Physicochemical, microbiological and organoleptic properties of cowpeas (Vigna unguiculata) yoghurt with the addition of gotu kola leaf (Centella asiatica (L.) Urban) extract

Abstract

Cowpea yogurt is a functional food product made from cowpeas and gotu kola leaves. This mixture of cowpeas and gotu kola leaves is expected to increase its functional value i.e., protein and antioxidant activity. This research aims to analyze the physicochemical, microbiological, and organoleptic properties of cowpeas yogurt with the addition of gotu kola leaf extract. The study used a Completely Randomized Design (CRD) with one factor, with the ratio of cowpea’s milk: gotu kola leaf extract, namely F1 (98%: 2%), F2 (96%: 4%), F3 (94%: 6%), K2 (100%: 0%), and K1 (100% pure milk). Testing parameters include viscosity, pH value, (moisture, ash, fat, protein, carbohydrate) content, antioxidant activity, total lactic acid bacteria, and organoleptic (color, aroma, taste, texture). The results showed that the highest pH and viscosity values in K2 were 3.77 and 419.59 cP; the highest moisture content in F3 was 85.04%; the highest ash, fat, and carbohydrate content in K2 were 0.62%, 1.87%, and 10.21%; the highest protein content in F1 was 3.25%; the highest antioxidant activity in F3 with an IC50 value of 87.008 ppm; the total lactic acid bacteria in K2 met the minimum SNI requirements of 107 CFU/mL; and K2 showed the most favorable overall organoleptic test. This study shows that the addition of gotu kola leaf extract affects on the physicochemical, microbiological, and organoleptic properties of cowpea yogurt.