On Food And Cooking Part 57

Seed Oils Nuts and soybeans are rich in oil, which is kept in the ma.s.s of storage tissue in tiny packages called oil bodies. Each is a tiny oil droplet whose surface is covered with two protective materials: phospholipid relatives of lecithin, and proteins called oleosins. The surface coating prevents the oil droplets from pooling together. Seed oil bodies are very similar in size and structure to the fat globules in animal milk. This is why when we eat nuts, they become creamy in the mouth rather than simply greasy. It's also one reason why for a thousand years cooks have made "milks" from almonds, soybeans, and other oil-rich seeds (pp. 494, 504).

Seed Flavors The most important contributors to the flavors of grains, legumes, and nuts are fragments of the unsaturated fatty acids in the oils and cell membranes, which have individual aromas described as green, fatty, oily, floral, and mushroomy. The outer bran layer grains contains the bulk of the seed's oils and enzymes, and so gives whole grains a stronger flavor, as well as contributing some vanilla and toasted notes from its phenolic compounds. Beans are especially rich in green and mushroom notes. Nuts, which are usually cooked with dry heat, contain products of the browning reactions with typical roasted aromas. The flavors of particular seeds are described below.

Handling and Preparing Seeds Preparations of particular seeds are described in more detailed surveys below. Here are some common aspects of using seeds in the kitchen.

Storing Seeds Because most of the seeds we eat are designed to survive a dormant, dry period, they are the easiest food ingredients to store. Whole seeds keep well for months in a dry, cool, dark place. Moisture encourages the growth of spoilage microbes, and physical damage, heat and light can accelerate the oxidation of seed oils that leads to stale, rancid aromas and bitter tastes.

The pest that sometimes infests grains, beans, nuts, and flours is the Indian meal moth (Plodia interpunctella). It originally came from ears of grain in the field but is now a common inhabitant of our pantries, where its eggs hatch into larvae that consume the seeds and generate unpleasant smells. There's nothing to do with a contaminated batch but discard it. Keeping seeds in separate gla.s.s or plastic jars will prevent one batch from contaminating another.

Sprouts The sprouted seed is a culinary custom of ancient lineage in Asia, but a very recent arrival in the West. Thanks to the sprout, anyone, anytime - even an apartment-dweller in Anchorage in February - can raise a good approximation to fresh vegetables with very little effort. Sprouting often improves a seed's vitamin content and digestibility. And with their nutty flavor and crisp texture, sprouts are simply a nice change from the usual vegetables.

Beans are most commonly sprouted, but many of our food seeds can be sprouted to advantage. Sprouted wheat and barley, for example, develop a sweetness as their enzymes begin to break down stored starch into sugars for the embryonic plant. Sprouts have a nutritional value midway between that of the dry seed, which they just were, and a leafy green vegetable, which they're on the way to becoming. Sprouts are higher in vitamin C and lower in calories than most seeds, and higher than most vegetables in protein (5% versus about 2%) and in the B vitamins and iron.

Cooking Seeds Seeds are the driest and hardest ingredients that cooks deal with. Most require both moisture and heat to make them edible. Most, but not all: the nuts are generally edible and nutritious fresh out of the sh.e.l.l or after a brief application of dry heat, thanks to their relatively tender cell walls and the cells' content of liquid oil rather than solid starch. But dry grains and legumes are hard and starchy. Hot water softens them by dissolving the strengthening carbohydrates from their cell walls, and moving into the cells to gelate the starch granules and either dissolve or moisten the storage proteins. This makes the seed more nutritious by exposing its nutrients to our digestive enzymes.

There are a few simple facts to remember about cooking grains and legumes in water.

The outer bran layer or seed coat is designed to control the pa.s.sage of soil moisture into the embryo and storage tissues during germination. It also slows the pa.s.sage of cooking water. Seeds that have been milled free of their coats or into small pieces cook much faster than whole seeds.

Heat penetrates seeds faster than water can, so much of the cooking time is moistening time. Presoaking seeds for a few hours or overnight can cut cooking times by half or more.

Most seeds get quite soft when they've absorbed enough liquid to be about 6070% water by weight. That quant.i.ty of water is the equivalent of about 1.7 times the dry weight of the seeds, or about 1.4 times their volume. Recipes generally call for much more water than this to allow for water lost to evaporation during cooking.

The texture of fully cooked seeds is soft and fragile at cooking temperatures, but firms during cooling. If an intact appearance is important, it's good to let grains and legumes cool down before handling them.

Turning Seeds into Meat Subst.i.tutesVegetarian cooks, particularly Buddhists in China and j.a.pan, have long used grains, beans, and nuts to make foods with the chewy texture and savory flavor of meat. Protein extracts from wheat (gluten or seitan, seitan, p. 468) and soybean ( p. 468) and soybean (yuba, p. 494) can be manipulated to simulate meat-protein fibers, and fermented to produce savory, meaty flavors. In seed mixtures, whole grains lend chewiness, beans a softer background and some sweetness and complexity of flavor, and nuts both richness and roastiness. p. 494) can be manipulated to simulate meat-protein fibers, and fermented to produce savory, meaty flavors. In seed mixtures, whole grains lend chewiness, beans a softer background and some sweetness and complexity of flavor, and nuts both richness and roastiness.

Of course the most important grain and legume foods are made from finely ground flours or extracts. Mix water with ground grains or with starch extracted from beans and the result is a dough or batter, which heat can turn into noodles or flat breads or cakes. Aerate doughs or batters with the help of yeasts or bacteria or chemical leaveners, and the result is raised breads and cakes. Doughs and batters are special materials in their own right, and are described in detail in the next chapter.

Seeds Concentrate Cooking Liquids Because grains and beans are dry and soak up water, they remove water from the liquid they're cooked in, and therefore effectively concentrate other materials in the liquid. In this way they create a sauce for themselves. When rice or polenta is cooked in milk, for example, the liquid between the grains becomes richer in both milk proteins and fat globules, and so more like cream. When grains are cooked in a meat stock, the stock become more concentrated in gelatin, and so comes to resemble a reduced stock or demiglace. Because grains and beans are dry and soak up water, they remove water from the liquid they're cooked in, and therefore effectively concentrate other materials in the liquid. In this way they create a sauce for themselves. When rice or polenta is cooked in milk, for example, the liquid between the grains becomes richer in both milk proteins and fat globules, and so more like cream. When grains are cooked in a meat stock, the stock become more concentrated in gelatin, and so comes to resemble a reduced stock or demiglace.

The Grains, or Cereals Of the approximately 8,000 species in the gra.s.s family, only a handful play a significant role in the human diet. Aside from bamboo and sugar cane, these are the cereals. While their grains are very similar in structure and composition, the differences have made for widely divergent culinary histories.

The major Eurasian cereals - wheat, barley, rye, and oats - originally grew wild in extensive stands on the temperate high plains of the Near East. Groups of early humans could harvest enough wheat and barley from these wild fields in a few weeks to sustain themselves for a year. Some 12,000 to 14,000 years ago, the first agriculturalists began to plant and tend wheat and barley seeds selected for their size and the ease with which they could be harvested and used; and farmers gradually spread these crops throughout western and central Asia, Europe, and north Africa. Each cereal had its advantages. Barley was especially hardy, while rye and oats were able to adapt to wet, cold climates, and wheat produced a uniquely elastic paste that could be filled with tiny bubbles and baked into tender raised breads. Around the same time, the inhabitants of tropical and semitropical Asia domesticated rice, with its special ability to grow in wet, hot growing conditions. Somewhat later in warm central and South America arose maize, or corn, whose plants and kernels dwarf those of the other cereals.

Grain Structure and Composition The edible portion of the cereal plant, commonly called the grain or kernel, is technically a complete fruit whose ovary-derived layer is very thin and dry. Three of the cereals - barley, oats, and rice - bear fruits that are covered by small, tough, leaf-like structures that fuse to form the husk or hull. Bread and durum wheats, rye, and maize bear naked fruits and don't have to be husked before milling.

All the grains have the same basic structure. The fruit tissue consists of a layer of epidermis and several thin inner layers, including the ovary wall; altogether, it's only a few cells thick. Just underneath the seed coat is the aleurone layer, aleurone layer, only one to four cells thick and yet containing oil, minerals, protein, vitamins, enzymes, and flavor out of proportion to its size. The aleurone layer is the outer layer and only living part of the only one to four cells thick and yet containing oil, minerals, protein, vitamins, enzymes, and flavor out of proportion to its size. The aleurone layer is the outer layer and only living part of the endosperm endosperm; the rest is a ma.s.s of dead cells that stores most of the carbohydrates and protein, and that takes up most of the grain's volume. Ab.u.t.ting onto the endosperm from one side is the scutellum, scutellum, a single modified leaf that absorbs, digests, and conducts food from the endosperm to the a single modified leaf that absorbs, digests, and conducts food from the endosperm to the embryo, embryo, or "germ," which is at the base of the fruit, and which is also well endowed with oil, enzymes, and flavor. or "germ," which is at the base of the fruit, and which is also well endowed with oil, enzymes, and flavor.

The endosperm (from the Greek: "within the seed") is often the only part of the grain consumed. It consists of storage cells that contain starch granules embedded in a matrix of protein. This matrix is made up of normal cell proteins and membrane materials, and sometimes of spherical bodies of special storage proteins which, squeezed together as the starch granules grow, lose their individual ident.i.ty and form a monolithic ma.s.s. There's generally more starch and less protein per cell near the center of the grain than there is near the surface. This gradient means that the more grains are refined by milling and polis.h.i.+ng, the less nutritious they get.

Milling and Refining People began treating the grains to remove their tough protective layers in prehistoric times. Milling breaks the grains into pieces, and refining sifts away the bran and germ. The very different mechanical properties of endosperm, germ, and bran make this separation possible: the first is easily fragmented, and the others are oily and leathery respectively. The germ and the bran - which in practice include the aleurone layer just underneath it - together account for most of the fiber, oil, and B vitamins contained in the whole grain, as well as some 25% of its protein. Yet these parts of the grain are usually removed entirely or in part from rice and barley grains, and from cornmeal and wheat flours. Why this waste? Refined grains are easier to cook and to chew, and more attractively light in color. And in the case of flours, the high lipid concentrations in the germ and aleurone layer shorten the shelf life of whole-grain flours substantially. The oils are susceptible to oxidation and develop rancid flavors (stale aroma, harsh taste) in a matter of weeks. Today most refined cereals in industrial countries are fortified with B vitamins and iron in order to compensate for the nutrients lost with the bran.

Breakfast Cereals Apart from breads and pastries, the most common form in which Americans consume grain is probably the breakfast cereal. There are two basic types of breakfast cereals: hot, which require cooking, and ready-to-eat, which are eaten as is, often with some cold milk.

The anatomy of a wheat kernel. It's a miniature but complete fruit, with a dry rather than fleshy ovary wall. The large ma.s.s of endosperm cells stores food to nourish the early growth of the embryo or "germ."

Hot Cereals Hot cereals have been eaten since the dawn of civilization in the form of gruels, porridges, and congees. Corn grits, oatmeal, and cream of wheat are modern examples. Cooking the whole or milled cereal in excess of hot water softens the cell walls, gelates the starch grains and leaches starch molecules out, and produces a digestible, bland mush. The only significant improvement brought by the machine age has been a reduction in cooking time, either by grinding the cereal finely enough that it's quickly cooked, or by partly precooking it. it Hot cereals have been eaten since the dawn of civilization in the form of gruels, porridges, and congees. Corn grits, oatmeal, and cream of wheat are modern examples. Cooking the whole or milled cereal in excess of hot water softens the cell walls, gelates the starch grains and leaches starch molecules out, and produces a digestible, bland mush. The only significant improvement brought by the machine age has been a reduction in cooking time, either by grinding the cereal finely enough that it's quickly cooked, or by partly precooking it. it Ready-to-Eat Cereals Ready-to-eat cereals are the more common breakfast cereal by far in the United States. Ironically, the industry that has come under fire for giving children little more than empty calories, a sort of early-morning junk food, began as a "pure" and "scientific" health food, an alternative to the destructive diet of turn-of-the-century America. Its story involves a uniquely American mix of eccentric health reformers, fringe religion, and commercial canniness. Ready-to-eat cereals are the more common breakfast cereal by far in the United States. Ironically, the industry that has come under fire for giving children little more than empty calories, a sort of early-morning junk food, began as a "pure" and "scientific" health food, an alternative to the destructive diet of turn-of-the-century America. Its story involves a uniquely American mix of eccentric health reformers, fringe religion, and commercial canniness.

In the middle third of the 19th century, a vegetarian craze arose in opposition to the diet of salt beef and pork, hominy, condiments, and alkali-raised white bread that was prevalent at the time. A pure, plain diet for America was the object, and the issue was not only medical but moral. As Dr. John Harvey Kellogg put it somewhat later in his Plain Facts for Old and Young, Plain Facts for Old and Young, "A man that lives on pork, fine-flour bread, rich pies and cakes, and condiments, drinks tea and coffee, and uses tobacco, might as well try to fly as to be chaste in thought." Kellogg and his brother Will Keith Kellogg, C. W. Post, and others invented such virtuous preparations as shredded wheat, wheat and corn flakes, and Grape Nuts. These precooked cereals did offer a light, simple alternative to the substantial breakfasts of the day, became widely popular, and quickly generated a large, inventive, and profitable industry. Today there are several major varieties of ready-to-eat cereals: "A man that lives on pork, fine-flour bread, rich pies and cakes, and condiments, drinks tea and coffee, and uses tobacco, might as well try to fly as to be chaste in thought." Kellogg and his brother Will Keith Kellogg, C. W. Post, and others invented such virtuous preparations as shredded wheat, wheat and corn flakes, and Grape Nuts. These precooked cereals did offer a light, simple alternative to the substantial breakfasts of the day, became widely popular, and quickly generated a large, inventive, and profitable industry. Today there are several major varieties of ready-to-eat cereals: The Composition of GrainsGrain composition varies a great deal; these are rough figures, a.s.suming a moisture content of about 10%. Unless otherwise noted, the grains are whole.

Grain Protein Protein Carbohydrate Carbohydrate Oil Oil

Wheat 14 14.

67 67.

2 2.

Barley 12 12.

73 73.

2 2.

Barley, pearled 10 10.

78 78.

1 1.

Rye 15 15.

70 70.

3 3.

Oats 17 17.

66 66.

7 7.

Rice, white 7 7.

80 80.

0.5 0.5.

Rice, brown 8 8.

77 77.

3 3.

Rice, wild 15 15.

75 75.

1 1.

Corn (maize) 10 10.

68 68.

5 5.

Fonio 8 8.

75 75.

3 3.

Millet 13 13.

73 73.

6 6.

Sorghum 12 12.

74 74.

4 4.

Teff 9 9.

77 77.

2 2.

Triticale 13 13.

72 72.

2 2.

Amaranth 18 18.

57 57.

8 8.

Buckwheat 13 13.

72 72.

4 4.

Quinoa 13 13.

69 69.

6 6.

Muesli is a simple mixture of thinly rolled grains, sugar, dried fruits, and nuts.

Flakes are made from whole grains (wheat) or grain fragments (corn) that are flavored, steam-cooked, cooled, rolled into thin flakes, and toasted in a drum oven.

Granola, a term coined by the Kelloggs 100 years ago, is now rolled oats flavored with sweeteners (honey, malt, sugar) and spices, enriched with vegetable oil, toasted and mixed with nuts and/or dried fruit.