14A-1 |
Production and evaluation of coffee-flavored yogurt |
F. KOREL, Food Engineering Dept., Celal Bayar Univ., Engineering Faculty, Manisa, 45140, Turkey, G. Tan, and N. Demir, Dept. of Food Science & Human Nutrition, Univ. of Florida, 359 FSHN Bldg., Newell Dr., PO Box 110370, Gainesville, FL 32611-0370. An antibiotic effect and reduction in the incidence of gastro-intestinal illnesses are the major nutritional and health benefits of consuming yogurt. Manufacturers have developed low fat, nonfat and fruit-flavored yogurts with improved compositional and nutritional properties. Researchers are continually experimenting to improve the quality of yogurt and to develop products having new flavors. The objectives were to evaluate the optimum coffee and sugar concentrations and their influence on quality of yogurt and to determine the acceptance of such a product by consumers. Milk was pasteurized at 90°C/20 min, subdivided into 2 lots, mixed with 4 or 5 % sugar and 5% skim milk powder and cooled to 42°C. The predetermined concentrations of instant coffee (0.5, 0.7, or 0.9%) and 3% starter cultures were added. The mixes were incubated at 42°C until pH 4.7 and cooled at 4°C overnight. Percent protein, % fat and % dry matter, apparent viscosity and whey syneresis measurements were determined at day 1. Sensory evaluation was performed using 10 trained panelists. The pH, titratable acidity, and lactic acid bacteria, yeast and mold counts were analyzed at day 1, 3, 6, 10, 14 and 20. The protein, fat and dry matter contents were in the range of 4.15-4.59 %, 3.00-3.25 %, and 16.53-18.96 %, respectively. The apparent viscosity and whey syneresis measurements were in between 3624-5904 cp and 40-52%, respectively, depending on sugar and coffee concentrations. The pH of the samples decreased, and the titratable acidity increased during storage. Lactic acid bacteria counts were decreased from 4.4x109 to 7.9x104 cfu/g. Yeast and mold counts were <10 cfu/g. Panelists liked the sample having 0.5% coffee and 5% sugar. In order to offer variety and competition in the market, coffee-flavored yogurt could be manufactured and could be an alternative for yogurt consumers.
Session 14A, Dairy Foods: General developments in dairy technology I
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