Evaluation of Volatile Compounds in Milks Fermented Using Traditional Starter Cultures and Probiotics Based on Odor Activity Value and Chemometric Techniques.

Li Zhang,Ruobing Liu,Si Mi,Yaxin Sang,Xianghong Wang

doi:10.3390/molecules25051129

Li Zhang, Ruobing Liu + Show 3 more

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https://doi.org/10.3390/molecules25051129

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Journal: Molecules (Basel, Switzerland)	Publication Date: Mar 3, 2020
Citations: 15	License type: CC BY 4.0

Affiliation: Hebei Agricultural University

Abstract

The volatile components of milks fermented using traditional starter cultures (Streptococcus thermophilus and Lactobacillus bulgaricus) and probiotics (Lactobacillus lactis, Lactobacillus bifidus, Lactobacillus casei, and Lactobacillus plantarum) were investigated by means of gas chromatography-mass spectrometry (GC-MS) combined with simultaneous distillation extraction (SDE). A total of 53 volatile compounds were detected, being 10 aldehydes, 11 ketones, 10 acids, 11 hydrocarbons, 7 benzene derivatives, and 4 other compounds. The starter culture was found to significantly affect the composition of volatile components in the fermented milks. Ketones and hydrocarbons were the dominant compounds in milk before fermentation, while acids were dominant compounds in the fermented samples. Compared with probiotics, there was greater abundance of volatile components in fermented milks with traditional strains. The importance of each volatile compound was assessed on the basis of odor, thresholds, and odor activity values (OAVs). Of the volatile compounds, 31 of them were found to be odor-active compounds (OAV > 1). The component with the highest OAVs in most samples was (E,E)-2,4-decadienal. Heatmap analysis and principal component analysis were employed to characterize the volatile profiles of milks fermented by different starter cultures. The results could help to better understand the influence of starter cultures on the odor quality of milks.

Highlights

Fermentation is a common method of producing new and palatable dairy products from milk [1].Fermented milk is widely consumed due to rich nutrition and for its sensory properties.The primary sensory attributes of fermented milk include texture, color, taste, and odor [2]
The objective of this study was to characterize the volatile profiles of milks fermented by different starter cultures including Streptococcus thermophilus s2 (STs2), Lactobacillus bulgaricus 8 (LB8), Lactobacillus lactis 28 (LL28), Lactobacillus bifidus 531 (LB531), Lactobacillus casei 475 (LC475), and Lactobacillus plantarum
There were greater abundance odor-active compounds detected in fermented milks with traditional strains (STs2 and LB8)

Summary

Introduction

Fermented milk is widely consumed due to rich nutrition and for its sensory properties. The primary sensory attributes of fermented milk include texture, color, taste, and odor [2]. Among these attributes, odor has played an important role in determining the acceptability and preference of fermented milk for customers. Odor has played an important role in determining the acceptability and preference of fermented milk for customers It is caused by one or more volatile compounds, generally, at a very low concentration level, that humans or other animals perceive by the sense of olfaction [3]. As an important fermented milk, yogurt has been extensively studied for its volatile components. Studies suggest that there are more than 90 different volatile compounds in yogurt, including carbohydrates, alcohols, aldehydes, ketones, acids, esters, lactones, sulphur-containing compounds, pyrazines, and furan derivatives [4,5,6]

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