Study On Processing Characteristics And Quality Of Sweet Potato Pulp Noodles

Sweet potato is rich in nutrients,high in vitamins and minerals,and relative ly balanced in amino acid composition.It is significant to develop staple sweet potato products suitable for people’s eating habits to improve their nutritional value.Compared with sweet potato flour,using sweet potato pulp to make noodles could save costs,simplify the process,reduce pollution,and increase the utilization rate of sweet potato tubers.This study used sweet potato pulp to replace part of wheat flour to make noodles.The effects of sweet potato pulp on dough processing characteristics and noodle quality were investigated,the processing technology of sweet potato pulp noodles was optimized,and the storage characteristics were further studied.This study could provide a theoretical basis for developing sweet potato pulp noodles.The main results are as follows:The effects of sweet potato pulp addition on dough processing characteristics and noodle quality were studied.The results showed that the quality of dough and noodles decreased with the increase of sweet potato pulp addition.When the additional amount of sweet potato pulp was less than 15%,there was no significant difference in dough processing characteristics and noodle quality compared with the control samples（wheat flour dough and noodles）.The dough was difficult to form when the addition amount exceeded 35%.Compared with the control,the free sulfhydryl content of 35%sweet potato pulp dough was increased by 10.45%,and the wet gluten content,elongat io n resistance,and extensibility were decreased by 13.64%,24.05%,and 40.71%,respectively.The optimum cooking time of noodles was shortened by 27 s.The cooking loss and water absorption were increased by 35.11%and 18.57%,respectively.The stretching resistance,tensile distance,hardness,springing,and chewiness of cooked noodles were decreased by 12.73%,49.11%,20.57%,6.82%,and 34.23%,respectively.The contents ofα-helix andβ-sheet in the dough decreased,while the contents ofβ-turn and random coil increased with the increase of sweet potato pulp addition.SEM confirmed that adding sweet potato pulp could weaken the continuity and integrity of the dough gluten network.Sensory analysis showed that the bright yel ow color of noodles deepened with the increase of sweet potato pulp,which improved consumers’acceptability.Compared with the control,the total essential amino acid content,total phenol content,DPPH,and ABTS free radical scavenging ability of 35%sweet potato pulp noodles were increased by 8.66%,27.50%,109.88%,and 312.28%,respectively.The results showed that adding sweet potato pulp could better realize the complementary effect of amino acids to improve the nutrition of noodles and enhance the ability of free radical scavenging.The processing technology of 35%sweet potato pulp noodles was optimized.The effects of resting time（10,20,30,40,50 min）,resting temperature（10,20,30,40,50°C）,and sheeting times（5,7,9,11,13 times）on the texture and tensile properties of35%sweet potato pulp noodles were studied.The quadratic orthogonal experime nt design with three factors and five levels was adopted based on the single-factor text experiment.Through response surface analysis,the optimal processing conditions of35%sweet potato pulp noodles were obtained as follows:resting time 28 min,resting temperature 29℃,sheeting times 9,tensile resistance and stretching distance of noodles were 21.35 g and 15.84 mm,respectively,and the quality of noodles was significa nt ly improved.The storage quality of 35%sweet potato pulp fresh noodles was studied.The effects of sodium diacetate,Nisin,andε-polyline on the quality and preservative effect of 35%sweet potato pulp noodles were studied by L₉（3⁴）orthogonal test.The results showed that the optimal ratio of compound preservatives was 0.30%sodium diacetate,0.08%nisin,and 0.02%ε-polylysine.The total number of colonies and mold of optimized noodles was better than the control,and the fresh-keeping period was extended to 48 h at room temperature（25℃）.