18F-30


Response surface methodology (RSM) for optimization of chocolate-flavored, peanut-soy beverage formulations

R. P. DESHPANDE, M. S. Chinnan, and K. H. McWatters. Dept. of Food Science and Technology, Univ. of Georgia, 1109 Experiment St., Melton Bldg., Griffin, GA 30223-1797

Interest in utilization of peanut and soy proteins in traditional as well as novel nutritious foods is growing. Hence, their functional and nutritional benefits were combined in a chocolate-flavored, protein-based beverage. Optimization using Response Surface Methodology (RSM) was done to achieve desirable physical and sensory character-istics. To determine optimum ranges of peanut, soy, and chocolate syrup, various pilot-plant scale beverage formulations were evaluated. Chocolate syrup was prepared by incorporating key ingredients (sweeteners, stabilizer, emulsifier, and flavor additives) in water and heating this blend to 75°C. Peanut flour, Soy Flour (SF), and Soy Protein Isolate (SPI) were finely ground, mixed separately with water, homogenized, filtered, and used as base stocks. Mixture proportions of base stocks [peanut (X1:31-59%) and soy-either SF or SPI-(X2:28-44%)] and chocolate syrup (X3:13-26%) were determined based on lysine content=51 mg/g protein, viscosity=37 mPa s, and visual stability index=1.00. Three component mixtures were heated (75 °C), homogenized, pasteurized (93 °C for 1 sec), cooled (35 °C), filled into sterile bottles, and refrigerated (4 °C). Sensory acceptability (n=41; 9-point hedonic scale) of 28 beverage formulations and control was measured in terms of nine response variables. Contour plots were generated from second degree models with L-pseudo-components. Superimposition of contour plots corresponding to each response variable resulted in optimum regions. Optimum ranges were X1:34-46%, X2:31-43%, and X3:22-24% for SF formulations; and X1:36-48%, X2:31-44%, and X3:18-24% for SPI. Any formulation within these regions had consumer acceptability ratings ³ 5 (control ratings: 6-7). Aroma and aftertaste were the attributes which limited maximum consumer acceptability. SPI resulted in a larger area of overlap and was a better source of soy protein, compared to SF. Optimum combinations of peanut, soy, and chocolate syrup obtained should result in an acceptable beverage providing consumers an additional choice of a nutritious and good-tasting product.

Session 18F, Product Development: General
2:00 PM - 5:30 PM, Sunday PM Room Hall I-2

2005 IFT Annual Meeting, July 15-20 - New Orleans, Louisiana