2016年11月12日托福阅读真题解析（新东方）_第3页

　　2016年11月12日托福阅读真题第三篇

　　题材划分：社科类

　　主要内容： 主要讲食物是如何保存的，以前的食物保存方法是的食物口感很差，营养丢失。为了让军队的人吃的好，法国政府搬出一个奖，奖励发明出新事物保存方法的人，该方法要便宜，食物好运输，好吃还要有营养。最开始是一个科学家做了一个真空实验，了解到声传播需要空气，于是推测食物保存也需要空气，但实验过后发现空气并不是sole reason。然后第二人在这个基础上用真空vessel之后又放在热水里，发现能很好保存了。但是大家并不知道原理是什么，只能猜测是something导致了变质。最后得到奖金的是一个厨师，他爸爸是个manager，在厨房工作的时候发现大家都是用糖来保存水果，于是就想到怎样保存食物，然后的方法与之前不同在加热后封好迅速冷却。

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　　相关知识背景：

　　Food preservation involves preventing the growth of bacteria, fungi (such as yeasts), or other micro-organisms (although some methods work by introducing benign bacteria or fungi to the food), as well as slowing the oxidation of fats that cause rancidity. Food preservation may also include processes that inhibit visual deterioration, such as the enzymatic browning reaction in apples after they are cut during food preparation.

　　Many processes designed to preserve food will involve a number of food preservation methods. Preserving fruit by turning it into jam, for example, involves boiling (to reduce the fruit’s moisture content and to kill bacteria, etc.), sugaring (to prevent their re-growth) and sealing within an airtight jar (to prevent recontamination). Some traditional methods of preserving food have been shown to have a lower energy input and carbon footprint, when compared to modern methods.

　　Some methods of food preservation are known to create carcinogens. In 2015, the International Agency for Research on Cancer of the World Health Organization classified processed meat, i.e. meat that has undergone salting, curing, fermenting, and smoking, as "carcinogenic to humans".

　　Maintaining or creating nutritional value, texture and flavor is an important aspect of food preservation, although, historically, some methods drastically altered the character of the food being preserved. In many cases these changes have come to be seen as desirable qualities cheese, yogurt and pickled onions being common examples.