Optimization of envelopment in enriched gluten free cakes with beta - carotene using response surface methodology

In celiac disease, patients are not capable to digest the gluten of food. Beta-carotene is precursor for vitamin A and one of the most powerful fat-soluble antioxidants. Enrichment of gluten free cakes with beta-carotene and extension of shelf life of beta-carotene by coating can improve nutritional quality of diet in celiac patients and even healthy people. In the present research the effect of coating of gluten free cakes on sustainability of added beta-carotene was investigated and effective factors on coating and enrichment of gluten free cakes were optimized. In the first phase, gluten free cakes were covered by alginate, xanthan, corn starch and caseinate polymer solution (1%) and sensory evaluated. In the second phase, beta-carotene was added into the cakes dough, directly or into the biopolymer solutions of sodium caseinate or corn starch and cakes were sensory evaluated. According to the results, cakes contain beta-carotene coated with corn starch solution were selected. The concentration of biopolymer and drying temperature was then optimized by response surface methodology (RSM). Based on RSM results, the optimum condition was 2.2% corn starch for biopolymer concentration and 42 ºC for drying temperature. After this, beta-carotene durability in optimized condition was evaluated. Results showed that reduction of beta-carotene in coated samples was significantly lower than control (without coating) during 10 days storage. Therefore, coating with 2.2% corn starch could increase durability of beta-carotene inside the cake during storage.