Evaluation of the effects of legume flour incorporation into wafer sheets


Thesis Type: Postgraduate

Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Engineering, Department of Food Engineering, Turkey

Approval Date: 2018

Student: BÜŞRA TUFAN

Co-Supervisor: SERPİL ŞAHİN, SERVET GÜLÜM ŞÜMNÜ

Abstract:

Changing consumer demands have directed food industry into development of alternative food products in terms of nutrition, authenticity, innovation and functionality. The main objective of this study was to develop wafer sheets by partial replacement of wheat flour by bean, carob, chickpea and lentil flours. In this regard, firstly nutritional components of the flours were analyzed. Wheat flour was replaced by 10%, 20% and 30% legume flour and its effects on specific gravity and rheology of the batters were studied. In addition, the effects of these flours on wafer sheet quality in terms of weight loss, hardness, color and sorption behavior were investigated. Only wheat flour containing samples were used as the control. Legume flour addition did not affect specific gravity of the batters. From rheological analyses, all batters were found to obey Power law with shear thinning behavior. Added flour type affected both consistency coefficient and flow behavior index, whereas legume flour content only affected flow behavior index. Lentil flour added samples had the lowest consistency coefficient and the highest flow behavior index. Increasing legume flour content decreased weight loss of wafer sheets upon baking. Lentil flour added samples gave the same weight loss as the control wafer. Hardness values increased when legume flour was added and increased further by increasing legume flour concentration. Carob flour, chickpea flour and 10% lentil flour containing samples had the same hardness values to the control. Color of 10% chickpea and 10% lentil flour samples were the same as the control wafer. Sorption analyses of the wafers indicated localized sorption and similar properties of water in multilayers to those of bulk water. The parameters of sorption implied that lentil and chickpea flour replacement maintained the same monolayer moisture content as the control wafer. It was concluded that wafer sheets with 10% lentil flour replacement had the highest quality.