Freeze Dried Blueberry Powder Fortification Improves the Quality of Gluten Free Snacks

摘要

Since Quinoa flour is an excellent source of natural antioxidant compounds and blueberries are rich in polyphenolic anthocyanins, this study was undertaken to improve and evaluate the quality of two blueberry powder fortified gluten free products, muffins and cookies. Control products were made with 100% Rice flour and Rice flour was replaced by 50% and 100% Quinoa flour to prepare muffin and cookies. 10% freeze dried Blueberry powder was used for fortification. Effect of flour replacements and Blueberry fortification on moisture content, water activity, antioxidant value, shelf life, sensory quality and textural properties were studied. Blueberry fortification improved the shelf life of the baked products, since, no significant increase in water activity and moisture content and no microbial growth were observed during 3 months of storage. Fortified Quinoa muffins and cookies were significantly harder because of the high fiber content of the Quinoa flour found by a Textural profile analysis using TA.XT plus Texture Analyzer. Although, baking reduced the antioxidant content to some extent, the total antioxidant activity, phenolic content and anthocyanin content were significantly increased with Blueberry fortification. Freeze dried blueberry powder fortified 100% Rice flour muffins and 100% Quinoa flour cookies were considered as the most acceptable products by consumer Sensory analysis using a 9-point hedonic scale. The study suggests that Quinoa flour is a good gluten free alternative and Blueberry fortification to snack products is a simple way to increase phytochemical and antioxidant content in diet.