Maintenance of green color in harvested vegetables and ultrastructural changes of their chloroplasts.

1)乙醇蒸汽处理对新鲜花椰菜小花的影响将花椰菜小花暴露于20 ℃的乙醇蒸汽中，持续24小时或连续6天。乙醇蒸气通过使0（蒸馏水）、10、25、50和100%乙醇溶液沸腾而产生。在贮藏过程中，25%~ 100%乙醇处理24 h后，与0 ~ 10%乙醇处理相比，花色的色相角下降缓慢，50%~ 100%乙醇处理的花色逐渐变暗，呈绿色。连续用乙醇蒸气处理，可使小花产生异味，叶绿体结构紊乱。这些结果表明，用25%乙醇蒸气处理24小时适合于保持绿色颜色。在另外的实验中，将挥发乙醇蒸气的“固体醇”立方体放置在具有花椰菜小花的穿孔聚乙烯袋中。“固体酒精”立方体处理保持了小花的绿色颜色，预计是一种方便的处理。 ...更多信息 本研究旨在探讨温度和光照对蔬菜沙拉用漂烫青花菜花保持绿色的影响。将新鲜小花在沸水中烫漂1分钟。将漂白的小花置于小托盘上，用塑料膜包裹并在5. C或10。C在照明（2,000勒克斯）或黑暗下。小花叶绿素含量在光照下比黑暗下下降得更快，且在10。C比5。C.光镜和扫描电镜冷冻断裂技术观察表明，经热烫处理后，叶绿体的形状基本保持不变，但基粒和基质类囊体发生了较大的变化。叶绿体的降解似乎在10。C比5。但光照对叶绿体降解的影响尚不清楚。这些结果表明，弱光和低温的管理是必要的，以保持在显示过程中的漂烫青花菜小花的质量。少

1) Effect of ethanol vapor treatment for fresh broccoli florets.Broccoli florets were exposed to ethanol vapor, for 24 hours or continuous 6 days at 20。C.Ethanol vapor was generated by babbling 0 (distilled water), 10, 25, 50 and 100% ethanol solution. Hue angles in 24-hours treatment with vapor of 25 to 100% ethanol decreased slowly compared with treatment with vapor of 0 to 10% ethanol during storage, and florets with vapor of 50 to 100% ethanol became gradually dull green color. Continuous treatment with ethanol vapor afforded the off-flavor and disorder in chloroplast of the florets. These results showed that 24-hours treatment with vapor of 25% ethanol is suitable for maintenance of green color. In the additional experiment, "solid alcohol" cubes that volatilize ethanol vapor were placed in perforated polyethylene bags with broccoli florets. The "solid alcohol" cube treatment maintained the green color of the florets and was expected as a convenient treatment.2) Effects of tempera … More ture and lighting for blanched broccoli florets during display.This study was conducted to elucidate the effects of temperature and lighting on the maintenance of green color in blanched broccoli florets being an item of vegetable salads. Fresh florets were blanched for 1 minute in boiling water. The blanched florets placed on small trays were wrapped with plastic film and stored at 5。C or 10。C under lighting (2,000 lux) or darkness. Chlorophyll contents in florets decreased more quickly under lighting than under darkness, and at 10。C than at 5。C.The observation of chloroplast with light microscope and scanning electron microscope with freeze fracture technique showed that the shape of chloroplast was kept in spite of blanching but considerable change was seen in grana and stroma thylakoid. Degradation of chloroplast seemed to be slightly faster at 10。C than at 5。C, but the influence of lighting on the degradation of chloroplast was not clear. These results suggest that managements of weaker lighting and lower temperature are necessary to maintain the quality of blanched broccoli florets during display. Less