Corn cob dry

Moisture increase with storage

Besides the original moisture in which cobs are stored there is strong evidence indicating

that moisture content inside and outside located piles in the Midwest were found to increase

during storage e.g. 36 months of storage study carried on by Dunning et al. (1948). Also, after

one year storage, sawdust piles slightly increased the interior moisture but more prominent the

surface of the pile became highly saturated (White et al., 1983). Also Smith et al. (1985) noted

that moisture increased differently depending on the layer of the pile as initially stored at 12-

18%. After 24 months, in large piles the outer 0.9m was 40 to 80% while interior reached 33%.

Besides weathering factors such as rainfall, snow, high relative humidity days, etc., the water

produced during respiration process would result into raise of water within the material. From an

hypothetical degradation of 10g of cellobiose per 100g of original DM (approximately 10%

degradation), would result in 5.56g of additional water to the material having double effect on

moisture content, firstly increasing the water content on the material and also reducing the

proportion of dry matter. It should also be important to highlight the potential positive feedback

22

that greater moisture could generate greater deterioration and, consequently, this deterioration

will potentially increase the moisture too. It has being cited that moisture gains also promotes

increases in temperature as a result of oxidation or fermentation (depending if the conditions are

aerobic or anaerobic) also leveraging microbial respiration between certain temperature range.

This heat produced could eventually be accumulated to the point of reaching uncontrollable

temperatures were spontaneous combustion could occur.