Is Eggshell’s Colour Related to Nutritional Value

◎供稿：陳傳光

雞蛋殼顏色主要有白、淺褐、褐和深褐之分。有人偏愛(ài)深褐色的雞蛋，認(rèn)為顏色越深雞蛋的營(yíng)養(yǎng)價(jià)值越高。那么，雞蛋殼顏色與營(yíng)養(yǎng)價(jià)值有關(guān)嗎？讓我們閱讀下文去尋找答案吧！

1) breed [bri?d] n. 品種（尤指人工培育的狗、貓或牲畜）

2) earlobe [??r?lo?b] n. 耳垂

3) indicator [??nd?ke?t?r] n. 標(biāo)志

4) orɡanic [???ɡ?n?k] adj.有機(jī)的；綠色的

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.

雞蛋殼有多種顏色，但我們?cè)诔型ǔ？吹降氖莾煞N顏色：白色和褐色。雖然褐色的雞蛋通常更貴，但蛋殼的顏色并不能反映蛋的質(zhì)量。根據(jù)科學(xué)家的說(shuō)法，褐色雞蛋和白色雞蛋的唯一區(qū)別在于產(chǎn)下它們的雞的品種。

你可能聽(tīng)說(shuō)過(guò)白羽雞總是下白色蛋，褐色雞總是下褐色蛋。母雞耳垂的顏色實(shí)際上是雞蛋顏色的最佳標(biāo)志。如果耳垂是白色，產(chǎn)下的雞蛋較大可能是白色的；如果耳垂的顏色更深，產(chǎn)下的雞蛋較大可能是褐色的。

關(guān)于雞蛋的另一個(gè)錯(cuò)誤觀點(diǎn)是褐色的雞蛋對(duì)身體更有益。這可能是因?yàn)楦F的有機(jī)雞蛋往往是褐色的，褐色食品通常比加工過(guò)的白色食品更健康。但蛋殼的顏色與雞蛋的營(yíng)養(yǎng)價(jià)值無(wú)關(guān)。

雞蛋盒上標(biāo)簽和價(jià)格的任何差異都取決于雞的品種。白羽雞能靠更便宜的飼料生產(chǎn)更多蛋，因此它們受到工廠化養(yǎng)殖場(chǎng)的青睞。褐色雞需要更高質(zhì)量的食物，并產(chǎn)下更高質(zhì)量的蛋。但是如果得到正確的照顧和食物，白羽雞也可以像褐色雞一樣輕松地產(chǎn)下更高質(zhì)量的蛋。