云南元谋野生毛葡萄的生物学特性和酿酒特性分析

本试验调查了元谋野生毛葡萄(V.quinquangularis Rehd.)的生物学特性,并以欧亚种坦娜葡萄(tannat)为对照,进行常规指标、功能性成分和感官分析,以研完其酿酒特性.结果表明,元谋野生毛葡萄植株生长势强,花期4～5月,果期5-9月,果粒圆,果皮蓝黑色;野生毛葡萄酒的总酚和原花青素含量较高,酒体呈深紫红色,果香浓郁,酸度适宜,结构性强,但酒精度低.元谋野生毛葡萄是酿造红葡萄酒的特色原料,具有很大的开发潜力.     

云南及其他产区赤霞珠干红葡萄酒总酚和原花青素含量的测定与分析

采用福林-肖卡法和优化铁盐催化比色法分别对来自云南迪庆高海拔产区与山东、河北等低海拔产区的7个赤霞珠单品种干红葡萄酒样品进行了总酚和原花青素含量的测定与分析,研究高原地区葡萄酒的一些基本特征以及产地和环境因素(如紫外线,海拔高度)对葡萄酒中总酚和原花青素含量的影响。结果表明,来自云南迪庆产区的迪庆2#样品总酚和原花青素含量最高,分别为3313 mg/L和12.90 mg/mL,迪庆1#样品除与河北怀来1#的总酚含量差异不显著外,与其他样品均差异显著。由此得出,产地对葡萄酒总酚和原花青素含量影响显著,且环境因素如高海拔造成的紫外线辐射增强能促进酿酒葡萄的次生代谢,从而导致葡萄酒中总酚和原花青素含量的增加。     

Evaluation of antioxidant activity of ten compounds in different tea samples by means of an on-line HPLC–DPPH assay

Tea (Camellia sinensis), a well-known traditional beverage in China, has drawn growing attention due to its various benefits to health. In this study, an on-line assay of coupling high performance liquid chromatography separation with 1,1-diphenyl-2-picrylhydrazyl free radical reaction system (HPLC–DPPH) was applied to evaluate the antioxidant activity of different teas. Twelve main chromatographic peaks were detected in tea, and they were identified as gallic acid, 3-galloyl-quinic acid, theobromine, (−)-gallocatechin, (−)-epigallocatechin, caffeine, procyanidin dimer, (−)-epicatechin, (−)-epigallocatechin gallate, (−)-gallocatechin gallate, 1,2,6-tri-galloyl-glucose and (−)-epicatechin gallate by comparing their retention times and DAD spectra with standard compounds respectively or with reference to our previous study. DPPH assay showed that ten out of twelve investigated compounds have free radical scavenging activity, and their contents were determined or estimated. Trolox equivalent antioxidant capacities (TEACs) of the ten active components were also determined. EGCG was the most potent antioxidant with a TEAC value of 5.822. Catechin components were the major contributors to the antioxidant activity of tea; they decreased during tea fermentation and led to the reduction of antioxidant activity. Different tea samples were scientifically classified and their antioxidant activities were comprehensively evaluated by on-line HPLC–DPPH assays coupled with principal component analysis and hierarchical clustering analysis. The results indicated that the combination of the on-line HPLC–DPPH assay, principal component analysis and hierarchical clustering analysis could be suitable for the bioactivity assessment and variety characterization of tea and its derived products. Additionally, a simple and rapid method for simultaneous capture of chemical quantitative analysis and bioactivity evaluation by determining contents of the bioactive compounds was firstly established. This method could provide a comprehensive evaluation of tea.     

基于熵权的TOPSIS和聚类分析评价方法的发酵辣椒品种适用性研究

目的 通过对不同品种辣椒品质差异的研究,构建发酵辣椒原料加工适应性综合评价方法。方法 选取46个不同品种辣椒,测定了农艺性状、色泽、质构特性和辣度等指标,通过TOPSIS法和聚类分析对不同辣椒的品质指标进行分析,并评判辣椒品种的加工适应性。结果 不同品种辣椒果实重量、色泽、硬度、辣度差异较大;根据生产用发酵辣椒原料特性,通过熵权TOPSIS法对不同品种辣椒进行评价,综合得分显示朝天椒相似接近度最大的品种是23号万家红,为0.8200;小米辣相似接近度最大的品种是15号云南小米辣10号,为0.7322;是适宜工业化使用的发酵辣椒品种;聚类分析将46种辣椒分为4类,各类别间的差异与辣椒的加工适应性相关。结论 建立发酵辣椒原料综合评价方法,为选择发酵用辣椒品种提供理论依据,助力发酵辣椒加工产业发展。     

云南省主要辣椒品种活性成分及其加工适应性

目的 研究云南不同品种辣椒活性成分的差异,并讨论其加工适应性。方法 以49份云南辣椒材料为研究对象,测定不同辣椒材料中总黄酮、总酚、总生物碱、总皂苷、维生素C、降二氢辣椒碱、辣椒碱和二氢辣椒碱的含量,利用相关性分析、主成分分析法与聚类分析法进行综合评价。结果 主成分分析将8项活性成分指标综合为3个主成分,其累计方差贡献率为71.774%。经综合评价,得分前3位的辣椒品种分别是49号(小米辣,小米辣)、35号(川优19,干椒)、43号(晶翠,小米辣),具有较高的综合加工适应性。采用聚类分析方法可将49份云南辣椒材料分为3类。其中35号(川优, 19干椒)、43号(晶翠,小米辣)、48号(朝天椒,朝天椒)聚为一类,可用于提取辣椒碱、辣椒油树脂等产品。49号(小米辣,小米辣)为云南本土调味品企业泡制加工用小米辣,被单独聚为一类,综合得分最高,综合加工适应性最佳。结论 采用主成分与聚类分析作为评价辣椒加工适用性的统计学分析手段,能够有效区分不同辣椒品种的活性特征,对进一步开发云南地区的辣椒资源、评价其加工适用性有一定的指导意义。