Modified Wheat Starches Used as Stabilizers in Set-Style Yogurt

Abstract

Yogurt was formulated with gelatin; native wheat starch (NWS); and modified wheat starches (MWS) (acetylated cross-linked, hydroxypropylated, or hydroxypropylated cross-linked). Yogurt samples were evaluated for chemical (fat, total solids, pH, titratable acidity); microbiological (yeasts/molds and lactic acid bacteria); and physical (rheological, textural, color, syneresis) properties during 60 days of refrigerated storage. Yogurt formulated with NWS exhibited a significantly greater storage modulus (G') and firmness compared with yogurts prepared with MWS. Minimal syneresis was measured in all yogurt samples. The titratable acidity of yogurt samples increased and pH decreased during storage. Yeasts/molds were not detected while lactic acid bacteria counts decreased ∼ 1 log CFU/g by day 60 in all yogurt samples. This study showed that the characteristics of yogurt formulated with NWS and gelatin were similar, so NWS may be used as an alternative stabilizer. The MWS stabilized yogurts were stable but had different consistencies than gelatin- and NWS-stabilized yogurts.