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毕业论文网 > 毕业论文 > 化学化工与生命科学类 > 化学工程与工艺 > 正文

薰衣草冷冻干燥过程及其品质研究毕业论文

 2022-06-04 22:40:55  

论文总字数:20594字

摘 要

薰衣草富含挥发油、香豆素、单宁、类黄酮等成分,其中黄酮类物质因具有天然优异的抗氧化性和抗癌活性,近年来受到国内外学者的广泛关注。新鲜薰衣草花蕙含水率达到60%(湿基),收获后极易萎凋、褐变和腐烂,直接影响薰衣草的药用价值。薰衣草通常采用晒干、热风干燥处理,会导致薰衣草药用成分大量流失,如何提高薰衣草干燥品质,提高其附加值成为我国薰衣草加工产业亟待解决的问题。

冷冻干燥是将含水物料冷冻成固体,在低温低压条件下利用水的升华性能干燥物料。本文分析测定了薰衣草中总黄酮、芹菜素、木犀草素的含量;考察了冷冻干燥工艺对薰衣草干燥动力学和有效成分的影响。主要研究内容和结果如下:

(1)采用紫外分光光度法和高效液相色谱法测定薰衣草中总黄酮、芹菜素、木犀草素含量。结果表明,总黄酮紫外分光的最大吸收波长为362nm,其含量测定的线性范围0.066~0.138mg/ml;芹菜素和木犀草素的出峰时间分别约为18.002min和12.316min,芹菜素在1.0×10-4~3.0×10-4µg有较好的线性关系,木犀草素在6.1×10-5~2.3×10-4µg有较好的线性关系。

(2)薰衣草冷冻干燥工艺条件对薰衣草干燥特性和有效成分含量的影响。不同冷冻干燥温度和冷阱下,薰衣草约在干燥时间100min左右从恒速干燥阶段进入降速干燥阶段;薰衣草冷冻干燥的最优干燥工艺条件,压力0.063KPa,冷冻干燥温度25℃,冷阱温度为-50℃。总黄酮含量2.639%,芹菜素素含量0.897%,木犀草素含量为0.0340%。

关键词: 薰衣草 冷冻干燥 总黄酮 芹菜素 木犀草素

Study on Freeze-Drying Process and Quality of Lavender

ABSTRACT

Lavender has rich in essential oil, coumarin, tannins, flavonoids and other ingredients. The flavonoids are natural compounds that have excellent antioxidant and anticancer ability. Thus, lavender is widely paid more and more attention all over the world. The water content of fresh lavender reaches up to 60% (wet basis). It will significantly influence the medicinal value of lavender because it is easily decayed. Lavender is usually dried by hot air or directly dried by sun. These traditional drying methods can cause the loss of its medicinal ingredients and lead to the lack of market competitiveness. It is the key to improve the dry quality of lavender for increasing its added value.

Freeze drying is based on the physical phenomenon of material sublimation, the water cut material frozen into solids, the sublimation of water in the low temperature and low pressure conditions, and thus dry materials. The content of total flavonoids, apigenin and luteolin were tested. Effects of freeze drying conditions on the drying characteristics and active ingredients of lavender were studied. The main research contents and results are as follows:

(1)The content of total flavonoids was determined by ultraaviolet spectrophotometry (UV). The content of apigenin and luteolin is tested by high performance liquid chromatography (HPLC). The results show that the maximum absorption wavelength of total flavonoids is 362nm. The linear range of the content measurement is from 0.066 to 0.138mg/ml. The peak of apigenin and luteolin are showed at 18.002min and 12.316min. Apigenin in 1.0×10-4~3.0×10-4µg has a good linear relationship, Luteolin at 6.1×10-5~2.3×10-4µg has a good linear relationship.

(2) Effects of freeze drying conditions on the drying characteristics and active ingredients of lavender were studied. Under different freezing drying temperature and cold trap, Lavender about drying time 100 min from the constant speed drying stage into the drying stage. The optimum drying conditions of lavender freeze drying, pressure 0.063 KPa, freeze drying temperature 25℃, cold trap temperature -50℃. Total flavonoids content 2.639% celery Susu content 0.897%, Luteolin content 0.0340%.

Keywords: Lavender; Frezzing drying; Total flavonoids; Apigenin; Luteoli

目 录

摘 要 I

ABSTRACT II

第一章 概述 1

1.1 薰衣草及应用 1

1.1.1 薰衣草主要成分 1

1.1.2 薰衣草药理作用研究进展 1

1.2 薰衣草的干燥方法 3

1.2.1 热风干燥 4

1.2.2 微波干燥 4

1.2.3 真空干燥 5

1.3 冷冻干燥技术研究进展 5

1.3.1 冷冻干燥原理 6

1.3.2 冷冻干燥过程研究 6

1.4 本文主要研究内容 7

第二章 实验 8

2.1 实验 8

2.1.1 主要原料及试剂 8

2.1.2 主要仪器及设备 8

2.1.3 冷冻干燥实验装置及步骤 8

2.2 含水率测定 10

第三章 薰衣草有效成分含量的测定 12

3.1总黄酮含量测定 12

3.1.1 总黄酮标样制备 12

3.1.2 总黄酮吸收波长选择 12

3.1.3 总黄酮标准曲线测定 12

3.1.4 总黄酮测定方法学考察 13

3.2芹菜素含量测定 14

3.2.1 芹菜素标样制备 14

3.2.3 芹菜素标样谱图 14

3.2.3 芹菜素标准曲线测定 14

3.2.4 芹菜素测定方法学考察 15

3.3木犀草素含量测定 16

3.3.1 木犀草素标样制备 16

3.3.2 木犀草素标样谱图 16

3.3.3 木犀草素标准曲线测定 16

3.3.4 木犀草素测定方法学考察 17

第四章 薰衣草冷冻干燥 18

4.1 薰衣草冷冻干燥特性研究 18

4.1.1 干燥温度对薰衣草干燥速率的影响 18

4.1.2冷阱温度对干燥速率的影响 19

4.2 薰衣草冷冻干燥工艺研究 19

4.2.1干燥温度对薰衣草有效成分含量的影响 19

4.2.2冷阱温度对薰衣草有效成分含量的影响 20

第五章 结果与展望 22

5.1 结果 22

5.2 展望 22

参考文献 23

致 谢 25

第一章 概述

1.1 薰衣草及应用

1.1.1 薰衣草主要成分

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