| Porous starch is a new type of modified starch which has a good absorption;it can adsorb any material other than the paste.Porous starch is also of security, drug-free,unrestricted use of measurement,so it has been applied in the areas of food industry,medicine,public health and other sectors.China is the largest producer of corn,corn starch is cheap and of better quality.This paper studied on preparation of porous starch with corn starch by glucoamylase catalysis,spray drying process and the effect of porous starch on the mainstream cigarette smoke.The effects of buffer pH,hydrolysis temperature,amount of glucoamylase, hydrolysis time and stirring rate on the preparation of porous starch were studied with hydrolysis ratio as indicators.In considering follow-up experiments and the efficiency, to determine the optimal conditions for the hydrolysis:buffer pH4.0,hydrolysis temperature 40℃,amount of glucoamylase 5μL,hydrolysis time 5 h,and stirring intensity 30%.The effects of sonication power,sonication time and slurry concentration on the preparation of porous starch were investigated before,during and after the starch being hydrolyzed.The indicators were hydrolysis ratio(HR),oil absorption ratio (OAR) and citron yellow absorbance(CYA).The results showed that: ultrasound-assisted hydrolysis was more effective than the average hydrolysis;the combination of sonication and hydrolysis has better performance than the sonication before and after hydrolysis.On the basis of single factor experiments,the orthogonal experiments were designed to optimize the best conditions as follows:sonication power 50%,sonication time 30 min,and slurry concentration 70%.The oil absorption ratio of porous starch preparation in the conditions was 170.82%.The effects of microwave radiation(middle power,higher power) on the preparation of porous starch were investigated before and after the starch being hydrolyzed with the OAR and CYA as indicators.The results showed that the porous starch radiated by higher power microwave before hydrolysis for 30 s has the highest ORA of 134.48%;the product radiated for 40 s has the highest CYA of 1.43 mg/g.Electron microscopy,X-ray diffraction and rapid viscosity analyzer were used to evaluate the micro-structure,crystal structure and pasting properties of porous starch which prepared by average hydrolysis,ultrasound-assisted and microwave-assisted hydrolysis.The results indicated that the characteristics of porous starch matched with their DH,DOB and CYA on the whole;also they can provide the intuitive theory and experiment reference for the application of ultrasound and microwave technology in the preparation of porous starch.Factors that had influence on the product appearance,OAR,CYA and micro-structure were mainly considered,including:sample introduction rate,material concentration,inlet temperature,outlet temperature and atomizer speed.The orthogonal experiments were designed to optimize the porous starch spray drying technics.The results were as follows:concentration of liquid material 15%,sampling introduction rate 30 mL/min,inlet temperature 160℃,atomizer speed 33250 r/min, and outlet temperature 65℃.Under these conditions,the OAR of the product was 109.24%,the CYA was 1.28mg/g.Porous starch o(?)ifferent amount was added into the cigarette filter tip to investigate its influence on the absorption of total particulate matter,tar,nicotine and carbon monoxide in the mainstream cigarette smoke.The results indicated that:the filter rod added 10 mg of porous starch has a positive effect on lowering the amount of total particulate matter,tar,nicotine and carbon monoxide in the mainstream cigarette smoke.The 10mg activated charcoal and corn starch were added into cigarette filter tip respectively to investigated the influence of different adsorbent on mainstream cigarettes smoke,and the results showed that the absorption properties of porous starch is superior to the activated carbon and corn starch. |
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