Different Storage Techniques Effect On The Quality Of Roasted Peanut

Roasted peanut is one important form of the peanut snack food. The fat content ofroasted peanut is high and the content of unsaturated fatty acids also is very high, so theroasted peanut is susceptible to rancidity deterioration by the influence of light, heat,oxygen, moisture, etc., which brings economic damage to the enterprise, thus, it isnecessary to study on the storage technology of roasted peanut. In the thesis, vacuumnitrogen storage technology has been used and a preliminary study on the roasted peanutnutrition changes in the storage processing. The main conclusions are as following:1. Regression analysis and parameter optimization of the vacuum nitrogen storagetechnology were optimized by response surface methodology and the optimal parametersare as follows: pumping time is23s, inflating volume is1.43L and the quality of peanut is134g. The nitrogen content is97.824%in the optimal condition. The pumping time andinflating volume has highly obvious influence on the nitrogen content of peanut shell, thequadratic partial regression coefficient of pumping time and inflating volume is significant.It indicates that the effect of experimental factors to response value is not a single linearrelationship. The size of vacuum packaging is26.8cm×18cm.2. The optimum extracted process of the roasted peanut kernels is as follows: theextract agent is petroleum ether, extraction time is7h, extraction temperature is55℃andthe solid-liquid ratio is1:12. The oil yield is99.21%in this experimental condition.3. The roasted peanut has four different packaging. The PV and AV of oil are increasedwith increasing storage time and the tendency was more obvious at later growth stage. Theeffect of peanut storage in the experiment is as follow: vacuum packing＞vacuum nitrogenpacking＞bag nitrogen packing＞normal packing. The best storage effect is vacuumpacking in the processing.4. Unsaturated fatty acid content in peanut kernel oil in both raw peanut and roastedpeanut is the highest, which is80%. The content of unsaturated fatty acid decreased andsaturated fatty acid increased from raw peanut to roasted peanut. In the absence ofpro-oxidative factors exist, the fatty acid composition of roasted peanut kernel remainedlargely unchanged in the accelerated aging process after vacuum nitrogen packaging.5. The protein content and soluble sugar content was22.6～24.34%and6.10～6.24%,respectively, in the four different kinds of packing roasted peanut, which were slightchange. Fat content of the four different storage techniques roasted peanut decreased,decreased the slowest by the vacuum packing and decreased the fastest by the commonpackaging.