Chapter Twenty-Four - Physicochemical properties of amadumbe flour derived from amadumbe corms subjected to different storage methods

Abstract

This study aimed to investigate the effects of different storage conditions, including evaporative cooling, on the proximate composition and the functional and morphological quality attributes of amadumbe flour. Amadumbe flour was derived from corms subjected to five storage conditions: low-cold storage, high-cold storage, CoolBot and evaporative cooler storage, underground storage, and ambient storage as a control. The corms were stored in three replications using a randomized complete block design. Three different experimental designs were used in this chapter. The first two experimental designs had two treatments: storage conditions and storage period. However, sampling was carried out on every 14th day for 70days in experiment one and on days 0 and 70 in experiment two. The third experimental design had three treatments: storage conditions, storage period, and temperature, and sampling was carried out on every 14th day for 70days. The data were analyzed using Duncan’s multiple range test at a 5% significance level. The results obtained in this study showed that both storage conditions and storage period had a significant impact (P<.05) on increasing crude fat, reducing sugar content, water-holding capacity, and oil-holding capacity, and decreasing the swelling power and solubility of amadumbe flour. High-cold storage was the best method for preserving the quality attributes of amadumbe flour. It resulted in the lowest reduction in moisture content (2.67%), crude protein (5.89%), swelling power (16.44%), solubility (20.41%), and L* (0.04%) and in the degradation of amadumbe flour starch granules. It also resulted in the highest increase in crude fat (55.56%), oil-holding capacity (94.58%), and a* (137.28%). Ambient storage was the worst storage method for preserving the quality attributes of amadumbe flour. It resulted in the highest decrease in moisture (7.02%), solubility (31.59%), and L* (2.51%). It also resulted in the lowest increase in crude fat (2.78%) and in reducing sugar content (91.75%), water-holding capacity (70.85%), and oil-holding capacity (85.99%). The microscopic morphologies of amadumbe flour were irregular and polygonal in shape. On day 0, the flours exhibited larger, densely packed granular particles connected by fibrous materials. After 70days of storage, there was a reduction in the size and compactness of the granular particles. This study found that CoolBot and evaporative cooler storage is the second-best storage method after high-cold storage. Therefore, evaporative coolers can be used as an alternative method in cases in which a refrigerator cannot be afforded.