【作者】 成纪予；

【导师】 叶兴乾；

【作者基本信息】 浙江大学 ， 食品安全， 2008， 博士

【摘要】 中国是杨梅的主栽培国,栽培面积占全球的99%以上。杨梅核是杨梅果汁和果酒酿造加工过程的副产物,占杨梅原料的10%左右。但是,至今尚未对其进行良好的加工利用,对于杨梅核的认识太少是限制其进一步利用的主要原因之一。本文首先检测和分析了杨梅核及杨梅核仁的成分,然后从油脂、蛋白质、活性炭、木醋液等方面对杨梅核的开发途径和利用前景进行较为全面的分析和探讨,旨在为杨梅核的开发利用提供理论基础。主要研究结果如下：(1)选择浙江省内常见的14种杨梅核(荸荠、东魁、晚稻、炭梅、乌紫、丁岙、早大、迟大、荔枝、早色、迟色、粉红、白杨梅、水晶杨梅),分析了其及核仁的理化特性。杨梅核主要成分是粗纤维(63.71～68.72%DW)。杨梅核仁富含脂肪(58.12～68.15%DW)和蛋白质(22.06～26.17%DW)。杨梅核仁对小鼠半致死剂量大于20.0g/kg(体重),说明杨梅核仁无毒。(2)杨梅核仁油是以油酸(35.61～49.58%)和亚油酸(34.04～49.30%)为主的油脂。超声波辅助提取与常规法相比,具有油品质好、更稳定、提取时间短、温度低的优点。超声波辅助提取杨梅核仁油,影响得率的各因素主次顺序为：料液比>提取时间>超声功率>超声频率。最佳工艺条件为：频率60kHz、功率10W、提取时间30min、料液比1:12,得率为59.22%。添加抗氧化剂可明显地提高杨梅核仁油的氧化稳定性,TBHQ效果最好。(3)杨梅核仁蛋白含有18种氨基酸,富含谷氨酸、精氨酸、天冬氨酸和蛋氨酸,赖氨酸为第一限制氨基酸。杨梅核仁蛋白碱浸提的最佳工艺条件是：pH值10、浸提温度50℃、浸提时间45min、料液比1:15,蛋白质提取率达到88.2%。杨梅核仁蛋白的等电点为pH3.5。碱提酸沉法得到的杨梅核仁分离蛋白的蛋白质含量高达91%。在不同环境(蛋白质浓度、pH、温度、盐浓度以及蔗糖浓度)下,杨梅核仁分离蛋白呈现出不同的功能特性(溶解性、持水性、持油性、起泡性、乳化性和凝胶特性),这为其在不同食品体系中的应用提供了理论基础。(4)采用水蒸汽活化法制备的杨梅核活性炭,其亚甲基蓝脱色力可达162mg/g,碘吸附量可达1219mg/g。杨梅核制备活性炭的优化工艺条件为：活化温度900～950℃,活化时间1.5-2h,水蒸汽用量250～300ml/50g杨梅核炭。活化温度对杨梅核活性炭的得率和吸附能力都有显著影响(P<0.05)；活化时间只对得率有显著影响(P<0.05),对吸附能力影响不显著；水蒸汽用量对得率和吸附能力均无显著影响。杨梅核活性炭对甲醛、苯、氨气、三氯甲烷四种有毒气体的吸附能力依次为：甲醛>三氯甲烷>苯>氨气。(5)杨梅核木醋液的主要成分是水,其次是有机酸,然后是酚类、酮类、醛类、酯类、醇类,除此之外,还含有其它如吡啶类、呋喃类、烷类等物质。在FRAP、DPPH和ABTS三种体外抗氧化体系中,杨梅核木醋液及其乙酸乙酯萃取物呈现出良好的抗氧化性能。杨梅核木醋液的抗氧能力与总酚含量呈正相关(R~2=0.8636～0.9896),可以推断酚类成分是起抗氧化作用的主要物质。杨梅核木醋液对多种革兰氏阳性菌(金黄色葡萄球菌、枯草杆菌、蜡样芽孢杆菌)和革兰氏阴性菌(大肠杆菌、鼠伤沙门氏菌、恶臭假单胞菌)有不同程度的抑菌作用。杨梅核木醋液的抑菌作用主要与酸性成分以外的组成成分有关。更多还原

【Abstract】 Bayberry （Myrica rubra Sieb. et zucc.） is mainly cultivated in China. As the byproduct of bayberry fruit juice or wine industries, the amount of bayberry stone, which comprise 10%or more by the weight of the bayberry fruits, is quite large. But bayberry stone has not been exploited at present, because of the lack of basic information on it. At first, the composition of bayberry stone and kernel was detemined and analyzed. A comprehensive and systematic research and discuss on bayberry stone, including oil, protein, activated carbon and wood vinegar was carried out. The objective of this study was to provide basis for exploitation of bayberry stone.The main results were presented as follows:（1） Forteen Chinese bayberry stones, include’Biqi’,’Dongkui’,’Wandao’,’Tanmei’, ’Wuzi’,’Ding-ao’,’Zaoda’,’Chida’,’Lizhi’,’Zaose’,’Chise’,’Fenghong’,’Baiyangmei’, ’Shujingyangmei’were collected from deferent areas of Zhejiang province, China, and main physico-chemical characteristics were measured. The main composition of bayberry stone was crude fibre （63.71-68.72%DW）. Bayberry kernel was rich in fat （58.12-68.15%DW） and protein （22.06-26.17%DW）. In acute toxicity test, the medium lethal dose of bayberry kernel on ICR rats was more than 20.0 g/kg （body weight）, which indicated bayberry kernel was actually no toxicity according the standard of toxicity grade classification.（2） Bayberry fatty acids mainly were oleic acid （35.61-49.58%） and linoleic acid （34.04-49.30%）. Compared to cold extraction method, ultrasonic extraction method has many advantages in oil quality and stability, and need shorter extraction time and lower extraction temperature. The influencing extents of the 4 factors are:material to liquid ratio> extraction time> ultrasonic power> ultrasonic frequency, and the optimal extracting parameters were obtained as the ultrasonic frequency 60 kHz, the ultrasonic power 10 W, the extracting time 30 min, and material to liquid ratio 1:12, and as result the yield is 59.22%. Antioxidant can improve the oxidative stability of bayberry kernel oil obviously, and TBHQ has the best effect.（3） Bayberry kernel protein possessed 18 amnio acids, and was rich in glutamic, arginine, aspartic and methionine acids while limited in lysine. The optimal alkaline extracting process of bayberry kernel protein was:pH10,50℃,45 min, and material to liquid ratio 1:15, and the extraction rate is 88.2%. The isoelectric point of bayberry kernel protein was 3.5. The protein content of bayberry kernel protein isolate prepared by alkali extraction and acid precipitation reached 91%. Under different conditions （protein concentration, pH, temperature, salt and sugar consentration）, bayberry kernel protein isolate showed different functional properties （solubility, water hold capacity, oil hold capacity, foamability, emulsifying property and gelation）, which provides theoretical basis for the application ranges of protein isolate in different food systems.（4） The iodine and methylene blue adsorption abilities of steam-activated carbon from bayberry stone reached 1219 and 162 mg/g, respectively. The optimal process of bayberry stone steam-activated carbon is:900-950℃,1.5-2 h and steam comsumption of 250-300 ml/50g bayberry stone carbon. Activation temperature had significant effect （P<0.05） on the yield and adsorption abilities of bayberry stone activated carbon. Activation time only had significant effect （P<0.05） on the yield, and steam consumption didn’t have significant effect on yield nor adsorption abilities. Bayberry stone carbon could adsorb some toxic gas such as formaldehyde, benzene, chloroform and ammonia, and adsorption effect is: formaldehyde> chloroform> benzene> ammonia.（5） The compositions of wood vigenar from bayberry stone were mainly water, and then orgnic acids, phenol compound, ketones, aldehydes, esters, alcohols, pyridines, furans, alkanes and so on. Bayberry stone wood vigenar and its ethyl acetate extract showed good antioxidative capacity in antioxidant systems such as FRAP, DPPH and ABTS in vitro. The antioxidative capacity of bayberry stone wood vinegar was linear positive correlation with their total phenolic content （R₂=0.8636-0.9896）, suggesting that phenol compound may be the key antioxiditive compositions. Bayberry had antibacterial effect on gram-positive bacteria （Staphyloccocus aureus, Bacillus subtilis and bacillus cereus） and gram-negative bacteria （Escherichia coli, Salmonella Lignieres and Pseudomonas putida）, which is mainly due to its components except acidic components.更多还原