【作者】 陈志刚；

【导师】 顾振新；

【作者基本信息】 南京农业大学 ， 食品科学， 2003， 硕士

【摘要】 糙米是稻谷脱壳后的一种形态，具有果皮、种皮、糊粉层、胚和胚乳等组织结构和生命活力。发芽糙米与糙米和精白米相比，含有丰富的维生素、矿质元素及多种促进人体健康和防治疾病的成分，因而发芽糙米的营养价值超过糙米，更胜于白米。日本在糙米研究和开发方面处于领先地位，并已进入产业化和商品化阶段。我国长期以来以精白米作为主要食用形式的，因而国内有关糙米研究方面的报道较少。本文以稻米为材料，研究了温度、外源钙和赤霉素处理对发芽糙米淀粉酶活力，主要成分及生理指标的影响。 研究了糙米、白米和发芽糙米营养价值及温度处理对发芽糙米中淀粉酶活力、淀粉和还原糖含量的影响。结果表明，发芽糙米营养价值高于糙米，更优于白米；在16～28℃温度范围内，低温能提高发芽糙米中α-淀粉酶和总淀粉酶活力，高温度使酶活力高峰提前出现，糙米最适发芽温度为22℃。发芽糙米中β-淀粉酶活力受发芽温度的影响较小。在发芽期间，糙米中淀粉含量随淀粉酶活力升高而降低，还原糖含量先升后降。 研究了Ca²⁺处理对发芽糙米生理指标、淀粉酶活力和主要物质含量的影响。在0～15 mmol．L^-1Ca²⁺浓度范围内，糙米的呼吸速率随Ca²⁺浓度的增加而上升。低浓度Ca²⁺能提高糙米的发芽率、发芽指数、活力指数和淀粉酶活力及淀粉等贮藏物质的降解。随着Ca²⁺浓度的升高这些作用减弱，超过5.0mmol．L^-1则产生抑制作用，最适浓度为0.5 mmol．L^-1。 研究了赤霉素处理对发芽糙米生理指标、淀粉酶活力、主要物质含量的影响。用0.02，0.2和2.0 mg．L^-1的赤霉素处理糙米，结果表明，在0.02～2.0 mg．L_-1 GA₃浓度范围内，赤霉素处理能显著提高糙米的发芽势、发芽率、芽长、活力指数、发芽指数和淀粉酶活力，同时能显著提高发芽糙米中淀粉降解量和还原糖、水溶性蛋白质和游离氨基酸含量，最适作用浓度是0.2 mg．L^-1。 研究了Ca²⁺+GA₃处理对糙米的发芽力、淀粉酶活力和主要成分及影响。结果表明，两者具有协同效应。在0～15 mmol．L^-1Ca²⁺和0.02～2.0 mg．L^-1 GA₃浓度范围内，Ca²⁺和GA₃以0.5 mmol．L^-1 Ca²⁺+0.02mg．L^-1 GA₃的处理对提高糙米发芽力和淀粉酶活力，加速淀粉、蛋白质等降解和还原糖、游离氨基酸等生成速度的效果为最好。更多还原

【Abstract】 Brown rice was made of paddy through removing husk, consisting of pericarp, seed coat, aleuronic layer, embryo, endosperm, rich in many vitamins, mineral elements and functional substances good for human health. It can germinate under proper environmental conditions. Some researches indicated the nutritional value of germinated brown rice was better than brown rice, much better than polished rice. Japan take the leading position in the research on brown rice germination, and a series of germinated brown rice products have been launched on the markets, In China, research on brown rice germination had scarcely carried out. With the increase of people’s life level and health awareness, nutritive and functional food would be pay substantial attention. As Chinese main meal, the research and development of nutritive and functional rice and its products would get interest. Therefore, in this paper, the research of the effect of temperature, gibberellic acid (GA3) and Ca2+ on amylase activities, main composition and physiological indexes in brown rice germinating was carried out. The results were as fellows:Nutritive compositions and their changes of brown rice from japonica rice variety "liao jing 294"during germination were investigated. It was showed that the contents of total amino acid and reducing sugar in brown rice were higher than polished rice (Chinese main meal), but lower than the germinated brown rice; Amylase activity in brown rice in the process of germination at 16 ~28 were investigated, -amylase and total starch enzymatic activities in brown rice germination at given temperature range were increased. The peak of amylase activity in the plot of amylase activity over time came up earlier at 28 than at 22 and 16 , but the highest amylase activity could be observed at 22 . Compared to -amylase, - amylase activity in brown rice was less dependent on temperature. During the period of brown rice germination, starch content in germinated brown rice decreased as amylase activity increased, however, reducing sugar content increased at the beginning, and then decreased at the end period.Brown rice treated with GA3 at 0.02, 0.2and 2.0mg. L-1, the same indexes described above of brown rice were investigated. It was showed that at the range of 0.02 to2.0mg. L-1, GA3 could improve germinating energy, germination percentage, germination index, vigor index, shoot length and amylase activity of brown rice significantly (p < 0.05), comparedwith untreated control group. The increase of these indexes above was strong positive correlation with GA3 concentration. In the meantime, starch and storage protein hydrolysis was accelerated, consequently the contents of reducing sugar, soluble protein and free amino acid in germinating brown rice increased. The optimum GA3 concentration was 0.2 mg. L-1Effect of exogenous Ca2+on the germination activity and several physiological and biochemical indexes of brown rice were determined. The respiration rate of brown rice rose with the increase of Ca2+concentration at the range of 0 to 15mmol. L-1. Low Ca2+ concentration (0.05-0.5mmol. L-1) could not only enhance the germination potential, germination rate, germination index and vigor index, but also enable storage substances (e.g. starch, protein) to degrade. Those indexes mentioned above would decrease with the increase of Ca 2+ concentration. When Ca2+concentration was up 5.0 m mol. L-1, inhibition effects were observed. The optimum Ca 2+ concentration was 0.5mmol.L-1.The role of exogenous Ca2++GA3 played in the induction of amylase activity was investigated during brown rice germination. Treating the brown rice with 0.5mmol. L-1 Ca2+ in combination of GA3 (0.02mg. L -1~2.0mg. L-1), amylase activity, the velocity of starch degradation and the content of reducing sugar increased. Of which, the combination of 0.5mmol. L-1 Ca2+ with 0.02mg. L-1 was optimum. Reducing sugar content had strongcorrelation with the amylase activity.更多还原