Optimization Of Enzymatic Extraction Of Arabinoxylan From Triticale And Its Preliminary Study On The Structure And Function

As a new natural black food resource,triticale is rich in non-starch polysaccharide(NSP),phenolic acid,anthocyanin and other biologically active substances.This experiment takes triticale as the research object,adopts ultrasonic-assisted enzymatic extraction method(xylanase,cellulase,the combination of xylanase and cellulase)to isolate arabinoxylan(AX)from triticale,and optimizes the extraction process by response surface methodology.Besides improving the yield of AX,the structure and in vitro physiological function of AX extracted by different methods(water extraction,alkali extraction and alkali extraction of residue after enzyme extraction)were also determined.Meanwhile,the relationship between AX structure and function was discussed to provide theoretical basis for further improvment of the processing and utilization of triticale.The main results were as follows:1.The results showed that the optimum conditions for ultrasonic-assisted xylanase extraction of AX were: xylanase,40 mg;ultrasonic time,90 min;ultrasonic temperature,56?;ultrasonic power,150 W.The yield of xylanase exteactable arabinoxylan(XAX)was4.83% under this condition.The optimum conditions for ultrasonic-assisted cellulase extraction of AX were: the dosage of cellulase was 42 mg,the ultrasonic time was 100 min,and the ultrasonic power was 225 W.Under this condition,the yield of cellulase extractable arabinoxylan(CAX)was 2.33%.The optimum conditions for ultrasonic-assisted composite enzyme extraction of AX were: the composite enzyme dosage was 40 mg,the ultrasonic temperature was 52?,and compound enzyme ratio was1.5:1.Under this condition,the yield of complex enzyme extractable arabinoxylan(CEAX)was 5.27%.2.The results of fourier transform infrared spectroscopy analysis indicated that the structural characteristics of the products extracted by different methods were consistent with AX.The results of molecular weight distribution showed that the average molecular weight of enzyme extracted and water ertracted AX was lower than that of alkali extracted AX.The results of monosaccharide composition analysis showed that AX obtained by different extraction methods was mainly composed of arabinose and xylose,and the A/Xvalues of AX obtained by enzyme extraction and water extraction were lower than that of AX obtained by alkali extraction.3.The glucose adsorption of enzyme extracted AX was higher than that of alkali extracted AX.The inhibition of enzyme extracted AX on ?-amylase was higher than that of alkali extracted AX.Likewise,glucose dialysis retardation index of water extracted AX was higher than that of alkali extracted AX.The scavenging efficiency of enzyme extracted and water extracted AX on hydroxyl radical was higher than that of alkali extracted AX.The chelating effects of XAX and CAX on iron ion were higher than XAX-1 and CAX-1respectively,but the DPPH radical scavenging effect of enzyme extracted AX was lower than that of alkali extracted AX.Meanwhile,the reducing power between AX extracted by different methods has no obvious difference.The adsorption capacity of enzyme extracted and water extracted AX to sodium cholate was stronger than that of alkali extracted AX,and the adsorption capacity of XAX and WEAX on grease was higher than that of XAX-1and WEAX-1.However,the adsorption capacity of enzyme extracted AX on cholesterol was lower than that of alkali extracted AX.In summary,AX extracted by different methods has hypoglycemic,antioxidant and hypolipidemic activities.Among all the AX,CEAX has better hypolipidemic ability than others,while XAX has relatively better hypoglycemic ability.These functional indexes are related to the weight average molecular weight,A/X values and esterified FA content of AX.