The effect of fermentation of high alkaloid seeds of Lupinus angustifolius var. Karo by Saccharomyces cerevisieae, Kluyveromyces lactis, and Candida utilis on the chemical and microbial composition of products

The usefulness of Candida utilis, Saccharomyces cerevisiae, and Kluyveromyces lactis to the fermentation of high alkaloid lupin seeds was examined. Seeds were mixed with water and sterilized at 121 °C for 20 min. After cooling, the mixture was inoculated with yeast and fermented for 48 or 72 hr at 30 °C. After enzymes deactivation samples were dried. Fermentation increased the content of crude protein (p   .05) after K. lactis and S. cerevisieae fermentation. After 72 hr fermentation the content of crude protein was significantly higher but several necessary amino acids content was lower in comparison with 48 hr fermentation time. Fermentation reduced (p < .05) phytate, raffinose family oligosaccharide content and also alkaloid content in the final products. Fermentation process increased total and lactic acid bacteria count, the number of yeasts and molds as well as the number of coliform bacteria. The three yeast strains used were not fully suitable for the fermentation of high alkaloid lupin seeds. Candida utilis strain was found as the most favorable because of better chemical and microbial characteristic of fermented products. Practical applications The present study reports, that the fermentation process increased protein content and partially improved quality microbial and antinutritional character of seeds by reducing raffinose family oligosaccharides, phytate content, and alkaloids Taking this into account, fermented lupin seeds could be recommended as an alternative, protein-rich component of diets for animals and people. However, it should be remembered that lupin is a potential allergen and its status after fermentation has not yet been investigated.