Study On Roasting Technology Of Hulled Peanut And Nitrogen-infilling For Its Antioxidation

Roasted peanut is an important peanut snack food in China. There are some problems exsisted in roasted peanut food, such as backward processing, long production cycle, high energy consumption, quality varying and so on. In order to improve the production technology, we try to use the vacuum drying technology instead of traditional baking methods, the production cycle was shorten and energy consumption was lower significantly. we also research the physical and chemical index variation of nitrogenfilled products in the long storage by using pumping nitrogen into peanut shell instead of antiseptic preservation, then compare the storing period time of peanuts among pumping nitrogen into peanut shell, vacuum packing, nitrogen-infilling packaging and customary packing.The main conclusions was obtained as follows:1,The composition of flavoring sauces for roasted peanut was optimized using orthogonal experiment:salt 60g/kg, liquorice lOg/kg, sodium cyclamate 0.65g/kg. Roasted peanuts using this recipe tasted sweet and crisp, was welcomed by people.2,Vacuum processing for flavor absorbing was studied, results showed that the effect of flavor absorbing by vacuum processing is far higher than customary processing.3,Analysis the effect of customary drying and vacuum drying on peanut moisture on crisping stage. The result shows that time consuming of vacuum drying is half of customary drying. We applied vacuum drying method for roasting process of hulled peanut, then testing the variety of acid value and peroxide value of vacuum drying products in 12 months, acid value of lipids reached 0.93 mg KOH/g after 12 months comply with GB1733.1-1933 standards of peanut oil. Peroxide value reached 18.9meq/kg after 6 months, slightly exceeding the standard. It shows that vacuum drying can prolong shelf life in some degree.4,We tested pumping nitrogen into peanut shell for antioxidant compared with adding antioxidant. Result showed that both of them can delay peroxide value's raising. The shelf life of roasted hulled peanut was prolonged from 3-5 months to one year. And we got a pure physical antioxidant processing patent of roasted hulled peanut, the patent number is 201110044702.6.5,Physical and chemical index variation of roasted pulled peanut was analysed on the same wrapper while pumping nitrogen into peanut shell, vacuum packing, nitrogen-infilling packaging or customary packing. The results showed that the effect of spoilage inhibiton by using pumping nitrogen into peanut shell is the same as nitrogen-infilling packaging.