A tip from a reader led the magazine to make this inquiry into spirulina cultivation.
The extreme alkalinity of the water used in spirulina cultivation caused the paint to peel away from the sides of this tank.
PHOTO: DAVID LAMPE
The idea of eating seaweed has—for a long time now—been included among the standard jokes referring to natural food "fanatics" who'll consume almost anything (no matter how unpalatable it may be) in pursuit of glowing health.
Recent developments, however, indicate that the jest may soon turn on its tellers! The fact is that algae could well become an increasingly familiar part of everyone's diet, as the soaring costs of producing and transporting "traditional" foodstuffs force people to look for alternative sources of nutrition. Among the many "future foods" now under investigation, single-celled marine plants stand out as potential sources of protein that are both easy and inexpensive to cultivate, highly productive, and amazingly nutritious.
Scientists began to investigate the notion of using algae as food in the 1950's and 60's, but most early research involved only the green varieties Chlorella and Scenedesmus. Unfortunately, such types presented problems in the areas of growth, harvesting, and digestibility, so their culture was gradually abandoned in favor of another, less troublesome species.
That variety—the probable algal superstar of the 80's—is Spirulina platensis, blue-green algae which have long been part of the diets of human beings. (The microscopic plants were eaten by the Aztecs in pre-Columbian Mexico and are consumed today by healthy Africans living on the shores of Lake Chad.) Even though Spirulina —which is composed of strings of tiny single cells, attached end-to-end to form a spiral shape—is especially well adapted to natural alkaline lakes in arid climates, its growth is no longer limited to such areas. In fact, research teams in several parts of the world are now using closed pond systems for spirulina cultivation, often on marginal land that would be totally unsuitable for most kinds of conventional agriculture.
According to many theories, the bluegreen algae were among the first forms of plant life to appear on the earth some billions of years ago. They're about the simplest to produce, most nutritious food source we could ever hope to find. Among the many varieties of such primitive plants, Spirulina scores incredibly high on a nutritional scale: It's rich in vitamins A and E, and the B-complex (in fact, this species is the highest nonanimal source of B-12, a vitamin that's often difficult to obtain in a vegetarian diet), and has an impressive array of trace minerals.
Spirulina is also chock-full of protein, containing a whopping 65-70% by dry weight (as compared to the approximately 35% protein content of soybeans and 45% of brewer's yeast). Furthermore, the algae provide complete protein, containing all of the eight essential amino acids that the body cannot manufacture.
Unlike other single-celled algae, Spirulina contains no cellulose in its cell walls, so the substance is much easier to digest than are the more fibrous forms, such as Chlorella. But perhaps the best news is that one needs to ingest only a small portion in order to receive the benefits of this nutritional powerhouse: Just two tablespoons—or 20 grams—of Spirulina powder (an amount which, by the way, contains only 78 calories) will provide 13 grams of complete protein ... almost one-third of the minimum daily amount most people require.
Eating the protein-packed wonder food is not quite as unappealing a culinary experience as you might expect. The Aztecs scooped their wild algae directly from the surface of Mexico's Lake Texcoco ... and made a sort of gravy, which they spooned over everything they ate.
Luckily, you don't have to consume Spirulina in its original stringy, pasty form (which is 70 to 90% water). After being harvested, the microscopic plants are nowadays dehydrated—by one of several simple methods—to produce a dark bluish green powder that has only a slight marine smell and taste. The flavor is so mild that it blends well with all kinds of seasonings and makes a tasty, nutritious addition to soups, dressings, dips, sauces, and juices. The powder can also be added to recipes for baked goods and sprinkled on salads, sandwich fillings, or casseroles.
When adding Spirulina to liquids, it's best to use a blender to insure thorough suspension of the powder. You should prepare only as much as you think you'll use in one day, though, since the mixture is apt to ferment if it's left sitting around too long.
One final word of caution: Be sure to store Spirulina powder in a dark, dry place ( and in a lightproof container) ... since the supplement's rich vitamin content and deep color are diminished by exposure to light and moisture.
Spirulina —an ideal "survival" ration that can be stored up to seven years with practically no loss of its protein content—often provides a boost to joggers, athletes, and tasters, and it can also be used as a supplemental ingredient in facial masks and infant formulas. The algae have even been mentioned as possible take-along food for travelers on long space missions ... or as the main crop of self-sufficient, floating settlements on the ocean.
Exactly where do these protein-rich algae come from, anyway? Well, worldwide production of Spirulina is currently between 500 and 800 tons a year, most of which is grown on modern algae farms in Mexico. Other producers—of much smaller amounts—include Thailand, Japan (where several algal strains have been commonly eaten for generations), and Israel.
In addition to the overseas operations, however, a few experimental farms have been established in the United States to investigate the possibility of quantity cultivation in this country. Several years ago, two enterprising researchers at the University of Texas—Dr. Tom Newsom and his colleague, Dr. Michael Leesley—built algae aquariums, troughs, and pools to test the productivity of Spirulina.
The Texas engineers estimated—from the results of their tests—that a ten-square-mile farm, growing only the marine plant, could feed two and a half million people a year ... and (on a smaller scale) that a group of 80 men and women could sustain themselves by keeping a mere 10 or 12 acres under Spirulina cultivation! Before the team was forced to abandon the promising project late last year because of a shortage of research funds, Newsom and Leesley had worked out an equipment setup that could be duplicated for at-home production of the nutritious food. Their simple plan involved a windmill-powered paddle wheel to stir the water gently and move the algae over a set of baffles, assuring constant exposure of the growing organisms to necessary sunlight.
Meanwhile, in 1975, an enthusiastic young entrepreneur named Larry Switzer formed the Proteus Corporation, to conduct further research into the mysteries of Spirulina platensis. His venture soon became successful enough to support the opening of a five-acre experimental farm in California's Imperial Valley, where a closed pond system is now processing several tons of the product each year.
Before you head out to the pond to start your own algae ranch, you should know that all researchers concede that there are still some bugs to be worked out of the Spirulina farming process at this stage of the game. However, those very problems are now at the center of ongoing studies that aim to make cultivation of algae a worthwhile activity for the individual.
One currently unsolved drawback is the presence of nucleic acids in Spirulina platensis, substances which—some scientists suggest—may be dangerous to humans by causing a high level of uric acid in the blood (which, in turn, could trigger the development of gout or kidney stones). Dr. Newsom, however, states that this particular algae contains only 4% nucleic material, a proportion that's equivalent to that in most of the vegetables we normally eat, and (according to Switzer) actually lower than the amount found in yeast or cheese.
It's possible, too, that Spirulina —when grown in outdoor ponds—could absorb (and concentrate) heavy metals, pesticides, or other pollutants from the air or from runoff water. Therefore, to insure the purity of its product, the Proteus operation tests its Spirulina crop constantly, employing the Japanese standard of 10 parts per million maximum ... which is well below the U.S. government standard for most vegetables of 40 PPM. (Of course, such a concern would be minimized—or even eliminated—for the at-home grower who cultivates algae in an indoor, closed pond system.)
It has also been suggested that Spirulina cultures might be subject to contamination by invading protozoa or other micro-organisms. However, most researchers now agree that the conditions in which the platensis species thrives (for instance, it enjoys temperatures of up to 95°F) and its strong alkalinity actually discourage the growth of problem organisms. For example, Tom Newsom reports that during the several years of his experimentation in Texas, his Spirulina cultures were never found to be contaminated by harmful micro-organisms.
Then, too, Spirulina cultivation presents the problem of a complicated crop care schedule. Algae farmers have to keep a close—and constant—watch on their "fields," since the growing food can double its bulk within 24 hours! This, of course, means that harvesting—and any necessary "weeding"—must be performed on a daily basis. On the other hand, though, it also means that if a crop does somehow become lost or contaminated, restarting the culture is a quick and easy process.
Both Switzer and Newsom agree that Spirulina farming will likely soon be possible for homesteaders who want to supply their own protein. As the Texas researcher says, "It can be done ... although the process is not as well understood—and hence isn't as 'easy'—as is regular gardening." All that's really necessary is equipment to agitate the water, and the nutrients (such as potassium, nitrogen, and a variety of trace elements) that must be added to duplicate the conditions under which Spirulina grows in the wild. In fact, adds Newsom, one could—and actually should —begin in-home experiments with algae cultivation using small aquariums (equipped with fluorescent lights) or greenhouse ponds.
The final step in Spirulina farming is drying the tiny strings of algae. After harvesting the crop in nets, researchers at the Proteus facility dehydrate the custard-like material in a spray dryer. A small-scale producer could simply dry the product in the sun, although some minerals are lost in the process of solar drying. The Texas engineers, however, often bypassed this step and ate their Spirulina wet, straight from the pond. In that form it has virtually no taste and retains all its minerals.
Whether you eventually grow algae in a fish tank or a five-acre pond (or simply buy the finished product in powder form at a health food outlet), you may well find that Spirulina has a place in your future. The tiny protein-rich plants may not be anything like the conventional foods we're all used to eating, but they do represent perhaps the first glimmer of a revolution in food production.
EDITOR'S NOTE: If you'd like more information on current breakthroughs in Spirolina research — or would like to order a copy of Larry Switzer's book on the subject, Spirulina The Whole Food Revolution — you can write to Proteus Corporation. The book is available for $5.00, plus $1.00 shipping and handling.