Re-formulating Monascus fermented durian seeds yogurt with strawberry (Fragaria x ananassa) puree to enhance its microbiological, physicochemical and organoleptic properties

Abstract

Healthy lifestyle and consumption of fermented products, is the trend that is popular among health-conscious individuals. Monascus fermented durian seed (MFDS) is a fermented product of durian seed using the Monascus purpureus culture. Even though MFDS possessed specific bioactive properties, such as competent antioxidant, anti-diabetes and anti-hypercholesterolemia. However, the addition of MFDS extract to yogurt has some limitations [e.g.: reduction of colour and taste preference]. Thus, there is a need for an innovative food technology method to enhance key organoleptic characteristics of a newly formulated yogurt product made of MFDS and strawberry puree. The aim of this investigation was to determine the effect of difference concentrations of strawberry puree on microbiology, physicochemical, and organoleptic properties of MFDS yogurt product. The results showed that all concentrations of strawberry puree [5%, 10%, 15%, and 20% (w/v) of the total mixture] have affected the microbial, physicochemical and sensory properties of re-formulated yogurt product. Strawberry purees caused an acidity increase of yogurt with pH value between 4.287 and 4.475. The recorded titratable acidity was 0.74% to 1.17%. The colour parameters such as lightness and yellowness also decreased, however, the values of redness, chroma, and hue increased. The shelf-life experiment (maximum of 7 days) of the re-formulated yogurt revealed a maximum syneresis of 22.52%. Based on the sensory evaluation preferences, re-formulated yogurt with 10% strawberry puree was the most favourable product, with a preferred value of the colour at 5.6 (rather like), the flavour at 5.8 (rather like), and mouthfeel (rather like).