Research On Phenolics And Antioxidant Activity In The Process Of Whole Wheat Noodles

Whole wheat flour was as the research object to study the effects of different wheat bran particle size and different wheat bran extrusion processing parameters on the phenolic substances content and antioxidant activity.The whole wheat noodle was taken as the research object to study the effects different wheat bran extrusion processing parameters on the phenolic substances content and antioxidant activity,and to study their changes during the processing of whole wheat noodles.Through the determination and correlation analysis of phenolic substances,flavonoids and antioxidant capacity during and after the machining process of whole wheat flour and noodle,the change law of phenolic substances in whole wheat flour and whole wheat noodle were revealed and the following conclusions were drawn:1.The content of phenolic substances and flavonoids and antioxidant capacity in whole wheat flour increased with the decrease of wheat bran particle size.Compared with other wheat bran particle size samples,their content of ultrafine grinding samples was higher than that of grinding powder.In ultrafine grinding samples,the total phenol content was 575.83 mg/100 g,the total flavone content was 586.11 mg/100 g,and the highest antioxidant capacity of total DPPH was 1451.86 ? mol/100 g.The extraction rate of phenolic substances and flavonoids were increased with the decrease of particle size and the increase of powder uniformity.There was no significant difference in the content of phenolic substances and flavonoids during the ground samples,so comminution was used in the follow-up experiments of processing and edible quality of integrated noodle products.2.During the processing bran extrusion stabilization of whole wheat flour during processing,the content of phenolic substances and flavonoids of whole wheat flour with different extrusion parameters were higher than that of non-extruded samples.It indicated that extrusion treatment could release the polyphenols and flavone for whole wheat flour.The total phenol content,total flavonoid content and antioxidant ability decreased with the increase of moisture content in material.The total phenol content and antioxidant ability increased with the increase of screw speed and extrusion temperature in the extrusion process,but the temperature could not exceeded 190?.The study showed that when the moisture content was 13%,the screw speed was 38.2 Hz,and the temperature was 160?.Total phenol content,total flavone content,total DPPH antioxidant capacity,total ABTS+· antioxidant capacity,total antioxidant capacity had reached the maximum.Therefore,choosing suitable extrusion stabilization processing parameters of whole wheat flour was conducive to the retention of phenolic substances and flavonoids in the bran.3.During the processing of whole wheat noodles,the content of phenolic substances,flavonoids and antioxidant activity were increased by dough-making process.The effect of proofing,slicing and drying process on the content of phenolic substances,flavonoids and antioxidant activity had little.The main influencing factor was proofing time.The results showed that 45 minutes of proofing could obtaine the the maximum amount of the phenolic substances,flavonoids and antioxidant activities.4.Whole wheat flour stabilized bran by different extrusion was processed into whole wheat noodle,the flavonoids were lost,but the phenolic substances and antioxidant activities were well retained or even improved.The effect of bran extrusion stabilization parameters on phenolic substances in whole wheat noodle was similar to the effect on whole wheat flour.The maximum values were reached at 13% moisture content,38.2 Hz screw speed and 160 ?,and it indicated that the noodle processing process had little effect on the phenolic substances in whole wheat flour.Therefore,the whole wheat flour noodle could be prepared by combining the extrusion stabilization conditions,which was beneficial to improve the antioxidant capacity of noodle.5.The phenolic substances content,DPPH free radical scavenging rate,ABTS+ free radical scavenging capacity and total antioxidant capacity was as indicators to determine the antioxidant capacity and to clarify the correlation between the changes of phenolic substances and their biological activities in whole wheat.The results showed that extrusion processing technology was conducive to release some phenolic substances,to increase the total phenolic content of whole wheat flour,to enhance their antioxidant activity,to retain the nutrients in bran,and to increase the nutritional value of whole wheat flour.The comparative experiments were carried out by DPPH· method,ABTS+· total resistance and other methods.The antioxidant activity was positively correlated with phenolic substances.Their antioxidant capacity in the bound state was significantly higher than in the free state.6.The changes of the composition,content and existing forms of phenolic substances in the whole wheat flour and noodle processing were studied by HPLC/UV.The liquid phase conditions were optimized.The characteristic phenolic compounds in whole wheat were gallic acid,protocatechuic acid,vanillic acid,caffeic acid,syringic acid,p-coumaric acid and ferulic acid.The free phenolic acids were mainly gallic acid and ferulic acid,and bound phenolic acids were mainly p-coumaric acid and ferulic acid.