Studies On The Influence Of Different Starch On Noodle Quality

Effects of physicochemical properties, composition and characteristics of five starches from different botanical sources(corn starch, potato starch, wheat starch, tapioca starch, potato starch) on noodle qualities were studied in this paper. Relationships between botanical sources and pasting properties of wheat and potato starches, and that between potato starches varieties and noodle qualities were compared. Finally, analysised the branched degree of amylopectin in the starch from different sources, then the microstructure of noodles was observed to explore the primary cause of different starch effect on noodle quality. the main conclusions are as follows:1. Potato starch with a relative large particle size, contains less amylose and more damaged starch, and has a high peak viscosity and a low initial gelatinization temperature. Wheat starch granule has two kinds of different morphology, high amylose content, low flour peak viscosity, high initial gelatinization temperature. Wheat, corn, cassava, and sweet potato starch crystal structure type is A-type, and potato starch is B-type.2. With the increase of the addition of starch, farinograph properties degraded. Stable time(ST) was extended when the addition of potato starch is 5%. Mixed flour peak viscosity increases and the initial gelatinization temperature decreases after starches were added. Potato starch showed good pasting properties when the addition was 5%-10%.3. Potato and corn starch can effectively improve the overall color of the dough sheet. With the increase of the addition of starch, the best pasta cooking time was shortened, absorption of dry matter decreased, dry matter loss and broken ratio decreased firstly and then increased. Noodles added with wheat starch showed high cooking loss ratio and broken ratio. Noodles added with potato and tapioca starch(≤10%) showed better cooking quality. TPA properties of cooked noodles were improved when the addition of starch was less than 10%. Cooked noodles added with wheat and potato starch had high hardness and chewiness, and that added with corn and sweet potato was softened, but the tensile properties was decreased. Cooked noodles added with potato and tapioca starch showed good cohesiveness. Noodles added with 5% potato starch had the highest sensory scores.4. In terms of different kinds of potato starch and wheat starch, the contents of amylose had significant negative correlation with peak viscosity, and significant positive correlation with pasting temperature. Partical sizes had significant negative correlation with initial pasting temperature, and significant positive correlation with peak viscosity. Break down, finalviscosityandconsistencehadlittlecorrelationwithcomponentofstarch.lowamylosecontentresultedinabetterpastingpropertiesofpotatostarchcomparedwithwheatstarch.5.thepeakviscosityofdifferentkindsofpotatostarchhadsignificantnegativecorrelationwiththeirdrymaterialslossandbrokenpiecesratio,whileitwassignificantlypositivecorrelatedwithsensoryscores,springiness,cohesiveness,resilience.thepastingtemperatureofpotatostarchhadsignificantnegativecorrelationwithdrymateriallossandsensoryscores,positivecorrelationwithspringinessandresilience.6.accordingtotheresultsoftheanalysisonenzymatichydrolysateoffivekindsofstarch,potatostarchandwheatstarchhadhigheroligosaccharidecontentsthantheothers(dp≥4),indicatingthatbranchingpointofwheatamylopectinlineduptightly,whilethatofpotatoamylopectinlineduploosely.7.byobservingthemicrostructureofdoughornoodles,wecouldseethatduringtheprocessofmakingnoodles,glutenabsorbthemoisturefully,thenetworkstructurewasformedgradually,thestarchgranulesareuniformlyembeddedintheproteinnetwork.whencookedfor30 s,thepotatostarchgranulesofnoodleshasbeenmostgelatinizedcompletely(theoptimumcookingtimeofnoodlesmadefrompotatostarchisshort).cookedfor60 s,thewheatstarchgranulesofnoodleshasbeengelatinized,thecompositenetworkofglutencombinedwithstarchwasformedbasicallycompleted.fortheadditionofpotatostarch,noodlesstructureisslightlyloose,butmoresolid.