5-fold increase on enzymatic activity in the alcoholysis of soybean oil to biodiesel. Moreover, the conversion of FAME was up to 95.45±2.73% after a 27-h reaction at 60°C. Our results indicated that combining bioimprinting with yeast display technique to prepare whole-cell biocatalyst could result in potential enzymes for bioconversion of biodiesel in organic solvents.

半乳糖激酶基因(GAL1)启动子是酿酒酵母(Saccharumyces cerevisiae)表达外源蛋白的高效诱导性启动子,其表达效率受到GAL4的调控和半乳糖的诱导,改变酵母的GAL基因型有助于提高外源蛋白的表达水平,但重组GAL菌株的菌株特性仍需要进一步研究以确保蛋白表达的稳定性.本研究分别对敲除了不同GAL1和插入不同GAL4基因拷贝数的重组GAL基因型酵母进行了生长发酵性能和遗传稳定性研究.结果表明,重组菌株的GAL基因型在传代过程中较为稳定,没有发生回复突变和遗传霉素(G418)和博来霉素(Zeocin)抗性恢复的情况;与对照原始MS-1酵母相比,重组菌株(SG1、DG115、DPG65和GQ21)的生长性能在葡萄糖培养基中的生物量略有下降.与半乳糖诱导培养基(yeast peptone galactose,YPG)相比,GAL1基因的敲除在甘油培养基(yeast peptone galactose glycerin,YPGL)中对酿酒酵母半乳糖利用的影响更为显著.其中,在YPG和YPGL培养基内,对照MS-1、SG1、DG115和DPG65利用完所有半乳糖分别需要20、20、20、26、20、44、44和68 h,而GQ21均无法利用半乳糖.GAL基因的敲除和插入没有影响酿酒酵母的热致死温度,原始菌株和重组菌株皆为54℃.本研究将为工业利用酵母表达系统大规模、低成本生产重组蛋白提供研究基础.

固定化酶是酵母表面展示技术的1个重要应用方向。本文应用食品级酵母展示表达系统进行表达,成功获得具有生物活性且固定在酿酒酵母细胞表面的β-1,3-1,4-葡聚糖酶,并测定其酶学性质。结果表明,与分泌表达的自由酶相比,展示表达的β-1,3-1,4-葡聚糖酶的酶学性质发生了改变。其最适温度为60℃,热稳定性增强。50℃保温3 h,对酶活几乎没有影响。60℃保温1 h后的酶活为初始酶活的129.2%。随着该温度下保温时间的延长,酶活迅速下降,保温3h后的酶活为初始酶活的64.6%。70℃保温1 h,酶活增加到初始酶活的109.2%;1 h后酶活开始下降;70℃保温3 h后残留酶活仅为初始酶活的35.8%。展示表达的β-1,3-1,4-葡聚糖酶最适pH为6.0,在pH 4~7范围内酶的稳定性较好。

Bacterial diversity of Tibetan kefir grains from different areas in China was investigated by culture-independent metagenomic methods, and comprehensive taxonomic profiling was done. Eleven genera and their proportions were found in all the 4 samples, and they were Lactococcus (40.93–72.02 %), Lactobacillus (10.50–47.89 %), Acetobacter (4.50–14.15 %), Shewanella (1.73–7.58 %), Leuconostoc (0.64–0.84 %), Pseudomonas (0.07–0.63 %), Streptococcus (0.02–0.22 %), Acinetobacter (0.05–0.12 %), Pelomonas (0–0.01 %), Dysgonomonas (0–0.01 %), and Weissella (0–0.01 %). Shewanella, Acinetobacter, Pelomonas, Dysgonomonas, Weissella, and Pseudomonas were the first time found in Tibetan kefir grains. α-Diversity analysis showed that they varied in bacterial richness and diversity while β-diversity showed that the variation of genera composition among sampling sites was small. Principal component analysis showed that Lactobacillus, Lactococcus, and Acetobacter were the main genera which caused the diversity. This study provided theoretical basis for further investigation and application of Tibetan kefir grains.