【作者】 欧阳建勋；

【导师】 夏延斌；

【作者基本信息】 湖南农业大学 ， 园艺产品采后科学与技术， 2011， 博士

【摘要】 辣椒素是一类重要的植物功能成分,基于其强烈的热辣作用,做为调味品和药品已有较多研究,但辣椒素抗有害生物的量效关系及将其应用于稻谷绿色储藏的研究未见报道。粮食的安全性问题,不光在生产环节有农药污染,在产后储藏环节亦有化学污染,经常使用化学药物防治虫、霉、鼠,导致3R(Resistance, Residue, Resurgence)(?)司题日益突出。当前,环境友好的生物农药研究方兴未艾,深入研究辣椒素和有害生物之间作用关系,可为安全储粮探索新的思路和方法。本研究针对我国稻谷与辣椒两大资源,探讨了辣椒素抵抗各种有害生物的量效关系,研究了辣椒素为主要成分的储粮防护剂的制备技术及其用于稻谷储藏的可接受性评价,并根据相关研究结论进行了稻谷储藏试验,为利用辣椒素防治稻谷储藏中的有害生物、实现“一剂多防”提供了科学依据,具有重要的理论和实践意义。本研究主要结论如下：1.辣椒素对储粮害鼠的驱避效应采用不同的辣椒素浓度(0.1%、0.2%、0.4%)及不同的施药方式(浸泡、喷雾、涂抹),以稻谷为诱饵,以储粮常见的4种老鼠为评价对象,以咬啮和粮损为评价指标,评价辣椒素的驱鼠效果。结果发现,采用0.2%以上的辣椒素溶液浸泡处理储粮编织袋片,并将其置于鼠笼内,对4种老鼠均有良好驱避效果,480 h内无咬损；采用0.2%辣椒素溶液,以浸泡、喷雾、涂抹3种施药方式处理储粮编织袋(理论使用剂量为85mg/m2),涂抹处理效果好,有效防护期大于350 d；以涂抹、直接添加、喷雾3种施药方式处理PVC储粮囤,其中前2种处理方式对稻谷储藏害鼠防治效果好,其有效防护期大于210 d。结合实仓防鼠效果与感官可接受性评价,本研究将鼠类驱避剂辣椒素的含量确定为0.2%。2.辣椒素对稻谷储藏害虫的驱避与触杀效果采用辣椒素滤纸药膜法,以4种储粮害虫为试验对象,以驱避率、死亡率、拒食、生长、繁育与因虫糙米损失率等为考察指标,研究辣椒素抗虫的效果。结果表明,辣椒素浓度大于2.0%时,对玉米象、赤拟谷盗和书虱的驱避效果相对明显,对谷蠹的驱避作用次之,但对4种储藏害虫的触杀作用不明显。按辣椒素占糙米质量比(4g/kg、2g/kg)均匀添加于糙米,玉米象和赤拟谷盗表现出明显的拒食作用,30d内糙米的因虫损失率,玉米象两个浓度处理组仅为空白对照的26.4%和35.4%；赤拟谷盗处理组仅为空白对照的24.8%和30.6%。采用不同的辣椒素添加剂量处理糙米,观察40d内对玉米象和赤拟谷盗的增殖作用。结果表明：辣椒素的添加剂量为0.05g/100g糙米时,玉米象组、赤拟谷盗组增殖数量分别为空白组的9.23%、26.1%；辣椒素的添加剂量为0.2g/100g糙米时,玉米象组存活数仅1头,赤拟谷盗存活数为0。说明辣椒素的添加使玉米象和赤拟谷盗的增殖受到了明显抑制,且随着辣椒素添加量的增加,抑制作用增大,同时加速了玉米象和赤拟谷盗的死亡。本研究将稻谷储藏防护剂中辣椒素的含量确定为2.0%。扩大中试表明,在浅圆仓表面粮层施用2%辣椒素粉剂40kg,可以控制书虱的发生和为害,在房式仓包装粮仓施用2%辣椒素粉剂20 kg,其防治书虱效果较10%书虱灵乳剂理想,可使书虱密度降低50%。3.辣椒素对稻谷表面的微生物的抑制效应通过分离培养,测定储藏稻谷谷粒表面的微生物菌落总数为4.9×103cfu/g,确定其主要微生物为黄曲霉和黑曲霉；在正常储藏温度范围内,辣椒素能保持良好的抑菌活性;辣椒素浓度为2.0mg/mL时,对黑曲霉和黄曲霉有明显的抑菌效果；扩充试验表明：2.0 mg/mL的辣椒素对供试菌种的抑菌效果由大到小依次为：金黄色葡萄球菌,沙门氏菌,枯草芽孢杆菌,大肠杆菌,黑曲霉,毛霉。4.辣椒素稻谷储藏防护剂的制备工艺优化通过单因素及正交试验,确定以乙醇为提取溶剂、超声波辅助法提取辣椒素的最佳工艺为：超声时间50rmin、粉碎粒度80目、提取温度50℃、料液比1：20。在此条件下,每g干辣椒粉可提取辣椒素19.8mg,辣椒素的一次提取率可以达到86.32%。以明胶与CMC为复合壁材,谷氨酰胺转氨酶作为固化剂,采用复合凝聚法制备辣椒素微胶囊,通过正交试验,确定其最佳工艺条件为：壁材浓度为1%,壁材明胶：CMC为9：1,芯材与壁材的比例为1：1,凝聚过程中的pH为4.6,其包埋产率为92.53%,包埋效率为91.23%。该条件下得到的辣椒素微胶囊粉末经扫描电镜(SEM)观察,其形状大都为不规则球形,粒径多在100μm左右。辣椒素经微胶囊化后,提高了其感官可接受性。5辣椒素用于稻谷储藏的可接受性评价本研究就辣椒素储粮制剂的安全性、溶解性、可接受性、稳定性以及使用成本等方面综合考虑,确定乙醇作为辣椒素稻谷储藏防护剂的最适溶剂；对研制的辣椒素储粮制剂不同浓度及不同的施药方式进行感官评价试验,结果属于感官可以接受范围；辣椒素不同添加量直接处理的稻谷,经储藏90天后的残留情况,糙米中的辣椒素残留量小均于添加量的10%,按照本研究确立的最大理论施药剂量8g/t处理稻谷,制成糙米后,辣椒素残留量小于0.8mg/kg,辣味残留完全可以接受。更多还原

【Abstract】 Capsaicin is a kind of important plant functional component. In more studies capsaicin is used as condiment and drug based on its strong hot effect. But research on preventing biohazard of capsaicin about the quantity-efficiency relation and its utilization in green storage of rice has seldom been reported. Grain safety problems, not only exist in production for pesticide contamination, also in postharvest storage for chemical pollution. Being suffered from harmful biohazard such as pests, mould, rats etc., grain was caused quantity loss and quality deterioration in the process of storage. While using chemical pesticides for prevention, it caused the 3 R (Resistance, Residue, Resurgence) problem increasingly. At present, it is prevalent to carry out environment friendly biological pesticide research. Further study of the relationship between capsaicin and harmful biohazard will explore new ideas and methods for safety grain storage.Rice and chilli are two kinds of rich resources in our country. This study discussed the quantity-efficiency relation of capsaicin preventing various harmful biohazard. Preparation technology of grain storage protective agent was then researched, in which capsaicin provided main effect. Its acceptability evaluation in rice storage test was also conducted. The study provided scientific basis for using capsaicin to control pests, repel rats, inhibit bacteria, and last realized a dose for more usage. Therefore it had important theoretical and practical significance in rice storage control. The main conclusions were as follows.1 Repelling effect on rats in grain storage of capsaicinDifferent capsaicin concentration (0.1%、0.2%、0.4%), different treatment methods (soaking, spraying and daubing), rice as bait, four kinds of common rats in rice storage, biting and rice damage as evaluation indicator were used to evaluate the repelling rat effect of capsaicin. The results found that woven fabric bag pieces were treated over 0.2% capsaicin solution, then placed in rat cages, had better repelling effect on four rats, with no biting damage in 480 h. Using 0.2% capsaicin solution by soaking, spraying and daubing 3 treatment methods on woven fabric bags (theory dosage 85mg/m2), daubing treatment effect was the best, which reached more than 350 d protection period. While daubing, adding directly and spraying 3 treatment methods on PVC grain storage, the front two methods had better preventing rats effect in rice storage, which reached over 210 d protection period. Combining prevention rat effect in real warehouse with sense acceptability evaluation,0.2% capsaicin concentration as rat repelling agent was determined. 2 Repelling and touch killing effect of capsaicin on pests in rice storageFilter paper absorption capsaicin solution as method,4 kinds of rice storage pests as test objects, repelling rate, death rate, resisting feed, growth, reproduction and cargo rice damage by pests as inspecting indicators, which were used to studied the preventing effect on pests of capsaicin. The result showed that when capsaicin concentration was over 2.0%, the repelling effect of was relative obvious to Sitophilus zeamais, Tribolium castaneum, Liposcelis bostrychophila, and inferior to Rhizopertha dominica. But the touch killing effect was not obvious to four kinds of pests in rice storage. According to the ratio of capsaicin to cargo rice 4g/kg and 2g/kg, Sitophilus zeamais and Tribolium castaneum appeared distinctly refusing feed effect. The damage rate of cargo rice in 30 days caused by Sitophilus zeamais was only 26.4% and 35.4% of blank control, similarly Tribolium castaneum caused damage rate only 24.8% and 30.6% of blank control. Reproduction effect of Sitophilus zeamais and Tribolium castaneum were observed according to adding different capsaicin quantity in cargo rice within 40 days. The reproduction number caused by Sitophilus zeamais and Tribolium castaneum was only 9.23% and 26.1% of blank control, according to 0.05g capsaicin per 100g cargo rice. When adding capsaicin 0.2g per 100g cargo rice, Sitophilus zeamais lived only 1 and Tribolium castaneum zero survived. The result showed that capsaicin had obvious inhibition effect on tested pests. The higher content of capsaicin the bigger the inhibition effect. Finally it accelerated death of tested pests.The study determined 2% capsaicin content in grain storage protective agent. In expand pilot test, using 2% capsaicin powder 40kg on the surface layer grain in shallowly along depot could control occurrence and harm of booklice. Compared with 10% booklice emulsifier,2% capsaicin powder 20kg treated on packaged grain storehouse had better effect and could reduce 50% booklice density.3 Inhibition effect of capsaicin on microorganism in grain storageTotal colonies were 4.9×103 cfu/g from storage rice surface by isolation and culture. The main grown microorganism was Aspergillus flavus and Aspergillus niger.Capsaicin could keep good inhibition activity during normal rice storage temperature. Capsaicin concentration 2.0 mg/mL had obvious inhibit effect on Aspergillus flavus and Aspergillus niger. Expansion pilot test showed that inhibition effect of 2.0 mg/mL capsaicin concentration on tested microorganism from high to low was Staphylococcus aureus, Salmonella. Bacillus subtilis, Aspergillus Escherichia coli, Mucor and Aspergillus niger. 4 Preparation technique optimization of capsaicin protective agent in rice storageBy single factor and orthogonal test, the study determined the optimal extraction parameter of capsaicin with ultrasonic wave and ethanol as solvent, which was ultrasonic time 50 minutes, particle size 80 mu, temperature 50℃, ratio of raw materials to solution 1:20. The extraction rate of capsaicin reached 86.32% after one extraction and capsaicin extracted from one gram chilli powder reached 19.8mg.Microencapsulation of capsaicin was prepared by complex coacervation of gelatin and CMC, glutamine transaminase as firming agent. The optimal technique parameters were as follows:wall material concentration 1%, gelatin/CMC 9:1, core/wall material ratio 1:1 and pH 4.6. The embedding yield was 92.53% and the embedding efficiency was 91.23%. Microencapsulation powder of capsaicin had irregular spherical shape, about 100μm particle size by scanning electron microscopy (SEM).Through microencapsulation the sense acceptability of capsaicin was improved. 5 Acceptability evaluation of capsaicin in rice storageThrough comprehensive consideration about safety, solubility, acceptability, stability and cost, ethanol was determined as the most suitable solvent of capsaicin protective agent in rice storage. Different capsaicin concentration, different treatment methods were used to sense evaluation of capsaicin protective agent. The results all belonged to sense acceptability range. Capsaicin residue in cargo rice was all less than 10% additive amount when adding different capsaicin content on rice 90 days later. If the maximum theory additive amount of 8g/t capsaicin protective agent in rice was counted, the capsaicin residue in cargo rice was less than 0.8mg/kg and hot taste residue could be completely accepted.更多还原