Chilled versus ambient aeration and fumigation of stored popcorn part 1: Temperature management

Abstract

During the summer of 1994, four commercial 121.5 tonne corrugated steel bins of stored popcorn were evaluated for chemical-free pest management and conditioning. Two of the bins were managed conventionally with intensive aeration for moisture conditioning and calendar-based fumigation treatments for pest control. In the other two bins grain temperatures were managed with the Purdue prototype grain chiller. They were monitored and chilled only as needed throughout the summer. The average grain temperature in the core of the chilled bins was 11.3 °C, which was well below the critical 15–17 °C limit for most insect development. The average temperature along the south wall of the two bins was maintained at 17.5 °C. Grain temperatures in the bins conditioned with ambient aeration never dropped below 23 °C, and thus were on average 6–18 ° higher during the same period. Electrical operating costs of chilled aeration were 0.11 cents per kg of popcorn.