A kind of production method of lychee yogurt

Abstract

A production method of lychee yoghurt relates to yoghurt. Litchi shells are cleaned after removing impurities, soaked in lactic acid solution, crushed, leached at a constant temperature, filtered, and the filtrate is filtered with a microfilter and then ultrafiltered. The constant volume ultrafiltration method is used, and the ultrafiltration litchi shells are first added to the trough of the ultrafiltration equipment for extraction. Then, pump the lactic acid aqueous solution into the trough during the ultrafiltration process. After stopping adding the lactic acid aqueous solution, stop the ultrafiltration, collect the permeate, and concentrate the permeate through the nanofiltration membrane to reach the polyphenol content in the concentrate. 0.15% to 0.20%, stop nanofiltration and concentration to obtain litchi shell polyphenol extract; mix milk powder, sugar, pectin and litchi shell polyphenol extract, homogenize, sterilize and cool to fermentation temperature; Pre-activated Lactobacillus bulgaricus and Streptococcus thermophilus are mixed, inoculated into the sterilized raw material solution for fermentation, cooled to 4°C and then ripened to form lychee yoghurt, which is lychee active bacteria coagulated yoghurt.

Description

technical field [0001] The invention relates to yoghurt, in particular to a production method of lychee yoghurt. Background technique [0002] my country is the main producer of litchi, with a planting area of ​​about 9 million mu and a total output of about 1 million tons, accounting for more than 80% and 70% of the world's planting area and output respectively. At present, in addition to fresh lychees in my country, with the improvement of lychee deep processing technology, more and more lychees are used to produce dried lychees, lychee beverages and lychee wine. Litchi shells are the main by-products of lychee deep processing, which are mainly discarded at present. Disposal not only pollutes the environment but also wastes resources. A large number of studies have shown that litchi shells are rich in anthocyanins, proanthocyanidins and other polyphenols with strong antioxidant functions. Therefore, if the polyphenols in litchi shells can be used, it will greatly improve t...

AI Technical Summary

Problems solved by technology

Our study found that when acid-extracted or organic solution-extracted litchi shell polyphenols were co-fermented with milk powder or liquid milk to prepare yogurt or directly added to fermented yogurt, the large molecular weight polyphenols (tannins) in litchi shell extracts Agglomeration reaction occurs with protein in milk, resulting in unstable curd state of yogurt, product precipitation and stratification, whey precipitation and rough taste