【作者】 夏天；

【导师】 马力；

【作者基本信息】 西华大学 ， 食品科学， 2010， 硕士

【摘要】 苦瓜,原产于亚洲热带地区,广泛分布于热带、亚热带和温带。自古以来,人们对苦瓜的药用价值都有所记载。近代研究发现,苦瓜含有的活性成分具有降血糖、抗菌、抗病毒、抗肿瘤等功能作用,因此作为能起到食疗作用的苦瓜越来越受到人们的关注。将苦瓜制成苦瓜饮料不仅可以满足人们对苦瓜的消费需求,而且为苦瓜精深加工提供了一个新方向。本文主要研究苦瓜的护绿工艺,果胶酶酶解苦瓜汁工艺,树脂除苦瓜汁蛋白工艺和苦瓜汁调配工艺,测定苦瓜汁中的蛋白质含量,以及运用气相色谱-质谱联用对苦瓜汁的有效成分和香气成分进行测定,以期为苦瓜汁的商品生产提供技术支持。本研究主要分为以下五部分:1苦瓜护绿工艺研究目的:探寻运用微波加热对苦瓜进行护绿的工艺条件,讨论护绿稳定性。方法:运用色差计测定经护绿后榨汁所得的苦瓜汁的-a及b值,并以护绿后苦瓜汁的-a/b值以及护绿后室温自然光放置1h后苦瓜汁的-a/b值的差值为指标,讨论微波时间、碳酸钠添加量、乳酸锌添加量以及氯化钠添加量等四因素对护绿稳定性的影响,运用响应面实验进行优化分析,得出最佳护绿工艺。结果:经预处理的苦瓜40g于护绿液(碳酸钠0.258g,乳酸锌0.028g,氯化钠0.685g,蒸馏水100mL)中微波加热133s,护绿稳定性最好。结论:该方法简便有效,可用于苦瓜护绿工艺的研究。2果胶酶酶解苦瓜汁工艺研究目的:研究果胶酶酶解苦瓜汁的最佳工艺条件。方法:运用果胶酶酶解护绿后所得的苦瓜汁,讨论果胶酶酶解时间、果胶酶酶解温度、果胶酶添加量对苦瓜汁浊度的影响,浊度由浊度计测定,浊度变化由酶解前后苦瓜汁的浊度差值表示,再运用响应面实验进行优化分析,得出果胶酶酶解苦瓜汁的最佳工艺条件。结果:经预处理的苦瓜40g,护绿后榨汁,加入果胶酶0.011g,于41℃水浴酶解2.45h(147min),酶解前后苦瓜汁的浊度差值最大,浊度变化最为明显,即澄清效果最好。结论:该方法简便有效,可用于果胶酶酶解苦瓜汁工艺研究。3树脂处理苦瓜汁及其对苦瓜汁后浑浊的影响目的:比较两种果汁专用树脂对经酶解后的苦瓜汁的蛋白质去除率以及后浑浊的影响,从而选择适宜的树脂类型和处理流速。方法:将经酶解后的苦瓜汁以不同的流速分别通过具有相同柱体积的LSA-900B型树脂和LSA-900C型树脂,测定不同流速下经树脂处理前后苦瓜汁蛋白质的含量以及浊度,并讨论蛋白质含量及浊度的变化。将LSA-900B型树脂和LSA-900C型树脂处理后的苦瓜汁封袋灭菌储存,测定在不同储存条件下经1个月储存前后苦瓜汁的浊度,讨论其浊度的变化,浊度变化以储存前后苦瓜汁的浊度差值表示,从而确定用于处理苦瓜汁的树脂类型及处理流速。结果:储存温度过高过低均可能导致苦瓜汁出现后浑浊,室温25℃储存苦瓜汁有利于防止苦瓜汁出现后浑浊。在同等条件下,LSA-900C型树脂较之LSA-900B型树脂具有更强的去除苦瓜汁中蛋白质的能力,同时通过LSA-900C型树脂处理的苦瓜汁也更不易在不同的储存条件下产生后浑浊现象,因此综合考虑,选择LSA-900C型树脂,以1.0mL/min流速处理苦瓜汁较为有效省时。结论:该方法简便易行,可用于处理用树脂的选型和处理流速的确定。4苦瓜汁的调配及其对苦瓜汁后浑浊的影响目的:调配出口感宜人的苦瓜汁饮料,研究木糖醇和柠檬酸的加入对苦瓜汁后浑浊的影响。方法:对经树脂处理后的苦瓜汁用木糖醇、柠檬酸进行调配,通过糖度计和酸度计的技术评定以及传统的感官评定,确定最佳的调配方案。并分别将经木糖醇、柠檬酸以及木糖醇和柠檬酸等三种方式调配后的苦瓜汁封袋灭菌储存,测定其在不同储存条件下经1个月储存前后苦瓜汁的浊度,讨论其浊度的变化,浊度的变化以储存前后苦瓜汁的浊度差值表示。实验结果表明:木糖醇添加量为10.0%(w/v),柠檬酸添加量为0.20%(w/v)时苦瓜汁的口感最佳,并且单独使用木糖醇、柠檬酸以及同时使用木糖醇和柠檬酸对苦瓜汁进行调配均对不同储存条件下经1个月储存后苦瓜汁的浊度差值影响不大,故运用木糖醇和柠檬酸调配苦瓜汁不会促使苦瓜汁出现后浑浊。结论:运用木糖醇和柠檬酸调配苦瓜饮料,即满足了人们对健康食品的需求心理,又使成品具有适宜的口感,具有市场前景。5苦瓜汁蛋白含量、有效成分和香气成分的测定目的:运用考马斯亮蓝法,测定经树脂处理后苦瓜汁中蛋白质的含量。运用气相色谱-质谱联用(GC-MS)分析经树脂处理后苦瓜汁中的有效成分和香气成分。方法:配制标准蛋白质溶液,运用紫外分光光度计测定标准溶液的吸光度,绘制标准曲线,测定经树脂处理后苦瓜汁的吸光度,从而确定苦瓜汁的蛋白质含量。运用GC-MS测定苦瓜汁中的有效成分和香气成分。结果:苦瓜汁中蛋白含量为17.12ug/mL;苦瓜汁中含有环氧乙烷甲醇,1,2-环戊二酮,邻苯二甲酸二丁酯,花生酸乙酯,7-十六酸甲酯,油酸乙酯,硬脂酸,2,2-亚甲基-苯酚,顺式-9-十六烯醛以及1,2-邻苯二甲酸二异辛酯等物质,这些都是苦瓜汁香气的重要组成成分,也是苦瓜汁中的有效成分。结论:考马斯亮蓝法简便、准确、可靠、重复性好,可用于测定苦瓜汁中的蛋白含量;GC-MS也可用于测定苦瓜汁中的有效成分和香气成分。更多还原

【Abstract】 Bitter melon is native to tropical Asia, and widely distributed in tropical, subtropical and temperate zone. From of old, people have recorded the medicinal value of bitter melon. And recent studies find that bitter melon contains a variety of active ingredients, which can reduce blood sugar and help our body to anti bacteria, virus, tumor and so on. Because of these, people pay more and more attention on bitter melon.Developing bitter melon beverage not only meet consumer’s demand, but also create a new direction of the fine and further processing of bitter melon. This paper has studied the technologies of green color protection, pectin enzymolysis, resin and flavoring. And then, determine the protein content, the active ingredients and aroma components. All what I have done are used to provide technical support to commodity production.The full text is divided into the following five parts:1 Study on the technology of green-maintainingObjective: Explore the process conditions of preserving green color and the stability of green-maintaining. Method: Use color difference meter to determine the values of -a and b of the bitter melon juice after green color protection and 1h later. Calculate the values of -a/b and those differentials. Discuss how microwave time, the adding amount of sodium carbonate, zinc lactate and sodium chloride affect the differentials, and then optimize by response surface analysis to find the best conditions. Result: The best conditions are pre-treated bitter melon 40g in the green-maintaining solution (sodium carbonate0.258g, zinc lactate0.028g, sodium chloride0.685g, distilled water 100mL) under the microwave heating 133s.Conclusion: The method is simple and effective, can be used for green-maintaining technology of bitter melon.2 Study on the technology of pectin enzymolysisObjective: Study on the pectin enzymolysis conditions of bitter melon juice. Method: Discuss how the time, temperatures and pectin additions affect the turbidities of bitter melon juice before and after enzymolysis. Calculate those differentials and optimize by response surface analysis. Result: The best conditions are adding pectin0.011g, under 41℃, with the enzymolysis of 2.45h(147min).Conclusion: The method is simple and effective, can be used for study on the technology of pectin enzymolysis.3 Study on the technology of resin treatmentObjective: Compare the two types of resins which are used to reduce the protein and maintain the clarification of bitter melon juice, and choose the better type and the juice flow rate. Method: Let the bitter melon juice flow through the resins of type LSA-900B and type LSA-900C respectively under the different flows rates, measure the protein content differentials and the turbidity differentials of the juice before and after resin treatments. Seal and sterilize the juice and store them 1 month under different conditions, discuss their turbidity differentials and determine the type and the juice flow rate to use. Result: Room temperature 25℃is suit for storing the bitter melon juice. The resin of type LSA-900C has better abilities of removing protein and maintaining the clarification of bitter melon juice. And the best flow rate is 1.0mL/min.Conclusion: The method is simple and can be used to choose the type of resin and the juice flow rate.4 Study on the technology of flavoringObjective: Flavor pleasant bitter melon juice with xylitol and citric acid, discuss whether the additions of xylitol and citric acid will affect the clarification of the juice or not. Method: Flavor bitter melon juice with xylitol and citric acid, and determine the flavoring scheme by organoleptic investigation. Discuss whether the additions of xylitol and citric acid will affect the turbidities after storage and make the decision. Result: Adding xylitol 10.0%(w/v), citric acid 0.20%(w/v) into the bitter melon juice will get a pleasant flavor, and the use of xylitol and citric acid will not promote the emergence of muddy in the juice after storage. Conclusion: Flavoring bitter melon juice with xylitol and citric acid meets people’health need of food and has market prospects.5 Determinations of effective and aroma components of bitter melon juiceObjective: Determine the content of protein by the method of coomassie brilliant blue and the active and aroma components by gas chromatography-mass spectrometry (GC-MS).Method: Prepare the standard protein solutions, determine their absorbance and draw the standard curve. And then determine the absorbance of bitter melon juice. Use GC-MS to determine the active and aroma components. Result: The protein content of bitter melon juice is 17.12ug/mL; bitter melon juice contains Oxiranemethanol, 1,2-Cyclopentane- dione, Dibutyl phthalate, Eicosanoic acid,ethyl ester, 7-Hexadecanoicacid,methyl ester, Ethyl Oleate, Octadecanoic acid, 2,2-methylenebis-Phenol, Cis-9-hexadecenal, 1,2-benzenedicarbo- xylic acid,diisooctyl ester and other substances, which are all the effective and aroma components of bitter melon juice. Conclusion: Coomassie brilliant blue method is simple, accurate, reliable and can be used to determine the protein content of bitter melon juice; GC-MS is also convenient for the determination of the active and aroma components of bitter melon juice.更多还原