Short-Term Hermetic Storage of Wet Maize and Its Effect on Quality

Abstract

Maize is a major crop grown in many regions of the world for human consumption, starch production, and animal feed. After harvest, maize is dried to avoid spoilage caused by fungal growth. However, in the humid tropics, drying maize harvested during the rainy season poses challenges. In such instances, temporary storing maize under hermetic conditions may preserve grain quality while waiting for conditions suitable for drying. Wet maize at the moisture contents (m.c.) of 18, 21, and 24% was stored for up to 21 days in both hermetic and non-hermetic jars. The stored maize was assessed, every 7 days, for germination and related parameters, presence of visible mold, and pH. After 21 days of storage at 18, 21, and 24% m.c., maize germination decreased by 28.5, 25.2, and 95.5 percentage points, respectively, in hermetic jars; and by 28.5, 25.2, and 94.5 percentage points in non-hermetic jars (control). There was visible mold on maize stored in non-hermetic jars after 21 days regardless of m.c. Maize at 21 and 24% m.c. stored in hermetic conditions underwent lactic acid fermentation that reduced the pH. The findings suggest that maize at 18 and 21% m.c. can be stored for 14 and 7 days, respectively, under hermetic conditions without significant loss of quality. Further research is needed to thoroughly assess the application of these findings for temporarily storing and subsequently drying maize on farms and along the grain value chain.

Hermetic Bags: A Short-Term Solution to Preserve High-Moisture Maize during Grain Drying

“…Previous research has documented no changes in the m.c. of grain stored in hermetic bags after several weeks [ 20 , 30 ]. The change in m.c.…”

“…Previous research has demonstrated that, during hermetic storage, the germination decreases more rapidly as the m.c. increases [ 21 , 30 ].…”

“…Research on the hermetic storage of maize at 21% m.c. revealed that germination, with minimal reduction, was maintained for only 7 days in jars [ 30 ]. Oxygen consumption and CO 2 production were plotted over time for maize kept in jars [ 30 ] and PICS bags at three m.c.s (18, 21, and 24%) (current study).…”

“…Maize was then divided into three batches, with each batch either being rewetted using a drum roller to achieve a target m.c. of 21 or 24% or dried to 18% [ 30 ].…”

“…Research has demonstrated that temporarily holding high-moisture maize in hermetic jars has minimal effects on maize quality [ 30 ]. This study shows that wet maize at 18 and 21% m.c.…”