【作者】 杨蕾；

【导师】 钟海雁；

【作者基本信息】 中南林业科技大学 ， 农产品加工及贮藏工程， 2010， 硕士

【摘要】 茶油(Camellia oil)作为我国特有的食用油,其营养价值和保健功用已为人们所熟知。随着人们生活水平的提高,广大消费者对具有保健作用的茶油必然越来越关注,所以,生产高品质的茶油已成为必要。不同的品种和制取方法对于茶油品质有一定的影响,所以,好的油茶品种和适当的制油方法有利于提高茶油的品质。浙江红花油茶(Camellia chekiangoleosa Hu.)属山茶科山茶属,是一种集庭院园林观赏和种仁可榨取食用油双重功能于一体的树种。一般适宜生长在温暖湿润地区海拔600-1200米的山区,主要分布在浙江省境内,另外,在福建、江西、湖北和安徽也有分布。浙江红花油茶的种植面积和年产量居全国油茶种类的第四位,其含油率和脂肪酸组成均优于普通油茶,是一种较佳的木本食用油料树种。水代法制油符合安全、营养、绿色的要求,对环境污染少,成本低。油茶籽脱壳可实现机械化,且油茶籽仁含油量高,属软质油料,适合于水代法取油。另外,大量研究表明,茶油香气和脂肪酸组成成分与油脂品质有密切联系。因此,研究浙江红花油茶的水代法制油工艺,弄清该茶油的香气和油脂主要组成成分,对提高茶油品质和保障消费者健康有着重要的意义。本课题采用浙江红花油茶籽为原材料,采用水代法制油,并且通过对该法制取的油脂进行感官评定实验、常规指标的检测、香气成分和脂肪酸成分的测定,进而对该油脂进行品质分析。反映茶油品质的重要指标如下：①茶油原材料——油茶籽的经济性状；②茶油香气；③常规指标；④脂肪酸组成。本文具体内容及基本结论如下：(1)根据国标测定浙江红花油茶籽的千粒重、出仁率、含油率、含水量等经济性状,通过与普通油茶籽的各项经济性状指标进行对比,证明了浙江红花油茶是一种优于普通油茶的食用油料树种。(2)将干燥的茶籽仁切成薄片,170℃焙烤10 min。准确称取焙烤后的茶籽仁10.00 g,磨碎后加一定比例的水,在不同温度下恒温水浴振荡(160 r/min)一定时间。然后在4000 r/min下离心10 min,吸去上层清油并称重。再吸去乳化层和水层,得浆渣,于55℃下烘12h后测残油率。单因素试验设计为：以水料比3：1(v/m),提取温度40℃,提取时间90 min和pH 8.0,作为基本条件,在改变其中一个条件的情况下保持另外三个条件不变而进行单因素试验。以提油率和清油收率为指标,通过该试验得到了浙江红花油茶水代法制油工艺的工艺条件：提取温度60℃,提取时间120 min,水料比3：1(v/m)和pH 9.0,经3次平行试验验证,该结论具有一定的可靠性。试验中,提油率最高可达到79.27%,清油收率达到84.83%。另外,本试验还发现油茶籽前处理中的焙烤环节不仅对提油率有影响,对所提取茶油的香气影响很大：经焙烤过的油茶籽所提取的茶油香气浓郁,清新,有较纯正的茶油特征香气；未经焙烤前处理的茶油香气清淡,并带有青草味。(3)对水代法制得的浙江红花油茶籽油进行感官鉴定实验,并将测定结果参照国标得出如下结论：实验中水代法提取的浙江红花油茶籽油符合标准植物油感官要求,具有植物油正常的色泽、透明度、气味,无焦臭、酸败及其他异味,气味和透明度这两项指标符合一级压榨茶油的标准,气味嗅觉在茶油等级中为极好。对该茶籽油的水分及挥发物、酸值、过氧化值、K值、皂化值等各项常规指标进行测定,并将测定结果参照国标得出如下结论：水代法提取的浙江红花油茶籽油除了水分及挥发物这项指标外,其他指标均符合符合一级压榨茶油的标准。另外,浙江红花油茶籽油皂化值的测定结果说明浙江红花油茶籽油小中分子量的脂肪酸含量比标准茶油高。(4)本实验以水代法制得的浙江红花油茶籽油为原料,通过HS-SPME方法结合GC分析技术对该茶油香气成分进行研究。优化了HS-SPME对茶油香气的萃取条件,并对萃取后GC的实验结果进行分析。以总峰面积、总峰面积与峰数比值、峰数及主要挥发物质峰面积为评价指标,研究了搅拌速度、吸附时间、解析温度及时间对茶油中香气物质萃取效果的影响,最终优化条件为：称取1.00g油样,40℃下以100r/min搅拌速度,顶空萃取25 min,之后在260℃下解析5min。另外对方法的可靠性进行了评价：研究所选定的11种标准品在表中列出的含量范围内具有良好的线性,相关系数(R2)在0.8543-0.9989间；各标准品的检测限在0.14ng/g-79.78ng/g间；‘本方法对茶油样品的加标回收率在91.70%-107.71%之间,平均值为98.87%；在重复性实验中,111种标准品在经7次连续检测中的RSD范围在2.46%～4.84%,可见该方法具有较好的可操作性。通过GC分析技术,对浙江油茶籽油和普通茶油的11种主要香气组分进行定性定量分析。该11种香气标准品为乙酸乙酯、苯甲醛、正壬醇、辛醛、壬醛、4-甲基-2-戊酮、乙酸丁酯、正辛醇、正丁醇、1-己醇、1-庚醇。实验结果表明：两种不同茶油的香气11种主成分含量相近,但具体浓度均有差异。(5)通过GC检测技术,对浙江油茶籽油和普通茶油的脂肪酸组分进行分析,浙江红花油茶籽油的脂肪酸组成和普通茶油基本一致,主要化学成分为油酸,但是存在一些差异：①浙江红花油茶籽油中油酸(C18：1)、亚油酸(C18：2)、肉豆蔻酸(C14：0)、木蜡酸(C24：0)在脂肪酸中的相对含量偏高；②浙江红花油茶籽油中检测出少量的花生酸(C20：0)和亚麻酸(C18：3),而普通茶油中并未检出。③浙江红花油茶籽油中棕榈酸(C16：0)、硬脂酸(C18：0)、二十二酸(C22：0)、二十二碳一烯酸(C22：1)在脂肪酸中的相对含量比普通油茶低；④浙江红花油茶籽油中不饱和脂肪酸的总含量比普通茶油高；⑤浙江红花油茶籽油中饱和脂肪酸的总含量比普通茶油低。对二种茶油脂肪酸组分对比分析可知,浙江红花油茶籽油的脂肪酸组成优于普通茶油。本文研究结果对于促进茶油生产工艺的改进,提高茶油品质,满足广大消费者的高品质茶油需求都具有十分重要的意义。更多还原

【Abstract】 Camellia oil as a unique edible oil in China,is famous for nutritional value and health-care functions. With.the improvement of people’s life, most of the consumers will inevitablely pay more and more attention to the tea oil that is good to health, therefore, the production of high quality camellia oil has become necessary.Different species of camellia and different methods of preparation for the camellia oil have certain impacts on the quality of camellia oil, therefore, a.good camellia species and appropriated methods of preparation for camellia oil can help to improve the quality of camellia oil. Camellia chekiangoleosa Hu.belongs to the genus Theaceae Camellia, and is a species with the double feature of ornamental gardens and its seed kernel can be extracted to edible oil. Generally, it is suitable for growing in warmming humid mountain areas with 600～1200 m altitude, mainly distributed in Zhejiang Province, and also in Fujian, Jiangxi, Hubei and Anhui. The growing area and the output of Camellia chekiangoleosa Hu.are in the nation’s fourth of Camellia oleifera species. Its oil content and fatty acid composition are better than Camellia oleifera, and it is an excellent edible oil trees.The method of aqueous extraction of oil is accord with the demands of safety, nutrition and green,and it has less environmental pollution and low cost.The Camellia oleifera’shelling can be mechanized, and its oil content is high, and then,it is suitable for aqueous extraction to take the oil.In addition, a large number of studies have shown that Camellia oil aroma constituent and fatty acid constituent are closely linked to the oil quality. Thus, the study of aqueous of Camellia chekiangoleo-sa seed oil and understanding the mainly aroma constituent and fatty acid constituent have important significance for improving value of camellia oil and protecting health of consumers.In this thesis,the Camellia chekiangoleosa’oil is extracted from Camellia chekiangoleosa seeds by. the method of aqueous extraction according to the qualification of the demands of safety,nutrition and green. The quality analysis of Camellia chekiangoleosa oil is analyzed by organoleptic assessment, routine indicators,aroma and fatty acids components.There are four important indicators reflecting the quality of Camellia oil such as:①raw material of Camellia oil-economic traits of Camellia chekiangoleosa;②aroma of Camellia oil,③routine indicators,④components of fatty acids.The thesis is organized as follows:(1)The economic traits of Camellia chekiangoleosa were measured, according to the national standards.The results showed that the synthesis characters of Camellia chekiangoleosa seeds, i. e. TGWT, kernel rate,oil content,water content,are better than those of Camellia oleifera.(2)Firstly, slice the arid Camellia chekiangoleosa seed kernel, and rosted them at 170℃for 10min. After that, weight 10.00 g of the kernel accurately, and grinde them, and mixed the power with a certain percentage of water. Then, the stable temperature Horizontal shaking bath under different conditions (160 r/min) in some time were carried at 170℃for 10min and centrifuged at in the 4000 r/min for 10 min for extraction of the upper free oil, and obtain their weight. Eliminate the emulsion phase and water phase to get the slurry residue, and dried at 55℃for 12 hours, then measure residual rate. Single-factor experiment was designed and set the seed meal:water at 1:3(m:v),incubation temperature at 40℃, incubation at 90mins,and PH at 8 as the basic conditions. Then change one of the conditions and keep the other three conditions the same.With the highest oil extraction rate and free oil recovery as indicators, the optimum extraction procedure was obtained as follows:seed meal: water at 1:3 (m:v),incubation temperature at 60℃,and time at 120 min.The result is reliable by being tested at 3 parallel test verification. In experiment, the highest oil extraction rate and free oil recovery were up to 79.27% and 84.83% respectively.In addition,this study also found that the baking process,a part of pre-treatment of camellia seed,is not only impact on the oil extraction rate,but also the aroma of Camellia oil:the Camellia oil with the pre-treatment of baking before extraction have pure and characteristic aroma of Camellia oil and go with aroma of herb without baking.(3)The aroma of Camellia chekiangoleosa oil,which was obtained by aqueous etraction,was described by sensory evaluation, and according to the national standard,the conclusion from the test results are as follows:the Camellia chekiangoleosa oils is conform to the requirements of oil sensory of standard vegetable oil.Two indices, odor and transparency, were better than those of oil-tea camellia oil specified in GB-11765. the indices of odor and olfactory is excellent according to standard of.olfactory sensory on the odour of camellia oil.Quality index of Camellia oils were tested,and according to the national standard,the conclusion from the test results are as follows:except for the water and volatile content,the other indices of quality of aqueous extracted oil were better than those of oil-tea camellia oil specified in GB-11765. In addition, the result of the value of Saponification of.Camellia chekiangoleosa oils shows that the content of fatty acid of small molecular weight was higher than that of camellia oils.(4)Camellia chekiangoleosa oil which was obatained by aqueous extraction in laboratory as materials,the aroma of camellia oil was researched by Head Space Solid Phase Micro-extraction(HS-SPME)contecting with GC.The conditions of HS-SPME extracting the volatile profiles of camellia were optimized, and the analysis effect of GC was verified. Total peak area, ratio of total peak area to number of peaks, peak number and peak area of main volatiles were as evaluation indexes. The effect of stirring rapidity, extraction time, desorption temperature and time for extracting volatile profiles was studied. Extraction conditions were found that:1.00 g oil sample in 15 mL vessel, exposure for 25 min at 40℃, stirring at 100r/min, and desorption for 5 min at 260℃in GC.Calibration curves of 11 standards showed good linearity, with coefficients of determination(R2) ranging from 0.8543 to 0.9989 and limits of detection(LOD) from 0.14 ng/g to 79.78ng/g,the recoveries from 91.70% to 107.71% with an average 98.87%. In repeted experiments,RSD coefficient of variation in seven times successive standards determinations ranged from 2.46% to 4.84%. The results showed that the method has a good maneuverability.The eleven main aroma conponents of Camellia chekiangoleosa oil and Camellia oil were qualitative and quantitative analyzed by GC,and the eleven aroma standards are Ethyl acetate,4-methyl-2-pentanone, N-butanol, Hexanol, Benzaldehyde, Butyl acetate, Heptanol, Octanol, Octanal, Nonanal, Nonanol. The results showed that,The contents of eleven aroma components of two different Camellia oil are similar, but the specific contents are different.(5)By GC detection technology, the fatty acid composition of Camellia chekiangoleosa oil and Camellia oil were analysed. The fatty acid composition of Camellia chekiangoleosa oil is mainly the same as Camellia oil.The main chemical components is oleic acid and also have several difference as follows:①The oil oleic acid (C18:1), linoleic acid (C18:2), myristic acid (C14:0)and tetracosanoate acid (C24:0) in Camellia chekiangoleosa oil are higher in the relative content in the fatty acids.②Camellia chekiangoleosa oil can be detected a little arachidic acid (C20:0) and linolenic acid (C18:3), but normal tea oil can’t detected them.③Compared with Camellia oil, Camellia chekiangoleosa oil oil is lower in palmitic acid (C16:0), stearic acid (C18:0), behenic acid (C22:0), Erucic acid (C22:1) in the fatty acids.④The total content of unsaturated fatty acids in Camellia chekiangoleosa oil is higher than in the camellia oil.⑤The total content of saturated fatty acids in Camellia chekiangoleosa oil is lower than in the camellia oil.By analysis of the fatty acid composition,the Camellia chekiangoleosa oil is better than camellia oil.The results are of great significance in the improvement of tea oil production technology,improving the quality of tea oil and meet the consumers demand of high-quality tea oil.更多还原