Production method of litchi yogurt

Abstract

The invention discloses a production method of litchi yogurt and relates to yogurt. The production method includes that litchi shells are subjected to impurity removal, soaking in a lactic acid solution, smashing, digestion and filtration to obtain a filtrate, the filtrate is subjected to filtration and then ultrafiltration through a microstrainer, a constant-volume ultrafiltration mode is adopted, an extract solution of ultrafiltered litchi shells in added in a feed trough of ultrafiltration equipment, a lactic acid water solution is pumped into the feed trough during the ultrafiltration process, ultrafiltration is stopped after the lactic acid water solution is stopped being added, permeate liquor is collected and concentrated via a nanofiltration membrane to be concentrated liquor with polyphenol content of 0.15%-0.20%, and concentration by nanofiltration is stopped to obtain a litchi shell polyphenol extract; milk powder, sugar and pectin are mixed with the litchi shell polyphenol extract evenly before being subjected to homogeneity and sterilization to be cooled to fermentation temperature; preactivated lactobacillus bulgaricus is mixed with streptococcus thermophilus, and a feed solution inoculated to sterilization is fermented and cooled to 4DEG C to be molded to obtain the litchi yogurt, wherein the litchi yogurt is litchi active-bacteria solidified yogurt.

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