Quality and Storage Characteristics of Hot Press Tortilla Prepared from Yam-Wheat Composite Flour

Abstract

Mixtures of refined wheat flour (RWF) with flours from different sources could impact the functional qualities and shelf life of wheat-based products. Storage stability is one of the most critical factors for tortilla quality. Tortillas made from yam (Dioscorea sp.) wheat composite flours were characterized. RWF was substituted with 5%, 10%, 15%, and 20% of fermented yam flour-brown (FYF) and unfermented yam flour-white (UYF). Farinograph water absorptions of UYF-composite flours (65.5% - 77.1%) were significantly (P < 0.05) higher than FYF-composite flour absorptions (60.5% - 61.5%). During storage, moisture contents of composite flour tortillas increased while the RWF-tortilla decreased. Tortilla from FYF-composite flour exhibited greater strength (3.1 N at day zero on average) compared to UYF-composite tortillas (2.1 N at day zero on average), while UYF-composite flour tortillas had good extensibility and rollability properties. The properties and composition type and ratios of flour blends affected tortilla quality during the storage period. The substitution of RWF with 15% or 20% UYF would be more suitable for making tortilla with improved properties compared to that of FYF.