| Tradition noodle is made from commom ingredients and it lacks some essential nutritional components.Moreover,the food industry is experiencing a constantly growing demand for novel and healthy foods.Mixed and wheat-less flours with high nutritional value are being used for noodle products making.Adlay seeds are the traditional food raw materials with high nutritional value and pharmacological effects.Therefore,the incorporation of adlay flour into wheat flour is one strategy for the development of healthy noodle products and would largely meet the requirement of people for nutritional staple food,which has broad market prospects.However,the presence of adlay flour would induce an adverse effect on the crumbling texture and cooking quality of noodles owing to adlay flour containing little gluten.In addition,due to adlay seeds are rich in unsaturated fatty acids,the off-flavor they emits during storage affects their edible quality and hinders its development,thereby affecting their sales and promotion.Till now,there have been few reports on effects of adlay on edible quality of noodles and its mechanism,especially on the storage stability of noodles.In view of this,compared to the blank group,the effect of adlay on edible quality of noodles was investaged.Meanwhile,the interaction between adlay starch and gluten was studied.Further,the edible quality and basic physiochemical indexes of adlay noodles during the storage was discussed,which is ultimately for the attempt to provide theoretical basis and technical support for the application of adlay in noodles.The main results are as follows:1.This paper investigated the effects of gluten contents and different sources and particle sizes of adlay on sensory scores,cooking properties,color and texture properties of noodles containing different adlay addition levels.The results showed that the overall quality of Xingren adlay noodles and Laos adlay noodles had no significant difference,and there was no significant difference with control group when the particle size of adlay was 100 mesh.In addition,the amount of gluten?2%?6%?10%?14%?16%?significantly showed a rising trend as adlay content?10%?30%?50%?70%?80%?increased.Under this optimal condition,the model had been expressed with the equation Y=9.6958+0.0343X-1.8388*10-4X2?R2=0.9968?.To verify whether the model can be used to make other coarse cereals noodles,30%sorghum powder,oat powder,buckwheat powder,mung powder,bean powder,brown rice powder and corn powder were added to fine dried noodle,respectively.The experiment showed that the relative error of gluten content between speculated results using this mathematical model and determined results of six kinds of coarse cereals noodles were less than 5%.The quality of six kinds of noodles were no significance with control group,which suggested that this quadratic polynomial model could be applied to make coarse cereals noodles,and had great practical value and innovation.2.To investigate changes in the rheological and structural properties of gluten gels in the presence of adlay starch and elucidate the possible interactions between gluten protein and adlay starch in composite gels at the molecular level,rheometer,sodium dodecyl sulfate polyacrylamide gel electrophoresis?SDS-PAGE?,Fourier transform-Raman spectroscopy,scanning electron microscopy and thermogravimetric analysis?TGA?were conducted.The results showed that adlay starch improved the viscoelastic behavior and water retention capability of gluten gels and caused more continuous and compact gel network,which was mainly attributed to its gelation and role as a filler in gluten protein gel network.The hydrogen bonds,disulfide bonds,electrostatic interactions and hydrophobic interactions were found to be involved in the formation of adlay starch-gluten composite gel through protein denaturing agents,of which disulfide bonds played a major role.As the adlay starch content increased,the conformation of S-S bridges in the gluten protein became more energetically stable?g-g-g?,and the?-sheet structure increased at the expense of the?-helical structure.In addition,the hydrogen bonds and hydrophobic interactions of gluten involved in the gel system were strengthened.However,a decrease in iron interactions and disulfide bonds were induced by the addition of adlay starch.Compared with control gel,less thermal stability of adlay starch-gluten composite gel might be due to the rupture of sulfhydryl-disulfide interchange.In conclusion,besides acting as an inert filler,adlay starch can also participate in hydrogen bonding and induce hydrophobic interaction strength to modify gluten protein aggregation,altering the rheological and structural properties of gluten protein gels.3.Adlay powder was used to substitute 10%and 50%wheat flour to make fine dry noodles.To pursue the optimal packaging methods for adlay noodles under natural storage,the changes of edible quality?cooking quality,sensory quality,color and texture quality?and the basic physiochemical indexes?water content,fat content,acid value,peroxide value,malondialdehyde content,total colony number?of adlay noodles packed with semi-closed paper,fully-closed paper and fully-closed PE were investigated.The results revealed that the edible quality of adlay noodles gradually deteriorated with the extension of storage time under three types of packing.Obvious off-flavor and wormhole phenomenon were observed in each treatment group after six months of storage,which resulted in the loss of commercial value of adlay noodles.In addition,a correlation existed between the edible quality and basic physiochemical indexes.Among them,the correlations between the various edible quality indexes and peroxide value,malondialdehyde content were positively or negatively significant?p<0.01?,which indicated that the deterioration of edible quality of adlay noodles during storage was mainly caused by lipid oxidation.However,the lipid oxidation rate of adlay noodles with fully-closed PE packaging was slower than semi-closed paper packaging and fully-closed paper packaging,indicating that fully-closed PE packaging coule effectively delay the adlay noodles deterioration.In conclusion,the optimum condition for adlay noodles storage was fully-closed PE packaging,and the storage period?shelf life?should not exceed six months.In conclusion,in this study,the model aboue adlay addition?X?and dry gluten content?Y?in adlaynoodleshadbeenestablishedandexpressedwiththeequation Y=9.6958+0.0343X-1.8388*10-4X2?R2=0.9968?,and the quadratic polynomial model could be also applied to make other coarse cereals noodles.The mechanism of effect of adlay on noodles quality was further investigated.It was found that starch,as the main component of adlay,can participate in hydrogen bonding and induce hydrophobic interaction strength to modify gluten protein aggregation besides acting as an inert filler,altering the rheological and structural properties of gluten protein gels.The storage quality of adlay noodle using fully-closed PE packaging was the best,and the storage period?shelf life?should not exceed six months. |
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