Spray-dried polyphenolic extract from Italian black rice (Oryza sativa L., var. Artemide) as new ingredient for bakery products.

Artemide is one of the Italian pigmented rice varieties richest in polyphenols, especially anthocyanins. The aim of this work was to obtain anthocyanin-rich powders from Artemide cv, useful as functional ingredients for bakery foods. The hydroalcoholic extract prepared from Artemide black rice was processed by both spray-drying (with and without coating agents: maltodextrins: MD; arabic gum: GA) and freeze drying, in order to obtain ingredients more stable during storage and baking. The polyphenols spray-dried with MD and GA (50:50, w/w) resulted the ingredient most stable to the storage and partially protected from thermal damage during the baking in a model biscuit. The enriched biscuits showed a significantly higher content of polyphenols, antioxidant capacity and anthocyanins respect to a control biscuit. The polyphenolic extract obtained from Artemide black rice can be considered a valuable source of polyphenols to produce functional foods or microencapsulated ingredients for nutraceutical applications.

Release of antioxidant capacity from five plant foods during a multistep enzymatic digestion protocol.

This study aimed at elucidating the influence of food matrix on the release of antioxidant activity from five plant foods (apple, spinach, walnut, red bean, and whole wheat). To this purpose a protocol based on sequential enzymatic digestion was adopted. The total antioxidant capacity (TAC) of both solubilized and insoluble materials was measured at each step. Results showed that the overall TAC obtained by enzyme treatments was usually higher than that obtained by chemical extraction-based methods. In apple most of the TAC was released upon water washing and after pepsin treatment, whereas in spinach, beans, and whole wheat the TAC released by treatments with bacterial enzymes was prominent. Walnut had the highest TAC value, which was mainly released after pancreatin treatment. Therefore, the enzyme treatment is fundamental to estimate the overall potential TAC of foods having a high amount of polyphenols bound to dietary fiber or entrapped in the food matrix.