Changes in Functional and Pasting Properties of Trifoliate Yam Flour during Storage

O A Abiodun,R Akinoso,O J Oluoti

doi:10.4314/jasem.v18i2.26

Abstract

This work aimed at determining the changes in functional and pasting properties of trifoliate yam flour during storage. Freshly harvested trifoliate yam tubers were processed into flour and stored in sealed low density polyethylene polyester for four months. Functional and pasting properties of the flour were evaluated monthly. Moisture contents ranged from 7.49 to 15.30 %. Moisture contents increased with month of storage. Bulk density ranged from 0.58 to 0.69 g/cm3, water absorption capacity 1.44 to 1.93 ml H2O/g and swelling index 1.38 to 2.22. The functional properties decreased with length of storage. Flour obtained at the initial period had the least peak viscosity (3180 cP) while the highest value (3338 cP) was at the second month of storage. Storage of trifoliate yam flour improved the holding strength and final viscosities of the flour. Holding strength and final viscosities increased with length of storage. Flour stored at fourth month had higher setback value (1098.5 cP). There were reductions in the pasting time of the flour with storage periods. There were no significant differences (p>0.05) in pasting temperatures of the flours. Storage of trifoliate yam flour for three months is advisable due to high moisture contents which may be detrimental to keeping quality of the flour.Keywords: Trifoliate yam flour; storage time; pasting properties; functional properties; environmental condition

Highlights

Yam flour is a fine powder made from processing of yam tuber
Amala is a traditional thick paste consumed in West Africa and it is prepared from blanched dried yam flour with particular texture (Akissoe et al, 2004)
Moisture content of the fresh flour was lower than the stored flours

Summary

Introduction

Yam flour is a fine powder made from processing of yam tuber. It is the major ingredient in the making of Amala in Nigeria when reconstituted (Akissoe et al, 2003). This paper presents the changes in functional and pasting properties of trifoliate yam flour during storage. Moisture content was analyzed using standard method of AOAC (2006), bulk density using Udensi and Okaka (2000) method, water absorption and swelling index using method of Iwuoha (2004). Moisture content of the fresh flour was lower than the stored flours.

Objectives

Results

Conclusion