Structural,Physicochemical And Functional Properties Of Potato Residue And Dietary Fiber

Potato(Solanum tuberosum)is the fourth important food crop in the world after wheat,rice and corn.During starch processing,a large quantities of waste residue has been generated which contain different organic materials such as protein,carbohydrate,starch,dietary fibre etc.Different particle sizes exhibit different effects on the processing qualities of residue.Moreover,limited information about production of potato dietary fibre(DFs)is currently available.In this study,effects of particle size on structural,physicochemical,and functional properties of potato residue and the quality characteristics of starch noodles thereof were studied.In addition,Structure,physicochemical,and functional properties of total,soluble,and insoluble dietary fiber from potato residues,as well as Effects of high hydrostatic pressure and cellulase modification on the structural,physicochemical,and functional properties of potato dietary fiber.The research results can provide basic data and theoretical basis for the application of potato residue and its dietary fiber in food industry.The results were as follows:Effects of particle size on the structural,physicochemical,and functional properties of potato residue and the qualities characteristics of starch noodles thereof were studied.The results showed that the protein,ash,dietary fiber content,water holding capacity(WHC)and water solubility(WS)was decreased with decreasing particle size while the starch,fat,phenolic content and ?-amylose activity inhibition ratio were increased in both freeze and oven dried sample.Ultrafine particles contained the highest phenolic content(2.26 mgCAE/g),glucose adsorption capacity(7.03 mmol/g),cholesterol adsorption capacity(16.54%)and showed better performance on noodles formulation.However,oil holding capacity and microstructure which obtained by scanning electron microscope and fourier-transformed infrared spectroscopy did not show any significant difference.It can be concluded that,potato residues could be successfully used to develop fiber enriched food products after fractionated with desired particle sizes.The structure,physicochemical and functional characteristics of total dietary fiber(TDF),insoluble dietary fiber(IDF)and soluble dietary fiber(SDF)isolated from potato residue were investigated.The results showed that the main components of potato dietary fiber were cellulose(42.93%)and pectin(27.82%).The SDF contained much more rhamnose and galacturonic acid,while the major monosaccharide in IDF was glucose.The physicochemical properties of TDF,IDF,and SDF were increased with the increasing of temperature and pH,while decreased with the increasing of NaCl concentration.Compared with TDF and IDF,SDF exhibited more porous structure in the surface,and had better glucose absorption ability,?-amylase activity inhibition ratio,and cholesterol absorption ability.The effects of high hydrostatic pressure combined with cellulase on the structure,physicochemical and functional properties of potato dietary fiber were studied.The results showed that high hydrostatic pressure,cellulase and high hydrostatic pressure combined with cellulase could improve the content of soluble dietary fiber.The content of soluble dietary fiber was the highest after the synergistic modification;FTIR results showed that the synergistic modification could effectively degrade lignin,and significantly improve the water solubility,water swelling capacity,glucose absorption capacity,?-amylase activity inhibition ratio,and cholesterol absorption ability of potato dietary fiber.In conclusion,ultrafine particle demonstrated best quality based on physiochemical and functional properties,also on starch noodles properties(textural and in vitro starch digestibility).Temperature and pH level had significantly positive effect on DFs to increase the physicochemical properties.Potato pulp is a good source of DF because of higher proportion of soluble(SDF)fibre.In addition,potato dietary fibre modified by HHP-enzyme treatment increase the SDF content which increase the food functionality as a used by food ingredient.