新茶:从营养学角度来讲,最新鲜的茶叶其营养成分不一定最好。新茶含有对身体有不良影响的物质如多酚类物质、醇类物质、醛类物质,这些物质还没有被完全氧化,如果长时间喝新茶,有可能出现腹泻、腹胀等症状。新鲜蔬菜:很多人都喜欢购买鲜嫩油绿的新鲜蔬菜,回家后趁着新鲜立即烹调食用。美国缅因州大学的食品学教授洛德·勃什维尔发现:西红柿、马铃薯和菜花经过一周的存放后,它们所含有的维生素C有所下降;而甘蓝、甜瓜、青椒和菠菜存放一周后,其维生素C的含量基本无变化。经过冷藏保存的卷心菜甚至比新鲜卷心菜含有更丰富的维生素C。另外,现在大量使用化肥和其他有机肥,特别是为防治病虫害,经常施用各种农药,有时甚至在采摘的前一两天还往蔬菜上喷洒农药。食用前最好略存放些时间,使残留的有害物质逐渐分解后再吃,对于那些容易衰败的蔬菜,也应多清洗几次再食用。 New tea: From the nutritional point of view, the freshest tea is not necessarily the best nutrition. New tea contains substances that have adverse effects on the body, such as polyphenols, alcohols, and aldehydes. These substances have not been fully oxidized. If they drink new tea for a long period of time, they may cause symptoms such as diarrhea and bloating. Fresh vegetables: Many people like to buy fresh greens and fresh vegetables, go home and take advantage of fresh cooking immediately. Lode Bourwell, a professor of food sciences at the University of Maine, found that after a week of storage of tomatoes, potatoes and cauliflows, vitamin C levels have dropped; while cabbage, melons, green peppers and spinach have been stored for a week, The content of vitamin C basically no change. Chilled cabbages contain even more vitamin C than fresh cabbages. In addition, large quantities of fertilizers and other organic fertilizers are now used, especially for the control of pests and diseases. Various pesticides are often applied, and pesticides are sometimes sprayed on the vegetables even a day or two before picking. It is best to eat a little time before eating so that the residual harmful substances gradually decomposed before eating, for those vegetables that are easy to decay, should also be cleaned several times before consumption.