Preparation of an imitation soy sauce from hydrolyzed dried yeast Candida utilis

Acid hydrolysis of dried fodder's yeast Candida utilis was studied by a cen tral composite design taking into account three independent variables: temp erature (105-165C), processing time (30-70 min) and HCl concentration (7.5- 17.5%). Response variables were: color, dry matter solubilization and amino nitrogen. Temperature was the most significant variable followed by acid c oncentration and processing time. Response surfaces were generated from fit ted polynomials. Higher temperatures to prevent amino nitrogen degradation were not investigated. As different effects were found for color developmen t and amino nitrogen, a combined function was tested which yields the behav ior of all responses simultaneously. The best conditions were: 150C, 15% HC l and 40 min. After neutralization with 6N NaOH and centrifugation, the raw sauce was supplemented with 12% NaCl, 0.1% monosodium glutamate, 2% vinega r and 0.1% sodium benzoate and evaluated by sensory analysis for eight dist inct attributes. Imitation sauce from yeast was at least as good as commerc ial hydrolyzed soybean sauce.