Abstract:
Yoghurt is a fermented dairy product associated with several beneficial nutritional and health
effects. Due to increased demand of yoghurt in Kenya, 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 hispanica L.) are a good source of proteins, omega-
3/omega-6 fatty acids, minerals, soluble dietary fiber and phytochemicals. This study sought
to develop chia enriched yoghurt and determine the nutritional (amino acids, fatty acids,
mineral and vitamin C contents), 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 chi a seeds as follows; 1.5% m/v (CEY 1.5), 2.5%
rn/v (CEY2.5), 3.5% m/v (CEY3.5), and corn starch (2%) (CEYO). The results of the
proximate composition indicated there was a significantly higher content of moisture, crude
ash, crude fat, crude fiber and carbohydrates in CEY 1.5, CEY2.5 and CEY3.5 than those of
CEYO. In the current study, the nutritional composition was significantly higher in CEYI .5,
CEY2.5 and CEY3.5 than in CEYO with regards to amino acids, fatty acids, minerals and
vitamin C, with values increasing with increase in quantity of chia seeds in the formulation.
The concentration of !auric acid and palmitic acid decreased significantly, between CEYO
and all chia enriched samples (CEYI .5, CEY2.5 and CEY3.5), with the increase in the
concentration of chia seeds in the yoghurt formulations. On the other hand, the concentration
of stearic acid, oleic acid, linoleic acid and a-linolenic acid gradually increased significantly,
as the quantity of chia seeds used in the yoghurt enrichment increased with CEY3.5
recording the highest concentration and CEYO the lowest. 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 CEYO and CEYI.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 CEYO and all the CEY. In conclusion,
CEYI .5, CEY2.5 and CEY3.5 showed enhanced nutritional (amino acids, fatty acids,
minerals and vitamin C contents), physicochemical (pH and titratable acidity) and sensory
properties compared to CEYO thus chia seeds could be a potential ingredient in yoghurt
formulation
