Research On Process Device And Quality Detection Method Of Passivating Enzyme In Germ Rice

Germ rice is a type of rice that is processed with less precision and retains the germ,which contains a variety of nutrients.However,during storage,a large amount of lipase,lipoxygenase and peroxidase will be secreted,which will cause the metabolism of nutrients in germ rice,resulting in poor quality.How to effectively delay the quality deterioration and prolong the shelf life of germ rice during storage is an urgent problem to be solved for germ rice.In view of the existing problems,an enzyme inactivation method using superheated steam combined with hot air was proposed,and the enzyme inactivation device and process,and the quality detection method of germ rice after enzyme inactivation were studied.The main research contents includes:(1)Device design of the germ rice inactivating enzyme.Starting from the demand for enzyme inactivation of germ rice,the overall structure of the enzyme inactivation device was designed,and the components of the heat transfer device were designed and selected through theoretical calculations.Trial production of the device required by the enzyme.(2)Design of germ rice crack detection system.Taking germ rice crack detection as the goal,determine the image acquisition method suitable for crack detection,and determine the camera lens model.After lighting test,it was determined that the backlight source was used as the detection light source;Gaussian filtering,Otsu threshold segmentation and watershed algorithm based on distance transformation were used to denoising,background segmentation and connecting the division of germ rice grains were carried out on the image to extract the single grain area of germ rice;the sub-pixel contour feature was used to extract germ rice cracks;a germ rice crack detection system was developed based on Qt and Halcon platforms.The accuracy rate was 93.57%.(3)Study on the technology of inactivating enzymes in germ rice.First,the effect of tempering process on germ rice cracks was tested,and it was proved that tempering can effectively slow down the occurrence of germ rice cracks after enzyme inactivation.10 s,20min slowing time,and 60℃ slowing temperature,the crack rate was the lowest;the intermittent enzyme killing process was used again to study the effect of enzyme killing on the moisture content,crack rate,whiteness and enzymes of germ rice under different temperature and humidity conditions.The results showed that the enzyme inactivation effect of 110℃,120℃ and 70%RH,80%RH treatment conditions was significant,and the moisture content was stable below the safe value,the whiteness has no obvious change,and the crack rate was about 20%.(4)Research on the storage period and quality of germ rice.Using texture,electronic nose and other technologies and comparing SS110(110 °C,80%RH,treatment 7 times),SS120(120 °C,80% RH,treatment 5 times),untreated germ rice,refined white rice and steamed grain rice for edible taste and flavor change comparison,it was found that the taste of the embryo rice after sterilization treatment was similar to that of refined white rice and the odor change of storage time was the best with steamed grain rice.