【作者】 刘万臣；

【导师】 刘兴华； 关文强；

【作者基本信息】 西北农林科技大学 ， 食品科学， 2008， 硕士

【摘要】 丁香(Eugenia caryophyllaTA Thunb)作为我国传统的天然植物,在抑菌、增香和防腐保鲜等方面具有广泛的活性,近年来又发现其在抗癌、抗氧化和抗衰老等方面具有较大的开发利用价值。本论文采用气相-质谱联用技术(GC-MS)分析了提取方法对丁香精油成分的影响,并对丁香精油主要活性成分的稳定性进行了初步探讨;采用DPPH·分光光度法对丁香精油抗氧化能力进行了测定;丁香精油对葡萄、冬枣采后主要病原菌的抑制效果及其与其他植物精油对樱桃保鲜效果进行了比较研究。论文为丁香精油在果蔬防腐保鲜剂上的开发利用提供了依据和应用参考。主要结果如下:(1)分离鉴定出5种果蔬主要致病菌,研究了丁香精油对致病菌的抑制效果,结果表明丁香精油对葡萄灰霉菌、葡萄链格孢菌、冬枣裸孢壳菌MIC均为3.13 mg/mL,对冬枣根霉菌的MIC为6.25 mg/mL;丁香精油对灰霉菌的MBC为3.13 mg/mL,对根霉菌、链格孢菌和裸孢壳菌的MBC均为6.25mg/mL;0.35mg/mL的丁香酚和乙酰基丁香酚均可完全抑制灰霉菌和链格孢菌的生长;乙酰丁香酚的抑菌活性大于丁香酚;β-石竹烯对灰霉菌和链格孢菌没有抑制效应,对丁香酚和乙酰丁香酚的抑菌活性没有增效作用。(2)超临界CO2萃取方法对丁香精油的提取率最高(18.4%),提取时间最短(2h),且无溶剂残留、能耗低;通过GC-MS分析出丁香精油有23种成分,主要成分为丁香酚、乙酰丁香酚和β-石竹烯,三者相对含量共占90%左右;随着萃取时间段的变化,丁香酚含量呈增高趋势,乙酰丁香酚含量变化不显著,β-石竹烯含量降低;丁香酚和乙酰丁香酚在中性介质中的稳定性较高,60℃保温5h仍趋于稳定,自然光照射会引起吸光度值的下降。(3)采用DPPH·分光光度法对丁香精油及其主要活性成分抗氧化能力的测定结果表明,丁香精油清除DPPH·的速度较快,3min左右即达到稳定,随着时间的延长DPPH·残留率变化较小,时间上优于BHT,抗氧化效果与BHT相当;丁香精油主要活性成分丁香酚清除DPPH·的速度较快,30s左右即达到稳定,乙酰丁香酚在30min左右达到稳定,β-石竹烯没有抗氧化性;β-石竹烯对丁香酚和乙酰丁香酚抗氧化无协同作用。(4)丁香精油熏蒸处理能够有效地抑制青椒贮藏过程中的腐烂,室温贮藏28d后3.0μL/L丁香精油熏蒸处理的青椒腐烂率为对照的47.6%,腐烂指数比对照降低58.1%,同时丁香精油处理还减缓了青椒可溶性固形物、可滴定酸、VC含量的下降。(5)丁香精油、香茅精油、艾叶精油和柠檬精油4种植物精油熏蒸处理能够有效地抑制樱桃贮藏中腐烂和果梗褐变的发生,有利于保持樱桃的硬度,维持可溶性固形物、TA、Vc的含量,风味口感均优于对照。其中丁香精油和香茅精油处理效果明显,艾叶精油、柠檬精油处理次之,芥末精油处理易产生药害,防腐保鲜作用不理想。更多还原

【Abstract】 Clove is traditional natural plant in China, have an extensive activities in the aspects of antimicrobial activity, flavoring agent, antibacterial materials in food and so on. In recent years, there had been found that it had bigger value at anti-cancer, anti- oxidize anti- decrepitude etc. The objective of this project is to study the fragrance compounds of clove oils usage GC-MS analysis, and also to discuss the stability of main active compounds from clove oil; to measure the free radical scavenging activities on DPPH·of clove oil; to study the antimicrobial effect of clove oils applied in main pathogens of grapes, Chinese dates and the fresh-keeping effect between clove oil and other natural plants essential oil applied in cherry were also studied. This research would provides a necessity to guide on developing and using clove oil on antisepticise and fresh-keeping.(1) Five pathogens were isolated and identified from fruit and vegetables, antimicrobial effect of clove oils on there were studied. Results showed minimum inhibitory concentration (MIC) of clove oil on Botrytis cinerea, Alternaria spp. Emericella nidulans were 3.13 mg/mL, on Rhizopus was 6.25 mg/Ml; minimum bactericidal concentration (MBC) of clove oil on Botrytis cinerea was 3.13 mg/mL, on Rhizopus、Alternaria spp and Emericella nidulans were 6.25 mg/mL. Eugenol and Eugenol acetate of 0.35 mg/mL all can completely inhibit the growth of Botrytis cinerea and Alternaria spp. Antimicrobial acitivity of Eugenol acetate stronger than Eugenol, whileβ-caryophyllene could not inhibite the growth of the phathogens and also have no positive impact on the antimicrobial acitivity of Eugenol and Eugenol acetate.(2) Supercritical fluid extraction (SFE) of essential oil from clove buds with CO2 was explored. Results showed the clove essential oil extraction rate by SFE was highest (18.4%) within three extraction methods, the extraction time was shortest (2h), and no chemical reagents residues in the final essential oils and low energy consumed. 23 fragrance compounds were identified by the GC-MS, the main chemical compounds were eugenol, eugenol acetate andβ-caryophyllene, their relative content higher than 90%. Along with the extractiom times increasing, the content of the eugenol presents increased, the content of eugenol acetate have no obvious change ,and theβ-caryophyllene decreased. Stability experiments showed that the Eugenol and eugenol acetate showed higher stability in the neuter medium, they still have better heat stability after 5 hours in a 60℃constant temperature bath, but the irradiation of nature light will cause its absorbance decreased lightly.(3) Scavenging ability on 1,1-diphenyl-2-picryhydrazyl (DPPH·) radicals of clove oil showed the speed of scavenge was quick and about 3 minutes have reached stabilization. The variety of DPPH·remain rate was slow with the time increasing, better than BHT, the antioxidant activity was equal to BHT. The main active chemical compound of clove oil was Eugenol which have high speed on scavenging DPPH·, about 30 seconds have attained stabilization, but the eugenol acetate attained stability in the 30 minutes. Theβ-caryophyllene has no antioxidant activity and there was no conjunction function with eugenol and eugenol acetate.(4) Clove essential oil suffocating process could effectively suppress storage rotten of green pepper. After 28 days at room temperature, the rotten rate of green pepper which treated by 3.0μL/L suffocating clove essential oil was comparison’s 47.6%, the rotten index reduces 58.1% compared to the comparison, simultaneously clove essential oil processing also slowed down the SSC, titrate acid(TA) and VC content dropment of green pepper.(5) 4 suffocating kinds of plant essential oil—clove essential oil, citronella essential oil, leaf essential oil of Artemisia argyi and lemon essential oil—could effectively control the occurrence of rotten and fruit peduncle turning brown in cherry storage, they were advantageous in maintains the cherry degree of hardness, they can maintain the content of SSC, TA and Vc, the flavor and the feeling of mouth surpasses the comparison. Clove essential oil and citronella essential oil processing effect is obvious, leaf essential oil of Artemisia argyi and lemon essential oil treated next best. Mustard essential oil processes easily to have the chemical damage, the function of maintains freshness not to be ideal.更多还原