Deterioration of Stored Rough Rice

Abstract
Grain preservative efficacies of citral and propionic acid (0.3% and 0.5% vol/wt in each case) were tested using high-moisture (17 and 21%) ''Ratna'' rough rice inoculated with conidia of 3 storage fungi (Aspergillus candidus, A. sydowi and Penicillium sp.). Citral (0.5%) reduced considerably the extent of fungal growth but not grain infection. Propionic acid (0.5%) was effective at both grain moisture levels and proved to be a better preservative than citral. The greater the grain moisture and the longer the storage, the higher was the level of compounds required for safe preservation. Consumption of inoculated control grains by albino rats was significantly less than by controls and their body weight decreased. No feed refusal and no significant decrease in body weight was noted with treated grains, thus proving that such grains had practically no adverse effect. Healthy grains and grains treated with citral and propionic acid were used in another feeding experiment where concentration was raised gradually (1-10% vol/wt) or rapidly (3-20% vol/wt). Each concentration was fed for only 4 consecutive days. A reduction in grain consumption and body weight was noted when the concentration of volatile compounds was raised rapidly. When the concentrations were raised gradually, grain consumption and body weight increased up to 2% treatment of each compound. Treatment of feed grains up to 2% of citral and propionic acid has no risk if performed gradually.