Abstract

Studies conducted in developing countries have shown that nearly 10% to 15% of paddy is lost during postproduction operations due to improper post-harvest techniques. These studies also found; major component of these losses occurred during storage due to practices. Hermetically sealed storage can be used as an alternative method for commercial scale paddy storage with a view to cut down post-harvest losses. Very less research studies have been conducted in this important area. Therefore, this study was conducted to evaluate the effect and impacts of commercial scale modified atmospheric storage conditions for altering of physical properties and quality parameters of paddy under tropical climatic conditions prevailing in Sri-Lanka. In the study storing paddy under commercial level modified atmospheric storage conditions for 9 months and compared quality changes of paddy such as physical properties, milling characteristics and other quality parameters compared against, paddy stored in conventional warehouse. Moreover, oxygen level, temperature inside the modified atmospheric storage and warehouse were also measured. It was observed modified atmospheric storage took 6 weeks to reduce oxygen level from 20.5% to 3.2%. Temperature fluctuation inside the modified atmospheric storage was very low in comparison with warehouse storage. Moisture content of initial warehouse samples and modified atmospheric storage were not significantly different. Modified atmospheric storage paddy samples reported similar initial values in terms of quality parameters such as impurities percentage, immature seed (Bol) percentage and damaged seed percentage even after 9 months of storage. Whereas those values were significant changed in warehouse samples. Weight/mass loss of grain during storage period was significantly low in cocoon (modified) samples. Bulk density and paddy kernel hardness values were significantly reduced in both storage methods against its initial values. Rice kernel whiteness was preserved by modified atmospheric storage in comparison to conventional storage. Germination percentage of paddy was significantly reduced from its initial value in both storage methods. Paddy kernel resistance against milling stress increased during modified atmospheric storage. It can be concluded that modified atmospheric storage has more advantages in comparison to conventional warehouse storage for large quantity commercial grain storage. However, modified atmospheric storage condition must be maintained throughout storage period to gain those advantages

Keywords: Commercial paddy storage; Modified atmospheric storage; Paddy quality