The effects of bleached and unbleached rosemary oleoresins on light-sensitized oxidation of soybean oil

Bleached and unbleached forms of a rosemary oleoresin (RO) in stripped and nonstripped soybean oil behave both as antioxidant and prooxidant in a light-induced oxidative system. At 0.02 and 0.05% levels, RO had the greatest antioxidant activity, while at 0.01 and 0.5% levels it had the highest prooxidant activity in both stripped and nonstripped soybean oil. Treatment of both soybean oil systems with tertiary butylhydroquinone controlled light-induced oxidation of the oil better than did the oleoresin treatments. The prooxidant activity of the 0.5% RO level was probably due to an excess of prooxidant components being carried into the oil at that level, whereas the reduced antioxidant activity at 0.01% was probably due to the low initial level of active antioxidant components being added to the oil. Published as Journal Series No. 10072, Nebraska Agricultural Research Division, Department of Food Science and Technology, University of Nebraska, Lincoln, NE 68583-0919.     

水肥处理对辣椒保护地土壤pH值的影响

探讨辣椒保护地的水肥耦合效应,采用二次回归正交旋转组合设计,建立了灌水定额、氮肥和磷肥对辣椒保护地土壤pH值影响的数学模型。通过模型分析得出:在辣椒保护地土壤养分含量高和施肥量大的条件下,灌水定额、施氮和施磷对辣椒保护地土壤pH值影响的大小顺序为:灌水>施氮>施磷。大量施用氮肥可使土壤酸化,灌水和高量施磷可减弱酸化效应,灌水与施氮、施氮与高量施磷对土壤pH值表现为拮抗作用。维持保护地土壤pH值种植前后稳定的水肥措施:灌水定额为170.71 m3/(hm2.次),施氮量为235.98 kg/hm2,施P2O5为239.38 kg/hm2。合理的施肥和灌水,可以控制土壤的酸化。     

番茄红素的层析分离

以V(正己烷)∶V(丙酮)=1 5∶1 0的混合液为展开剂的硅胶薄层层析结果表明番茄红素油树脂中主要含有5种组分,番茄红素的Rf值为0 83;以V(正己烷)∶V(丙酮)=1 5∶1 0的混合液为洗脱剂,番茄红素油树脂经过硅胶柱层析分离,可得到w(番茄红素)=18 9%的番茄红素晶体产品;紫外可见光分光光度计检测结果表明,从番茄红素油树脂中还分离出β 胡萝卜素、叶黄素和玉米黄质。     

姜辣素的提制及抗氧化性能的研究

提出了姜渣分离纯化姜辣素的新工艺,并对姜辣素的性能进行了表征。通过测定体系的过氧化值(POV)和酸价(AV)变化,考察了姜辣素在油脂中的抗氧性能;探讨了温度、环境介质等因素对其抗氧效果的影响。     

Pungency threshold of capsaicin produced by in vitro culture of placental tissues of capsicum frutescens mill.

Production of capsaicin in free and immobilized placenta was compared in order to assess their capsaicin production ability. In immobilized placenta, maximum accumulation of capsaicin was on the 14th day of culture with a production of 2045 ug/culture, whereas in free placenta, the accumulation reached maximum on the 7th day (2050ug/culture). It was found that there was no significant difference between free and immobilized placenta in terms of capsaicin production, suggesting that immobilization is not necessary to enhance capsaicin accumulation in piacentai tissue. Pungency threshold of capsaicin produced in in vitro grown free piacentai tissues of Capsicum frutescens was done by Scoville heat units (SHU) method. Pungency analysis of capsaicin produced in free piacentai tissue showed that on day zero, pungency of tissue culture produced capsaicin (0.2267x10⁵ SHU) was comparable to standard natural capsaicin (0.222×10⁵ SHU), while on the 3rd day pungency of tissue culture produced capsaicin (0.3639×10⁵ SHU) was slightly lower than standard natural capsaicin (0.4415×10⁵ SHU).     

辣椒红色素纯化方法的研究

以辣椒油树脂为原料,重点研究了其纯化工艺.结果显示:用石油醚和pH10左右、浓度40%的丙酮溶液的混合液对辣椒油树脂进行萃取,萃取次数达到5次以上,即可得到较为优良的辣椒红色素产品.同时此法能有效地利用辣椒素成分,提高辣椒的利用率.     

陇东地区干红辣椒中辣椒红素的提取工艺研究

辣椒红素是一种重要的天然红色素,可从干红辣椒中提取得到。用浓度15％的氢氧化钠溶液除辣,采用不同有机溶剂对辣椒红素的提取工艺进行了比较研究。分别考察了丙酮、正己烷、乙酸乙酯以及乙酸乙酯与丙酮的混合溶剂对辣椒红素提取的影响,实验结果表明：正己烷为比较好的提取溶剂,在温度为80℃时提取4 h,可以从陇东地区辣椒中得到高产率、高色价、无异味的辣椒红素。     

超临界CO2萃取黑胡椒中有效成分的研究

用超临界CO2萃取技术,首先在低压、低温的条件下选择性萃取黑胡椒精油,进而在高温、高压及极性夹带剂的协同作用下,萃取富含胡椒碱的黑胡椒油树脂。另外,利用分子蒸馏技术纯化超临界CO2萃取的黑胡椒精油,得到适用于日化行业的无色、无辛辣感的挥发油,并通过GC-MS对比分析其香气成分。研究结果表明,超临界CO2萃取黑胡椒精油的较优条件为:萃取压力10MPa、萃取温度35℃、萃取时间1.5h,在该条件下产物得率为3.01%;超临界CO2萃取黑胡椒油树脂的最佳条件为:m(原料)∶m(体积分数95%食用乙醇)=2∶1、萃取压力30MPa、萃取温度50℃、萃取时间4h,在该条件下油树脂得率为7.88%,油树脂中胡椒碱质量分数为65.79%。     

分子包埋法制备姜油树脂微胶囊的研究

以姜为原料，经乙醇直接浸泡和索氏提取法获得的姜油树脂为心材，以β-环糊精和阿拉伯胶为壁材，经乳化、均质、喷雾干燥，制取姜油树脂微胶囊，并对其主要技术参数进行了测定。通过正交试验分析，以姜油树脂的包埋率为指标，确定了心壁材比、包接温度、搅拌时间、阿拉伯胶和β-环糊精比四个因素的最佳值，得出了姜油树脂微胶囊化的最佳工艺条件。