| Antheraea perny has a long culture history in China,the tussah pupa skin is usually regarded as a by-product of food processing,in which the content of chitin is very considerable,the chitin extracted from tussah pupa skin can be degraded into low molecular weight chitosan(LMWC)containing a variety of bioactivities,which can be widely used in various fields.However,there are few studies at home and abroad.This study conducted research based on this uses to improve the utilization rate of tussah pupa skin and make it have higher application value and economic value.Skin of tussah pupa used as raw material,in this study,and after deacetylation reaction,chitosan was prepared and enzymatically degraded to obtain LMWC.The physical and chemical properties of LMWC were studied and the LMWC was prepared into effervescent tablets.The experimental results were as follows.(1)Chitin was obtained through deproteinization and decalcification from tussah pupa skin,and the chitin yield was 36.31±1.21%.During the chitosan preparing experiment,the primary lye method and the intermittent lye method were compared,and it was found that the intermittent lye method could obtain better degree of deacetylation,and the molecular weight of the prepared chitosan was 374.13 k Da.The structure of tussah pupa chitosan was compared with that from commercially chitosan by Infrared Spectroscopy,the results showed that the two kinds of chitosan had similar main characteristic absorption peaks.(2)Degradation of tussah pupa chitosan,at 50?,pH5.0,cellulase dosage was2500 U/g,enzymolysis was carried out for 24 h.The 75.0%ethanol-precipitated low molecular weight chitosan(75.0%EP-LMWC),87.5%ethanol-precipitated low molecular weight chitosan(87.5%EP-LMWC)and 87.5%supernatant low molecular weight chitosan(87.5%S-LMWC)was obtained by the ethanol fractionation precipitation,the molecular weights were 8292.69 Da,10124.45 Da and 5342.00 Da,respectively.According to TLC results,87.5%S-LMWC contained ingredients with a degree of polymerization below 7.In the three kinds of LMWC,87.5%EP-LMWC had relatively good hygroscopicity,87.5%S-LMWC had relatively good moisture retention.In the stability study,it was found that with time and temperature increased,the Maillard reaction gradually progressed,the content of reducing sugars gradually decreased.In order to ensure stability and extend the utilization time,LMWC was best stored in the range of 20-30?.In the study of antioxidant activity,it was found that LMWC had the ability of scavenging·OH radical,DPPH radical and reduction ability.Among them,the best antioxidant ability was 87.5%S-LMWC.In the antibacterial activity study,it was found that 75.0%EP-LMWC had the best effect on inhibiting the growth of E.coli,and 87.5%EP-LMWC had the best effect on inhibiting the growth of S.aureus.(3)Using 87.5%S-LMWC as raw material,the formulation of tussah pupa LMWC effervescent tablets was optimized through orthogonal experiments.The result showed that with lactose as the filler,effervescent disintegrants ratio(sodium bicarbonate:citric acid)1:1.25,effervescent disintegrants addition amount was 40%,87.5%S-LMWC addition amount was 7.5%,PEG6000 usage amount was 5%,stevia usage amount was 3%,the prepared effervescent tablet has qualified appearance,rapid disintegration and good taste.In summary,this study took tussah pupa skin as the research object,the tussah pupa LMWC extracted and prepared has good antioxidant and antibacterial abilities.On this basis,the tussah pupa LMWC effervescent tablet had prepared,which enriched the types of effervescent tablets and increased the antioxidant active ingredients in effervescent tablets,improved the utilization rate of LMWC,in order to improve the comprehensive utilization system of sericulture,tap the potential of deep-level development of tussah pupa,increase the income of sericulture farmers,and increase the added value. |
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