响应面法优化“紫娟”茶中花青素提取工艺的研究

利用响应面分析法(Response Surface Analysis,RSM)对紫娟茶中花青素的提取工艺进行了优化。在单因素试验基础上,根据中心组合(Box-Behnken)试验设计原理和响应面分析法选取试验因素与水平,采用三因素三水平的响应面分析法对各个因素的显著性和交互作用进行分析,优化紫娟茶中花青素提取工艺。结果表明,紫娟茶中花青素提取的最佳工艺条件为:采用酸性甲醇为提取溶剂,提取温度29℃,提取时间132 min,料液比1︰26;在此条件下浸提液中花青素的质量浓度可以达到5.94 mg/mL。     

响应曲面分析法优化葡萄籽原花青素提取工艺的研究

采用响应曲面分析法对葡萄籽原花青素的提取工艺进行优化。对提取率影响因素进行单因素分析后,以Box-Behnken设计(BBD)评价提取剂浓度、料液比、提取时间和提取温度4个因素显著性和交互作用的分析,得出葡萄籽原花青素的最佳提取条件为:丙酮浓度75%,料液比1∶10(w/v),时间44 min,温度51℃。在该条件下,葡萄籽原花青素提取率的预测值为2.90%,验证为2.88%,纯度为55.92%。     

六堡茶紫芽鲜叶花青素提取工艺优化研究

以六堡茶紫芽鲜叶为研究对象,结合超声辅助提取,使用响应面法分析超声温度、提取时间以及料液比对花青素提取效果的影响。以紫芽花青素含量为响应值,通过响应面试验优化花青素超声提取条件。结果表明,对花青素提取影响由大到小的因素依次为：料液比>提取时间>超声温度。最佳提取工艺为：超声温度60℃,提取时间13min,料液比1:12,此条件下测得六堡茶紫芽鲜叶花青素含量为：1701.29nmol/g,是普通绿芽的7倍。     

木薯叶提取液制备及其对甲鱼生长的影响

本研究优化了木薯叶提取液制备的条件,并且检测该提取液对甲鱼生长性能、血液化学指标的影响。试验首先对提取木薯叶的溶剂提取法进行工艺优化,确定最优提取条件,包括：溶剂浓度、料液比、提取温度、提取时间4个因素。其次将提取液经处理后加入甲鱼饲料中,通过分析检测甲鱼存活率、生长性能、饲料转化性能、机体营养组成、血液生化及免疫能力指标,来确定其对甲鱼生长的影响。试验结果表明,木薯叶提取制备的最优工艺为：乙醇浓度50％,料液比（mL/g)40 ∶ 1,提取温度70 ℃,提取时间2 h;通过对甲鱼饲养的研究,表明饲料中添加木薯叶提取液能提高甲鱼的生长速度,降低饲料系数,并能降低甲鱼机体内血糖、胆固醇、甘油三酯水平,以及降低血清丙二醛含量,从而提高了甲鱼的糖代谢、脂肪代谢和免疫能力。因此,本研究不仅首次将木薯叶提取液作为添加剂加入甲鱼饲料,同时也为木薯叶提取液作为天然低毒的饲料添加剂提供了理论依据。     

黑豆种皮中红色素的提取及稳定性研究

以黑豆种皮为原料提取红色素,对红色素的提取工艺和稳定性进行了研究.结果表明:以酸性乙醇为提取剂,在60℃条件下提取2h,方法简便、提取率高达17.36%;黑豆红色素对热、亚硫酸钠、蔗糖、苯甲酸钠以及部分金属离子较稳定,可用于功能食品添加剂、保健药物和化妆品等.     

草莓叶叶黄素循环组分超高效液相色谱分析

为建立草莓叶叶黄素循环组分超高效液相色谱(UPLC)的分析方法,优化草莓叶叶黄素循环组分的提取条件,建立适宜的UPLC测定方法,通过研究强光下各组分含量的变化规律进行验证,结果表明,以丙酮为提取剂,不经过皂化直接提取,采用C18色谱柱,以乙腈∶甲醇=9∶1为流动相,流速0.5 m L/min,波长445 nm,柱温30℃能较好地分离及测定草莓叶叶黄素循环各组分,方法快速稳定,检测时间仅需1.2 min。强光下,玉米黄质、叶黄素循环库和脱环氧化程度均明显升高而紫黄质下降,符合叶黄素循环调控规律,证实此方法可靠。可见,实验所建立的UPLC测定方法适合草莓叶叶黄素循环组分分析。     

蕹菜梗叶绿素浸提工艺的优化及其理化性质

利用单因子试验和正交试验探讨了蕹菜梗叶绿素的最佳浸提工艺,并对其理化性质进行分析。结果表明,蕹菜梗叶绿索的最佳浸提工艺为：乙醇浓度85％、料液比1：50、提取温度70℃、提取时间4h,其提取率为0．1957mg·g^-1;蕹菜梗叶绿素易溶于有机溶剂,但不溶于水,其可见光区的最大吸收波长为410nm,且具有较好的耐光和耐热性。     

响应面法优化海南可可豆中原花青素的提取工艺

本研究采用响应面分析法确定海南可可豆中原花青素提取的最佳工艺条件,对提取得率的影响因素进行单因素分析后,探讨料液比、乙醇浓度、提取时间和温度间的显著性影响和交互作用。结果表明：可可原花青素的最优提取工艺条件为乙醇浓度67%、料液比1∶20（g/mL）、提取时间88 min、提取温度76 ℃。此工艺条件下,可可原花青素提取得率为6.21%。此结果为海南可可豆的开发利用提供基础理论依据。     

紫芽茶树不同季节主要生化成分变化分析

以紫芽茶树武夷奇种C18-1的一芽二叶为试验材料,采用单因素分析优化茶树花青素总量的提取方法,并分析其不同季节主要生化成分差异。结果表明:溶剂浓度、浸提时间、浸提温度等因素对茶树花青素总量提取均有影响,本研究获得花青素最佳提取方法为:采用3%的盐酸乙醇溶液,在80℃条件下回流浸提1 h。水浸出物、咖啡碱、茶多酚、花青素及游离氨基酸含量均随季节不同而呈现不同的变化规律,且季节性差异显著;水浸出物、咖啡碱、游离氨基酸均在春季中含量最高,茶多酚和花青素均在夏季中含量最高。      

桔梗软糖制备工艺研究

以桔梗为原料,果胶和木薯淀粉为复合凝胶剂、白砂糖为甜味剂、柠檬酸为酸味剂,采用单因素和正交试验优化配方,通过感官评价和质构分析,对桔梗凝胶保健软糖进行工艺优化。得到最佳配方为:桔梗水提液质量浓度为0.3 g/mL,果胶与木薯淀粉的添加比例为6∶1,糖浓度60%,柠檬酸添加量0.3 g。最佳工艺为:果胶加入4倍水,木薯淀粉加入2倍水室温下分别溶胀30min,在95℃恒温水浴锅中将二者混合,加入桔梗提取液、甜味剂与酸味剂,浇注成型,35℃下干燥含水量为20%。采用该配方和工艺制成的软糖色泽亮丽,酸甜适口,口味独特,柔软而具有弹性,感官综合评分平均值为(95±1)分。     

黑甜玉米花青素提取方法研究及应用

本研究以甜玉米为材料,分别对化学、超声波、微波、酶法4种花青素提取方法进行优化,综合比较发现,微波提取方法的花青素吸光度值最大(1.072),花青素含量达到560 mg/kg,提取效果最佳,酶法辅助提取的方法不佳.对黑甜玉米杂交组合BS634×SP5029和W55×SD-4鲜子粒花青素组分分析发现,BS634×SP50...     

茶红素分离及稳定性研究

采用茶汤有机试剂萃取分离,并分别经过反相C_(18)柱层析纯化,制备出乙酸乙酯层、正丁醇层和酸性正丁醇层三部分茶红素。根据紫外可见光波扫描计算出色价,并研究了茶红素在不同条件下的稳定性。结果表明,30%、50%和70%甲醇梯度洗脱,纯化后3类茶红素液相检测发现无咖啡碱和茶黄素,仅有少量儿茶素杂质。纯化后色素色价分别为乙酸乙酯层128.04,正丁醇层91.04,酸性正丁醇层76.16。遮光处理,p H=3酸性条件,45℃以下贮藏,有利于茶红素的稳定性。     

Optimization of the ultrasound-assisted extraction of tryptophan and its derivatives from rice (Oryza sativa) grains through a response surface methodology

An analytical ultrasound-assisted extraction (UAE) technique has been optimized and validated for the extraction of tryptophan and its derivatives from rice grains. A Box–Behnken design in conjunction with a response surface methodology based on six factors and three levels was used to evaluate the effects of the studied factors prior to optimizing the UAE conditions. The significant (p < 0.05) response surface models with high coefficients of determination were fitted to the experimental data. The most significant (p < 0.0001) effect is the solvent-to-sample ratio while quadratic effects caused by temperature and solvent-to-sample ratio were of moderate importance (p < 0.05). The optimal UAE conditions were as follows: extraction time of 5 min, ultrasound amplitude of 30%, cycle of 0.7 s⁻¹, extraction temperature of 30 °C, 8% methanol in water as the extraction solvent at pH 3 and a solvent/solid ratio 5:1. The method validation ensured that appropriate values were obtained for the LOD, LOQ, precision and recovery. Furthermore, the method was successfully applied to the analysis of a number of rice samples of different varieties. It was demonstrated that this particular UAE method is an interesting tool for the determination of tryptophan and tryptophan derivatives in rice grain samples.     

高花青素甘薯的研究及利用

甘薯品种中花青素含量的高低主要由基因型决定,但环境条件对其也有一定的影响.紫色甘薯块根在发育过程中花青素的积累一般在栽后3～6周增长最快,此后增长缓慢.花青素在块根内的分布通常是外层高于内层,块根膨大期间的土壤平均温度与花青素含量呈极显著负相关.甘薯花青素对光和热的稳定性较好,利用紫色甘薯可加工成一系列的产品.     

Determination of Glycoalkaloids in Potatoes and Potato Products by Microwave Assisted Extraction

Potato glycoalkaloids can reach levels that are harmful to human health. A rapid and reliable microwave assisted extraction method for quantitative analysis of α-solanine and α-chaconine content in raw potato and potato based products is presented. A chemical microwave was used to determine optimal temperature and pressure conditions for the extraction of α-solanine and α-chaconine from Idaho grown tubers and six commercially available mashed potato products. Recovery efficiency of glycoalkaloids was 37% greater by microwave assisted extraction (19.92 mg/kg glycoalkaloid) as compared to conventional solid/liquid methods (12.51 mg/kg glycoalkaloid). Optimal extraction of glycoalkaloids from potato samples dissolved in methanol was achieved using a microwave reactor set to 90 °C for ten minutes. The interior of Idaho grown tubers was determined to contain lower levels of glycoalkaloids (19.92 mg/kg dry weight; 6.5 ± 1.78 mg α-solanine and 13.40 ± 1.65 mg α-chaconine), as compared to commercial potato products (33.86–81.59 mg/kg).     

Improve Anthocyanin and Zinc Concentration in Purple Rice by Nitrogen and Zinc Fertilizer Application

Zinc (Zn) is an essential micronutrient for plant growth and development, and anthocyanin is a secondary metabolite compound generally produced under stress conditions; both have benefits to human health. Rice is a staple food crop for most of the world’s population, and purple rice is well known as a natural source of Zn and anthocyanins, but their stability depends upon many factors. This review focuses on the opportunity to increase Zn and anthocyanin compounds in purple rice grains via Zn and nitrogen (N) management during cultivation. Variation in grain Zn concentration and anthocyanin compounds is found among purple rice varieties, thus presenting a challenge for breeding programs aiming at high grain Zn and anthocyanin contents. Genetic engineering has successfully achieved a high-efficiency vector system comprising two regulatory genes and six structural anthocyanin-related genes driven by endosperm-specific promoters to engineer purple endosperm rice that can provide new high-anthocyanin varieties. Grain Zn and anthocyanin concentrations in rice can also be affected by environmental factors during cultivation, e.g., light, temperature, soil salinity and nutrient (fertilizer) management. Applying N and Zn fertilizer is found to influence the physiological mechanisms of Zn absorption, uptake, transport and remobilization to promote grain Zn accumulation in rice, while N application can improve anthocyanin synthesis by promoting its biosynthesis pathway via the use of phenylalanine as a precursor. In summary, there is an opportunity to improve both grain Zn and anthocyanin in purple rice by appropriate management of Zn and N fertilizers during cultivation for specific varieties.     

工业大麻中大麻二酚提取工艺优化和生物活性分析

为优化工业大麻中CBD提取工艺,建立CBD高效液相分析方法,评估CBD体外酶抑制活性和抗氧化活性,拟通过设计单因素实验,以溶剂种类、超声时间、料液比、提取次数为影响因素,CBD含量为评价指标优化提取工艺,并通过检测CBD对黄嘌呤氧化酶、多酚氧化酶的抑制率及ABTS自由基的清除率监测其体外酶抑制活性。结果表明:甲醇为提取溶剂、提取2次、超声10 min、料液比1:20 g/mL为最佳提取条件。生物活性实验表明CBD能明显抑制酶活,其对XOD、PPO、ABTS的C50分别为1.18μg/mL(40s)、1.03μg/mL (60s)、4.99μg/mL和1.68μg/mL。该工艺操作简单、稳定可靠、成本较低,为工业大麻花叶中CBD的提取及定性定量提供一种新的技术方法,且该方法提取的CBD酶抑制活性和抗氧化活性好,具有重要的药用价值。