Physicochemical properties and microbial safety of reduced‐sugar chocolate‐flavored milk

Abstract

This study investigated the impact of sugar reduction on the physicochemical properties (pH, water activity (aw), total soluble solids (TSS), viscosity, and color) and microbial safety (total mesophilic and psychrotrophic bacteria, yeast and mold, total coliform, Escherichia coli, and Listeria monocytogenes) of chocolate-flavored milk stored under refrigeration (4 ± 1°C) for 28 days. When compared with the full-sugar chocolate milk (control), the 50% reduced-sugar (w/v) formulation containing concentration of stevia (56.27 mg/L) and monk fruit extract (81.90 mg/L), optimized based on the sensory responses by 107 consumers, showed no significant changes in pH, aw, and microbial growth. However, TSS and viscosity were significantly lower with higher lightness and yellowness but lower redness values in the reduced-sugar sample compared to the control, but no significant changes were observed over the storage period. Consequently, 50% of added sugar (w/v) could be reduced to formulate chocolate milk with acceptable physicochemical properties and microbial safety. Practical applications Flavored milk is a source of recommended dietary allowances for vitamin D and calcium but can contain up to 10% of added sugar (w/v). However, the intake of high levels of added sugar has been associated with several chronic diseases. Hence, there is a need to reduce added sugar. But the impact of sugar reduction has mainly been investigated from a health perspective. There is limited data available on how this impacts physicochemical and microbial properties. These aspects are crucial to be assessed before the new product could be launched in the market. Hence, the findings from this study will provide insights to the dairy industry on the stability of a new product in terms of physicochemical and microbiological safety when considering sugar reformulation programs.