Application of Response Surface Methodology (RSM) for Optimization of Anti-Obesity Effect in Fermented Milk by Lactobacillus plantarum Q180

Obesity, a condition in which an abnormally large amount of fat is stored in adipose tissue, causing an increase in body weight, has become a major public health concern worldwide. The purpose of this study was to optimize the process for fermented milk for the production of a functional product with an anti-obesity effect by using Lactobacillus plantarum Q180 isolated from human feces. We used a 3-factor, 3-level central composite design (CCD) combined with the response surface methodology (RSM). Concentration of skim milk powder (%, X(1)), incubation temperature (℃, X(2)), and incubation time (h, X(3)) were used as the independent factors, whereas pH (pH, Y(1)), anti-lipase activity (%, Y(2)) and anti-adipogenetic activity (%, Y(3)) were used as the dependent factors. The optimal conditions of fermented milk for the highest anti-lipase and antiadipogenetic activity with pH 4.4 were the 9.5% of skim milk powder, 37℃ of incubation temperature, 28 h of incubation time. In the fermentation condition, the predicted values of pH, anti-lipase activity and anti-adipogenetic activity were 4.47, 55.55, and 20.48%, respectively. However, the actual values of pH, anti-lipase activity and anti-adipogenetic activity were 4.50, 52.86, and 19.25%, respectively. These results demonstrate that 9.5% of skim milk powder and incubation at 37℃ for 28 h were the optimum conditions for producing functional fermented milk with an anti-obesity effect.