Exploration Of Content Change Of Several Nutritional Ingredients In Germination Process Of Highland Barley

Hordeum vulgar L.var.nudum Hook.f.is the featured crop in the Tibetan plateau in China.Its abundant nutritional ingredients can meet the requirement of modern healthy diet which makes it credited with health benefits in grain crop.However,as foodstuff,highland barley has a rough taste and also lower digestibility.Although the protein content is higher when it is procecced into the form of powder,meanwhile,the mucedin become lower.As a consequent,it can barely aggregate to form the gluten network.This imposes restrictions on the application of highland barley.In addition,the starch content of highland barley powder is close to the general cereal materials.But it also becomes a limit of application because its high content of amylopectin and solution viscosity.Germination is a process that the embryo of the plant seed grows to break through the testa.The nutritional ingredient storing in embryo will perform a series of changes during the process.The palatability of germinated and processed seed is between the raw seed and the seed germinated only.The germinated and processed seed is an intact viable seed which is featured by containng the germ.The germinated seed can improve the taste,easily digested and absorbed.Also,it can decrease the loss of embryo and richer the nutrition components.The content of γ-aminobutyric acid(GABA)is especially abundant and this deepens the functional implications of highland barley.With single-factor screening method,this study explored the effect of different germination conditions on germination rate of highland barley,such as treating temperature and culture time.The results show that when considered the culturing temperature at 27℃ and culturing time for 18 h as a constant,the optimized germination rate was obtained under the conditions of soaking for 6 h at 22~27℃ which was higher than 85%.And,when considered the soaking temperature at 27℃ and soaking time for 6h as a constant,the optimized germination rate was obtained under the conditions of culturing for 15~21h at 22~27℃ which was higher than 80%.It was not good for highland barley to perform germination when the soaking or culturing temperature is below 22℃ or above 32℃.Meanwhile,the study investigated the changing rule of the active components such as β-glucan,Vitamin E and γ-aminobutyric acid under the differnet soaking and culturing temperature and time.Highland barley β-glucan was determined and analyzed by phenol-sulfate method.The results showed that the highest β-glucan content was 10.01% which was obtained under the conditions of soaking for 6h at 27℃,then cultured at 27℃.Comprehensively considering with the germinating rate(higher than 80% as the standard),the optimized culturing time was between 15 to 21 h.Highland barley γ-aminobutyric acid was determined and analyzed by spectrophotometer method.The results showed that the highest GABA content was 27.385mg/100 g which was obtained under the conditions of soaking for 3~9h at 32℃,then cultured at 27℃.But the germination rate is only 68% under.Considering with the germinating rate,the optimized treating condition was soaking for 6h at 27℃ and culturing for 15~21h at 27℃.The GABA content is 25.557mg/100 g.Highland barley Vitamin E was determined by HPLC method.The results showed that the highest content was 0.471mg/100 g when the sample was soaked for 6h at 27℃,then cultured at 22℃.By contrast,the Vitamin E content of the untreated raw seed was 0.460mg/100 g which is not low.Therefore,this study concluded that both the β-glucan content and GABA content of germinated highland barley are higher than ungerminted seed.The germinating treating has lesser impact on the Vitamin E content of highland barley.This study lays a basis on processing the germ products of highland barley.