Effect of drying process on survival of environmental starter culture and nutritional value

Abstract

Since Poland is one of the largest producers of rapeseed, the products of its processing – oil cake and rapeseed meal – could be promising alternatives in animal nutrition and, in the future, could also be used as food additives for humans. Fermentation, of these post-waste raw materials, eliminates the bitter taste and enriches the ferment with nutrients. Due to the fact that fermented rapeseed meal has a high water activity, it is possible to develop virtually all groups of microorganisms in it. Therefore, it is advisable to use a fixation method that will ensure the microbiological stability of the fermented product. The purpose of this study was to develop a starter culture for the fermentation of rapeseed meal and to investigate the effect of the drying process of fermented rapeseed meal on the survival rate of the starter culture. Fermented rapeseed meal was dried at 48°C for 33 h. After 30 days of storage of the dried meal, the survival rate of the starter culture was checked. Since the fermented rapeseed meal was meant to be used as feed for pigs, a low-temperature drying process was used in the study. Drying the fermented rapeseed meal made it possible to stabilize the product and allowed it to be stored safely, without signs of mold, for 30 days. The drying temperature of 48°C did not negatively affect the biological value of the nutrients or the survival of the starter culture in dried rapeseed meal after rehydration.