| Summary: | In this study, the effects of flaxseed-mucilage (2, 4, and 6%), Stevia (0, 50, and 100%), and ultrasound (5, 10, and 15 min at a constant frequency of 20 kHz) on physico-chemical properties, antioxidant activity, color, and sensory evaluation of formulated flaxseed-mucilage cocoa milk (FCM) product were evaluated using a response surface methodology. Results demonstrated that increasing the flaxseed-mucilage content reduced (p<0.01) the pH and the extent of sedimentation, decreased (p<0.01) the lightness (L*) and increased (p<0.01) the viscosity in all test samples. The effect of Stevia on various physico-chemical properties was also significant (p<0.01). Further, increasing the ultrasound treatment time reduced the product viscosity (p<0.01). With the application of desirability function concept, the optimum formulation conditions for preparing the FCM were established as 2.5% flaxseed-mucilage, 1% Stevia and 10.9 min ultrasound treatment time. The characteristics product obtained under the optimized conditions were pH 6.34, viscosity 10.4 mPas, sedimentation 0.71%, L* value 48.4, and overall acceptability value 4.98. Antioxidant activity and total phenolic content of the optimized FCM were notably higher than those in the control sample, and the associated peroxide values were low.
|
|---|