蓝莓原汁加工关键技术研究及货架期预测

发布时间：2018-01-01 01:07

本文关键词：蓝莓原汁加工关键技术研究及货架期预测　出处：《安徽科技学院》2017年硕士论文　论文类型：学位论文

【摘要】：蓝莓果实含有丰富的营养元素及功效活性成分,具有极高的抗氧化性能和保健价值,传统的蓝莓饮品普遍蓝莓原汁含量低,添加各种食品添加剂。本文致力于研究不含任何食品添加剂,更加突显蓝莓保健功能的原汁产品。重点研究了蓝莓原汁加工过程中的热烫、酶解、杀菌关键技术,并预测了蓝莓原汁的货架期。主要研究内容及结果如下:(1)热烫条件对蓝莓原汁品质的影响探讨不同热烫条件对蓝莓原汁营养成分及抗氧化活性的影响,旨在寻求适宜的热烫温度和时间。研究表明:热烫可以明显降低蓝莓中的POD活性,80℃热烫6～15s、85℃热烫3～15s、90℃热烫3～15s POD均能完全失活。适度的热烫可以改善蓝莓原汁的色泽,有利于榨汁过程中可溶性固形物的溶出,增加可溶性固形物和总糖含量,提高蓝莓的出汁率。但热烫降低了蓝莓原汁的总酸度、维生素C含量、花青素含量、总酚含量、总黄酮含量、SOD活力和抗氧化活性。综合考虑热烫对蓝莓原汁营养成分和抗氧化性能的影响,在保证酶失活的前提下,应尽可能选择较低的热烫温度和较短的热烫时间,最终选择的热烫条件为80℃热烫6s。(2)蓝莓酶法取汁工艺条件优化为探讨复合酶对蓝莓酶解取汁的效果,在单因素试验的基础上,利用响应面法优化了蓝莓酶法取汁工艺。结果表明:建立的花青素含量和出汁率对酶处理条件的二次多项回归方程模型极显著,回归模型拟合度良好,能有效对蓝莓原汁的花青素含量和出汁率进行分析和预测。通过响应面分析,最佳的酶解工艺条件为:酶添加量0.0084%、酶解温度45.40℃、酶解时间2.26 h,此时蓝莓原汁的花青素含量38.4877 mg/100mL,出汁率为79.8344%。与对照组相比,最优条件下制备的蓝莓原汁的出汁率、总酸度、花青素、可溶性固形物、总酚、总黄酮含量显著增加,色差、总糖含量、SOD活力差异不显著,维生素℃含量显著下降,DPPH自由基清除能力提高了 8.84%,·OH自由基清除能力提高了 4.3%。(3)杀菌条件对蓝莓原汁品质的影响探讨了不同巴氏杀菌和高压蒸汽杀菌条件对蓝莓原汁微生物指标、营养成分及抗氧化性能的影响。结果表明:80℃杀菌4～16 min、105℃杀菌30～120s,可有效杀灭微生物。杀菌不利于蓝莓原汁色泽的保持;杀菌后总酸度变化不显著;杀菌后可溶性固形物、总糖、维生素℃、花青素、总酚、总黄酮含量和SOD活力显著下降,DPPH自由基和·OH自由基清除能力显著下降。但总体上可溶性固形物、总糖、花青素、总酚、总黄酮保存率仍保持在85%以上。综合考虑杀菌条件对营养成分及抗氧化活性的影响,在保证杀菌充分的情况下,选择80℃杀菌8 min、105℃杀菌60s两种杀菌条件。(4)蓝莓原汁贮藏品质的变化及其货架期预测探讨了80℃杀菌8min、105℃杀菌60s两种产品的贮藏品质变化,采用ALST法中的Q_(10)模型对产品的货架期进行了预测。结果表明:截至蓝莓原汁货架期测试终点时,两种杀菌条件的蓝莓原汁,在4、27、37℃三个贮藏温度下菌落总数和大肠菌群均未检出。蓝莓原汁的可溶性固形物含量和总酸度在贮藏过程中相对比较稳定,花青素含量下降速度较快,4℃有利于产品品质的保持。8℃杀菌8 min的样品在20℃条件下的货架期为91d,4℃条件下的货架期为165d。105℃杀菌60s的样品在20℃条件下的货架期为102d,4℃条件下的货架期为194d。
[Abstract]:Rich in nutrients and the effect of active ingredients of blueberry fruit containing high antioxidant properties and health value, traditional blueberry drinks generally blueberry juice content is low, add a variety of food additives. This paper is devoted to the study of food does not contain any additives, highlight the function of health care products. The blueberry juice studied blanching, blueberry juice in the process of enzymatic hydrolysis, the key technology of sterilization, and to predict the shelf life of blueberry juice. The main research contents and results are as follows: (1) effects of blanching conditions on the quality of blueberry juice to explore the effect of different blanching conditions on nutrition and antioxidant activity of blueberry juice, to seek suitable Blanching Temperature and time. The research showed that blanching in blueberries can significantly reduce the activity of POD, 80 DEG C hot 6 ~ 15s, 85 DEG C hot 3 ~ 15s, 90 DEG C hot 3 ~ 15s POD were completely inactivated. Hot moderate Blueberry juice can improve the color, is conducive to the juicing process of soluble solids dissolution, increase the soluble solids and total sugar content, improve blueberry juice yield. But blanching reduces the total acidity of blueberry juice, vitamin C content, anthocyanin content, total phenolic content, total flavonoid content, SOD activity and antioxidant activity. Considering the effect of blanching on blueberry juice nutrition and antioxidant properties, on the premise of enzyme inactivation, as far as possible to choose low Blanching Temperature and shorter blanching time, the final selection of the blanching conditions of 80 DEG C hot 6s. (2) blueberry enzyme method to optimize the process conditions of juice compound enzymolysis effect on Blueberry juice enzyme, on the basis of single factor test, surface method to optimize the enzymatic extraction process of blueberry juice using response. The results showed that the anthocyanin content is established and the juice rate of enzyme treatment on a number of two The regression equation model was significant, the regression model fit well, can be effective to the blueberry anthocyanins content and the juice rate analysis and forecast. Through response surface analysis, the best hydrolysis conditions were: enzyme dosage 0.0084%, hydrolysis temperature 45.40, hydrolysis time of 2.26 h, the anthocyanin content of blueberry juice the 38.4877 mg/100mL, the juice rate of 79.8344%. compared with the control group, the optimal conditions for the preparation of blueberry juice yield, total acidity, anthocyanins, soluble solids, total phenol, total flavonoids content increased significantly, color, total sugar content, SOD activity had no significant difference, vitamin C content decreased significantly DPPH, free radical scavenging capacity increased by 8.84%, OH free radical scavenging capacity was increased by 4.3%. (3) effects of sterilization conditions on the quality of blueberry juice of different pasteurization and sterilization conditions of blueberry microbial indicators of high pressure steam, Effect of composition and antioxidant properties of nutrients. The results showed that: 80 C sterilization in 4 ~ 16 min, 105 C sterilization of 30 ~ 120s, can effectively kill the microorganisms. The sterilization is not conducive to maintaining the color of blueberry juice; after sterilization of total acidity did not change significantly after sterilization; soluble solids, total sugar, vitamin C, anthocyanins. Total phenolics, flavonoids content and SOD activity decreased significantly, DPPH free radical and OH free radical scavenging capacity decreased significantly. But on the whole, soluble solids, total sugar, anthocyanins, total phenolics, flavonoids preservation rate remained above 85%. Considering the impact of sterilization conditions on nutritional components and antioxidant activity. In the case of fully ensure the sterilization, sterilization 80 C 105 C 8 min, 60s two kinds of sterilization sterilization conditions. (4) changes and prediction of shelf life storage quality of blueberry juice to 80 DEG C sterilization 8min, storage quality changes of 105 C sterilization 60s two products, using A LST method in Q_ (10) model to predict the shelf life of products. The results show that the as blueberry juice shelf life test end point, two kinds of sterilization conditions of blueberry juice in 4,27,37 C three storage temperature of total bacterial count and coliform bacteria were not detected. Blueberry juice soluble solids the content and total acidity in the process of storage is relatively stable, anthocyanin content decreased faster, there are 4 DEG.8 DEG C to maintain the shelf life of sterilization of the 8 min samples under the condition of 20 DEG C to the quality of products is 91d, the temperature of 4 DEG C for the shelf life of the shelf life of 165d.105 C 60s samples at 20 DEG C for sterilization under the condition of 102d, the temperature of 4 DEG C for the shelf life of 194d.

【学位授予单位】：安徽科技学院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS255.44

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