Functional Properties of Fruit Fibers Preparations and Their Application in Wheat Bakery Products (Kaiser Rolls)

Abstract

In recent years, there has been an increase in consumer interest in functional foods enriched with health-promoting ingredients, which include dietary fiber. Therefore, the present study investigated the functional properties of fruit fiber preparations, i.e., cocoa, chokeberry, and apple fiber preparations, then designed wheat bakery products, kaiser rolls, with these fibers and evaluated the designed products. The fiber preparations selected for the study were evaluated for water binding properties (WHC), solubility (WSI), total polyphenol content, and antioxidant activity using a spectrophotometric method. In the designed bakery products, the weight losses occurring during baking were determined, specific mass, and hardness were evaluated, and sensory evaluation was carried out using a descriptive method. The tested fiber preparations showed varying water solubility, ranging from approximately 17% for cocoa fiber to approximately 30% for chokeberry one. The highest values, both in polyphenol content and antioxidant properties, were characteristic for chokeberry fiber, at 7.0 mg GAE/1 g and 10.1 Trolox/100 g, respectively, while the lowest values were for apple fiber (1.6 mg GAE/1 g, 3.6 Trolox/100 g). Baked products, kaiser rolls, with the proportion of the tested preparations at a lower addition level (3% flour replacement) had more favorable sensory characteristics than those containing a higher proportion of fiber (6% flour replacement). Considering all the tested fiber preparations, the rolls with the addition of chokeberry fiber preparation were the most favorable in terms of sensory characteristics. As the proportion of apple and cocoa fiber preparations in the rolls increased, the hardness and intensity of the bitter taste also increased. The designed bakery products could be a valuable addition to the assortment of semi-confectionery breads (yeast doughs), where the unfavorable bitter taste could be masked by the addition of, e.g., dried fruits (cranberries, raisins), nuts, sunflower seeds, or fruit filling.