摘要：在常规发酵乳的制作工艺的基础上，以紫薯粉和全脂奶粉作为主要原料，以 保加利亚乳杆菌和嗜热链球菌为复合发酵剂研制紫薯发酵乳。本论文利用超高压技 术预处理紫薯发酵乳能使紫薯发酵乳的抗氧化能力较大程度被保留，同时杀菌效果 与巴氏杀菌无明显差异。采用单因素试验和正交试验，以感官评定、菌落总数和抗 氧化能力为指标，筛选出最佳工艺条件。超高压的工艺条件为：压力 300MPa，保压 时间 20min。优化的发酵工艺参数为：紫薯粉与水料液比为 1:20，紫薯液与复原乳 混合比例为 1:3，蔗糖添加量为 3%，发酵剂接种量为 0.2%，发酵温度为 42℃，发酵 时间为 8h。工艺优化后的紫薯发酵乳色泽鲜艳、酸甜适口、营养丰富，抗氧化能力 强，乳酸菌活菌总数为 3.4×107CFU／mL，pH 值为 4.45，脂肪含量为 4.7g/100g， 蛋白质含量为 3.5g/100g。66258

毕业论文关键词：紫薯；发酵乳；超高压；单因素；正交试验

The development of ultra-high pressure pre-processed purple potato fermentation milk

Abstract: On the basis of the traditional fermented milk production process, purple sweet

potato powder and whole milk powder were used as the main raw material, Lactobacillus bulgaricus and Streptococcus thermophilus were used as compound fermentation agents to develop purple potato fermented milk. In this paper, ultra-high pressure technology is used to pre-ferment the purple potato fermented milk, the antioxidant ability of fermented milk of purple sweet potato was preserved to a large extent, and the bactericidal effect was not different from pasteurization. The single factor test and orthogonal test were used to select the optimum conditions under the sensory evaluation, total number of colonies

and the antioxidant capacity. Ultra high pressure process conditions are: pressure 300MPa, holding time 20min. The optimum fermentation parameters were as follows: the ratio of purple potato powder to water to material was 1:20, the ratio of purple potato liquid and whole milk powder was 1: 3, the amount of sucrose was 3%, the inoculum quantity of

fermentation agent was 0.2%, the fermentation temperature was 42℃, the fermentation

time was 8h. After the optimization, the fermented purple sweet potato milk has bright color, rich nutrition and strong antioxidant ability and tasted moderately sweet and sour. The total viable count of Lactobacillus was 3.4×107CFU / mL, pH value was 4.45, fat

content was4.7g/100g, and protein content was3.5g/100g

Key words: Purple potato; Fermented milk; Ultra-high pressure; Single factor; Orthogonal test

目录

1.前言 1

1.1 超高压技术的概述 1

1.1.1 超高压技术的原理 1

1.1.2 超高压技术的可行性 1

1.1.3 超高压技术在食品加工中的应用 1

1.1.4 发酵乳应用超高压技术的功效 2

1.2 紫薯发酵乳的介绍 2

1.2.1 紫薯简介及功效 2

1.2.2 发酵乳的现状 2

1.3 研究目的 2

1.4 研究意义 3

2. 实验材料与方法 4

2.1 实验材料 4

2.1.1 实验材料与试剂 4

2.1.2 实验仪器设备 4

2.2 实验技术路线 5