Saturday, September 10, 2011

Farm Bulletin: Wheat Fruits


If you're like me and have been confused about wheat, corn and whether to soak beans or just cook them and get it over with, contributor Anthony Boutard of Ayers Creek Farm has the answer for you. So stick with this one, read it all the way through, and all will be revealed.

Not too many years ago, the term "wheat berry" slipped into the culinary lexicon, probably from the purveyors of sugary breakfast material. We know it is a lost cause, but as berry and wheat growers, it still sticks in our craw. Not only is there nary a trace of resemblance between a kernel of wheat and a berry, but it has also displaced two very good words to describe the food: wheat kernels and wheat grains. They are part of our language. We talk about a "grain of truth" or a "kernel of truth," never a "berry of truth." Ah, but as so often happens, there is grain of truth in the term, even though it obviously seeped out of some sort of crude marketing scheme now lost to memory. Both berries and wheat kernels are types of fruit.

A flint corn kernel split the same way as the wheat at top, with the embryo at the bottom. The lighter band of cells just under the skin is the aleurone layer.

The wheat kernel (top, with the relatively small embryo at the left) is a fruit characteristic of the grasses. Kernels of corn, millet, barley and wheat, and the seed you sow to grow a lawn, are all a fruit called a caryopsis. But, you aver, fruits are seeds surrounded by pulpy flesh, often sweet and delectable, and wheat looks just like a seed. Actually, a fruit is the ovary tissue that remains with the seed after it detaches from the mother plant, whether it is fleshy, pulpy or dry. The outer part of the wheat kernel, called the bran, or the pericarp among botanists, is actually the remains of the plant's ovary tissue that has dried, forming a hard protective coat. Inside the thin pericarp lies the seed itself. If you look very closely, the fruit of wheat has a characteristic shock of white bristles at the top of kernel.

If you soak a kernel of any grain for a day or so and, when it is soft, slice it lengthwise with a razor, you can easily see the various parts of the caryopsis with a hand lens or a microscope. I have found the macro setting on a digital camera with good resolution is a very useful microscope. As noted, the pericarp forms the outer skin. Inside, there a single layer of relatively large cells that looks almost as if someone drew a thin line just inside the pericarp. Called the aleurone, it is the outermost layer of the endosperm tissue. The kernel has a vault of food contained within the endosperm, and the aleurone layer provides the enzymes, the keys, needed to unlock the food. Inside of the aleurone is the starchy part of the endosperm. It is mostly starch with some protein and oils in the mix. This part of the endosperm contains the food necessary to grow a root in order to provide water and minerals to the growing plant, and a leaf to start the process of making sugars from the sun. Just add water, and life hastens again. Even when it is dormant, a seed is living and respiring, and this why seeds gradually loose their viability. Some after a year, some after a decade or more.

At the base of kernel lies the embryo, or germ as it is known to millers. This fatty bit of tissue is a fully assembled plant ready to grow roots and leaves. The first leaf is fully grown. Called the scutellum, and this leaf remains pressed against the endosperm, never to see the light of day. The scutellum is unique to the grasses, and its primary role is to absorb the nutrients released from the endosperm as rapidly as possible, and transfer them to the growing roots and leaves. Most of the fats in the kernel are in the scutellum. All plants except orchids produce endosperm cells. In most plants, the endosperm is absorbed by the embryo and stored in the seed leaves cotyledons. The two halves of the chickpeas are the seed leaves that absorbed the endosperm.

When cooking mature grains and pulses, such as wheat or beans, we always recommend soaking them overnight. Yes, this requires a modicum of planning and foresight. Some people resist and just cook them, or haul out the heavy metal in the form of a pressure cooker. True, if the grains or beans are fresh, you can soften them and render an edible food. But this impatience and lack of finesse means a less flavorful bean or grain in our experience.

Why is that, you might ask? Allowing the plant's own enzymes to work on the starches and proteins for a day or so, and starting the process of breaking down the starches and proteins naturally, makes for a more tender and sweeter grain or bean. Moreover, in many of the seeds, complex compounds are released into the surrounding soil during germination that are not always good to eat. The compounds may be protective in function, or serve as attractants to root fungi. You can smell and taste these compounds in the soaking water, and decide whether they will enrich your life. The only beans we cook in the soaking water are black turtles. One silly notion often floated out there is that soaking leaches out the minerals. This idea that nutrients pour out of a germinating seed willy nilly makes no sense at all, but is repeated endlessly. As noted, some of the compounds actively released by the seed are best poured down the sink.

2 comments:

Erica said...

Thank you for this fantastic post! I love it when food, politics, health, marketing and science all come together, and it has happened with great form in this article.

KAB said...

Glad you found it informative, Erica! Anthony is a writer always worth the reading.