Screening of starter cultures for oat-based non-dairy yoghurt

Abstract: In this project a selection of different starter cultures was used to ferment oat-based yoghurt made with different plant proteins. The fermentation capacity of the starter cultures was investigated by continuous monitoring of the pH during the fermentation process of the yoghurts. Furthermore, the ability of each starter culture to use different energy sources was investigated as well as their ability to produce lactic acid in combination with each protein. A sensory profile test was carried out to determine some chosen sensory attributes of the yoghurts as well as to categorize the starter cultures. The results from this screening shows that both different starter cultures and a specific starter culture in combination with different proteins yields different end products. The starter culture used in plant-based fermentation should thus be selected with the food matrix in mind. The traditional yoghurt starter cultures used in this screening gave rise to yoghurts with general higher pH and lower amounts of lactic acid. They were also sensory described as sweet and lacking in acidity. Starter culture G in combination with protein 17, 10, 11 and 3 gave rise to the most acidic yoghurts, while starter culture H in combination with protein 17, 16, 10 and 3 gave rise to the yoghurts which were perceived as most sweet. The results from this screening may be seen as a database of different starter cultures in combination with different plant proteins. It could be further extended to include other starter cultures as well as other proteins. The results can be used as a starting point in product development of new plant-based fermented products.