Physico-chemical Sensory and Microbiological Evaluation of Set and Fruit Yoghurt in Sabaragamuwa Province, Sri Lanka
K. L. S. R. De Silva
Department of Food Science and Technology, Faculty of Applied Sciences, Sabaragamuwa University of Sri Lanka, P.O.Box 02, Belihuloya, Sri Lanka.
R. M. U. S. K. Rathnayaka *
Department of Food Science and Technology, Faculty of Applied Sciences, Sabaragamuwa University of Sri Lanka, P.O.Box 02, Belihuloya, Sri Lanka.
*Author to whom correspondence should be addressed.
Abstract
The aim of this study was to evaluate the quality of yoghurt supplied to the consumers from retail outlets in Sabaragamuwa province Sri Lanka. Set yoghurt samples (50), which represent yoghurt samples from five manufacturers and fruit yoghurt samples (30), which represent yoghurt samples from three manufacturers were collected. All collected samples were analyzed for chemical composition (fat, protein, total solid, solid non fat, ash, pH, and titrable acidity), physical (syneresis and firmness), microbial (total bacterial count, Coliform count and yeast and mold count), and organoleptic (color, appearance, taste, odor, texture and overall acceptability) properties. Chemical, microbiological and physical properties of most of the tested yoghurt samples were within the Sri Lankan Standards. However, total plate count, yeast and mold count of some fruit yoghurt samples were not within the Sri Lankan standards. Highest and lowest microbial and physical properties respectively were recorded by the products of manufacturer D and C respectively. However, those two products were the mostly preferred products in terms of sensory evaluation. Yoghurt of good quality in terms of microbial, physical and chemical properties should be encouraged for consumption.
Keywords: Yoghurts, chemical composition, E-coli, syneresis, standard