Study on Grain Quality Attributes of Rice Varieties Stored in Selected Packaging Materials for Nine Months

Abstract

Sri Lanka has achieved self-sufficiency in rice production over the past few years. Since over production are experienced possibilities of rice exportation need to be studied. This study was conducted to evaluate suitability of some packing materials; common poly-sacks, hermetic sacksand PET 10/LLDPE 60 bags for the storage and their effect on the rice grain quality attributes during storage. Seven rice varieties At 362, At 593, At 11-1425, HHz36, At 306, Bw367 and At 405 which has the potential for exportation were stored for nine months in above packs. Physical quality parameters, cooking and eating quality parameters, nutritional quality parameters and microbiological parameters were evaluated in all rice samples before and after storage. There was a significant increase (p^O.05) in moisture content with storage time and moisture increment was more prominent in poly-sack compared to other two materials. Bulk density, true density, and thousand grains mass decreased over storage time for all the packaging materials where it was more significant in poly-sack samples compared to initial and PET 10/LLDPE 60 bags showed higher values than hermetic. Grain dimensions and gelatinization temperature were not affected by all storage methods. Ash and fat content also decreased during storage methods compared to initial samples. Though, there was an increment in microbial count of rice varieties stored in hermetic and poly-sacks during the nine months, it was within safety level. Higher rice weevil damage was detected in poly-sacks than hermetic stored rice, no weevil damage was found in polyethylene. The results of this study concluded that most of the rice grain quality attributes were favorably affected by PET 10/LLDPE 60 bags than hermetic and poly-sack packaging because the hermetic package lost its air tight condition due to insect damage and act more similar to poly-sack package.