Physicochemical, rheological, microbiological and sensory properties of newly developed coffee flavored kefir

Abstract

Kefir is a functional beverage and little known to consumers. This study aimed to develop and characterize the physicochemical, rheological, microbiological and sensory properties of coffee flavored kefir. Kefir formulations were prepared by adding different amounts of skim milk powder, instant coffee and refined sugar into the fermented milk. The optimal formulation was determined using the desirability function and subjected to Temporal Dominance of Sensations (TDS) test, acceptance and purchase intention. The responses of dry matter, ash, protein, carbohydrate, total energy value, pH, color, antioxidant capacity, acid acetic bacteria, mesophilic cocci, viscosity and TDS test showed significant differences (p < 0.05) between the formulations. However, water activity, lipid content, Lactobacillus spp. and yeast counts showed no significant differences (p ≥ 0.05). All beverages showed non-Newtonian rheological behavior and high probiotic counts. The formulation with maximum coffee addition presented higher overall desirability. This sample was characterized by lower total energy value and higher antioxidant capacity and chroma. In the TDS test, the coffee flavor attribute was the dominant, followed by the bitter taste, cappuccino taste and residual taste. The optimal formulation presented good sensory acceptance and purchase intent.