Food is any substance that animals consume to provide nutrition for the body and maintain life. For example, bread, cheese, meat, milk, and wine.


1   Properties

1.2   Taste

  • Sweet
  • Sour
  • Salty
  • Bitter
  • Umami (e.g. soy sauce)
  • Spicy: This will burn your tongue when you eat it. This can be neutralized with milk and yogurt
  • Hot: This burns your mouth after building up slowly; it can be prevented by drinking water and eating rice and milk.

Sweeter food tastes more sweet when salt is added, as in salted caramel. [Brynn]

Flavor perception happens entirely in your brain. External stimuli (sight, sound, through-the-nose smell) cause your brain to recall/construct a mental model of the flavor experience, then internal stimuli (taste, spiciness, through-the-through aroma) augment and update that model. Finally, your brain projects the the result into your mouth (sort of like ventriloquism), where you perceive it as flavor.

There's been a lot of research work in this field over the past decade or so. Search for multisensory flavor perception or neurogastronomy.

Food manufacturers make chip bags noisy in order to subconsciously convince you the chips taste good, "research has shown that if people hear the sound of the packaging crumpling while they're eating the chips they will think the chips are crisper, crunchier, fresher ... better"

2   Toxicity

Almost all fungus produce various types of mycotoxins, mushroom poisons. They do this because it's their way of defending themselves from bacteria.

Funnily enough not all mushroom poisons are effective against humans. Humans are quite resistant to a lot of different toxins, like those in chocolate, onions, tea etc etc. Some of the stuff that's very bad for some of our best friends like cats and dogs. The varieties of Penicillin for example, the mushroom poison in blue cheese, is straight up lethal to guinea pigs. But not to humans, although some have allergic reactions.

It all depends on the capabilities of our livers, the organ that's primarily responsible for breaking down toxins in our body, and exactly how our cells function inside. Allergic reactions depend on how the immune system identifies threats. Every animal is slightly different in that regard, and some can eat stuff that we would consider poisonous, and to some our every day foods are pure death.

3   Classification

3.1   Vegetable

A vegetable is a plant that can be consumed as food.

  • Sun-dried tomato
  • Lentils
    • Contain anti-nutrients if eaten raw
      • Need to be let to sit in hot water
    • Seem to be mostly carbs, little protein, but cheap
  • Cabbage
  • Lettuce
    • Cultivated by ancient Egyptians
    • Spread to Greek and Romans
    • Used for salads and sandwiches
    • Easy to grow
    • Cooked and served by Romans with oil-and-vinegar dressing
    • During the 81-96 reign of Domitan, the tradition of serving a lettuce salad before a meal began
    • Kinds
      • Leaf
        • Used for salads
      • Romaine
        • Used for salads
        • Most often in Caesar salds
      • Iceberg (Crisphead)
        • Heat sensitive
        • Mostly water. Not good for nutritition
  • Arugula (rocket)
    • Grown since ROman times
    • Often used much like lettuce
    • Rich perrery taste
    • Pungent flavor
  • Scallions
  • Corn. Commercial varieties are sweet

3.1.1   Nightshades


Its nutritional output, compared to the effort put in, is pretty good. Potatoes are satiating, contain fairly large amounts of Vitamin C compared to other staples, and grow readily in conditions unfavourable to other staple crops. Ireland is a famously fertile island, but the frequent rains lead to damp soil, and, especially in the west, it is acidic, rough, and surprisingly unfertile. This meant that grain staples (wheat, oats, barley, and another New World import, maize) were not as popular for Irish farmers as they were in Britain, since the production process was more labour intensive and less profitable. Irish farmers instead preferred to use their land for pasture, and Ireland developed a dairy industry and livestock export market.

Thanks to the combination of these factors, the potato was an obvious staple. When mixed with butter or milk, it isn't missing any major vitamins. Comparable regions elsewhere in Europe, particularly Italy, saw frequent outbreaks of pellagra, caused by the low levels of niacin in maize, their staple crop. It was much easier to grow, especially in poor soil; it was much more efficient, and could be grown on comparatively small plots of land.

Throughout the eighteenth century, and into the nineteenth, this last point became increasingly important. The custom for inheriting land in Ireland had been to divide it equally among the male children, rather than simply pass it to the oldest son (I'm simplifying somewhat for brevity). The Popery Act (1703) codified this into law for Catholics, with the exception that, if the eldest son converted to Anglicanism, they would inherit the entire estate. The idea was to entice converts and reduce the number of Catholics holding large estates, but as the century progressed and Ireland's population boomed, those who refused to convert (and they were many) saw their holdings become increasingly small. For context, Ireland's population in 1821 was nearly 7 million - about the same as it is today. Great Britain's population was 14 million - today it's 66 million!

In England, this population boom had been absorbed by the industrial revolution, as rural workers flocked to factory towns and cities. Ireland, however, remained predominantly rural - even Belfast did not really develop as an industrial city until the latter part of the nineteenth century.

Most noticably in the west, there was now a large population, with smaller and smaller plots of poor quality arable land, far from industry or the chance to emigrate. The potato - easy, efficient, was the obvious choice for a staple crop.

Dairy has high levels of the fat-soluble vitamins A and D, the only two major nutrients missing from potatoes.

4   Form

4.1   Chemical Compounds

The three main categories of compounds are acids, bases, and salts.

5   Cuisine

5.1   Presentation

In China, the menus consist of pictures with descriptive titles. In the US it is mostly words; pictures appear only in fast-food chains. Notably, at high-class restaurants words tend to be more specific, e.g. "Ethiopian-blend coffee".

6   Cooking

When you don't cook, your kitchen is pretty much empty. Any recipe you see is a special trip to the grocery store just to make it, and you'll probably want to load up on a lot of stuff so you're not running to the store every day. This is a pretty significant up-front cost. $100 just for groceries? That doesn't sound cheap, it sounds expensive, though you can get a whole lot of meals out of them. If you don't cook as much as you hoped, food will spoil and you throw out a lot of what you bought. You have no basis of what's over or under priced or what places sell good quality ingredients. it is impossible to cook healthy food cheaply. It definitely is! Just this is a very valuable skill, and like any skill it needs to be learned.

6.1   Mise en place

Mise en place is French for “putting in place” and is used for prepping kitchen equipment and food before serving. Mise en place, which first began being used in the late 1800s, is most commonly used today in professional kitchens, cooking shows, cooking classes, and restaurants.

7   Utensils

7.1   Chopsticks

Chinese chopsticks are long and not as pointy. Chinese people share food. Chinese chopsticks are long so people can reach dishes far away.

Japanese chopsticks are short and pointy: short because people don't share food, and pointy because Japanese eat more fish, and pointed chopsticks help get the bones out of the meat.

Korean chopsticks are made out of silver, which they believe can detect arsenic poisoning.

8   Storage

I also get a lot of questions about expiration and best by dates. Expiration means it is no longer advised to eat after that day due to relative risk to safety, like drinking milk past expiration. You might get by with a few days passed, but it's a gamble. Best by means the quality of that food item is going to go down after that day. Think stale chips. They won't make you sick but they won't taste very well either.

8.1   Preservatives

What is spoilage? It's when other organisms or chemical processes eat or break down the food into something inedible.

To piggyback on this, there are six things that micro organisms need to survive. In Public Health, we refer to this as FAT TOM. Food, Acidity, Time, Temperature, Oxygen, and Moisture. You limit one or several of these and the organism cannot survive. Some examples are vacuum sealing or canning. You're limiting the organisms access to food (F) and oxygen (O). However, there are always exceptions. Some bacteria don't need oxygen and are anaerobic. So other means are put into place like adding preservatives that change the pH to make it more acidic (A) or limiting the amount of free water (M). (T)ime and (T)emperature should be self explanatory.

Follow the recommended cooking instructions. Learn the minimum temp/time of different meats. Also, how the meat was prepared will change the cooking temp/time. A ground beef burger will have a higher temperature requirement than a beef steak.

Food goes bad for several reasons: microbial growth, oxidation of the food, moisture loss or gain, etc.

There's 3 main additional types

Antimicrobial: These are preservatives that will block the normal functioning of bacteria in food either stopping or slowing down their growth

Antioxidants: These will stop or slow down the oxidation process of fats and lipids that cause meat, etc to go rancid

Anti-enzymatic: These stop or slow down the enzymes in fruit, etc that cause them to ripen.

Sugar, like salt, is a desiccant which will draw water out of cells. Salt, sugar, and acids do the same thing - draw water away, or make the water inhospitable for bacteria. Salt and sugar are already mentioned at length and they preserve food by making water unavailable to microbes because the concentration of salt or sugar is too high.

To understand why sugar or salt cam act as preservatives you need to understand the mechanism behind it. People have mentioned you "take away the water" but that isn't really the mechanism. That would be drying. The mechanism is called osmosis. This is how chemical balance is maintained in cells. The wall between the cells slow water to come through depending on the concentration of certain chemicals uh the cell. If there is a lot of sugar outside the cell, the wall will bring water from inside to the other side to get the concentration to match. In order to kill the cell the concentration difference needs to be quite high, so you can use sugar or salt buy you'll need lots of it. That's why sugar cubes keeps indefinitely, but sugary food can still go bad especially after opening.

Another very common preservative what I don't see mentioned is acid. Low pH also prevents microbes from growing - particularly dangerous ones. This is one reason why you will see anything from baby food to beverages to mayonnaise with acid added especially citric, phosphoric, vinegar, lemon juice, and a favorite ascorbic (aka vitamin C). PH is also a primary reason that beer and wine cannot harbor pathogens although alcohol helps a lot with that too.

Pickling, which uses acidic preservatives like vinegar to kill and keep bacteria out or you use fermentation to create lactic acid to kill bacteria.

For example, sulfates, nitrates, citric acid, and other chemicals are added to food and drinks to prevent microbial growth, but these compounds also react with available oxygen to prevent the compounds in the product itself from being broken down by the oxygen. These are a very common form of preservatives in most food that lists “preservatives” on the ingredient label.

If we consider that things other than chemicals can be preservatives, the packaging of a material is really the most effective and easily implemented preservative for food and drink. The plastic packaging often used for food that spoils easily is almost always a multi-layered multi-functional film that blocks oxygen from getting through to the food, blocks moisture from entering or leaving, and prevents microbes from reaching the food. Furthermore, vacuum packaging or flushing the package with nitrogen, heating the food prior to or after packaging (retort, pasteurization, HPP, etc.), and adding oxygen scavengers to the plastic itself (also sulfites usually) will improve shelf life.

This, it's called Modified Atmosphere Packaging (MAP). Most fresh foods, such as produce and meats, are packaged in an inert gas such as nitrogen to prevent oxidative browning and aerobic bacterial rotting.

Drying also takes away the water. For jerky, jellies, jam, and fruit preservatives.

Bacon and fish are preserved by smoking them, which makes the outer layer toxic to bacteria.

Cheese keeps because it's acidic, salty, and low in readily digestible sugars. It's basically pickled milk solids. Cheese doesn't really "keep". It's just spoiled in a tasty way that is non-toxic to humans.

Honey is supposedly the only naturally occurring food that never spoils. It is mainly sugar. The osmotic pressure in any cells that end up in the honey would be so high that any water in the cell rushes out and thus kills the cell.

8.2   Canned food

Napoleon's army was responsible for the invention of canned food. He offered a prize for inventing it. Nicolas Appert won the prize. It was 50 years before Pasteur so they had no idea of why food get spoiled. The french first invented it, but they used glass jars, it was the british who improved it by using metal cans instead of glass to increase durability

Glasslock is sold under Kinetic Go Green, Martha Steward, and Wean Green.


1 x 6.3 cup 2 x 3.5 cup 1 x 1.6 cup
1 x 3.3 cup 1 x 1.5 cup
1 x 3.1 cup 1 x 1.6 cup 1 x 0.7 cup

vs $26

1 x 6.3 cup 1 x 3.5 cup 1 x 1.6 cup

So for $14 I get:

1 x 3.5 cup
1 x 3.3 cup 1 x 1.5 cup
1 x 3.1 cup 1 x 1.6 cup 1 x 0.7 cup

9   Appetite

Appetite is the desire to eat food, felt as hunger.

10   Distribution

Commissaries provide food for airlines, Starbucks, and variety of other places which can't haven an on-site kitchen, but just-in-time logistics mean that they'll be able to compete on palatability rather than merely price.

It will probably be possible someday to build the Amazon Web Services of food, with 1.0 being a `demand aggregator`_, and 2.0 being building out a nationwide set of contract kitchens.

11   Preservation

Prior to the invention of refrigerators, food preservation imposed serious constraints. The best options were to suspend perishable items in rivers, wells, or at the bottom of lakes. Absent these tactics, staple foods were heavily salted, spiced, pickled, canned, or dried to prevent bacterial growth.

Refrigerators remove heat from the compartment and pump it to the outside. This occurs via three main components:

  1. a pump that compresses gas, raising its temperature and pressure
  2. a valve that expands gas, which drops temperature and pressure
  3. radiators that allow gas to exchange heat with the surroundings and come to thermal equilibrium with the surrounding environment

Cooling cycle of a refrigerator.

By repeating this cycle, heat is continuously removed from the inside of the refrigerator.

Note that the compressor pump isn't running all the time. Instead, it's controlled by a thermostat_.

12   Waste

Food waste public service announcements put all the responsibility on consumers. However, a lot of "ugly" food won't survive distribution, because the weird shape make it prone to getting smushed, bruised, rot, and make everything else in the create rot. Most "ugly" produce gets turned into soups, sauces, salsa, jam, etc. [1]

The amount of produce wasted because of labor problems (can't get a crew to harvest) and bad weather (melons that rot in the field because it's too hot and wet) is much larger than the amount of produce thrown out because it's "ugly". [1]

After produces leaves the farm, most of it goes to a packinghouse. This where they cool, was, short, and package it. The only time packing houses throw out produce is when it's actually inedible. Produce gets graded by size and prettiness. If it looks funny but can survive distribution, it still ends up in grocery stores, just lower class ones. Wealthy people don't realize that ugly produce is commonly sold because they buy their produces at high end places, e.g. farmer's markets, and never see ugly produce, and therefore mistakenly conclude it's getting wasted. [1]

Some examples of ugly produce being used:

If there is no processing market, it often gets fed to livestock. That is actually the purpose of livestock historically- they eat stuff we can't, and turn it into meat, milk, and eggs that we can. Feeding food waste to livestock also reduces the amount of land dedicated solely to feeding livestock. [1]

Grocery stores give almost-but-not-quite expired food to food banks for tax breaks.

13   See also

14   Further reading


15   References

[1](1, 2, 3, 4, 5, 6) Sarah Taber. 2019-01-17.

"Why is it so easy to be thin in Japan?" Their convenience stories, vending machines, and fast food offer a variety of healthy options. American counterparts offer almost exclusively unhealthy options.