Neutral pH nonfat dry milk beverages with turbidity reduced by sodium hexametaphosphate: Physical and sensory properties during storage

There has been ascending demand on beverages enriched with dairy proteins. Calcium chelators can improve transparency and stability of beverages with nonfat dry milk (NFDM) resulting from dissociation of casein micelles. In this study, vanilla-flavored model beverages with 5% or 10% w/w NFDM were manufactured with or without 0.43% w/w sodium hexametaphosphate (SHMP), physical properties were studied during 70-day storage at 4 degrees C and room temperature (RT), and sensory properties were evaluated during storage at 4 degrees C. SHMP resulted in decreased turbidity, particle diameter, and zeta-potential magnitude. The turbidity was stable at 4 degrees C but increased from 161 to 315 NTU and 333 to 818 NTU, respectively, for beverages with 5% and 10% NFDM after 70-day storage at RT. SHMP resulted in insignificant and significant increase in viscosity for 5% and 10% NFDM beverage, respectively. The 10% NFDM beverage with SHMP also developed into a gel during storage at RT but remained fluidic at 4 degrees C. Descriptive sensory analysis suggested that SHMP resulted in soapy flavor and salty taste of beverages with decreasing vanilla and milky flavors after 70-day refrigerated storage. Findings from the present study suggest that SHMP may be used to reduce the turbidity of refrigerated beverages based on NFDM.