Yer Bademi Sütü (Horchata) Yan Ürünlerinin Ekmek Üretiminde Değerlendirilmesi Üzerine Bir Çalışma
Functional foods are not only necessary for nutrition but also contribute our mental and physical well-being and help prevention or reduction of risk factors for several diseases. In recent years, tigernut has potential use in the field of developing functional foods. From this plant, the non-alcoholic drink is made named as tigernut milk or Horchata de Chufa. High quantity of by-products which are rich in terms of dietary fiber and minerals are obtained during tigernut milk production. The aim of this research is to investigate the physicochemical and functional properties of tigernut milk by-products and the breads containing different ratios of by-products. First, proximate compositions of by-products were determined. Also some functional properties, total dietary fiber and mineral content of by-products were investigated. Additionaly, some physical, nutritional and functional properties of breads were evaluated. Different wheat flour: by-product ratios were used in the bread formulations (90:10, 92:8, 94:6, 96:4, 100:0). According to the compositional structure of by-products, carbohydrate had the highest percentage. The water holding capacities of tigernut milk by-products which obtained from yellow and brown kinds of tigernut were found as 6,46 and 6,53 mlwater/gsample and their oil holding capacity were found as 6,54 and 6,57 mloil/gsample, respectively. Total phenolic content of by-product which obtained from yellow kind of tigernut was found as 20.65 mg gallic acid/kg sample and higher than the other by-product. The total antioxidant capacities of the by-products were determined high, as well. Also it is observed that by-products contain sodium, potassium and magnesium minerals at high levels. Furthermore, tigernut milk by-products have nearly %50 dietary fiber content. According to the results of physical analyzes, specific volume values were decreased significantly as dietary fiber ratio increased to %10 in bread formulations. Weight loss had the highest value with 14.32 percent in control bread. In color analysis, the highest ∆E values for both crust and crumb color were determined in breads which had %10 by-product as 42.57 and 13.33, respectively. When textural properties of breads were investigated, hardness and chewiness values gradually increased with increasing by-product ratio until the 90/10 ratio. Total antioxidant capacity (TAC) of breads were measured by using two different methods (CUPRAC and DPPH) as functional properties of breads. Also, total dietary fiber and mineral analyzes were performed to obtain the nutritional value of breads. According to the nutritonal and functional results of breads, not only amounts of total phenolic contents (TPC) and total antioxidant capacities but also total dietary fiber (TDF) and mineral contents increased as the by-product ratio was increased. The TPC of the breads were increased from 15.1 mg gallic acid/kg sample to 18.3 mg gallic acid/kg sample and also TDF levels of breads increased from %6.55 to %9.15. As a conclusion, tigernut milk by-products have important amounts of dietary fiber, minerals and antioxidant components. Therefore, they might be used as functional and healthy food ingredients in bakery products. In addition, mixing of wheat flour with spesific rates of tigernut milk by-products did not affect adversely the physical properties of bread.