| Fresh-cut fruits and vegetables are full of characteristic of fresh quality, convenience, andnutrition-rich. They have been developed in Europe, America, Japan and other countries rapidly. Inrecent years, the consumption of fresh-cut sweet pepper in China is increasing year by year. Fresh-cutsweet pepper industry has great potential for development. In this study, four north china maincultivated sweet pepper varieties are used to evaluate the Fresh-cut processing suitability.On this basis,the optimum variety for fresh-cut processing are used to test the effect of ultra-high pressuretechnologies on fresh-cut sweet pepper quality. The main results as follows:1,The ascorbic acid content,firmness, thickness,total soluble solids, production rate and sensoryevaluation of four sweet pepper including 'No.105Zhongjiao','TaLanduo,''No.0808' and 'No.216Cuilong' were investigated during the storage time of full fruit and fresh-cut fruit.The data wereanalyzed by analytic hierarchy process and grey correlative degree analysis method. The results byanalytic hierarchy process showed that sensory quality, ascorbic acid content and production rate werethe most important quality indices used for evaluating fresh-cut processing suitability of sweet pepper,and their relative weight were44.94%,23.73%,14.04%,respectively,82.71%of the total weight. Theresults by grey correlative degree analysis showed that'TaLanduo'was optimum for sweet pepperfresh-cut processing because of its sensory quality and production rate, followed by 'No.105Zhongjiao';while cultivar '0808' and 'No.216Cuilong' were suit for cooking.2,On this basis of the Fresh-cut processing suitability evaluation, the quality (firmness, color,sensory evaluation and ascorbic acid content), microbial safety(bacterial, mold and yeast), and enzymeactivity (POD,CAT,SOD,AAO) of the fresh-cut ripe green and yellow TaLanduo fruit are tested underthe pressure-time treatment. The results show that: under different treatment, for the ripe green fruit, theascorbic acid content was increased by10.2%compared to control, under the treatment of175Mpa10min, downward trend in other treatment. While the ascorbic acid content of yellow fruit wassignificantly decreased with the rise of presser and time. At the treatment of100Mpa5min, the sensoryquality of green and yellow fruit was significantly improved, it tasted sweeter, crisper and the aroma issofter and fresher than control. But compared with the green fruit, the yellow fruit on the tolerance ofthe pressure and time is even worse. The maximum presser which the green fruit and yellow fruit canbear was250Mpa,5min and175Mpa,5min. In microbiology,the number of microbial infection of greenfruit were lower than the yellow fruit. At the treatment of250Mpa20min,the Bacterial killing capacityof green fruit were higher than the yellow fruit, and the fungi number of green fruit were not detected.For the enzyme activity, the treatment of POD, CAT,SOD, AAO activity research the maximum was175Mpa5min,175Mpa5min,175Mpa5min,100Mpa10min and175Mpa10min,175Mpa10min,100Mpa5min,100Mpa5min,respectively. Therefore, Ultra high pressure could not only kill bacteria,yeasts and molds, keep the nutrition of green fruit and its enzyme activity, but also can improve thesensory quality of fresh-cut green fruit. And the effect was obviously about fresh-keeping to fresh-cut green fruit. But for the yellow fruit, the number of microbial infection were higher and the killingcapacity were lower than the green fruit under the high pressure treatment. And there was an obviousdecline on nutrition, sensory and enzyme activity. The effect about fresh-keeping was worse than greenfruit. |
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