红枣中有效组分的分步萃取研究
发布时间：2018-10-19 17:54
【摘要】：红枣(Ziziphus jujuba dates),又称大枣,是一种鼠李科(Rhamnaceae)枣属植物(Ziziphus jujubaa Mill)的成熟果实,原产于我国黄河流域,已经有3000多年的栽培历史。据中国统计年鉴统计,2012年我国红枣产量已经达到588万吨,占世界红枣产量95%以上,并且每年仍保持着10%以上的年增长率增长。目前,除少量红枣鲜食外,大部分被加工成干枣被直接消费或干制后作为其他产品加工的原料。在红枣精深加工中,常用乙醇萃取枣酊、水提醇沉制备红枣多糖和碱液提取红色素,但加工过后的红枣残渣并未进行二次、三次利用,造成了极大的浪费。因此,本文提出分步萃取技术,依次进行红枣中枣酊、多糖及色素的提取分离,使红枣资源得到充分利用。主要研究结论如下1.以枣粉为原料,对主要营养成分进行测定,各组分含量结果如下:还原糖56.64%、水分18.04%、粗纤维4.21%、灰分3.25%、蛋白质2.89%、粗脂肪4.21%;对枣酊萃取工艺进行温度(40、50、60、70℃、时间(1、2、3、4 h)和料液比(1:20、1:15、1:10、1:5 g/mL)的三因素四水平实验,获得了最佳萃取工艺:萃取温度60℃C、时间2 h、料液比1:10 g/mL,该工艺下获得枣酊感官品质最佳,其总糖含量49.5%、乙醇含量17.84%、含膏量47.38%,提取率达47.38%,并通过GC-MS从枣酊中鉴定出35种挥发性成分。2.以经95%乙醇提取过后的红枣残渣为原料,对提取温度(60、70、80、90℃)、时间(1、2、3、4 h)和级数(1、2、3级)等因素进行研究,获得了枣酊残渣多糖提取的最佳工艺:温度80℃、时间2 h,该条件下多糖得率3.02%,且提取三次提取率可达98.32%。并以红枣多糖、氨基酸为原料,褐变程度、颜色、pH值变化、挥发性成分及感官评分为指标,探讨了温度(100、120、140℃)和时间(0.5～5 h)对红枣多糖美拉德反应的影响。结果表明:随着反应时间的延长,A420 nm增大、色差值先增大后减小、pH值升高、产物褐变程度加深,且温度越高影响越大。温度和时间均对美拉德反应产物的感官特性具有极显著影响(p0.01),120 ℃和14℃处理产生的挥发性物质种类比100 ℃处理更为丰富,当高温处理时间低于3.5 h,浸提液挥发性物质主要为3,6,9,12-四氧十四烷-1-醇、甲氧基乙酸乙酯和4,8-二甲基十一烷,超过3.5 h则以十四烷和十九烷为主。此外,120℃热处理2.5～3.5 h对浸提液感官特性和香气成分的形成最为有利。最终,反应产物的整体喜好度、香气强度、香气持久性、甜香、烤香、焦苦评分分别与10、14、13、14、4、14种挥发性物质具有统计显著(p0.05)的相关性,以这些物质为自变量建立回归模型可对样品的整体喜好度、香气强度、香气持久性、甜香、烤香、焦苦的评分进行很好地预测。3.以提取红枣多糖的残渣为原料,A272 nm为指标,对氢氧化钠浓度、超声温度、时间、功率、料液比等因素进行研究。获得了红枣色素提取的最优工艺:料液比1:15 g/mL、超声温度70 ℃、时间40 min、功率76 W,该条件下红枣色素得率为6.30%,各因素影响的显著性大小:料液比超声温度超声时间超声功率;碱溶剂提取的最佳温度80 ℃,时间40 min,红枣色素提取率为2.40%。研究表明采用乙醇、水、碱液可实现分步提取红枣中香精、多糖及色素,能够充分利用红枣资源,将三者利用率换算成原始红枣粉末其总利用率达56.70%。
[Abstract]:Red date, also known as jujube, is a mature fruit of the genus Rhamnaceae, native to the Yellow River basin of our country, and has more than 3000 years of cultivation history. According to the statistics of China's Statistical Yearbook, the output of red jujube in China has reached 588.8 million tons in 2012, accounting for over 95% of the world's red date production, and the annual growth rate of more than 10% is still maintained. At present, in addition to a small amount of red date fresh food, most of the raw materials processed into dry date are directly consumed or dried as raw materials for processing other products. In the deep processing of red dates, the red jujube polysaccharide and the alkali liquor are extracted with ethanol to extract the red date polysaccharide and the alkali liquor to extract the red pigment, but the processed red date residue is not subjected to secondary and tertiary utilization, thus causing great waste. Therefore, the extraction and separation of jujube tincture, polysaccharide and pigment in red date were carried out in order to make red date resources fully utilized. The main findings are as follows. The main nutritional components were determined with jujube powder as raw material, and the contents of the components were as follows: reduction sugar 56. 64%, moisture 18. 04%, crude fiber 4.21%, ash 3.25%, protein 2.89%, crude fat 4.21%, and temperature (40, 50, 60, 70 鈩，
本文编号：2281901
[Abstract]:Red date, also known as jujube, is a mature fruit of the genus Rhamnaceae, native to the Yellow River basin of our country, and has more than 3000 years of cultivation history. According to the statistics of China's Statistical Yearbook, the output of red jujube in China has reached 588.8 million tons in 2012, accounting for over 95% of the world's red date production, and the annual growth rate of more than 10% is still maintained. At present, in addition to a small amount of red date fresh food, most of the raw materials processed into dry date are directly consumed or dried as raw materials for processing other products. In the deep processing of red dates, the red jujube polysaccharide and the alkali liquor are extracted with ethanol to extract the red date polysaccharide and the alkali liquor to extract the red pigment, but the processed red date residue is not subjected to secondary and tertiary utilization, thus causing great waste. Therefore, the extraction and separation of jujube tincture, polysaccharide and pigment in red date were carried out in order to make red date resources fully utilized. The main findings are as follows. The main nutritional components were determined with jujube powder as raw material, and the contents of the components were as follows: reduction sugar 56. 64%, moisture 18. 04%, crude fiber 4.21%, ash 3.25%, protein 2.89%, crude fat 4.21%, and temperature (40, 50, 60, 70 鈩，
本文编号：2281901
本文链接：https://www.wllwen.com/shoufeilunwen/boshibiyelunwen/2281901.html
