The use of different temperatures and inulin: whey protein isolate ratios in the spray drying of beetroot juice

Abstract

Beetroot juice powders produced by spray drying under different temperatures and inulin:whey protein isolate (IN:WPI) ratios as carrier agents were evaluated. When it was used higher temperature, higher WPI concentration resulted in particles with higher betalains content (412.2 mg/100 g d.b.). For the antioxidant activity, values were found in a range of 61.5–90.8%. The color parameter values of the beetroot juice powders indicated intermediate lightness and saturation of coloring, which was closer to red. The mathematical model that best adjusted to the adsorption isotherms was the GAB and the monolayer moisture contents were between 5.1 and 6.5 g/100 g (d.b.). The higher concentration of IN resulted in lower stability of the powders when stored in environments with different water activities. Temperature of 170°C and IN:WPI proportion of 1:2 provided the best properties to the beetroot juice powder, which has the potential for the use and aggregation of functional properties in food matrices.

Practical applications The use of natural colorant in processed foods and beverages is important for increasing the consumer acceptability of these products and beetroots are an excellent source of betalains, quite used by the food industry as a natural colorant. The results of this study represent the possibility of the attainment of an extract powder rich in betalains, being formed of polymeric materials with innovation grade for the food industry by applying them in food matrices to create synergy between the functional properties of several products.