CHANGES IN PHYSICOCHEMICAL PROPERTIES OF INSTANT KUNUN ZAKI FLOURS PRODUCED FROM MILLET (PENNISETUM TYPHOIDUEM) AND MALTS OF COWPEA (VIGNA UNGUICULATA) AND SOYBEAN (Glycine max) DURING STORAGE.

ABSTRACT

In this study, instant kunun zaki powders were produced from millet-cowpea malt and millet- soybean malt. The instant powders were packaged in polypropylene plastics and stored for 3 months. During this period, studies of the changes in physiochemical and functional properties of the packaged flour were carried out every 30 days for 3 months. Production of instant powders was by blending millet with malt of cowpea for millet cowpea malt (MCm) and millet with malt of soybean for millet-soybean malt (MSm) each in the ratio of 70:30 w/w. Ginger was added to each blend in the ratio 15:1 w/w. The blends were incubated at 28+30C for 15 minutes and instantized by steam-heating for 10 minutes followed by oven drying at 500C to a moisture content of 6.23% for MCm and 6.34% for MSm. The flour blends were then packaged in polypropylene plastic (12x18cm) and stored for three months at 28+30C. During this storage period, studies of the changes in physiochemical properties of the packaged flour were determined every 30 days. The results showed that diastatic activities of cowpea and soybean increased with malting, with that of cowpea being higher (63.330L) than that of soybean (30.000L). Protein and sugar contents increased after malting, whereas fat and TBA content decreased with malting. During storage however, there was a general increase in moisture content, sugar, fat, TBA, tannin and trypsin inhibitor in all the samples. Protein content decreased with storage. Water absorption capacity, bulk density, solubility, dispersibility and viscosity decreased with storage time. The particle sizes of the flours increased with storage.