Physicochemical properties,antioxidant activity and inhibition of α‐glucosidase of a novel fermented pepper (Capsiccum annuum L.) leaves‐based vinegar

The aim of this study was to utilise by‐product pepper leaves for vinegar production due to its nutritional value. Changes in physicochemical and functional properties in four main process from raw material (leaves) to lactic acid (juice), alcohol (wine) and acetic acid (vinegar) fermentations were evaluated and compared. Their nutritional compositions were significantly different and particularly the wine and vinegar had higher total phenol content and their expanded diversity than the juice and then leaves (P < 0.05). Difference in values for phenolic compound was highly correlated with their α‐glucosidase inhibitory (AGI) and antioxidant capacities in DPPH and superoxide radical scavenging and reducing power assays (r = 0.919–0.981); vinegar ≥ wine > juice > leaves. Especially, AGI activity was greatly enhanced depending on fermentation steps beyond expectation. Thus, these data confirm that pepper leaves is a good functional source and the vinegar fermentation improved the functionality in stages.     

树莓叶黄酮类物质提取工艺条件优化

采用单因素实验和正交实验,研究微波提取法提取树莓叶中的黄酮类物质最佳提取工艺条件,结果表明：微波提取法提取树莓叶中总黄酮的最佳提取条件为：提取时间3min,料液比1g：40mL,乙醇体积浓度50％,功率250W,得率为5．81％。     

硼对不同硼效率甘蓝型油菜嫁接植株下部叶片矿质养分含量的影响

土壤培养条件下,研究缺硼对不同硼效率甘蓝型油菜品种及其相互嫁接植株下部叶片硼及其它矿质养分含量的影响。结果表明,缺硼条件下,硼高效油菜品种青油10号（QY10）下部叶片硼含量最高,低效品种Bakow（Ba）最低,嫁接植株介于高效品种与低效品种之间。推断甘蓝型油菜下部叶片硼含量受根系（砧木品种）和地上部（接穗品种）共同影响。硼对油菜下部叶片其它矿质元素影响的受控部位不完全相同,缺硼对氮、磷、钙和锌的影响主要取决于地上部,与根系关系相对较小,对钾的影响主要由根系决定,而对镁、锰、铁、铜的影响不明确,可能受地上部和根系共同控制。     

Analysis of chemical compounds and toxicological evaluation of Forsythia suspensa leaves tea

To determine the compositions of Forsythia suspensa leaves tea (FSLT) and its safety, the chemical compounds were analysed with some methods, and the toxicity was evaluated in Kunming mice and Wistar rats. The results showed that FSLT contained rich flavonoid, lignans, triperpene acids, amino acids, and mineral elements. In the acute toxicity study, none of the mice died, and no obvious poisoning symptoms were observed after 14 days in mice at the dose of 15 mg/g·body weight (bw) FSLT; in the sub-chronic toxicity, no abnormal or dead rat was found at the dose of 1, 3, and 10 mg/g·bw during 90 days feeding administration; there was no significant difference in bw and food consumption; no significant differences were found in each hematology and serum biochemistry parameter and organ/body weight ratio comparing with the control experimental group. The results revealed that the FSLT has low or no toxicity via oral administration. Therefore, FSLT is very suitable and safe to be used as a new resource food.     

云南复烤烟叶不同地点醇化过程中可培养真菌种群分析

为较全面的了解云南复烤烟叶在不同地点醇化过程中真菌多样性,挖掘其中的有益微生物,提高烟草醇化品质,以复烤烟叶为试验材料,利用18S rDNA克隆测序技术,系统研究了其醇化过程中可培养真菌的种群结构。结果表明,醇化过程中,复烤烟叶叶面真菌数量除曲靖仓库在6月有所上升外,其余各地均随着醇化的进行而逐渐下降,其中曲靖和楚雄两地非常接近,元江最少;通过形态特征及18S rDNA鉴定,烟叶叶面真菌包括根霉属真菌、青霉属真菌、曲霉属真菌等24个真菌属（种）。不同地点,不同时期烟叶叶面真菌的数量、种类及优势种群不尽相同,而根霉属真菌始终为优势种群。     

杜仲叶发酵饮料的研制

以杜仲叶提取液、白糖、牛奶为主要原料,采用对比实验、正交实验找出最佳发酵工艺条件和配方,通过酵母菌、醋酸菌、乳酸菌发酵,开发出营养丰富,且具有一定疗效作用的天然保健饮料。     

沉香叶黄酮类化合物的提取及其抗氧化活性

以沉香叶为原料,采用溶剂浸提的方法提取黄酮类化合物,利用1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）法、2,2-联氮-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐（2,2’-azinobis-(3-ethylbenzthiazoline-6-sulphonate),ABTS）法和铁氰化钾还原法测定提取物的抗氧化能力。在单因素试验的基础上,选择乙醇体积分数、提取温度、液料比为自变量,以黄酮类化合物得率为响应值,采用响应面法优化提取工艺。结果表明,沉香叶黄酮类化合物提取的最优工艺为乙醇体积分数60%、提取温度60 ℃、液料比20∶1（mL/g）、提取时间3 h,在此条件下黄酮类化合物的得率为2.88%（m/m）。抗氧化实验结果表明,沉香叶黄酮提取物具有较强的清除DPPH自由基和ABTS＋·能力,其半数有效质量浓度值分别为（1.14±0.08） mg/mL和（0.23±0.01） mg/mL。     

The availability of soluble oxalates in stir‐fried silver beet (Beta vulgaris var. cicla) leaves eaten with yoghurt

Silver beet (Beta vulgaris var. cicla) leaves contain oxalates, and the addition of yoghurt, a food rich in calcium, to stir‐fried leaves was investigated as a way of reducing the soluble oxalate content. Fourteen participants ingested 115 g stir‐fried silver beet leaves with or without standard yoghurt and low‐fat yoghurt, respectively. Stir‐fried silver beet leaves contained 209.1 ± 0.1 mg of total oxalates per meal fresh weight (FW) and 109.2 ± 0.1 mg of soluble oxalates per meal FW. The proportion of soluble oxalates was reduced from 52% to a mean of 30% of the total oxalates when standard yoghurt or low‐fat yoghurt was added. The mean absorption of oxalate was determined by measuring the output of oxalate in the urine over a 6‐h period following ingestion of the meals. The mean absorption of oxalate from stir‐fried silver beet leaves was 2.41%, which reduced to 1.10% and 0.89% when consumed with standard yoghurt and low‐fat yoghurt, respectively.