In addition to enjoying the consumption of food, there is a lot of food science and history that is fun as well. Below are a few of my favorite food questions and some of the answers I found. Please let me know if you have any food questions – email food@themurmur.com.

Asparagus and Smelly Urine
I have always been intrigued by the phenomenon of eating asparagus (even one small piece) and having smelly urine the next time I go to the bathroom. I have been even more intrigued by the many different conversations about this phenomenon – mostly because it seems that not everyone experiences this.

It turns out that sulfur-containing amino acids are present in asparagus; they break down during digestion into sulfur groups, which can make the urine smell. However, it remains unclear why some people have smelly urine while others do not. Some think about half of the population has a gene that breaks down the sulfurous amino acids in asparagus into their smellier components. Others think that everyone digests asparagus the same way, but only about half of us have a gene that enables us to smell the specific compounds formed in the digestion of asparagus. I am still intrigued…if any of you do not get smelly asparagus pee (and would not mind if I took a whiff), let me know.

The Sweet Potato Vs. The Yam

Despite their similar appearance, these tuber vegetables are unrelated. The sweet potato is the root of a member of the morning glory family. It is native to Central America and is now cultivated in most sub-tropical areas of the world. There are many varieties that differ in size, shape, and color. The two main categories are ‘soft’ and ‘firm,’ referring to their consistency when cooked. The soft ones often have orange flesh and are often incorrectly called yams. The firm varieties have white or yellow flesh. Sweet potatoes have a 3-6% sugar content, which is increased by storage at warm temperatures and during the early stages of the cooking process when enzymes break down the starch into glucose. The sweet potato provides more calories, minerals, and vitamin A (indicated by the orange color), but less protein, than the regular old white potato.

Yams are the root of a plant that is related to the grasses and lilies. It is thought to have originated in Asia, but similar to the sweet potato, is now grown on most of the continents. The origin of the word yam is interesting. Portuguese slave traders watched Africans digging up the roots and asked what they there were. The Africans replied with nyami, meaning ‘something to eat.’ This became inhame in Portuguese, then igname in French and yam in English. Yams have a bitter taste when raw and must be cooked to be edible. Similar to the sweet potato, there are many different varieties. However, we tend to see the same variety of sweet potato and yam in our grocery stores. Yams have a high starch content and tends to be less sweet than the sweet potato.

Water Chestnuts
I love putting water chestnuts in my stir-fry, but I have always wondered where they come from. The water chestnut is a corm (a swollen underwater stem tip) of a plant that is related to the grasses. There is an outer capsule that surrounds the white kernel, which is approximately the same size and shape as a chestnut. The plant grows primarily in Asia. The kernel is usually boiled (and then often canned), but can also be roasted.

Fruit or Vegetable?
Definitions of fruit and vegetables are confusing. The most basic definition of the word vegetable is that it means “a plant.” Fruit is anatomically defined as the edible layer (technically the plant ovary) that surrounds seeds. Therefore, anatomically, green beans, eggplants, cucumbers, tomatoes, and corn kernels are all fruits. We usually use the terms fruit and vegetable to define culinary customs that reflect when we eat what. In this context, fruits are unified by their sweetness while vegetables are eaten with a meal, resulting in the abovementioned items being considered vegetables. (Somebody please explain avocado to me, then - Ed.) These everyday definitions were even used by the US Supreme Court when they made the decision that a New York food importer who was shipping in tomatoes duty-free under the claim that they were fruit was found guilty when it was decided that the tomato was a vegetable.

Resources: McGee, H. On Food and Cooking, 1984. Davidson, A. The Oxford Companion to Food, 1999.