◎供稿：陈传光

鸡蛋壳颜色主要有白、浅褐、褐和深褐之分。有人偏爱深褐色的鸡蛋，认为颜色越深鸡蛋的营养价值越高。那么，鸡蛋壳颜色与营养价值有关吗？让我们阅读下文去寻找答案吧！

1) breed [briːd] n. 品种（尤指人工培育的狗、猫或牲畜）

2) earlobe [ˈɪrˌloʊb] n. 耳垂

3) indicator [ˈɪndɪkeɪtər] n. 标志

4) orɡanic [ɔːˈɡænɪk] adj.有机的；绿色的

Chicken eggs come in many colours, but there are two that we often see at the supermarket: white and brown. Though brown eggs are often more expensive, the colour of an eggshell says nothing about the quality of inside. According to the scientists, the only difference between brown eggs and white eggs lies in the1)breedof the chicken that lays them.

You may have heard people say that white-feathered chickens always lay white eggs and brown chickens always lay brown eggs. The colour of a hen’s2)earlobesis actually the best3)indicatorof what colour its eggs will be. If it’s white, the chicken’s eggs will likely be white, and if it’s darker, they will likely be brown.

Another wrong idea about eggs is that brown eggs are better for you. This may have come from the fact that more expensive4)organiceggs tend to be brown, and brown foods are usually healthier than the processed white versions. But an eggshell’s colour has nothing to do with the egg’s nutritional value.

Any difference in labels and pricing on egg cartons depends on the breed of the chicken. White egg-laying chickens can produce more eggs on cheaper diets, so they are favoured by factory farms. Brown egg-laying chickens require higher quality food and lay higher quality eggs. But given the right care and food, white egg-laying chickens can just as easily lay higher quality eggs as the brown egg-laying chickens.

鸡蛋壳有多种颜色，但我们在超市通常看到的是两种颜色：白色和褐色。虽然褐色的鸡蛋通常更贵，但蛋壳的颜色并不能反映蛋的质量。根据科学家的说法，褐色鸡蛋和白色鸡蛋的唯一区别在于产下它们的鸡的品种。

你可能听说过白羽鸡总是下白色蛋，褐色鸡总是下褐色蛋。母鸡耳垂的颜色实际上是鸡蛋颜色的最佳标志。如果耳垂是白色，产下的鸡蛋较大可能是白色的；如果耳垂的颜色更深，产下的鸡蛋较大可能是褐色的。

关于鸡蛋的另一个错误观点是褐色的鸡蛋对身体更有益。这可能是因为更贵的有机鸡蛋往往是褐色的，褐色食品通常比加工过的白色食品更健康。但蛋壳的颜色与鸡蛋的营养价值无关。

鸡蛋盒上标签和价格的任何差异都取决于鸡的品种。白羽鸡能靠更便宜的饲料生产更多蛋，因此它们受到工厂化养殖场的青睐。褐色鸡需要更高质量的食物，并产下更高质量的蛋。但是如果得到正确的照顾和食物，白羽鸡也可以像褐色鸡一样轻松地产下更高质量的蛋。