Effects of storage strategies on physicochemical properties of stored wheat in Ethiopia

Abstract

A postharvest management intervention of wheat grain needs to be examined from technological quality perspectives before its introduction to users. This study was conducted to evaluate the effects of different grain storage strategies on the physicochemical properties of stored wheat. The experiment included six treatments: Filter-cake treated wheat in a polypropylene bag, triplex treated wheat in a polypropylene bag, metal silo, Purdue Improved Crop Storage (PICS) bag, Super GrainPro bag, and polypropylene bag (control). Data on water activity, protein, ash, wet gluten, sedimentation value, and farinograph were determined at two months interval for six months. Mean ash contents of wheat after six months of storage had ranged from 1.58% in Super GrainPro bag to 1.79% in the control while filter-cake and triplex treated wheat exhibited higher ash than wheat in other interventions. Mean wet gluten content after six months had ranged from 24.7% in the control to 27.8% in the Super GrainPro bag. Baseline wet gluten and sedimentation values of wheat in the control, triplex, and filter-cake treatment diminished unlike those in the hermetic containers. Mean farinograph water absorption of wheat after six months had ranged from 54.1% in PICS bag to 61.2% in the control. Storage period did not affect all the measured parameters, except farinograph water absorption, of wheat stored in hermetic containers. Hermetic containers are better options to maintain physicochemical properties of stored wheat compared to the commonly used polypropylene bag. However, the application of filter-cake and triplex powders resulted in increased water absorption and ash content apart from diminished wet gluten content and sedimentation values. This condition may pose a negative influence on the baking performance of flour from wheat treated with the powders. Hence, effective removal of filter-cake and triplex from the treated wheat needs further investigation.