| Black wheat is a high-quality wheat produced by crossing rye and common wheat.Its nutritional value is higher than that of common wheat and it contains a variety of bioactive substances.It is an important natural black grain resource and has great potential for product development,which is in line with the future trend of food development.However,the gluten protein strength of black wheat flour is low and there is a lot of dietary fiber,which makes it difficult to form dough with good viscoelasticity.glutamine transaminase(TG)and Glucose Oxidase(GOD)are enzyme preparation amendments which can improve the structure of protein network and improve the stability of protein.In order to improve the gluten protein strength of black wheat flour and develop products made by black wheat flour with excellent quality,this paper intends to add TG and GOD to black wheat flour,study its influence on the physical and chemical properties and quality of black wheat flour dough,and prepare wonton wrapper to explore its optimal formula.The main research methods and results are as follows:(1)In order to explore the physicochemical composition and nutritional value of black wheat flour,automatic Kjeldahl nitrogen analyzer and inductively coupled plasma emission spectrometer were used to determine the basic composition of black wheat flour,and wheat flour was used as the control.The results showed that compared with wheat flour,black wheat flour had higher contents of ash,fat,protein,anthocyanin,total polyphenols,total dietary fiber,soluble dietary fiber,total pentosan,soluble pentosan and minerals,which indicated that black wheat flour had higher nutritional value and could bring many health benefits to consumers.However,the content of starch and wet gluten of black wheat flour was lower,which was 8.56% and29.04% less than that of wheat flour,respectively,which indicated that the gluten content formed by black wheat flour was lower,this could affect the physicochemical properties of black wheat flour dough.(2)In order to improve the physical properties and quality of black wheat flour dough,mixing experiment instrument,rheometer and Fourier transform infrared spectrometer were used to explore the effects of different TG supplemental levels on the thermal mechanical properties and rheological properties of black wheat flour dough,and explained the changes in protein secondary structure.At the same time,the effects of different addition levels of TG on cooking quality of wonton wrapper made from black wheat flour were studied.The results showed that with the certain conditions of blending and awakening,the viscosity and formation time of black wheat flour dough firstly increased and then decreased with the increase of TG supplemental level,the water absorption decreased,the protein weakening degree and recovery increased first and then increased,and the stability of dough was improved.The addition of TG increased the elastic modulus and viscosity modulus of black wheat flour dough,and enhanced the comprehensive viscoelasticity.In addition,the content of secondary ordered structure,disulfide bond and glutenin macropolymers of dough protein increased,and the protein elasticity and structural stability were improved.The protein crosslinking degree was enhanced and the gluten network structure was improved.However,excessive TG addition was led to excessive protein crosslinking,forced exposure of starch particles,and decreased strength and stability of dough.On the whole,TG could promote protein aggregation and crosslinking in black wheat flour dough and improved physicochemical properties of black wheat flour dough,and the improvement effect was best when TG content was 0.8% to 1.1%.When the TG supplemental level was 1.1%,the loss rate and fracture rate of the wonton wrapper made from black wheat flour had the lowest values of 3.99% and 4.00%,which were reduced by 27.06% and 95.81%,respectively,compared with the TG supplemental level of 0%,this indicated that appropriate addition of TG could improve the cooking quality of wonton wrapper made from black wheat flour.(3)In order to improve the gluten protein strength of black wheat flour dough,rapid viscosity analyzer,texture analyzer and scanning electron microscope were used to explore the effects of different GOD addition levels on gelatinization properties,dough tensile properties and microstructure of black wheat flour,and explained the changes in protein components.At the same time,the effects of different dosage of GOD on cooking quality of wonton wrapper made from black wheat flour were studied.The results showed that with the certain conditions of blending and awakening,addition of GOD increased the viscosity of starch system and improved the gelatinization stability of starch.The stability and gluten strength of dough increased with the increase of tensile strength.The content of glutenin macropolymers increased,and the protein structure was more stable.Starch particles and fibers were tightly wrapped in the gluten network structure,with fewer holes and better gluten network structure.However,GOD could reduce the extension of black wheat flour dough,and excessive GOD could cause a large amount of hydrogen peroxide gas,which damaged the stable structure of dough and was not conducive to the overall strength and tightness of gluten network structure.Overall,GOD could promote the cross-linking of disulfide bonds and significantly improved the physicochemical properties of black flour dough.When the addition amount of GOD was 0.8%,the improvement effect was the best,and the ratio of gliadin to glutenin(0.81)was closed to the optimal ratio(1.0).The addition of GOD significantly decreased the cooking loss rate and fracture rate of wonton wrapper made from black wheat flour,and increased the soup transparency(P < 0.05).When GOD was 0.8%,the loss rate and fracture rate had the lowest values of 4.05% and 5.00%,which were 25.96% and 94.76% lower than GOD addition of 0%,respectively.The results showed that proper amount of GOD could improve the cooking quality of wonton wrapper made from black wheat flour.(4)In order to develop new products of black wheat flour,gluten,GOD,TG,xanthan gum and complex phosphate were used to prepare wonton wrapper made from black wheat flour.The optimal formula of wonton wrapper made from black wheat flour was obtained through single factor and orthogonal experiments,and the cooking and sensory qualities of wonton wrapper made from black wheat flour before and after optimization were measured to verify the optimal formula.The results showed that with the certain conditions of blending and awakening,the five amendments increased the hardness,adhesiveness,chewability and sensory score of the wonton wrapper made from black wheat flour,and improved the texture and sensory quality of the wonton wrapper made from black wheat flour.The optimal formula was obtained by orthogonal test: gluten content was 7%,GOD content was 0.3%,TG content was 0.3%,xanthan gum content was 0.5%,compound phosphate content was 0.5%.Compared with before optimization,the addition of compound improver reduced the water absorption rate and loss rate of the wonton wrapper made from black wheat flour,and improved the cooking quality.The optimized wonton wrapper made from black wheat flour did not break when boiling to the optimum cooking time,which indicated that the preparation of wonton wrapper made from black wheat flour by adding compound improver was suitable.After optimization,the surface of the wonton wrapper was smooth and even,with obvious transparent texture,and the entrance was smooth,chewy and delicate.The sensory score reached 91 points,which increased by 33.82%compared with before optimization,and the sensory quality reached the best. |
PDF Full Text Request