【作者】 唐晓珍；

【导师】 尹燕枰；

【作者基本信息】 山东农业大学 ， 作物产品品质改良与质量检测控制， 2008， 博士

【摘要】 彩粒小麦是指籽粒果种皮或糊粉层颜色与生产上常用小麦不同的小麦,现已经报道的有紫粒、黑粒、蓝粒、紫蓝粒、绿粒小麦等。许多品系(种)的彩粒小麦被证实富含蛋白质、氨基酸和对人体有益的微量元素或矿物质,具有较好的加工品质,且籽粒中含有大量天然色素,主要为花青素类色素,应用价值和开发潜力很高。本文以我校孙兰珍教授选育的17个红、黑粒小麦品系和山东昌邑提供的绿粒小麦为材料,通过全麦粉营养成分分析,筛选出具有营养特色的品系。以筛选出的彩粒小麦品系为材料,分析其面粉加工品质,根据其加工品质,进行彩粒小麦粉产品开发与品质评价;以彩粒小麦麸皮为材料进行天然色素的提取、结构、理化性质和抗氧化能力等研究,为彩粒小麦麸皮色素的开发利用提供依据。该研究结果对拓宽彩粒小麦的开发利用途径,提高彩粒小麦麸皮的附加值,促进彩粒小麦功能性食品天然化等具有重要理论意义和实践价值。主要研究结果如下:1.18个品系彩粒小麦全麦粉的各种营养成分分析及评价以济麦19为对照,对12个红粒、5个黑粒、1个绿粒全麦粉的淀粉、脂肪、纤维素、蛋白质、17种氨基酸、11种矿物质、B族维生素等营养成分进行了较系统地分析,其结果表明,彩粒小麦具有低淀粉、低脂肪、高蛋白质、高氨基酸、高矿物质、高维生素含量的特点。利用含量比较、差异显著性分析等方法,从营养角度筛选出了5个各具营养特色的品系(绿麦、红6、红5、D4红、黑3)。绿麦的纤维素、蛋白质含量是所有彩麦中最高的。红粒小麦中,红6的各种氨基酸、矿物质、B族维生素含量最高;红5硒含量最高;D4红淀粉含量最高。黑粒小麦中,黑3的各种氨基酸、蛋白质、矿物质、B族维生素含量最高,其它黑粒小麦品系营养特色不突出。相关性分析表明,这5个彩麦品系的蛋白质含量、氨基酸总含量、矿物质总含量两两之间呈极显著正相关(p<0.01),并都与淀粉含量成极显著负相关(p<0.01)。说明彩麦的营养差异主要是淀粉、蛋白质、氨基酸、矿物质之间含量的差异,从而使该彩粒小麦具有了低淀粉、高蛋白质、高氨基酸、高矿物质等高营养品质。2.彩粒小麦面粉面包品质评价及其与RVA值的相关性分析根据5个彩粒小麦面粉RVA值的分析预测,绿麦制作的面包品质最好,D4红次之,二者优于济麦19,红5较差,黑3更差,红6最差。相关性分析显示,5个彩粒小麦粉RVA各值间存在极显著或显著相关性,可以相互参照预测加工产品品质,提高预测准确性。面包感官评分结果与彩粒小麦粉RVA值分析、预测结果一致,说明可以根据彩粒小麦粉RVA值对其面包感官品质进行准确预测。面包质构评价结果与感官评价结果一致,说明可以采用质构特性值评价面包加工品质,以避免感官评价的主观性。彩粒小麦粉面包质构品质与RVA值呈极显著或显著相关性,说明彩粒小麦粉RVA黏度也可以准确预测面包的质构品质。3.彩粒小麦麸皮色素提取工艺研究采用酸化乙醇法提取红5、绿麦麸皮中色素,确定了色素提取工艺条件:色素最大吸收波长都在530nm左右,最佳提取pH为1.0、提取温度60℃、提取时间1h。最佳酸化乙醇浓度红5为50%,绿麦为40%。最佳料液比红5为1:20,绿麦为1:15。得率红5为13.62%,绿麦为15.07%。二者差异不大,推测所提取的两种粒色小麦色素性质类似。4.色素结构推测利用紫外-可见光谱法、薄板层析法等研究了绿粒小麦麸皮色素的光谱学特性、结构特性,确定了该色素为黄酮类花色苷化合物,在3位羟基上形成糖苷,4位上没有苯基或甲氧基,5位上有取代基,具有4′位羟基,含有3种色素成分,推断是天竺葵色素、芍药色素、锦葵色素。5.色素稳定性研究绿粒小麦麸皮色素的稳定性显示,该色素为水溶性色素。随pH值的改变,色素的λmax基本不变,而峰高明显下降直至消失。色素溶液色调随pH值改变而变化,呈现pH1(紫红)→pH 3(粉红)→pH 5(浅黄)→pH 7(浅灰色)→pH9(绿色)→pH11(灰绿色)的趋势,并呈可逆性。该色素不耐80℃以上高温,在20～60℃吸光度值和色泽变化不大。该色素对光不稳定,日光直射3d明显褪色,色素损失60%以上;避光贮存60d时保留率达89.2%,而室内自然光下仅为61.2%。金属离子对该色素有增色作用,由弱到强依次为Fe3+、Al3+、Ca2+、Zn2+、Sn2+、Cu2+、Mg2+、Mn2+、K+,色素颜色逐渐加深,但加入Sn2+、Al3+、Fe3+后色素溶液有沉淀出现,影响该色素在食品中的应用。茶多酚对该色素有很强的增色作用,Vc、H2O2、蔗糖、柠檬酸对其有褪色作用,Na2HSO4对其有较强褪色作用。食盐对其有增色、稳定作用,3.0%食盐量增色作用稍高于1.0%食盐量。山梨酸钾、苯甲酸钠对其有明显的增色作用,0.1%浓度增色作用高于0.2%浓度。6.色素抗氧化功能的研究绿粒小麦麸皮色素抗氧化试验结果显示,该色素对猪油有较好的抑制氧化作用,其中0.05mg/ml抑制氧化作用最强。比Vc具有更高的总抗氧化能力、抗超氧阴离子自由基能力、抗活性氧能力、清除DPPH·能力。其总抗氧化活力为51.060U/mL,是Vc的1.732倍;抗超氧阴离子自由基活力单位为79525.862U/L,比Vc高2.373%;抗活性氧活力单位为3776.31U/mL,是Vc的1.241倍;浓度越高清除DPPH·能力越强,色素浓度高于0.05mg/mL时比0.1mg/mLVE具有更高的清除效果,但只有5mg/mL色素浓度清除效果高于0.1mg/mLVc;与Vc协同清除DPPH·能力明显增强,当色素液浓度大于0.1mg/mL时,协同清除能力超过0.1mL 0.1mg/mL Vc。样本方差显示0.05mg/mL色素液与Vc的协同效果提高最大,生产中可以选择0.05mL 0.05mg/mL色素液与0.05mL0.1mg/mLVc进行协同清除DPPH·。更多还原

【Abstract】 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.更多还原