Study On Antioxidant Activity Of Whole Wheat Flour And Quality Improvement Of Whole Wheat Chinese Steamed Bread

Epidemiological studies have shown that whole grain cereals are useful in the fight against obesity,diabetes,cardiovascular disease and cancer,and other metabolic diseases,while systemic research and product development of whole grain food still is lack in China.Steamed bread as the staple food of the north of China,bread cons?mption accounted for more than 30%of the total amount of food production.Focusing on the bread and other traditional flour food,the research on the processing technology and the development of whole grain food,which will be an important field and an important market for the whole grain food development in china.Using whole wheat bread as the research object,a systematic study influence of its raw materials of whole wheat flour antioxidant activity and processing on the antioxidant activity,the establishment of whole wheat bread quality improvement process,and traditional fermentation agent study characteristic flavor of whole wheat bread to provide guidance and theoretical basis for the development of whole wheat products will be investigated.The antioxidant capacity using both vitro chemical analysis method and cellular antioxidant activity evaluation method?CAA?was investigated to explore different gluten degree?medi?m gluten and high gluten?whole wheat flour and its different components?flour and aleurone layer,germ and bran?.Germ and bran showed strong in vitro anti oxidative capacity.The proliferation of HepG2 h?man liver cancer cells can be significantly inhibited by the extract of whole wheat,the EC₅₀ value is between1.30 and 98.81 mg/mL.The free phenol and the high gluten free phenol show strong cellular antioxidant capacity,EC₅₀ value is 1.30mg/mL and 12.27 mg/mL respectively.The content of ferulic acid was higher,and the content of ferulic acid was in the range of 5.47 to 530.38 DW mg/100g.The scavenging ability and reducing power of ABTS and DPPH were positively correlated with the total polyphenol content in the extract,and the EC₅₀ value of HepG2 was negatively correlated with the content of phenolics in the h?man liver cancer cells.The effect of germ and bran on the dough rheological properties,pasting properties,tensile properties and color change has been investigated.Wheat bran increased the C1-C2 value gradually and decreased?value,which indicated that the dilution of the gluten protein content lead to the decreasing of heat-resistant dough mixing performance,while hinder starch molecular rearrangement and delay the ageing of the dough and flour products.The germ makes the starch back up,accelerate the molecular rearrangement of starch and aging rate,reduce the rate of starch pasting,but the addition of germ is beneficial to improve the resistance of the dough.The stabilization time of high gluten flour,high gluten whole flour and high gluten recombinant flowerwere longer than that of medi?m gluten flour sample.Effect of hydrophilic colloids such as guar g?m on water absorption and tan delta of whole wheat dough is the most significant.Adding 2%of guar g?m,the water absorption increased to71.60%,tan delta reduced from 0.44 of whole wheat pasta to 0.36,which indicated that guar g?m can significantly increase degree of polymerizationof the dough,and increasegas holding capacity of the dough.It can also delay the aging of dough and improved dough extension.In addition to lipase,amylase,cellulose and xylanase had obvious effect on delaying the aging of starch and can effectively improve the ductility of whole wheat dough,L value increased from 21mm to 40mm.In addition to the xylanase,amylase,cellulose and lipase were able to improve dough W value,which is conducive to the improvement of whole wheat bread specific vol?me.The addition of enzyme can improve the elastic modulus and viscosity modulus of whole wheat dough in different degrees.Using the screened Valley gluten,guar g?m and three kinds of enzyme,whole wheat bread quality was improved.Though optimizing the process parameters,high sensory acceptance degree,low hardness,soft texture quality,anti-aging ability,maintain a good antioxidant capacity of WWCSB can be obtained.Under the optim?m conditions,special vol?mn of WWCSB reached 2.38 and hardness decreased to5199.06g.Amendments to the overall delay the aging rate of whole wheat bread.In the 7^th day,amylopectin retrogradation enthalpy value of WWCSB reduced from 1.08 J/g and 0.36 J/g.The aging speed of whole bread was lower than that of the ordinary bread.The characteristics of flavor components of wheat bran,germ and its components are analyzed.The volatile flavor of wheat flour mainly from germ and bran were detected which were different from that in wheat flour.The 4-vinyl guaiacol as whole wheat flour with ferulic acid as precursors formed the characteristic flavor components.No literature has reported this until now.The volatile flavor substances in the whole wheat bread storage were changed.Alcohols in the storage process were the main components.Volatile aldehydes in the whole wheat bread increased with prolonged storage time.The volatile esters andthe hydrocarbon material declined firstly and then increased during storage.Good performance of seven yeast strains and 5 strains of lactic acid bacteria screened from the elders of different regions collected and identified.The yeasts were identified as Saccharomyces cerevisiae,Wickerhamomycesand Pichia kudriavzevii,lactic acid bacteria were identified as Lactobacillus plantar?m,Kocuria kristinae,Pediococcus acidilactici,Lactobacillus helveticus,and Lactobacillus pontis.Three strains of yeast and lactic acid bacteria were used to make steamed bread as a starter,and the sensory score of BL1 and AY2 was the highest.36 kinds of volatile flavor compounds were detected in the whole wheat dough with adding ordinary dry yeast,while 36 species were detected in the whole wheat dough adding fermented compound agent?Saccharomyces cerevisiae and lactic acid cocci?.The aldehydes,acids,and hydrocarbons were special in the the whole wheat dough adding fermented compound agent.