Study On Sulfur Free Processing Technologyof Konjac Dry Chips

The content of polyphenol and the activity of Polyphenol oxidase were both high in fresh Amorphophallus KONJAC,and enzymatic Browning was very serious.In the traditional production of KONJAC chips,it is necessary to fumigate KONJAC chips with sulfur in order to restrain the enzymatic browning and improve the sensory quality of the chips.As the sulfur fumigation treatment is not conducive to environmental protection and the health of the processing personnel,the KONJAC food processed with sulfur dry chips is also not conducive to the health of consumers,therefore,the dry processing technology without sulfur is of great significance to the production of KONJAC chips.At the same time,because of the surface conjunctival characteristics of Dextran,KONJAC chips are slow in drying speed,drying time is longer,production efficiency is low.In this paper,the methods of enzyme killing,drying and the quality of KONJAC flour were systematically and deeply studied on the basis of the study of the distribution characteristics of the activity of fresh KONJAC corm Polyphenol oxidase:1.Based on the activity distribution of fresh KONJAC CORM,the effects of high temperature steam and microwave irradiation on enzyme inactivation were studied by single factor test and orthogonal test design.The results showed that the activity of Polyphenol oxidase in different parts of fresh Amorphophallus KONJAC CORM was obviously different.Compared with the epidermis and the subcutaneous layer,the activity of Polyphenol oxidase in the subcutaneous layer was stronger The optimum technological parameters for steam inactivation of enzyme in KONJAC chips were as follows: the thickness of KONJAC chips from 3 to 10 mm was treated with saturated steam at 100 °C for 5 min,the thickness of KONJAC chips was 5mm,the microwave power was 800 W and the treatment time was 90 s.2.In order to study the best drying technology of KONJAC chips and reduce the energy consumption,the orthogonal experiment was carried out on the basis of hot air and microwave drying.The results showed that the optimum hot air drying technology was75 °C,the thickness of KONJAC chips was 5 mm,the air volume was 80m3/h,the optimum microwave drying technology was 800 w micro blog power,the thickness of materials was 7mm,the loading capacity was 15.38 kg/m2;The optimum drying technology of KONJAC chips was as follows: the fresh KONJAC chips were dried to 40% moisture content by the optimum microwave drying method,and then dried to 15% moisture content by the optimum hot air drying method.3.In order to study the quality of KONJAC chips processed by the technology of drying KONJAC chips without sulphur,and to provide a practical basis for the market approval and popularization of KONJAC flour and KONJAC food processed by this technology,the contents of glucan,starch,protein,sulfur dioxide,crude fiber,calcium,potassium,magnesium and iron in KONJAC flour were determined.The results showed that the content of glucan was 56.20%(dry basis),the content of sulfur dioxide was 0.027mg/g,the safety of KONJAC dry tablets was higher than that of sulfur-added foods.To sum up,the results of this study have important reference value for the large-scale dry processing technology of KONJAC chips,as well as for the protection of processing environment and workers' health.