提高黑玉米全谷物饮料色素含量及稳定性的研究

发布时间：2017-12-27 06:15

本文关键词：提高黑玉米全谷物饮料色素含量及稳定性的研究　出处：《沈阳农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着人们生活水平的不断提高,对膳食营养和保健功效的要求也不断增强,全谷物饮料备受青睐。全谷物饮料是保留谷物中胚乳、胚芽和皮层等几乎全部成分加工而成的一类新型饮品,其中富含膳食纤维与多种抗氧化活性物质,具有增强饱腹感、延缓衰老、预防常见心脑血管疾病等功效。同比普通玉米相比,黑玉米具有更高的的营养价值及保健功效,其微量元素的含量可达到其他谷物的2～8倍,其中的黑玉米色素具有清除人体中的自由基,减少脂质堆积的作用。目前我国黑玉米多用于鲜食,加工产品较少。市售的黑玉米饮料普遍存在黑色素含量低、产品稳定性差等问题,导致黑玉米营养成分流失和资源的极大浪费。本研究以新鲜黑玉米为原料,首先研究玉米芯色素的提取及稳定性;其次研究利用碱处理提高玉米籽粒中色素的含量;最后优化玉米全谷物饮料复合稳定剂的最佳配方;并分析原料及黑玉米全谷物饮料的抗氧化活性。主要研究结果如下:1.采用酸化醇法提取黑玉米芯中的色素。以色素提取率为指标,通过单因素及正交试验确定玉米芯色素的最佳提取工艺为:料液比1:20,处理温度60℃,处理时间2h,pH3.0,此条件下玉米芯色素的提取率为32.73%。2.黑玉米芯色素稳定性的研究结果表明:该色素在不同pH值条件下依次呈现:红色、紫红色、紫色、黑色、绿色和黄色;色素在酸性条件下色素较稳定;对光、热的稳定性差;K+、Ga2+、Na+和Mg2+对色素的稳定性影响不显著(P0.05);而Cu2+和Fe3+则显著降低色素的稳定性(P0.05);添加蔗糖和可溶性淀粉使色素的吸光度值显著下降(P0.05),添加柠檬酸使色素的吸光度值显著上升(P0.05),柠檬酸对黑玉米芯色素有增色效应。3.利用碱处理提高黑玉米籽粒中色素含量。通过单因素及响应面试验优化碱处理的最佳工艺为:NaOH浓度1.5%,处理温度80℃,处理时间2min,此条件下色素的吸光度值为:0.77±0.00,处理后玉米籽粒的感官评分为:80.3±2.7。4.通过单因素及正交试验优化黑玉米全谷物饮料复合稳定剂的配方为:羧甲基纤维素钠1.4‰,海藻酸钠1.3‰,蔗糖酯0.6‰,微晶纤维素1.8‰,此条件下饮料的沉淀率为 33.07±0.13％。5.未经碱处理及经过碱处理的黑玉米籽粒为原料制作的黑玉米全谷物饮料吸光度分别为0.17和0.43,DPPH自由基的清除率分别为93.13%和80.57%;1%的黑玉米芯色素溶液吸光度为1.57,DPPH自由基的清除率为89.84%;加入黑玉米芯色素溶液的饮料吸光度为0.59,饮料的吸光度相比未添加色素时提高了 37.21%,DPPH自由基清除率为16.37%。6.成品黑玉米全谷物饮料外观呈浅紫黑色,色泽均匀,口感爽滑,无明显的分层或沉淀现象,并具有浓郁的黑玉米香气。
[Abstract]:With the continuous improvement of people's living standards, the requirements for dietary nutrition and health care are increasing, and whole grain drinks are favored. Whole grain beverage is a new beverage processed from almost all components including grain, endosperm, germ and cortex. It is rich in dietary fiber and various antioxidants. It has the effects of increasing satiety, delaying senility and preventing common cardiovascular and cerebrovascular diseases. Compared with ordinary corn, black corn has higher nutritional value and health function than the common corn. Its trace elements can reach 2~8 times of other cereals. The black corn pigment has the function of scavenging free radicals and reducing lipid accumulation in human body. At present, most of the black corn in China is used for fresh food, and the processed products are less. There are many problems in the black corn beverage sold in the market, such as low melanin content and poor stability of products, which lead to the loss of black corn nutrition and the great waste of resources. In this study, fresh black corn as raw material, the extraction and the stability of the first study of corncob pigment; secondly increase content of pigment in maize grain by alkali; the best formula finally optimization corn cereal beverage compound stabilizer; antioxidant activity and analysis of raw materials and whole grain black corn beverage. The main results are as follows: 1. the pigment in black corn cob is extracted by acidification alcohol. Taking pigment extraction rate as an index, through single factor and orthogonal test, the best extraction process of corncob pigment was determined: the ratio of material to liquid was 1:20, the treatment temperature was 60 C, the treatment time was 2h, pH3.0, and the extraction rate of corncob pigment was 32.73%. Study on the stability of pigment black corncon 2. the results showed that the pigment conditions were presented at different pH values: red, purple red, purple, black, green and yellow; pigment under acidic condition is stable; the light and heat stability of K+, Ga2+, Na+; and Mg2+ did not affect the stability of the pigment significant (P0.05); while Cu2+ and Fe3+ decreased significantly the stability of pigment (P0.05); adding sucrose and soluble starch and pigment absorbance value decreased significantly (P0.05), adding citric acid to the pigment absorbance value increased significantly (P0.05), citric acid has the hyperchromic effect of black corn pigment. 3. the content of pigment in black corn grain was improved by alkali treatment. Through single factor and response surface test, the best process of alkali treatment is as follows: NaOH concentration 1.5%, treatment temperature 80 degrees, and treatment time 2min. Under this condition, the absorbance value of pigment is 0.77 + 0. After treatment, the sensory score of corn grain is 80.3 + 2.7. 4. through single factor and orthogonal test, the formula of compound stabilizer for black corn whole grain beverage is optimized: carboxymethyl cellulose sodium 1.4, 1.3 sodium alginate, 0.6 sucrose ester and 1.8 microcrystalline cellulose. Under this condition, the precipitation rate of beverage is 33.07 + 0.13%. 5. without alkali treatment and after alkali treatment of the black corn as raw material and black corn grain beverage absorbance were 0.17 and 0.43, DPPH free radical scavenging rates were 93.13% and 80.57%; the black corncon absorbance of 1% to 1.57, DPPH free radical scavenging rate was 89.84%; add black corncob pigment solution of the beverage was 0.59. The absorbance of the beverage compared to not add pigment increased by 37.21%, DPPH free radical clearance rate was 16.37%. 6. the product of black corn whole grain beverage the appearance of a purple black, uniform color, taste and smooth, no obvious stratification or precipitation phenomenon, and has the aroma of black corn.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS275.4

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