Fungal Susceptibility at Four Temperature‐Moisture Combinations and Carbon Dioxide Kit Color Reader Evaluation

Abstract

The susceptibility of shelled corn to invasion by storage fungi was assessed using a carbon dioxide (CO2) test kit. Shelled corn samples were rewetted to either 16 or 21% wb moisture content (MC) and incubated ≤80 hr at either 24 or 30°C in sealed glass jars. CO2 concentration in the jars was quantified using the color number (0–5) of an indicator gel, which was determined either by visual comparison to a color card (VR) or using a Digital Color Reader (DCR). Plots of DCR color numbers versus time were smoother than those for VR color numbers. The DCR was better able to distinguish differences among samples, especially when color numbers were <2.0. The highest coefficients of determination (r2) for linear regressions of color number versus ergosterol difference were 0.75 for the DCR readings and 0.73 for the VR readings. Rankings of fungal susceptibility were similar at all four temperature‐MC combinations and many r2 values for linear regressions comparing readings at other conditions with those at 21% MC and 24°C were statistically significant (α ≤ 0.05). Incubation conditions and time of prior storage had a noticeable yet relatively minor effect on which fungi infected the kernels.

Temporal valuation of corn respiration rates using pressure sensors

“…Huang et al (2013) and Chidananda et al (2014) reported that respiration rate increased when temperature and grain moisture content increased. Moog et al (2010) reported that the temperature had a greater effect than moisture content on fungal susceptibility measurements during the storage of shelled corn samples. G omez et al (2014) mentioned that the high temperatures accelerate chemical reactions and respiration rates as well as they expedite the occurrence of the climacteric peak.…”

CO2 respiration rates of einkorn wheat at different temperature and moisture contents

“…Lacey et al (1994) concentrations increased with the increase in storage duration, grain moisture content, and temperature. Moog et al (2010) reported a similar effect where the temperature had a higher effect than grain moisture content on fungal susceptibility measuring during the storage of shelled corn cereals. Huang et al (2013) Lacey et al (1994) cited that respiration increased linearly with temperature up to 35 °C and that it also increased with time and seed moisture content in barley, wheat, rapeseed, and linseed.…”