论文标题:神秘果稳定化措施的探讨
Research on Stability Approaches of Synsepalum Dulcificum
论文作者
论文导师 刘成伦,论文学位 硕士,论文专业 食品科学
论文单位 重庆大学,点击次数 91,论文页数 61页File Size865K
2007-10-01论文网 http://www.lw23.com/lunwen_151552692/
Synsepalum Dulcificum;; component;; cyclic voltammetry;; preservation;; chitosan
本文采用干法灰化法、酸碱滴定法、电化学法和DPPH?法等测定了神秘果的灰分、灰分的pH值、总酸度、有效酸度、抗坏血酸(AA)的含量和抗氧化能力。采用循环伏安(CV)法制备了聚对苯二酚膜修饰玻碳电极,利用其电催化氧化作用建立了抗坏血酸的定量研究分析方法,探讨了其催化氧化机理。研究发现,聚对苯二酚修饰电极(PHQ/CME)可催化抗坏血酸的氧化作用,使得氧化峰电位负移,峰电流明显增加,其氧化峰电流与AA浓度在0.001mol/L～0.025mol/L范围内呈良好的线性关系;经测定,神秘果中抗坏血酸的含量为46.98mg/100g。该法可作为一种新的测定神秘果中抗坏血酸的方法。 在对神秘果进行保鲜的研究中,分别用魔芋葡甘聚糖和壳聚糖保鲜液在常温下对神秘果进行了涂膜保鲜试验。结果表明,魔芋葡甘聚糖膜因干燥时间过长、涂膜厚度不均匀等缺点,不适用于神秘果涂膜保鲜。而采用壳聚糖作为涂膜保鲜剂时,通过测定贮藏过程神秘果的腐烂率、失重率、DPPH?自由基清除率、总酸度、VC含量和感观品质等理化性能指标表明,保鲜液配方为:壳聚糖:1.5%,抗坏血酸:1.0%,吐温-80:0.1%,甘油:1.0%时,该保鲜膜能抑制神秘果体内营养物质的消耗,降低失重率,抑制其呼吸强度,延缓了果实的衰老过程,具有良好的保鲜效果,保质期从5天延长到18天。
The functional properties of Synsepalum Dulcificum including mineral content, total acidity, available acidity, vitamin C quantity and antioxidant activity have been determined with acid-base titrations, electrochemistry technology and DPPH agent etc in this paper. In the mensuration of vitamin C quantity, the polyhydroquinone film modified glassy carbon electrode(PHQ/CME) is prepared by CV, the quantitative determining of ascorbic(AA) acid is established by electrocatalytic oxidation, and its electronoc catalysis oxidation mechanism is explored. The results are showed that PHQ/CME could catalyze the oxidation of AA, the peak voltage removed toward the minus side and the peak currents were stronger. The peak currents were linear to the content of AA in the range of 0.001mol/L～0.025mol/L by DPV which can be a new method of measuring the vitamin C quantity in Synsepalum Dulcificum. The content of vitamin C in Synsepalum Dulcificum is 46.98mg/100g. In the study of preservatio, Synsepalum Dulcificum was coated with Konjac Glucomannan and chitosans to lengthen the preservation time. Drying time of Konjac Glucomannan film was so long, and the thickness of the film was so unequal that this agent can not be used as the preservation of Synsepalum Dulcificum. While using the Chitosan as the preservation agent, the indexes such as rot rate, weight-lost rate, DPPH? scavenging capability, sense-index, total acidity and the content of VC are assayed during storage. The results are showed that the optimum components of the film is that 1.5% of filming agent, 1% of antioxidant, 0.1% of emulsifying agent and 1.0% of plasticizer. During the storage period, the Chitosan film could decrease the fruit nutrition loss and weigh-loss rate, inhibit the respiration, and delay the senescent course. The effect of preservation was good, and the storage days are extended from 5 days to 18 days.
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