| Color wheat refers to the wheat has different color in the kernel pericarp or aleuronic layer. Color wheat consist of purple, black, blue, dark blue and green pericarp ones according the reports of them. Many cultivars (lines) color wheat have been proved to contain rich protein, amid acid and microelements or metal elements that are beneficial to humans. The wheat has better possession quality, and furthermore, there is plenty of natural pigment in the kernel, most of anthocyanin, which has high application value and possession potential. This study bases on 17 red, black wheat lines cultivated by professor Lan-zhen Sun of our university and green wheat line supplied by Changyi Shandong as materials, through testing nutrition of whole meal and filtrating nutritious feature lines. Then take the filtrated color wheat lines as material to test its flour possessing character and developing color wheat's flour products and quality evaluation according to it. And then further research will be done by extracting the natural pigment from the bran and analyzing its structure, physical and chemical characters, and antioxidant activity. Owing to this study, the processing rang of color wheat will be broaden, and the planting area will be expanded, and the farmers'income will increase, too. And this study will boost the development of our nation's natural pigment, and make the color wheat's functional food more natural. The main research results are as following:1. Analysis and evaluation all kinds of nutrition of whole meal of 18 color wheat linesThe experimentation analyses systematically the starch, fat, cellulose, protein, 17 kinds of amid acid, 11 kinds of metal elements and vitamins etc of whole meal from 12 lines red wheat and 5 lines black wheat and green wheat line. The results indicate that the 18 color wheat lines have the character of low starch, low fat, high protein, high amid acid, high metal elements, high vitamins. 5 color wheat lines with different nutrition characters are selected from the nutrition point of view through the analytical method of content comparison, difference and so on. Green wheat has the highest content of cellulose and protein. In the red wheat lines, Red6 has the highest content of all kinds of amid acids, metal elements and Vitamin of B family; Red5 the highest content of Selenium (Se), RedD4 the highest content of starch. In the black wheat lines, Black3 has the best value of all kinds of amid acid and its total content, protein, metal elements content and Vitamins of B family; and other kinds of black wheat are common of these characters. Correlation analysis display there is an very significant positive negative correlation between the contents of protein, amid acid and metal elements (p<0.01), and they all are very significant negative correlation (p<0.01) with starch content. The results show the difference of color wheat mostly come from the difference between the starch, protein, amid acid, metal elements, so the color wheat lines have the all kinds nurture character of low starch, high protein, high amid acid, high metal elements.2. The quality evaluation of color wheat's bread and the correlation analysis of bread quality with RVA valueThe forecast result of RVA value of 5 color wheat lines is that the bread quality of green wheat is the best in all wheat cultivars (lines), RedD4 is better than Jimai19, Red5 is worse than Jimai19, black3 is worse than Red5, Red6 is the worst.The correlation analysis indicates there are very significant or significant difference between each RVA value, so RVA value may forecast more veracity process quality by complementarity each other. The result of sensory quality evaluation accords with the forecast result of RVA value of the bread, so RVA value can forecast veracity sensory quality of color wheat breads. The result of TPA character evaluation accords with the result of sensory quality evaluation, so TPA value may evaluate bread quality to avoid the subjectivity of sensory evaluation. There is significant difference between TPA with RVA value, it indicates RVA value can forecast veracity TPA quality of color wheat breads.3. Bran pigment extraction method research of color wheatThe pigment of Red5 and Green wheat's bran is extracted through the method of acidification alcohol, and there are some same characters here: the high absorption wave-length of the pigment are both around 530nm, the optimal extracting pH=1.0, extracting temperature 60℃and extracting time 1h; And the different ones: the optimal acidification alcohol concentration of Red-6 is 50%, and proportion of material and liquid is 1:20; while as to Green, the values are 40% and 1:20 respectively. In terms of the closely similarity, it can be estimated that the two kinds of pigments have a similar character. However, the attainment rate of Green is 15.07%, higher than Red5 13.62%, therefore, the bran pigment of Green is chosen to do the pigment property assays.4. Conjecture of pigment structureIt is proved that the pigment belongs to anthocyanin compound of flavone series. There is no phenyl or methoxy in the 4th place, and there is a substituting group in the 5th place, hydroxide in the 4th'place, and the hydroxide in the 3rd place forms indican. TLC (thin-layer chromatography) shows that the pigment consists of 3 kinds of integrant, and AICI3 assay deduces that the three kinds probably are pelargonidin,paeonidin,malvidin。5.Study on pigment stabilityThe pigment belongs to water soluble pigment. With the change of pH value, itsλmax keeps steady on the whole, while the peak high changes significantly. The color of the solution changes according its pH values: pH1 (mauve), pH3 (pink), pH5 (light yellow), pH7 (light grey), pH9 (green), pH11 (celadon). And the change of color is reversible, which features the character of anthocyanin pigment. It is affected largely by the temperature, while a little less affection in the range of 20~60℃. It is unstable for light, and sunlight irradiation will destroy it and markedly fade; storing away from light can keep a higher attaining rate than storing it in a light room. Therefore, in order to assure the color of products, the procession of extraction and application should try best to avoiding light. Metal ions have the function of improving the hue of the pigment, and the promotion order from weak to strong is that: Fe3+, Al3+, Ca2+, Zn2+, Sn2+, Cu2+, Mg2+, Mn2+, K+. The color of the pigment transits from dark red to red, however some sediment will appear while using Sn2+, Al3+, Fe3+, which affects the its using in food. Tea polyphenol has a strong effect of enhancing color, and Vc, H2O2, sugar and lemon acid have an effect of fading the color, while Na2HSO4 fading effect is strong. Common salt and Sodium Benzoate have the effect of enhancing and stabilizing the pigment. In the term of potassium stannate, it enhances the color with a concentration of 0.1%, while the effect decline with prolong of time; and it fades the color with a concentration of 0.2%.6. Research of the pigment's antioxidant activityThe pigment extracted from bran of green wheat to identify its antioxidant activity, and the results show that: a certain concentration of the pigment has antioxidant activity upon lard, and the optimal concentration is 0.050mg/ml. Compared with Vc, the pigment has higher activity in total antioxidant, super free radical scavenging, active oxygen scavenging and DPPH·scavenging. Its total antioxidant activity is 51.060 U/ml, 1.732 times of Vc, and its super free radical scavenging activity is 79525.862 U/ml, 2.373% higher than Vc, and its active oxygen scavenging activity is 3776.31 U/ml, 1.241 times of Vc, and as to the activity of DPPH·scavenging, there is a trend of higher concentration has higher activity which will be significant improved by the cooperation with Vc, and in industrial practice, the optimal condition in scavenge DPPH·with mixture of the pigment solution and Vc by the capacity of 0.05ml each and 0.05 mg/ml, 0.1 mg/ml respectively.
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