Research Of The Deodorization Technology Of Konjac Flour

Konjac flour, as the raw materials of Amorphophallus konjac products, smells fishy, and seriously affect the unique flavor and taste, and restricting the rapid development of industry and the market expansion of konjac. So the technique of how to remove the bad smell has important research value and economic significance.In this study, konjac powder as the raw material, using the principle of low concentration of hydrophilic organic solvent can remove the peculiar smell of konjac powder, first, analyzed the volatile substances in the extracting fluids by ethanol; then, compared the flavor remove effects of ethanol and acetic acid in different conditions; finally, using ultra-sonic and microwave-assisted extraction for further bad flavor removing research. These main results are as follows:1.After the SPME-GC-MS analysis, the volatile substances in extracting fluids by ethanol are quite complex, mainly including trimethylamine, camphor, nonanal, oxidized linalool oxide, etc.2.Using the ethanol for Konjac flour bad flavor removing, the optimum extracting conditions are:the concentration is30%, extracting for4h, temperature80℃。Under these conditions, the glucomannan content of konjac flour is65.48%, trimethylamine content321.35mg/kg, smell sensory evaluation score5.3, almost no bad smell.3.Using the acetic acids for Konjac flour bad flavor removing, the optimum extracting conditions are:concentration is30%, extraction time was4h, extraction temperature is60℃. Under these conditions, the glucomannan content of konjac flour is66.82%, trimethylamine content161.82mg/kg, smell sensory evaluation score6.7, almost no bad smell.4.Using ultra-sonic treatment for Konjac flour bad flavor removing, the optimum conditions are:ultrasonic power80w, ultrasonic time30min, solid-liquid ratio is10:150, under these conditions, the glucomannan content of konjac flour is72.94%,trimethylamine content142.90mg/kg, smell sensory evaluation score7.6, the viscosity values is17.52Pa-s, obviously no bad smell.5.Using microwave treatment for Konjac flour bad flavor removing, the optimum conditions are:microwave power is700w, microwave processing time12min, solid-liquid ratio10:150, under these conditions, the glucomannan content of konjac flour is70.35%,trimethylamine content223.74mg/kg, smell sensory evaluation score7.6, the viscosity value14.35Pa·s, no obvious smell in konjac flour.6. After the four kinds of odor removal method of various physical and chemical indexes, under the optimal conditions of acetic acid, the ultrasonic assisted extraction of konjac flour in addition to smell the best.