Effects Of Cooking Degrees Of Whole Potato Flour On The Characteristics Of Recombinant Potato-Wheat Dough And The Quality Of Noodles

Whole potato flour is a product made from fresh potato,it contains all the dry compositions of potatoes except for potato skins.Due to its good storage and convenience,it has gradually become a research hotspot of potato products in recent years.The current researches on potato flour mainly focus on the effect of addition of whole potato flour,the variety of potato and the processing technology of whole potato flour on the quality of dough and flour products.And through the research of quality improvers to improve and optimize the quality of potato whole flour products.But the whole potato flour used is mostly cooked flour with poor processing characteristics,so some researchers use raw whole potato flour as the raw material of noodle products to improve its processing quality.However,the properties and applications of the whole potato flour prepared at different cooking degrees have not been reported.Therefore,exploring the physical and chemical properties of whole potato flour with different cooking degrees and their effects on the quality of recombinant potato-wheat noodles has profound significance for expanding the application scope of whole potato flour and developing new potato noodles.Therefore,this thesis uses the commercially available potato snowflake flour as a control to explore the effects of potato cooking degrees on the quality of whole potato flour,recombinant potato-wheat dough and the quality of recombined dried noodles,and provide a scientific basis for the more general utilization of whole potato flour.The main conclusions are as follows:(1)Steaming and microwave were used to obtain whole potato flour with different cooking degrees.Studies have shown that proper cooking can improve the physical,chemical and structural properties and functional properties of the whole potato flour.In terms of physical,chemical and structural properties: Long-term cooking treatment will reduce the whiteness of the whole potato flour,showing a darker color.X-ray diffraction images show that the whole potato flour structure of low cooking degree is the most stable;the shape observation and scanning electron microscope observation showed that the destroyed starch granules in the whole potato flour increased with the increase of cooking degree.In terms of functional characteristics: the increase in the cooking degree of the whole potato flour will lead to the enhancement of water retention and swelling,which is manifested as an increase in viscosity;The gelatinization characteristic parameters also show that the peak viscosity of high cooking degree of whole potato flour increases,that is,the gelatinization swelling degree increases.Among the whole potato flours with different cooking degrees,the lowest viscosity and final viscosity of the whole potato flour of the middle cooking degree group is the highest,indicating that it has the strongest shear resistance at high temperature and the largest cold paste hardness at room temperature.Among the rheological properties,the steady rheological properties indicate that the paste formed by the whole potato flour is a non-Newtonian fluid.The increase in cooking degree will reduce the apparent viscosity of the whole potato flour paste,which is more conducive to flow.The dynamic rheological properties show that the whole potato flour with low cooking degree has better viscoelasticity.(2)The properties of the recombinant potato-wheat dough prepared by the whole potato flour of different cooking degrees are different: LRPF-WF(recombinant whole potato flour-wheat flour made from low cooking degree of whole potato flour)has the longest dough forming time and stable time,the best stability and resistance to mechanical stirring,better tensile properties and texture properties.Moreover,the dough of LRPF-WF is better than RPF-WF(recombinant whole potato flour-wheat flour made from raw whole potato flour)in terms of shear resistance,internal strength and deformation resistance.Therefore,the whole potato flour with low cooking degree helps to strengthen the gluten network structure of the recombinant potato-wheat dough and increase its elasticity.The cooking degree of whole potato flour has a negative impact on the properties of recombinant potato-wheat dough: With the increase of the cooking degree of whole potato flour,the forming time,stable time,mechanical stirring resistance,deformation resistance and recovery ability of the recombinant potato-wheat dough are weakened,and the breaking force,hardness,elasticity and chewiness of the recombinant potato-wheat dough are reduced.Between the recombinant potato-wheat dough made from whole potato flour with the same cooking degree,the chewiness,internal strength and deformation resistance of the test group were better than those of the control group.That is,with the same cooking degree,the homemade whole potato flour is more conducive to the processing of recombinant potato-wheat dough.(3)Using commercially available whole potato flour as a control,the cooking quality and texture characteristics of recombinant potato-wheat noodles maded from whole potato flour with different cooking degrees were determined.The cooking characteristics show that: the optimal cooking time of recombinant potato-wheat noodles is negatively correlated with the cooking degree of the whole potato flour;The cooking loss rate of recombinant potato-wheat is positively correlated with the cooking degree of the whole potato flour,which was manifested in the increase in the degree of muddy soup during the cooking process.The texture characteristics show that in the texture profile analysis mode,the adhesiveness and chewiness of the recombinant potato-wheat noodles decrease with the increase of the cooking degree of the whole potato flour,while the stickiness and chewiness of noodles made from LRPF-WF have the highest value among all the recombinant potato-wheat noodles;In the stretching mode,the noodles made from LRPF-WF,MRPF-WF(recombinant whole potato flourwheat flour made from middle cooking degree of whole potato flour)and SLRPFWF(recombinant whole potato flour-wheat flour made from low cooking degree of whole potato flour that can be sold)have better breaking force and stretching distance;In the shear mode,the shearing force of the recombinant potato-wheat noodles decreased with the increase of the cooking degree of the whole potato flour.Principal component analysis was carried out on 17 quality index parameters of recombinant potato-wheat noodles,and after comprehensive score analysis,it was concluded that the noodles made from MRPF-WF had the highest score,which was consistent with the highest sensory evaluation result.(4)Using homemade whole potato flour with different cooking degrees,the microstructure of the recombinant potato-wheat noodles before and after cooking was measured.Scanning electron micrographs showed that the shape of oval starch granules disappeared after the recombinant potato-wheat noodles were cooked;Laser confocal microscopy observations showed that before cooking,the degree of adhesion among starch particles and dispersion of the gluten protein network structure in the recombinant potato-wheat noodles increased with the increase of the cooking degree of the whole potato flour;Infrared spectroscopy showed that the contents of irregular curls and α-helix in recombinant potato-wheat noodles were changed before and after cooking.Before cooking,the percentage of α-helix in the noodle made from LRPF-WF is lower while the percentage of β-sheet in the same noodle is higher.That is,the structure compactness of the recombinant potato-wheat noodles made from LRPF-WF is better than other recombinant potato-wheat noodles.