Study On Physicochemical Properties And Functional Properties Of Superfine Grinding Potato Residues

Potato residues,a by-product of starch processing,has high nutritional value but it is rarely used in food and has a certain development prospect.In this thesis,by optimizing the technological conditions of superfine grinding treatment of potato residues,the physicochemical properties and functional characteristics of potato residues before and after grinding and different particle sizes were explored in order to obtain high-quality primary product of potato residues and provide the basis for the development of potato residues in food.The results were as follows:(1)With the powder yield of potato residues as the index,the effects of fan power,main engine power and grinding time on the powder yield were explored through single factor test,and the optimal process conditions were obtained by response surface analysis.The optimal conditions were as follows: fan power was 0.32 k W,main engine power was1.07 k W,and grinding time was 26.50 min.Under these conditions,the powder yield of potato residues prepared was 61.83%.The content of heavy metals,toxic substances and pathogenic bacteria in the potato residues prepared by the optimal process was detected,and the results met the relevant standards of the state and the industry.(2)The potato residues prepared by the optimum technology was sieved by standard sieves,and the potato residues with different particle size was obtained.In the powder properties,with the decrease of particle size,the change trend of specific surface area increased significantly,the color was brighter,showing a better pale yellow,and the fluidity decreased,it is mainly because of the electrostatic effect in the process of superfine grinding and sieving,and the smaller the particle size,the greater the influence(3)Results of composition and hydration properties of potato residues: Particle size mainly affected the content of dietary fiber,and then affected the water holding capacity,solubility,swelling power and oil holding capacity,and the maximum value appeared at B>500.This indicated that superfine grinding treatment had a positive effect on the hydration properties of potato residues.(4)Detection results of infrared spectrum and X-ray diffraction: The potato residues with different particle sizes and before and after grinding had similar peaks in the infrared spectrum and X-ray diffraction diagram,respectively,indicating that the changes of particle size and specific surface area caused by superfine grinding had no special effect on the cellulose crystal structure and starch crystal in the potato residues,nor had it introduced new functional groups or generated new compounds.The results of scanning electron microscopy showed that with the reduction of particle size,the potato residues particles gradually became smaller,and the shape tended to be spherical,and the uniformity was improved,which was consistent with the result of particle size distribution.(5)Adsorption capacity of potato residues: Except that the maximum adsorption capacity of cholesterol appeared at B300(p H 2)and B400(p H 7),the peaks of cation exchange capacity,sodium cholate adsorption capacity,glucose adsorption capacity and sodium nitrite adsorption capacity DPPH radical,ABTS radical and hydroxyl radical scavenging capacity all appeared at B>500,which were 0.71 m L/g,53.10 mg/g,17.99mmol/g(glucose concentration: 400 mmol/L)and 395.40 ?g/g,71.28%,84.59% and82.31%,respectively,indicating that the potato residues with smaller particle size had better functional characteristics.