Thermal stability of yeast hydrolysate as a novel anti-obesity material

We examined the thermal stability of yeast hydrolysates before and after ultrafiltration (UF) in vitro, and the anti-obesity activity of yeast hydrolysates before and after heat treatment in vivo. Yeast hydrolysate after UF showed significantly higher thermal stability than before UF. Yeast hydrolysates before and after UF showed 3 and 4 thermal transition peaks in their thermograms, respectively, and the total thermal denaturation enthalpies of yeast hydrolysates before and after UF were 69.5 and 36.5 J/g, respectively. For the anti-obesity activity study, yeast hydrolysates before and after heating were administered ad libitum with water to 7-week-old male SD rats. The administration of yeast hydrolysate (YH-control; no heat treatment, YH-1; heat treatment at 140°C, and YH-2; heat treatment at 160°C) significantly increased mRNA expression of cocaine- and amphetamine-regulated transcript (CART) compared with control rats (saline administration). However, there was no significant difference between the heat-treated groups and YH-control and there was no significant difference in neuropeptide Y expression between the heat-treated groups and YH-control. These results suggest that yeast hydrolysate can be use an anti-obesity material after heat treatment.