Research On Potato Residue Micronization Technology And Its Application In Noodle

Sweet potato residue is the main by-product of sweet potato processing,which retains the main nutrients.Most of them are directly buried or incinerated,which has low economic benefit and heavy environmental burden.Although the natural source of sweet potato residue is rich in DF,which has the effects of reducing weight,reducing hypertension,hyperlipidemia,hyperglycemia and preventing cardiovascular diseases,and can be used as an important processing filler in modern diet.But sweet potato residue has a tight structure and a rough taste,which may adversely affect the color,texture,flavor and taste of the food after being added to the food.Therefore,it has become a research hotspot in recent years to improve its structure,physicochemical properties and functional properties by using appropriate modification techniques.Meanwhile,as a high glycemic index food with a single nutritional structure,noodles are prone to high blood sugar after meals,which may lead to an increase in the incidence of metabolic complications such as diabetes and cardiovascular diseases in the long term.Based on this,the effects of three modification methods(heat treatment,potassium carbonate treatment and thermally assisted potassium carbonate treatment)on DF composition,particle size,structure,physicochemical properties and functional properties of sweet potato residue were compared and analyzed.The optimal modified sweet potato residue DF was added to noodles in order to obtain noodles with good texture and slow blood glucose reaction.The effects of DF content in sweet potato residue on cooking characteristics,texture characteristics,sensory quality,multi-scale starch structure,in vitro digestion of starch and volatile flavor substances of noodles were further studied.The objective is to lay an experimental foundation for the industrial application of DF sweet potato residue in noodles.The main research contents and conclusions are as follows:(2)Sweet potato residue DF was treated by three modification methods: heat treatment,potassium carbonate treatment and thermally assisted potassium carbonate treatment.The composition,particle size distribution,structural properties(microstructure,crystal structure,short-range ordered molecular structure and thermogravimetric),physicochemical properties(water holding capacity,oil holding capacity and water swelling capacity)and functional properties(cholesterol adsorption capacity,sodium cholate adsorption capacity,nitrite ion adsorption capacity,glucose adsorption capacity and α-glycosidase activity inhibitory rate)were compared and analyzed.The results showed that the SDF/IDF ratio of modified DF increased from0.36% to 0.38%-0.40%,and the average particle size decreased from 175.67 μm to112.86 μm to 47.42 μm.The SEM results showed that the DF structure of sweet potato residue treated by the three modification methods was loosened,and the DF of sweet potato residue by thermally assisted potassium carbonate treatment showed typical honeycomb structure characteristics.XRD results show that the relative crystallinity value increases from 18.1% to 22.53%-37.35%.FT-IR results showed that DF spectra of modified sweet potato residue were similar,but some peak intensities were changed.The TG results showed that the DF thermal stability of modified sweet potato residue was improved.The physicochemical properties and functional properties of DF treated with three modification methods were improved by the change of structural properties,among which the thermally assisted potassium carbonate treatment showed the best performance.(2)Sweet potato residue treated with heat-assisted potassium carbonate was selected as the research object.The effects of 0%,5%,10% and 15% sweet potato residue addition on the cooking characteristics,texture characteristics,multi-scale starch structure and digestive characteristics of noodles were analyzed.The analysis of cooking characteristics showed that the optimal cooking time,water absorption and cooking loss rate of noodles with sweet potato residue were improved.The analysis of texture characteristics showed that the hardness,springiness,chewiness and adhesiveness of noodles with sweet potato residue were enhanced.The analysis of sensory evaluation showed that sweet potato residue had a certain effect on the color of noodles,but the sensory score of the color was still within the acceptable range(≥80).The appropriate levels of addition(5% and 10%)made the noodles have a good sensory score.The analysis of multi-scale starch structure showed that the relative crystallinity value of the noodles added with sweet potato residue increased from 11.97% to 12.44%-13.86%.The self-assembled V-type starch complex(RS5)is formed,which is conducive to the generation of RS.In addition,the order degree of starch structure and the strength of intramolecular hydrogen bond were improved by appropriate levels(5%and 10%),R1047/1022 increased from 0.925 to 0.937-0.945,R1022/995 decreased from 1.119 to 1.081-1.106.As well as,the structure of noodle gluten network was uniform and compact at appropriate levels(5% and 10%),while the continuity of protein and starch matrix was not favorable at 15% level.The analysis of digestive characteristics showed that the contents of RDS decreased,the contents of RS and SDS increased,and the p GI decreased from 98.45 to 87.46-79.69.DF of sweet potato residue can effectively shield the action sites of amylase on starch chains and limit the interaction between amylase and starch,thus reducing the digestion of starch by forming a more compact and ordered structure.(3)Sweet potato residue treated with heat-assisted potassium carbonate was selected as the research object.HS-SPME-GC-MS and electronic nose were used to analyze the effects of different sweet potato residue addition levels of 0%,5%,10%and 15% on the volatile flavor substances of noodles.The results showed that 31,48,56 and 62 kinds of flavor substances were detected in the noodles.Among them,aldehydes are the main flavor components.After adding sweet potato residue,a small amount of heterocyclic,olefin,ester,phenol and ketone give the noodles more rich flavor.