Physicochemical Properties, Sensory Evaluation and Shelf Life Characteristics of Chia Enriched Yoghurt

Abstract

Consumers today are showing increased concern about food and health. The nutritional value of food can be improved by enriching with other nutritious products. In Kenya, the demand for yoghurt has been on a constant increase with some processors seek to incorporate artificial and highly processed ingredients such as stabilizers and emulsifiers as additives in order to improve nutritional value, thickening and stabilizing properties. Besides having good gelling properties, chia seeds (Salvia hispanicaL.) have been reported to contain essential nutrients and phytochemicals. This study sought to develop chia enriched yoghurt and determine the physicochemical (pH, total titratable acidity and syneresis), sensory and shelf life characteristics of chia enriched yoghurt (CEY). The treatment involved enriching yoghurt with varied amounts of chia seeds as follows; 1.5% m/v (CEY1.5), 2.5% m/v (CEY2.5), 3.5% m/v (CEY3.5), and corn starch (2%) (CEY0). The results of physicochemical characteristics showed chia seeds had no effect on the pH and titratable acidity values of the yoghurt. From the results of sensory analysis, the panelists preferred the texture, taste, colour and appearance of CEY0 and CEY1.5 over those of CEY2.5 and CEY3.5. In shelf life studies, pH decreased significantly while titratable acidity and syneresis increased significantly during refrigerated storage in both CEY0 and CEY1.5, CEY2.5 and CEY3.5. In conclusion, CEY1.5, CEY2.5 and CEY3.5 showed enhanced physicochemical (pH and titratable acidity) and sensory properties compared to CEY0 thus chia seeds could be a potential ingredient in yoghurt formulation.