Study On Pericarp Degradation And Relevant Enzymes During Pepper (Piper Nigrum L.) Peeling By Solid State Fermentation

Pepper(Piper nigrum L.)is known as "black gold",is the important spices,is widely planted in Hainan and Yunnan in China.More than 90%of pepper products were white pepper.Traditional retting,mechanical,enzymatic and fermentation were white pepper processing methods.Solid-state fermentation is traditional method in China,the advantage of this method is that,the fermentation time is short,the cost is low,suitable for use in rural areas.Studied on the changes of major enzymes,analyzed the pepper peel pectin component structure in solid state fermentation,In order to explore degradation of pepper pericarp of pepper in solid-state fermentation process,clarify biochemical mechanisms of biological peeling foundation.The main contents and conclusions are as follows:(1)Determination the changes of major enzymes,the results show that the whole pepper in solid-state fermentation process,polygalacturonase highest activity in the fermentation 48h of 164.81 U/mL;pectinesterase inmaximum enzyme activity 1454.29 U/mL at 36h;cellulase activity has a maximum at 48h 1327.32 U/mL;minimal xylanase activity,60h when the maximum 534.15 U/mL;protease in 48 h and reached the peak 550 U/mL,undetected pectinlyase activity.Then using high purity enzymes,including pectinase pectinase P4716(both main component of polygalacturonase,pectinesterase,and a small amount of hemicellulase and cellulase),cellulase,xylanase,alone and in combination peeling test results were as follows:with the increase the enzyme concentration of the solution,the relative peeling rate will increase,which polygalacturonic acid,pectin esterase,pepper peeling is a key enzyme;used alone cellulase,hemicellulase when after peeling pepper at different times had no effect,and pectin esterase synergy of pepper fruit peeling rate has improved to some extent,cellulase,hemicellulase synergistic effect in pepper peeling process.(2)Analyzed the changes of peeling,during the 48 h after Inoculation,with the extension of fermentation time,the content of pection were gradually decreased.water-soluble pectin content decreased from 35.70 mg/g to 22.12 mg/g,acid-soluble fruit the rubber content 46.11 mg/g down to 4.27 mg/g,the chelate pectin 27.38 mg/g down to 13.06 mg/g.(3)Infrared spectroscopy,ion chromatography and HPLC were used to analyze the changes of pectin components and their contents during pepper peeling by solid-state fermentation.The results showed that the water-soluble pectin and acid-soluble pectin were high degree of esterification pectin,while the chelating pectin was low degree of esterification pectin.The content of water-soluble pectin increased in the first 36 h and then decreased during fermentation,while the content of acid-soluble pectin and chelating pectin increased after ripening with ethephon and then decreased during the whole fermentation process.Galacturonic acid in the pectin backbone was degraded rapidly in 24-48 h.Arabinose in the branch chain was degraded rapidly in 12-24 h,while galactose in the branch chain was degraded rapidly in 12-24 h.Galactose and arabinose were almost completely degraded in 48-60 h.