Microbiological, physico-chemical, and sensory quality of yoghurt supplemented with gelatinized pigeon pea (Cajanus cajan (L.) Millsp.) flour

Recent advances in functional food research fostered new food ingredients that can alleviate the properties already found in these foods. Among them, product diversification in fermented foods totally benefitted because of the array of raw materials that can be mixed with milk-based fermented milk products like yoghurt. Legumes were reported to have bioactive ingredients that can potentially increase the beneficial effects of yoghurt by increasing the viability of yoghurt starter cultures. In this study, the effect of supplementation with gelatinized pigeon pea flour on the microbiological, physicochemical, and sensory properties of yoghurt during 14 days of refrigerated storage was determined. Supplementation of yoghurt with gelatinized pigeon pea flour significantly increased the viability of Lactobacillus delbrueckii subsp. bulgaricus, fermentation rate and total titratable acidity, and significantly lowered the pH of the supplemented yoghurt. However, no significant effect on the viability of Streptococcus thermophilus was found. Results of sensory evaluation showed that the addition of gelatinized pigeon pea flour to yoghurt significantly affected the colour, texture and consistency of yoghurt, and imparted a perceivable aftertaste, but did not significantly affect the aroma, sourness, sweetness, and overall acceptability of the product. The findings suggested that pigeon pea flour can be considered a potential ingredient for yoghurt supplementation.