【作者】 汪志君；

【导师】 李式军；

【作者基本信息】 南京农业大学 ， 蔬菜学， 2002， 博士

【摘要】 硒是人和动物必需的微量元素，硒与人类疾病、健康的关系一直是国内外医学研究的热点问题。现有的研究成果证明硒有减轻动脉粥样硬化，减少心血管系统疾病的死亡率，清除人体自由基，提高免疫能力，延缓衰老，预防某些癌症的发生等作用。但世界上有40多个国家和地区缺硒。在我国有72％地区属缺硒或低硒地区，由此造成人体缺硒或低硒，对健康不利。 大麦是硒敏感型植物，把大麦经浸渍、发芽、烘干等工艺制成麦芽，在这个过程中把无机硒转化成有机硒，不仅可以得到满足人体需要的补硒量，还可以避免由于麦芽过量吸收硒带入食物链而导致人或动物中毒的发生。 我们把麦芽作为富硒载体不仅因为麦芽营养价值高，而且兼有食用、药用、酿造用等多种用途，因而麦芽在食品工业中占有很重要的地位，特别是在酿造工业上，麦芽是酿制啤酒的主要原料。2001年我国啤酒产量达2200万吨，需麦芽300万吨，但由于国产啤麦制麦性能较差，麦芽的质量指标很难达到原轻工部部颁优级品的标准。因此国内许多麦芽厂、啤酒厂都采用进口啤麦来制麦、酿酒。据国家有关部门统计，近几年我国每年都要从国外进口啤酒大麦200万吨左右，约占全国啤酒大麦总量的55％左右。进口啤麦价格高，由此造成企业生产成本上升，经济效益下降，这种状况对我国啤酒工业的发展极为不利，同时也影响我国啤酒大麦种植业的发展。 硒不但参与人体的生化反应，而且对植物的生长也有一定的刺激作用，把硒与赤霉素（GA₃），抗生素P一起制成制麦添加剂用于制麦，特别是用于提高麦芽质量指标的研究，目前国内外还未见报道。 本试验富硒麦芽的制备工艺成熟，主要采用与啤酒麦芽制麦相同的工艺过程，浸渍（浸断水）、发芽（恒温发芽，定时通风供氧，降温）、烘干（程序升温，回风焙焦）。在此过程中，研究不同浸麦度、不同硒浓度，以及抗生素P、赤霉素（GA₃）配合亚硒酸钠处理对麦芽总硒、有机硒富集的效果。在此基础上研究了它们对麦芽呼吸强度、α-淀粉酶、蛋白酶、谷胱甘肽过氧化物酶、多酚氧化酶、过氧化物酶活性的影响。同时也研究了硒及硒配合赤霉素（GA₃）、抗生素P对啤酒麦芽色度、α-氨基氮、无水浸出率，糖化力、库尔巴哈值等质量指标的影响。研究的主要结果如下： 1．富硒的最佳浓度条件及效果 在低浸麦度范围内大麦发芽时吸收硒的量随着浸麦度的升高而增多，浸麦度达到42％时麦芽的硒含量最高，浸麦度超过42％时麦芽中的硒含量逐渐下降。在浸麦度42％时用亚硒酸钠处理，随着亚硒酸钠处理浓度的增加麦芽中总硒和有机硒的含量逐渐增加，当亚硒酸钠浓度为150mg·L^-1时麦芽中有机硒含量最高为4.5μg·g^-1，总硒5.0μg·g^-1，有机硒占90％，之后随着亚硒酸钠浓度增加有机硒含量则逐渐降低。以100mg·L^-1亚硒酸钠配合抗生素P处理，抗生素P浓度为100mg·L^-1时，麦芽中的总硒和有机硒含量最高，分别为3.5和3.4μg·g^-1，且有机硒含量是对照的1.3倍。 硒元素与添加剂对麦芽主化特性及酿造性能的影响以 100mg·L”’亚硒酸钠配合赤霉素GA。处理，GA。浓度为0．05 mg·L“‘时，麦芽中的总硒和有机硒含量最高，分别为8．4和7．sug·g”‘，且有侧含量矾照的3。3倍．2．富硒的生理变化 在亚硒酸钠浓度小于150 mg·L”‘时，麦芽的呼吸强度随瞰增加而增加；浓度大于 150 p·L‘时麦芽的呼吸受到抑制，瞰越大抑制作用越强。亚硒酸钠处理浓度超过 200 p·L”‘时，对麦芽的生长产生抑制作用． 100 p·L’l亚硒酸钠配合抗生素 P处理麦芽，抗生素 P浓度小于 200 mg·L”‘时，随着杭生素＄A的增加，呼吸强度也增大；浓度大于200 mg·L‘时，浓度增大呼吸强度受到抑制．100 mg·L”’亚硒酸钠配合 GA3处理，GA3浓度小于 0．10 mg·L“’时，随着 GA ＄A的增大对麦芽的呼吸促进也越大；浓度大于 0．10 mg·L‘时则抑制麦芽的呼吸．3．富硒中酶活性的变化 对麦芽 a－淀粉酶活性，亚硒酸钠单独处理浓度为 150 mg·L“‘时最高，且第三天达到的最高峰值，t匕对照提高 14o；100 mg·L“’A硒酸钠N己合抗生素P处理，抗生素浓度 200 mg·L‘时 a－淀粉酶活性提高最大，其第三天达到的最高峰值比对照提高70％；100 mg·L”‘亚硒酸钠配合 GA，处理，GAa浓度 0二0 mg·L”‘时对 a－淀粉酶活性刺激最大，在发芽第 H天就达到最高峰，比对照增加 147％。 对麦芽蛋白酶活性，亚硒酸钠单独处理浓度为150 mg·L”‘时最高，第三天达到的最高峰值比对照提高390；100mg·L”’L硒酸钠6c合抗生素P处理，抗生素浓度200 mg·L”‘时蛋白酶活性提高最大，且第三天达到的最高峰值比对照提高 33％；100mg·L”‘亚硒酸钠配合 GAs处理，GAs浓度 0二0 mg·L”时对蛋白酶活性刺激最大，最高账提前到发芽第二天，活性比对照增加63％。 GSHIX活性在亚硒酸钠单独处理浓度为 200 mg L”‘时活性提高最大；100 mg L“1硒酸钠6己合杭生素 P或 GA。处理，分别在抗生素浓度为 200 mg·L”’和 GA。浓度为0．10 mg·L更多还原

【Abstract】 Selenium is an essential trace element to human and livestocks The relation between selenium and health is always attended to in the medical areas. The existing results show that selenium has many functions ,e.g. lightening arteriosclerosis, decreasing the death rate of cardiovascular disease, eliminating free radicals , enhancing the ability of immunity, deferring caducity, preventing the appearance of some cancers. Selenium deficiency or potential deficiency is very common and serious in the world. In China, about 72% of the territory is short of Se, people there suffer form Se deficiency which is no benefit to health.Barley is sensitive to selenium and it can forbid excessive content of selenium causing human to be toxic. Inorganic Se could be transformed into organic Se after malt steeping, germinating and kilning, which not only satisfies human need but also keeps human being and animal from the overtaking of Se by malt.Malt was used as a carrier of Se, not only, for it’s nutritious, edible and medicinal but also for it’s useful in food industry, especially in brewing. Malt is the main material of beer, and the annual output of barley was 3 million tons in 2001 in china. Most of domestic malt factory and beer brewery preferred to using importing barley for it’s good quality, on the contrary for bad of home barley. According to statistics China has imported about 2 million tons barley a year recently, hitting 55% of total Chinese barley output. The higher price of imported barley increased factories’ production cost and decreased economic benefit, which was no benefit to both the beer industry and the barley planting in China.Selenium is not only nutritious to human, but also a stimulant of plants. Malting additives composed of Se, gibberellin GAs and antibiotic P were used during malting, especially for improving malt quality, which was barely reported.The malting technology of enhancing includes steeping, germinating and kilning, Effects of different steeping degree, different concentration of Na2SeO3 and different concentration antibiotic P or gibberellin GAa and Na2SeO3 on total-Se and organic Se , and respiratory intensity, a -amylase, proteinase, GSH-Px, POD and PPO activity of malt were investigated. Finally, wort colour, a -AN, extract, diastatic power and Kolbach value of malt quality were involved. The results are shown as follows:1. ENHANCED SELENIUM OPTIMUMO CONCENTRATION With the steeping degree higher, Se content of malt increased during 0~42%, and over higher it decreased. Se content increased with Na2SeOs concentration higher. The optimum concentration of Na2SeO3 was 150mg - L-1. Total Se was 5 u g - g-1. And organic Se was about 90%. The total Se and organic Se content were 3.5 and 3.4 u g - g-1 respectively, and organic Se content was 1.3 times of the control. When malt was treated with 100 mg - L-1 Na2Se03 and 100 mg - L-1 antibiotic P, the total Se and organic-Se content were 8.4 u g - g-1 and 7.8 u g - g-1, respectively. When malt was treated with 100 mg - L-1 Na2SeO3 and 0.05 mg - L-1 gibberllin GAs, the organic Se was 3.3 times of the control.2. PHYSIOLOGY CHANGESRespiratory intensity of malt increased when treated with 0-150 mg - L-1 Na2SeO3, while it was inhibited when Na2SeO3 concentration higher than 150 mg - L-1. And malt growth was inhibited when Na2SeO3 concentration higher than 200 mg - L*1.Respiratory intensity of malt increased when treated with 100 mg - L-1 NaaSeOs plus 0-200 mg -L-1 antibiotic P ,while higher concentration of antibiotic P(>200 mg -L-1) did the reverse. Respiratory intensity of malt increased when treated with 100 mg - L-1 Na2SeO3 plus 0-0.1 mg - L-1 gibberllin GAs, while higher concentration of gibberllin GA3.(>0.1mg - L-1) did the reverse.3. ENZYME ACTIVITY CHANGESa -amylase activity of malt was highest when treated with 150 mg *L~’ Na2SeO3 alone, about 14 percent higher than the control, a -amylase activity of malt was the highest when treated with 100 mg - L-1 Na2SeO3 plus 200 mg - L’1 antibiotic P, about 70 percent hi更多还原