| Rapeseed is an important oil crops worldwide, minimize rapeseed production losses, to ensure the quality of rapeseed safety is of great significance. This paper mainly studies the efficient drying, storage and quality detection technology of rapeseed. Mainly includes the following four parts:(1) Hot air temperature, rapeseed’s moisture content and volume of hot air as the main factor were investigated. Response surface methodology was adopted to optimize rapeseed fluidized bed drying process. Taking drying time, acid value and peroxide value of rapeseed oil, the germinating capacity of seeds as target parameters, the four factors were scored by using the comprehensive evaluation of the membership-degree method. In addition, the quadratic polynomial regression model was established to optimize the drying techniques, the model fit better. The results showed that effects order of three factors on rapeseed fluidized bed drying were as follows:hot air temperature, the volume of hot air, and then rapeseed’s moisture content. The optimal parameters of fluidized bed drying method for rapeseeds were air temperature of 57.93℃, rapeseed’s moisture content of 22.56% and hot air volume of 58.66m3/h, then the largest comprehensive score of 0.865 was obtained.(2) In this experiment the NMI20-nuclear magnetic resonance analyzer was used to measure the oil content of rapeseed, optimize the quality and the water content of test samples. Then compared it with Soxhlet extractor method, and the precision of experiment was carried out. The results show that the determination coefficient of nuclear magnetic resonance analysis software of oil and water content R2 is equal to 0.9991, and it fits very well. Reasonable weight of the sample is between 1 g and 1.5 g, and was dried to constant weight; Compared with Soxhlet extractor method, has good contrast, the method is applied to the determination of the oil content of rapeseed with a high precision.(3) Studying on the main factors affecting the safe storage of rapeseed, and using different packaging materials to do storage experiments (temperature:20 degrees,35 degrees, moisture content:8.4%,14.3%, packaging materials:high barrier, middle barrier, low barrier, inferior barrier), then measured the quality each 20d, summed up the changes during storage of rapeseed, and drew a conclusion:During the storage, the germination rate and oil content of rapeseed showed a downward trend with the long storage time, and a significant positive correlation between them. At the conditions of the same temperature and moisture, high barrier packaging materials plays a positive role in keeping the germination rate and oil content of rapeseed. The germination rate and the oil content were affected distinctly by the storage time and packaging materials (P<0.01). With the extension of storage time, the number of molds and yeasts increased to a peak firstly, and then declined gradually. Effect of storage time and packaging materials on the total number of rapeseed surface mold was very significant (P<0.01).The oil acid value and peroxide value of the rapeseed stored in different packaging materials was increased with the long storage time. The positive correlation coefficient is 0.918. The oil acid value and peroxide value were affected distinctly by the storage time and packaging materials (P<0.01).The germination rate of rapeseed has extremely negative correlation with mold, acid value and peroxide value; the oil content of rapeseed has extremely negative correlation with mold, acid value and peroxide value; there was a significant positive correlation between mold and the acid value, which has a significant correlation with peroxide value.(4) Using an electronic nose to analysis the rapeseed samples which were stored for 120 days (8%,35℃), electronic nose detection data points changed greatly when it was stored for 40 days. It suggests that at this point, the most violent rapeseed quality change. The optimal extraction conditions which was chose using solid phase micro extraction (SPME) technology (50/30μm DVB/CAR/PDMS, extraction temperature of 70, balance for 60min, analytical time 3min) combined with the GC-MS technology analysis found that, volatile species of rapeseed will increase in the storage, Principal component analysis was performed for all volatile substances of various species, satisfied the requirements of the principal component analysis. And we concluded that Undecane (A1)、Dodecane (A2)、 Dodecane,2,6,10-trimethyl-(A4)、 Pentadecane,4-methyl-(A12)、 Hexadecane,2-methyl-(A17)、 Octadecane (A18)、 1-Dodecene (A22)、 1-Tridecene (A23)、 7-Hexadecene, (Z)-(A24)、 2-Tetradecene, (E)-(A25)、 1-Octanol (B2)、 1-Nonanol (B4) Benzeneacetaldehyde (C3)、 Nonanal (C4)、 Undecanal (C8)、2-Nonanone (C2)、2-Pentadecanone, 6,10,14-trimethyl-(C3)、 2(3H)-Furanone, dihydro-5-pentyl-(F2) Dimethyl phthalate (F3) may be highly related to the quality changes during storage of rapeseed. |
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