About ten years ago, Japanese growers started producing square (or rather cubic) watermelons. Not only could they be packed and shipped more efficiently, they took up less room in small Japanese refrigerators. The growers discovered consumers were also willing to pay a much higher price for the fruits, and soon they were offering square apples, Buddha-shaped pears, and now heart-shaped watermelons. Too bad Valentine’s Day falls in February, or you could buy one for your sweetheart…for only a couple hundred dollars.
You can make your own shaped fruit. You’ll need to buy or construct a plastic mold. Fit the mold around an immature fruit on the vine, and as it grows and expands, it conforms to the mold. Because the watermelon’s skin contains chlorophyll, the pigment that allows plants to absorb energy from light, a clear plastic mold is best. Still, you can get away with an opaque mold because plants’ leaves do most of the light harvesting. Besides, it’s ethylene gas, produced in plant tissues, that triggers fruit ripening. The gas diffuses from cell to cell, and turns on genes that make enzymes that soften fruit and turn carbohydrates to sugars. In apples and oranges, other enzymes degrade the chlorophyll, thereby allowing red, yellow, and orange pigments to emerge. Those colors signal ripeness to animals that the plant needs to carry away its seeds.
And speaking of oranges, here’s the latest in shaped fruits: a five-sided orange. While it has no romantic appeal (at least to me), it has a minor practical value: it won’t roll off your table.