Research On The Rice Storage Quality And Quick Determinant Technology Of Electronic Nose

The rice storage quality and quick determinant technology of electronic nosewere studied in this paper. The rice samples at (13.5±0.1)%,(14.5±0.1)%,(15.5±0.1)%,(16.5±0.1)%moisture content were stored210d at30℃,25℃,20℃,15℃respectively oxygen concentration were2%,5%,10%,21%controlled by N2,which were reaped in2010. We detected the changes of rice quality indicators permonth, at the same time we detected the changes of rice odor under different storageconditions through the electronic nose. According the experimental analysis of allthree factors under four levels we can get the following conclusions:(1)Variation of texture quality of riceThe texture quality of rice is related with its initial moisture content; with timewent on, the hardness and the springness of rice under different storage conditionsincreased, while the adhesive would go down, the samples under higher temperatureand moisture changed more rapidly than the lower one on the texture quality(thehardness of sample storage under15℃,13.5%moisture,21%oxygen concentrationadded9.69%, while the one storage under30℃,16.5%moisture,21%oxygenconcentration added58.33%).(2)Variation of MDA valuesWith the time went on, the MDA values of rice samples under different storageconditions increased, the higher of the moisture and the temperature, the more rapidlyof the MDA values changed, lower oxygen concentration can delay the increase ofMDA values. Temperature, moisture, oxygen concentration and storage time affectedthe variation of MDA values significantly, and their four factors had the interaction, tothe MDA values, temperature was of its greatest impact, then was moisture, storagetime, the oxygen concentration one by one.(3)Variation of the number of moldWith the time went on, the number of mold of rice under different storageconcentrations increased, temperature and moisture affected the number of moldsignificantly, while the effect of oxygen concentration depended on the temperatureand moisture, oxygen concentration affected the rice of high temperature and moisturesignificantly, but it was opponent to the low temperature and moisture samples.(4)Variation of rice odor detected by electronic nose The characteristic radar charts of rice samples under different storage conditionsand storage times were different from each other; using the PCA, LDA method toanalyze rice samples, it can distinguish them well; after optimizing the sensors, thefocus of PCA analysis was better; taking a back to sub-experiment to the clusteranalysis of rice samples, its correct rate was up to91.7%.(5)Correlation analysis between rice physical and chemical quality and electronicnose detectionMaking a correlation analysis between rice physical and chemical quality andelectronic nose detection, in the PCA chart, the correlation was not obvious, but in theLDA chart, there was a good correlation between the number of mold and thedistribution of rice samples; there was a high correlation between the number of moldand the response signals of electronic nose; making a PLS analysis to predict thenumber of mold, it showed that there was a big relative deviation, however, result ofcorrect rate that whether the samples were moldy was up to100%.