Optimisation of minimal media for production of aroma compounds typical for fermented milk products

The aim of this research was to optimize the composition of minimalgrowth media containing lactose and milk, in which lactic acid bacteria (LAB) would produce the maximum amount of volatile aroma compounds typical for fermented milk products. Ingredients used for the preparation of media were casein...

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Bibliographic Details
Main Authors: Nevenka Mazić, Rajka Božanić
Format: Article
Language:English
Published: Croatian Dairy Union 2008-08-01
Series:Mljekarstvo
Subjects:
Online Access:http://hrcak.srce.hr/index.php?show=clanak&id_clanak_jezik=41249
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Summary:The aim of this research was to optimize the composition of minimalgrowth media containing lactose and milk, in which lactic acid bacteria (LAB) would produce the maximum amount of volatile aroma compounds typical for fermented milk products. Ingredients used for the preparation of media were casein, tri-sodium-citrate, lactose, milk minerals, whey proteins and milk with 1.5% fat. The several prepared media differed mainly in the amount of citrate and whey proteins. Fermentation was carried out at room temperature until the media reached pH value of 5. Samples were evaluated for sensory characteristics using quantitative descriptive analysis (QDA). In all media the target pH was reached after 68-71 hours of fermentation, depending on citrate level. Fermentation and the production of aroma compounds were more intensive in media that contained whey proteins compared to media with only casein. Increased citrate level had a positive influence on the aroma production. Citrate increased the initial pH of the media and acted as a buffer during fermentation, which lead to longer fermentation and prolonged production of aroma compounds. At pH around 5, the desired cultured aroma was the most intensive, whereas sour taste was less dominant. The substrate with 0.25% citrate and 0.1% whey proteins, at pH 5, was rated as best regarding its sensory characteristics.
ISSN:0026-704X
1846-4025