Effect of native and chuño starches from andean potato addition on rheological properties of pot-set yoghurt

CRUZ ORTIZ, G; TORRES QUINTEROS, L; ITURRIAGA, L; BUSTOS, AY; GEREZ, L

Zurich

Simposio; 8th International Symposium on Food Rheology and Structure; 2019

Yoghurt is a widely-consumed fermented dairy food internationally and also renowned for its health benefits, nutritional value and digestibility. Hydrocolloid stabilizers, are often added to the milk base to maintain or enhance yoghurt properties including texture, viscosity and consistency and to prevent whey separation. In this work, the influence of starch from andean potato cultivars (solanum species called rosadita) before and after the freezing and drying process of potatoes known as ?chuño? On the rheological and pshysical properties of pot-set yoghurt were evaluated.Cow´s milk yoghurt was prepared following a standard formulation made with skim milk powder (10% w/v) without (cy) and with the addition of 2.5% (w/v) of native potato starch (ny) and ?chuño? Potato starch (chy). Fermentation of yoghurt was monitored via ph value. Rheological properties and syneresis rate were determined at 1 and 7 storage days. Our results showed that yoghurt with starch (native and chuño) addition exhibited higher apparent viscosity-shear rate profiles and dynamic viscoelastic moduli and less syneresis than control yogurts without hydrocolloids. On the other hand, viscoelastic moduli and syneresis of chy were higher than of ny. All the samples studied, showed little variation in their flow, viscoelastic behaviour and syneresis rate with storage time (7 days). This work showed that andean potato starch and chuño are a promising alternative to improve physical and rheological properties of yoghurt.