Storage stability and nutrient content of whole maize meal and degermed maize meal

Abstract

Two types of maize meal, dried to a moisture level of 8·0% to forestall mould growth, were placed in airtight containers and stored at room temperature (27°C) for 3 months. Fat acidity value of the whole meal was more than double its original value (from 34·72mg KOHj100 g to 78· 76 mg KOHl 100g) after 2 weeks storage, and at this stage, taste panel results on cooked samples showed development of off-flavour and bitterness. After 12 weeks storage, the fat acidity value of the whole meal was 246·43 mg KOH/l00 g. On the other hand, the initial fat acidity value of the degermed meal, 12·11mg KOH/lOO g, increased to only 36·28 mg KOH/100 g after 12 weeks storage and no odours were detected when cooked samples were tasted. These results showed that development of off-flavours and after-taste due to fat rancidity was much faster in the whole maize meal than was found in the degermed maize meal. Analyses for nutrient content showed that thiamine, riboflavin, iron and phosphorus were significantly reduced by degermination whilst the protein content was only slightly reduced