Carbon Dioxide Production in Stored Maize as Affected by Moisture Content, Level of Broken Corn and Foreign Materials and Infestation by Sitophilus zeamais Motschulsky

Abstract

Carbon dioxide gas production in maize, mixed with 0, 5 or 10% broken corn and foreign material (BCFM), and 0 or 100 adult maize weevils at 13, 16 or 19% moisture content (mc) was studied in 1.8 liter thermos containers which were held at 26.6°C and 60±5% r.h. for 80 days. CO 2 was measured at 7 day intervals using an infrared gas analyzer. At 13 or 16% mc, higher CO 2 production was measured in infested maize than in uninfested maize, and BCFM did not significantly affect CO 2 production. At 19% mc, CO 2 production was greatly increased regardless of the presence of insects and BCFM. CO 2 produced over 12 weeks was 110–166g/kg. The number of live maige weevils after 80 days was 538 in 13% mc, 344 in 16% mc and 48 in the 19% mc Therefore, respiration of fungi such as Aspergillus glaucus, Aspergillus candidus and Aspergillus terreus other than that of insects appeared to more greatly influence CO 2 production than did the insects at 19% mc The moisture content and presence of maize weevils were major factors affecting respiration during storage, but level of BCFM did not significantly affect CO 2 production. The CO 2 produced over 12 weeks was 135–147 g/kg in infested maize at 13% and 136–144 g/kg at 16% mc.