【作者】 王萍；

【导师】 李焕荣；

【作者基本信息】 新疆农业大学 ， 食品科学， 2012， 硕士

【摘要】 新疆枣栽培面积近400万亩,产品以干枣为主,品种单一,食用不方便,研究开发在食品领域应用范围广的枣深加工产品是枣产业健康发展的基础,以鲜枣为原料制作的枣粉具有营养成分损失小、风味独特、应用范围广等特点将会有良好的市场前景。本研究以新疆新鲜哈密大枣为原料,研究了鲜枣去皮及护色的工艺、枣粉加工工艺及工艺参数；研究了同时蒸馏萃取,水蒸气蒸馏萃取,溶剂浸提萃取三种方法对枣浆挥发性香气成分提取效果的影响；研究了枣浆加热温度、加热时间与风味物质形成的相关性、枣粉贮藏过程中的风味物质的稳定性,得出实验结果如‘下：1、采用单因素及止交试验,研究了碱液浓度、温度、去皮时间对鲜枣去皮效果的影响,得出的最佳去皮工艺参数为：碱液浓度4%,碱液温度90℃～95℃,处理时间3min。2、研究了不同浓度的亚硫酸氢纳、抗坏血酸对去皮后枣果肉护色效果的影响,得出亚硫酸氢纳具有较好的护色效果,最佳护色浓度为0.2%,此时枣浆的L值为53.76,b值为24.78。3、通过对喷雾干燥和冷冻干燥工艺所制枣粉分析认为：冷冻干燥工艺所制得枣粉营养成分保持较高,但成本较高；喷雾干燥工艺对枣粉色泽、营养成分有一定影响但成本低且技术成熟。采用单因素及正交试验,研究了进风温度、出风温度、进料温度对枣粉喷雾效果的影响,得出最佳喷雾干燥工艺参数为：进风温度145℃、出风温度为70℃,物料温度为40℃。4、通过对同时蒸馏萃取、水蒸气蒸馏萃取、溶剂浸提萃取三种方法对枣浆挥发性香气成分提取效果的研究认为,溶剂浸提法机溶剂消耗大量、提取时间较长、提取工艺繁琐；同时蒸馏萃取法提取所得香气种类多,有效香气组分相对含量也较多,但由于需要高温处理,产生了与原本红枣香气有差异的物质；水蒸气蒸馏法提取的香气成分较多、并且有效香气物质种类较多,最佳方法为水蒸气蒸馏萃取法。5、为使以鲜枣为原料所制粉的风味成分满足不同消费者的需求,试验探索了枣浆热处理温度、时间与风味形成的相关性。研究了枣浆在不同热处理温度、处理时间后对其香气成分的组成和相对含量的影响,得出风味成分最多、相对含量最多的热处理温度为105℃,处理时间为4h、其次是120℃,2h处理组。气相色谱-质谱联用法(SPME-GC-MS)对挥发性成分定性分析得出经热处理后枣浆的香气组分达到了110种,有效香气组分达到了75种,其中烷烃类和芳香族及其衍生物为主要特征成分,其次是醛类、酯类、酸类、酮类、醇类,占总相对含量的88.04%,在加热过程中酯类和酸类含量增加,芳香族及衍生物含量变化不明显,醇类物质明显减少。6、研究了热处理温度和时间对枣浆色泽的影响,结果表明随着加热温度的升高和加热时间的延长,色泽L值降低,即色泽加深。7、分析了不同加工工艺、枣浆热处理条件所得枣粉风味成分的变化,表明冷冻干燥的枣粉香气成分较少,采用喷雾干燥所得枣粉的香气成分较多、风味浓郁,枣粉的风味成分与枣浆的热处理条件密切相关,综合分析以上结果认为以鲜枣为原料,通过对枣浆进行不同条件的热处理以获得不同风味的枣粉具有实现可能性。更多还原

【Abstract】 Cultivation area of Jujube of Xinjiang is nearly400million acres, dry dates as the main product, which species are single and not convenient to consume. Researching and development of deep processing product of jujube,which is in wide use in the field of food, is the basis of healthy development of Jujube industry. The jujube powder made by fresh dates is low loss of nutrients,unique flavor and a wide range of applications, which has a good market prospect. The fresh jujubes of Hami, Xinjiang were used as raw material to study peeling of fresh jujubes, color protection technology, jujube powder processing technology and process parameters in this paper. The effects of simultaneous distillation and extraction, steam distillation and extraction, solvent extraction on extraction efficiency of volatile components of date syrup were studied. Correlation of heating temperature, heating time, the formation of flavor substances and the stability of flavor substances in the storage were studied. The results showed that:1. The effects of alkali concentration, temperature and peeling time on the peeling of jujube were studied by orthogonal test, the best process parameters of peeling were obtained:alkali concentration was4%, the temperature of alkali concentration was90℃～95℃and the processing time was3min.2. The influence of sodium hydrogensulfite-and ascorbic acid with different concentration on the effects of color protection of jujube pulp. The result showed that the effect of sodium hydrogensulfite was better, the optimal concentration was0.2%,under these conditions L was53.76,b was24.78.3. The analysis of jujube powder made by spray drying and freeze-drying were that:the nutrients of jujube powder made by freeze-drying remained high, but the cost is high. Spray drying has some influence on the color and lustre and nutrients, and the the technology was mature. The effects of air inlet temperature, outlet air temperature and feeding temperature on the the dates powder spray results, the optimum spray drying process parameters are:inlet air temperature145℃, outlet air temperature of70℃, the material temperature is40℃.4. Extraction efficiency of simultaneous distillation and extraction, steam distillation and extraction, solvent extraction on volatile aroma of jujube pulp was studied, the result showed that:large consumption of solvent, long extraction time and tedious process of extraction were the feature of solvent extraction; Simultaneous Distillation and Extraction of aroma types derived and effective aroma compounds relative was more, however, due to the need of high temperature treatment, resulting in a difference with the original jujube aroma is substance; Extracted by steam distillation of the aroma components and effective types of aroma substances are more, the best way is steam distillation and extraction method.5. In order to satisfy the requirements of different consumers for the aroma component of jujube powder made by the raw material of fresh jujube, the correlations of temperature, time of treatment and the formation of flavor were detected. The effects of different dealing temperature and dealing time on the composition and relative content of aroma was studied, the optimal conditions were obtained as followed: heat treatment temperature was115℃, dealing time was6h, the followed team was120℃,2h. The aroma component of jujube pulp dealed with heat treatment was analyzed by SPME-GC-MS, the kinds of aroma component were to110, the main characteristic components were alkanes and aromatics and their derivatives, aldehydes, lipids, acids, ketones, and alcohols were followed,88.04%of the total relative content. The contents of lipids and acids were increased, but aromatics and their derivatives were decreased.6. The effects of heating treatment temperature and time on the color and lustre of jujube pulp were studied, the results showed that:with the heating temperature increased and the heating time extended, L became smaller that was the color was deeper.7. The changes of aroma component of jujube powder with different processing and dealing conditions were analyzed, the result showed that:the aroma component of jujube powder dealed with freeze-drying was less, the aroma component of jujube powder dealed with spay drying was more and the flavor was rich, the flavor compounds of jujube powder was close related to the dealing conditions. Based on the above analysis, the reality of different flavors of jujube powder made by jujube pulp dealed with different heating treatment condition was possible.更多还原