Thermal Stabilization of the Betalain Extract Using Encapsulation and Co-pigmentation and its Application in the Model Drink

Abstract

One of the important challenges about using of the betalains is their low stability against light and heat. Therefore, the main goal of this research was to stabilize the extracted betalain from red beet against thermal treatments. To investigate the thermal stability of the betalain, encapsulation (using maltodextrin, gum Arabic, gum farsi, whey protein concentrate (WPC) and alpha and beta cyclodextrins) and co-pigmentation method using pure co-pigments such as gallic acid, ferulic acid, quercetin and rutin (at different molar ratios of 2.5-100:1 co-pigment/betalain) and rosehip extract (at two molar ratios of 50:1 and 100:1 gallic acid equivalent/betalain) were applied. The results indicated that WPC was the most effective wall material which maintained the higher betalain (81.50 mg/100 g powder) during drying and, after using the microcapsules in the model drink, the highest retained betalain (48.20 %) was related to the WPC microcapsules. Alpha and beta cyclodextrins and pure phenolic co-pigments did not have any significant effect on the betalain stability. Rosehip extract at two molar ratios of 50:1 and 100:1 (gallic acid equivalent/betalain) led to increasing of the betalain retention which was also obvious during storage at accelerated temperature and light condition, even after 14 days; so that the betalain content of the sample containing rosehip extract did not decreaseduring 14 days storage.

Keywords

• betalain extract
• co-pigment
• encapsulation
• stabilization