A free amino acid analysis method for the identification of fermented and blended yogurt drinks

Abstract

The invention discloses a method for identifying fermented type and formulated type yogurt beverages. Yogurt beverage is precipitated by sulfosalicylic acid, the content of free amino acids in liquid supernatant is measured by an amino acid analyzer, and the content ratios of four characteristic amino acids-alanine, valine, lysine and proline of total free amino acids are judged to establish the amino acid analysis method for identifying fermented type and formulated type yogurt beverages. According to the method, the similarity of the fermented type and formulated type yogurt beverages in the aspects of mouthfeel and physical behavior is avoided, the difference of the contents of the free amino acids of the fermented type and formulated type yogurt beverages is fully utilized, and a problem that the fermented type and formulated type yogurt beverages cannot be rapidly identified is solved; and the identification method can be operated simply and conveniently and has high accuracy and good application prospect.

Description

technical field [0001] The invention belongs to the technical field of dairy product identification, and relates to a method for identifying fermented and blended yogurt drinks, in particular to a free amino acid analysis method for identifying fermented and blended yogurt drinks. Background technique [0002] Fermented yogurt drinks refer to drinks made from fresh milk or dairy products, inoculated with lactic acid bacteria starter for fermentation, and then sterilized and diluted, while blended yogurt drinks refer to fresh milk or dairy products As raw materials, add water, sugar solution, and use sour agents such as lactic acid, citric acid or fruit juice to adjust the pH to below the isoelectric point of casein (pH4.6). Fermented yogurt drinks have become popular in the domestic market, such as Wahaha's "Shuangwaiwai" and "Fruit Yogurt" are all fermented yogurt drinks, and their popularity and market share are very high. However, before the emergence of fermented yogurt...

AI Technical Summary

Problems solved by technology

Both are normal temperature products, there is no difference in appearance and state, but fermented and blended yogurt drinks have great differences in nutrition, production technology, especially production costs, and blended products are far more profitable. higher than fermented products

However, there are currently no relevant identification and testing standards, nor is it mandatory for such products to indicate "fermented" or "blended" on their packaging labels. It is difficult for consumers to distinguish between these two yogurt drinks, so it is urgent to establish An identification technology of fermented and blended yogurt drinks as a practical and effective method to regulate the market

[0003] At present, GC-MS, HPLC-MS, fluorescence spectroscopy, near-infrared spectroscopy, and electrophoresis techniques are used at home and abroad to analyze proteins, fatty acids, volatile components, and vitamins in milk and its processed products. It only analyzes the content of nutrients in milk or dairy products. At present, there are no literature reports or standards for the identification of fermented and blended yogurt drinks, and there is no quick and easy way to identify fermented and blended yogurt drinks.