FUNCTIONAL PROPERTIES OF THE CELL-FREE SUPERNATANT OF BUTTERMILK FERMENTED WITH L. delbrueckii subsp. lactis 210. EFFECTS OF SPRAY-DRYING.

BURNS, P.; DUARTE, J.; BÉLANGER, L.; CARON-MARQUIS, R.; MATAR, C.; REINHEIMER J.A.; VINDEROLA, G.

Montreal, Canadá

Simposio; 6th International Symposium on Probiotics; 2010

Buttermilk is a low-cost by-product of the manufacture of butter with a chemical composition similar to that of skim milk. We aimed at fermenting buttermilk with a proteolytic strain of L. delbrueckii subsp. lactis in order to assess the effects of spray-drying of the cell-free supernatant (CFS) containing peptides on its immunomodulating capacity. L. delbrueckii subsp. lactis 210 was used for the fermentation of 16% (w/v)  buttermilk for 24 hs at constant pH 6 using Ca(OH)2. CFS was recovered by centrifugation and spray-dried. The profile of peptidic fractions released was studied by RP-HPLC. The safety and functionality was studied in Balb/c mice. Animals received the CFS (liquid or spray-dried) by gavage for 2, 5 or 7 consecutive days. Liver was plated (traslocation assay) in order to verify safety. The number of IgA, IgG, IL-6, IL-4, IL-10, IFNγ and TNFα-producing cells was determined on histological slices of the small intestine by immunohistochemistry. No translocation to liver was observed. The number of IgA-producing cells was enhanced, compared to controls, for the all feeding periods assessed when the CFS was administered as a spray-dried powder and for the feeding periods of 2 and 5 days when it was administered as a liquid (before spray-drying). The number of IgG and IL-6-producing cells was not modified in any case. The number of IL-10, IL-4 and IFNγ-producing cells was significantly enhanced when the CFS was administered as a liquid but not as a spray-dried powder. However, the opposite situation was observed for TNFα-producing cells. The CFS obtained presented functional properties related to the enhancement of the intestinal health when administered as a liquid or as a spray-dried powder. However, the technological treatment applied (spray-drying) might have affected the immunostimulating capacity of the peptides present in the CFS. A powder enriched with peptides released from buttermilk proteins was obtained by spray-drying with potential applications as a functional food additive.