EFFECTS OF MOISTURE-TEMPERATURE REGIMES ON STORAGE OF YELLOW MUSTARD SEEDS (SINAPIS-ALBA L)

Biochemical and mycological changes in yellow mustard seeds stored at temperature-moisture levels typical of commercial storages in western Canada were monitored for 147 days under declining and constant temper ature regimes. Parameters assessed included the following: time requir ed for development of off-odours and visible mould, free fatty acids, conductivity (seed electrolyte leakage), germination, occurrence of pa rticular fungi and their association with off-odours, oil content and seed colour. Of the quality parameters monitored, the presence of off- odours was most closely related to the onset of deterioration in quali ty of stored yellow mustard. Post-harvest Eurotium spp were associated with the development of off-odours. Conductivity increased and germin ation decreased at 44 degrees C. Generally, Eurotium spp increased and Alternaria decreased in seed stored at high temperature and moisture conditions. In samples stored at an initial temperature of 31 degrees C and 110 g kg(-1) moisture content (MC), off-odours occurred by 28 da ys and visible mould by 63 days; at 31 degrees C and 98 g kg(-1) MC no off-odours or visible moulds were present after 147 days. Moisture co ntent/ temperature/time safe storage guidelines were derived from the laboratory data and related to yellow mustard data collected from farm bins in Manitoba and Saskatchewan. The guidelines are intended for es timating yellow mustard storability, particularly during the first 5 m onths after binning by producers and grain handlers in the northern co ntinental climatic zones of western Canada. Yellow mustard is less lik ely to spoil than canola under the same seed moisture, temperature and time storage conditions.