Background. Dietary fiber is not only used for its nutritional properties, but also for its functional and technological properties. The food industry produces significant amounts of by-products which are problems in their disposal. Usually, these products are used
in animal feeding. However, the high content of dietary fiber could permit their usage in food products. The dietary fiber in the diet has been recommended on the level 25-30 g/day. Thus, to supplement daily diet, dietary fiber should be incorporated into frequently consumed foods. The objective of this study was an effort to use raspberry pomace, by-product of food processing, in cookies.
Material and methods. The material of the study was raspberry pomace sourced directly from a fruit processing plant. Pomace is obtained in a dried form. Two sorts of raspberry pomace were applied: crumbled (ME) and non-crumbled (NM). These preparations were used as replacement of flour at the level 25 and 50%. The baked goods were sensory evaluated by a consumer method. Contents of neutral detergent dietary fibre (NDF) and its fractions were determined by the detergent method according to Van Soest and total dietary fibre (TDF), soluble dietary fibre (SDF) and insoluble dietary fibre (IDF) according to Asp et al.
Results. The content of dietary fiber in raspberry pomace was very higher. These by-products were found to be rich in cellulose and lignin. Cookies with dietary fiber preparations contained much more dietary fiber – NDF (from 10.1 g/100 g – 25% NM to
24.7 g/100 g of products – 50% NM) in comparison with the control sample (1.7 g/100 g of product). The use of raspberry pomace in cookies resulted in fiber contents increase. Moreover, the addition did not have negative influence on organoleptic characteristics of the product and was accepted by consumers.
Conclusions. The substantial dietary fiber content of fruit by-products and, in particular, fruit seeds, should attract the interest of dieticians.