peer pressuring apple.

Umma-bear (as I've been calling her lately) checked out this amazing book from the library called "How to Boil Water" (Food Network Kitchen). In it are great tips about how to wean yourself off take-out and restaurants, including necessary items for a functional kitchen and tutorials on basic culinary skills (using knives, cutting veggies, boiling eggs, etc). 

In the section about fruits, it mentioned that to ripen an avocado or a pear, put it in a brown paper bag with a ripe apple or banana. I had never heard of this before: I have had to eat many unripened peaches and avocados!

When fruits ripen, they produce ethylene gas (C2H4, the simplest dikene with a single double bond) which acts as a plant hormone. Ethylene gas activates regulatory genes called ethene-responsive-elements(ERE's) which in turn regulate other genes leading to the plant ripening, including breaking down chlorophyll, breaking down acids and pectin, and turning starch into sugars. Placing fruits in a brown bag(so moisture goes out) with a ripe apple/banana allows them to be exposed to ethylene and ripen faster.

Both of these are ethene-insensitive, but still delicious!

Farmers take advantage of this gas by picking fruits when not yet ripe, then exposing them to ethylene just before putting them out on markets. On the flip side, ethene not only ripens fruit but also causes senescence(death), which means farmers/transporters have to be extra careful to separate fruits producing ethylene from those that are sensitive, so that fruits arrive in their best state. Ethene can penetrate paper, cardboard boxes, and even concrete walls. Ethylene producing fruits include apples, apricots, avocados, bananas, mangos, melons, peaches, and pears.

I tried to think of a witty analogy for this (my favorite pastime activity). So far the most obvious and available one is that peer pressure= ethylene. I have found out (happily) that I've picked up new habits from the very friends I adored them in! My sleep schedule is a perfect example. Living with my lovely roommate last year,  I usually went to bed at midnight and woke up before 8.

One useful tip for those flower-receivers: if you add ethanol to the water flowers are standing in, the flowers will last longer before petal senescence. Ethanol interferes with synthesis of ethene!  Heins and Blakely