Research On Processing Technology Of Dried Potato Slice Heat Pump For Frying

Potato is a kind of grain and vegetable crops with rich nutritional value and medicinal value.The potato resources in our country are very rich,but its great economic value is yet to be explored.In the "twelfth five-year" plan of potato processing industry,our country put forward to "optimize the structure of processed products,improve the potato processing capacity,improve the proportion of potato deep processing products".In early 2015,our country put forward the development strategy of "staple" potato.In 2016,the ministry of agriculture officially issued the guiding opinions on promoting the development of the potato industry,proposing to "industrialize the development of potato as the main grain product".At present,there are many kinds of potato products in the market,but most of them have higher requirements for equipment of the production process and do not conform to the dietary habits of various places in China.Therefore,it is of great significance to research and improve the production process of potato delicacies with local characteristics.There is a habit of eating "potato slices" in southwest China.However,due to the lack of standard and uniform production technology and uneven quality,most of these products are produced by our own home or in small workshops,resulting in the waste of potato raw materials.In this paper,the heat pump processing technology of dried potato slices for frying is studied.The main research contents and conclusions are as follows:1.To explore the heat pump drying characteristics of the potato slices and better drying technology,through to the commonly used seven thin layer drying model selection,and use the Origin software processing the test data under the condition of different thickness,temperature,load,through linear regression fitting processing,set up the Page mathematical model for describing the law of potato slices heat pump drying equation,and then verified equation fitting effect is better.Based on the drying test,the optimal heat pump drying process of potato chips was obtained through the orthogonal test: the slice thickness was 3.0mm,the temperature was 50℃,and the load was 1500 g.2.To improve the heat pump drying rate of potato slices and the quality of dried slices,the potato slices were pretreated by blank control,blanching,steaming,steaming+ultrasonic,etc.,and the effects of different pretreatments on the heat pump drying rate of potato slices and the quality of dried slices were studied.The results showed that compared with the blank control group,steam steaming,steam steaming and ultrasonic pretreatment could improve the heat pump drying rate of potato slices,and the drying time was reduced by 8.6% and 22.9% respectively,and the improvement effect of steam steaming and ultrasonic treatment was significant.Besides,the dried potato slices of the steam+ultrasonic group were found to have the best quality.3.To improve the appearance and color of potato chips obtained by frying potato slices,reduce the fat content,obtain better taste and crispness,and improve the sensory quality of potato chips,the pretreatment technology was studied.By comparing the effects of different pretreatment on the quality of potato chips,such as hot blanching,steaming and steam + ultrasound,the results showed that the fat content of potato chips could be reduced to different degrees by the three pretreatments,among which the effect of steam + ultrasound group was the most obvious,and the fat content decreased by23.83% compared with the control group.Moreover,the crisp chips in the steam+ultrasonic group had a smooth appearance without big bubbles,presenting a uniform and bright yellowish color,with the moderate greasy degree and good taste,the best crispness,the highest total score of sensory evaluation and the best comprehensive quality.Scanning electron microscopy was used to observe the microstructure of deep-fried chips,and it was found that small holes were forming on the surface of the chips in the steam + ultrasonic group,and approximate size and evenly distributed cavity structure was also formed inside the chips,thus giving the chips a better crispness.4.To select potato varieties that are suitable for processing into dried potato slices and can get higher quality crisp chips by frying,a quality comparison study was conducted by processing 9 common varieties of potato into dried slices and fried crisp chips.The results showed that the color,hardness,and so on various aspects of potato chips of different varieties were significantly different,and the chemical components such as reducing sugar and protein content were slightly different.Besides,the correlation analysis between chemical composition and color of raw potato,quality of dried potato slices,and quality of fried chips were further discussed,which provided the theoretical basis and technical guidance for the selection of potato chips and fried potato chips.5.To extend the shelf life of dried potato slices,it is necessary to explore the suitable storage conditions and packaging methods.The effects of storage temperature,humidity,and packaging method on the moisture content,reducing sugar content,color,and the total number of colonies of dried potato slices during storage were studied.The results showed that the storage temperature was 25℃,the relative humidity was 65%,and the packaging method of aluminum foil bag filled with nitrogen could ensure the moisture content and the total number of colonies to reach the standard during the storage of dried potato slices,and the effect on reducing sugar content and color in the dry slices was small,which ensured the better quality before the storage of dried potato slices and was more conducive to the storage of dry slices.