干燥花生荚果在不同温湿度条件下的水分含量及霉变研究

Study on moisture content and mildew of dried peanut pod under different temperatures and humidities

研究了不同温湿度条件下干燥的花生荚果(水分含量近6%)在储藏过程中的水分含量变化及霉变现象。结果表明:花生荚果在RH 70%条件下,20℃时经14 d水分含量升至9.18%,无霉变;25℃时经15 d水分含量升至8.47%,稳定而无霉变;30℃时经14 d水分含量升至7.95%,稳定且无霉变。花生荚果在RH 80%条件下,20℃时经10 d水分含量升至10.21%,再经4 d后升至11.27%,出现霉变;25℃时经13 d水分含量升至9.82%,出现霉变;30℃时经13 d水分含量升至9.50%,出现霉变。花生荚果在RH 90%条件下,20℃时经5 d水分含量升至10.44%,再经3 d升至12.75%,出现霉变;25℃时经5 d水分含量升至10.28%,再经2 d后升至10.71%,出现霉变;30℃时经7 d水分含量升至9.54%,出现霉变。同样湿度条件下温度升高花生荚果水分含量降低,20~30℃时,干燥花生荚果在RH 70%条件下吸湿的水分含量不超过10%且不霉变,RH 80%条件下水分含量快速升高并在2周内霉变,RH90%条件下在8 d左右时霉变,因此,超过20℃储存干燥花生荚果时相对湿度不宜大于70%。

The moisture content(m.c.) and mildew of dry peanut pod(nearly 6% m.c.) were measured under different temperatures and relative humidities during storage.At 70% RH,m.c.of the peanut pod increased to 9.18% at 20℃ after 14 days.At 25℃,m.c.was 8.47% after 15 days.At 30℃,m.c.was7.95% after 14 days.No mildew appeared under these conditions.At 80% RH,m.c.increased to 10.21%at 20℃ after 10 days,and then reached 11.27% after another 4 days and mildew appeared.At 25℃,m.c.increased to 9.82% and mildew appeared after 13 days.At 30℃,m.c.reached 9.50% m.c.and mildew appeared after 13 days.At 90%RH,m.c.increased to 10.44% after 5 days and then increased to 12.75%after another 3 days and mildew could be observed.At 25℃,m.c.increased to 10.28% after 5 days,and then to 10.71% after another 2 days and mildew appeared.At 30℃,m.c.increased to 9.54% after 7 days and mildew appeared.In conclusion,under the same humidity,m.c.of peanut pod decreased with the increase of temperature.At 20-30℃,no mildew appeared when RH was 70% and m.c.was not higher than10%.M.c.increased rapidly and mildew appeared when RH was 80% within two weeks.When RH was90%,mildew appeared after 8 days.Therefore,the relative humidity of dry peanut pod during storage should not exceed 70% RH when the temperature is higher than 20℃.