丁香提取物对草莓保鲜效果的研究

发布时间：2019-03-17 16:19

【摘要】：草莓色泽鲜艳,营养价值高,酸甜可口,深受大众的喜爱。但由于皮薄汁多,在室温环境下只能存放一到两天便会腐烂发霉。目前,草莓等浆果类最常用的贮藏方法是冷藏结合化学保鲜剂处理,但是长期使用化学保鲜剂会产生腐烂真菌的抗药性,并且会造成食品安全问题和环境污染问题的频频发生。因此,寻找一种可以替代化学杀菌剂的安全有效、无公害的天然保鲜剂对草莓果实的贮藏保鲜具有非常重要的意义。本实验以"丹东九九"草莓为研究对象,用四种不同体积分数的乙醇提取液对同样规格的新鲜草莓进行浸泡处理,通过各项品质指标的变化情况研究分析丁香提取液对草莓的保鲜效果,并从抗氧化性能和体外对灰霉菌抑菌作用等几个方面进行了保鲜机理的探讨,同时探寻丁香提取液对草莓保鲜的最佳浓度,为丁香提取物在果蔬保鲜应用中提供理论依据。同时,本实验又从品质和抗氧化性能方面研究了丁香提取物一壳聚糖复合保鲜液对草莓的保鲜效果,探索了丁香提取液和壳聚糖的最佳配比,为健康无害高效的复合防腐保鲜液的发展提供理论依据。主要研究结果如下:(1)所有草莓在贮藏期间都在不断腐烂变质,贮藏时间越长腐烂程度越重,不同体积分数的丁香提取液对草莓均有显著的保鲜作用,对草莓的呼吸代谢确实起到一定的抑制作用。丁香提取液对草莓的保鲜效果随浓度的增加而增强,且4%的丁香提取液对草莓的保鲜效果最好。(2)草莓在贮藏前4天期间自身抗氧化能力较好,贮藏4天以后草莓的自身抗氧化能力降低;不同体积分数的丁香提取液对草莓抗氧化能力都有显著的协助作用;在贮藏期间所有草莓的抗氧化性能都在不断衰弱,贮藏时间越长衰弱程度越重。丁香提取液对草莓的保鲜效果随浓度的增加而增强;且4%的丁香提取液对草莓抗氧化性能的协助效果最佳。(3)丁香提取液对灰霉菌有明显抑菌作用,且丁香提取液的抑菌效果随浓度的增加而增强;通过灰霉菌的生长情况可以猜测,丁香提取液不仅影响灰霉菌孢子数量,还对其生理代谢造成严重影响。丁香提取液对灰霉菌的抑菌效果随浓度的增加而增强,且丁香提取液的最小抑菌浓度(MIC)为2%左右。(4)壳聚糖-丁香提取液浸泡处理对草莓样品营养价值下降、衰老腐败、组织变软等具有一定的抑制作用,对草莓的抗氧化性等性质起到明显的协助作用。壳聚糖-丁香提取液复合保鲜剂处理组与对照组相比有明显的保鲜效果,且随着丁香提取液浓度的增加而增强,但当丁香提取液的浓度达到4%时,保鲜剂的保鲜效果有所下降。所以,1%壳聚糖+4%柠檬酸+2%丁香提取液的涂膜剂的保鲜效果最佳。在贮存前期,草莓的抗病变、抗氧化能力会迅速提高,但是随着时间的延长抗病性会逐渐衰竭。
[Abstract]:Strawberry color bright, high nutritional value, sweet and sour delicious, popular favorite. But because of the thin juicy skin, stored at room temperature for only one to two days will rot moldy. At present, the most commonly used storage methods for berries, such as strawberries, are cold storage combined with chemical preservative treatment, but long-term use of chemical preservative will lead to the resistance of rotting fungi, and will cause frequent food safety problems and environmental pollution problems. Therefore, it is very important to look for a kind of natural preservative which can replace chemical fungicide and has no pollution on strawberry fruit storage and fresh-keeping. In this experiment, "Dandong Jiujiu" strawberries were soaked in four different volume fractions of ethanol extract, and fresh strawberries of the same size were soaked. The preservative effect of clove extract on strawberry was studied and analyzed through the change of quality indexes, and the preservation mechanism of clove extract on strawberry was discussed from several aspects, such as antioxidation ability and in vitro bacteriostatic effect on Botrytis cinerea, and so on. At the same time, the optimum concentration of clove extract for strawberry preservation was explored, which provided the theoretical basis for the application of clove extract in fruit and vegetable preservation. At the same time, the fresh-keeping effect of clove extract-chitosan compound preservative solution on strawberry was studied from the aspects of quality and antioxidation, and the optimum ratio of clove extract and chitosan was explored. It provides a theoretical basis for the development of healthy, harmless and efficient compound preservative and preservative solution. The main results were as follows: (1) all strawberries were rotting and deteriorating during storage, and the longer the storage time was, the heavier the degree of rot was, and the different volume fraction of clove extract had significant preservation effect on strawberry. It does play a certain role in inhibiting the respiration and metabolism of strawberry. The effect of clove extract on strawberry preservation was enhanced with the increase of concentration, and 4% clove extract had the best effect on strawberry preservation. (2) Strawberry had better antioxidation ability 4 days before storage. The antioxidant capacity of strawberry decreased after storage for 4 days. The extract of different volume fraction of clove had significant effect on the antioxidant ability of strawberry, and the antioxidant activity of all strawberries was declining during storage, and the longer the storage time was, the worse the degree of antioxidation was, and the longer the storage time was, the more the degree of antioxidant activity of strawberry was weakened. The preservative effect of clove extract on strawberry was enhanced with the increase of concentration. The 4% clove extract had the best antioxidation effect on strawberry. (3) the clove extract had obvious bacteriostatic effect on Botrytis cinerea, and the bacteriostatic effect of clove extract increased with the increase of concentration. It can be guessed from the growth of Botrytis cinerea that the extract of clove not only affects the number of spores of Botrytis cinerea, but also seriously affects its physiological metabolism. The bacteriostatic effect of clove extract on Botrytis cinerea increased with the increase of concentration, and the minimal inhibitory concentration (MIC) of clove extract was about 2%. (4) the nutritional value of strawberry sample was decreased by soaking in chitosan-clove extract. Senescence and decay, tissue softening and so on have a certain inhibitory effect, and play a significant role in the antioxidant properties of strawberry. Compared with the control group, the chitosan-clove extract compound preservative treatment group had obvious preservation effect, and increased with the increase of the concentration of clove extract, but when the concentration of clove extract reached 4%, The preservative effect of preservative was decreased. Therefore, 1% chitosan and 4% citric acid 2% clove extract had the best preservative effect. In the pre-storage period, the anti-disease and anti-oxidation ability of strawberry will increase rapidly, but the disease resistance will gradually decline with the prolongation of time.
【学位授予单位】：沈阳农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TS255.3

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