by Richard L. Howey, Wyoming, USA
In times long gone, many people used to grow their own food, make their own soap, and keep animals for their meat and/or by-products, such as, milk and eggs, not to mention, hides for garments and shoes or furniture, and feathers for pillows and comforters. Also if you couldn't produce all of these things for yourself, you might produce a surplus of certain items in order to barter with others; often people whom you knew and trusted. What this meant was that these people had a pretty good idea of what they were eating and using in their households.
Ah, progress! Today we don't to need concern ourselves with such mundane trivia, because we have a plethora of beneficent government agencies overseeing our welfare. We have the Food and Drug Administration which insures that our poultry, fish, beef, pork, shellfish, mutton, eggs, milk, prescription drugs, and over-the-counter medications are all up to standard and safe for us. Then, of course, we also have the Environmental Protection Agency to insure that we have clean air and water. Human beings are quirky creatures and we like to believe that we are fundamentally in control of our world. Sometimes, this is a difficult illusion to maintain: AIDS, the medieval plagues (the Black Death), the plagues of locusts, floods, volcanic eruptions, typhoons, tornados, hurricanes, bovine spongiform encephalopathy (Mad Cow Disease), Creutzfeld-Jakob disease, foot and mouth disease, leprosy, malaria, and schistosomiasis—not to mention the myriad forms of cancer. Sometimes, all of us are tempted to think that it might be better if things were simpler—in short, we know too much and we know too little.
Think about it for a minute. These governmental agencies have official standards for "acceptable" levels of arsenic, lead, radon, dioxin, mercury, cyanide, etc. in our water, air, and food. There are "limits" for the number of rat hairs, parts of tomato worms, insect parts (cockroaches), etc. that can be in our food (even in our chocolate candy!!!) These are some of the prices we pay for modern technology; progress necessarily entails compromises. However, in the U.S., the average human life span increased by over 30 years in the last century and, in spite of all the meteorological, health, and seismic catastrophes—the human population continues to grow at an alarming rate, so perhaps, statistically at least, we shouldn't worry too much about a few cockroach legs in our chocolate or tomato worms in our catsup.
What does all of this have to do with microscopy? Well, there are whole areas of microscopy devoted to the analysis of food products and water supplies. Take a piece of the finest mesh nylon cloth you can obtain and tie it securely over one of your faucets and leave it for several weeks. When it is ready to examine, remove the nylon and using a wash bottle filled with your tap water, rinse the contents into a small Petri dish. You may find a few diatoms and a few algal forms right off, but there may be other organisms that are still encysted. Take some artesian water and boil it for 5 minutes along with a few wheat grains and/or 1 inch pieces of Timothy hay. Place in small culture dishes which are carefully covered to prevent contamination from cysts in the environment. After a day or two, when a rich bacterial growth has developed, inoculate the dishes with the material from your nylon filter. This may let you know about some of the micro-beasties that may be lurking in your drinking water.
In most places in industrialized countries, water is carefully monitored for potential problems from micro-organisms and, ironically, it is industrialization that has made chemical contamination a much greater risk in such countries than micro-organisms. If you don't find anything from the filter, you can feel comforted. In some places, such as where I live, our water comes from several sources: a large underground aquifer, a river, a lake and several sizeable reservoirs. I have collected numerous samples from the river, the lake and the reservoirs and I could provide a long list of organisms which are in these sources, but happily, are not in our drinking water.
As I sit here writing this at the kitchen table, I am looking at a jar of Spice Islands brand celery salt and the label informs me that it has two ingredients: salt and ground celery seed. It further tells me that: "Only the finest ground celery seed from India are blended in this aromatic flavor-enhancer." Who would have thought it, celery in India? When I think of India, I think of rice and wonderfully rich varieties of curry with many different sorts of condiments and chutneys, but I have never associated India with celery, apparently a major failing on my part. My wife has been cooking with celery salt for years, yet I must confess, I have never looked at it under the microscope. I will, I will, I promise. Why? Because, all spices have interesting structures to be examined, but for our immediate purposes, they often contain adulterants (as against, adolescents—sorry, I just couldn't resist) and it's interesting to know just what's been added to spice up our spices. Now, in all fairness, let it be said that there are companies which conscientiously and rigorously apply the methods of quality control, but even the best of us are still, after all, human and fallible. This means that, in spite of someone's best efforts, sometimes, bits and pieces of things other than what he wanted or intended to have included, end up in certain of our food products. On the other hand, there are suppliers who intentionally adulterate various products with substances that are bulky and cheap in order to keep their costs down and their profits up. So, for example, one may find in some inexpensive brands of coffee, the addition of various types of ground grains or in teas, one may find that they contain a significant number of leaves which have never been anywhere near a tea plant. Spices are also likely candidates for adulteration and especially when the spices are finely ground. If you buy a jar of whole cloves, you can readily tell that you're getting cloves; but, when you buy powdered cloves, there is the possibility for the introduction of substances other than cloves. Ground peppers of various sorts are also likely to contain foreign substances.
In almost any kind of dried plant product, there is the likelihood of a few bits of stem or some weed seeds which escaped removal during processing, but when you find 10%, 20%, or even more material belonging to plants other than those listed on the labels, then you have every right to be suspicious. If, for example, you buy a jar of dried, chopped chives and you discover that 25% of it consists of lettuce leaves, it might explain why that omelet you fixed for Sunday breakfast tasted so bland. And the same explanation would apply when you discover that the dried minced onion that your wife put into the goulash last week consists of 35% wood shavings! Although these two examples are fictitious, I wouldn't be at all surprised to learn that someone has tried marketing such combinations. Think of the possibilities—add some willow leaves to bay leaf pieces, some dried fern leaves mixed with basil, ground oak leaves in the oregano—on and on—all it takes is a little ingenuity and a complete lack of ethics. So, if you like doing a bit of detective work, the spice cabinet is a good place to begin. Coffees and teas, especially herbal teas, also provide interesting material for examination as do bits of various sorts of crackers and breakfast cereals.
It used to be that in some of the older brands of toothpaste, one could find diatoms. These occurred as diatomaceous earth, diatomite, or Fuller's earth and the toothpastes were advertised as having miracle properties for whitening teeth. Well, yes, I should imagine so—you were polishing your teeth with a paste containing what was essentially ground glass—stripping that old, dull layer of enamel right off your teeth. In the last few years, there have been a number of new tooth cleaners advertised as having super-whitening properties and maybe some of those use diatoms. I don't know, I haven't checked, but I do wonder.
From aged cheeses, and ones which have developed a lovely gray-green fur from having been left in the refrigerator too long, one can extract interesting samples of molds. Fungi are fascinating, eerie, and, sometimes, downright scary with their uncanny ability to colonize bizarre ecological niches. The wonderfully rich flavor of Roquefort depends on a mold, but, the other side is, that relatives of this organism are quite willing to invade our bodies in the form of yeast infections, athlete's foot and a myriad of other disorders that flesh is heir to. Athlete's foot—what a misnomer! I've had it and yet I subscribe rigorously to the philosophy of Robert Maynard Hutchins, one-time president of the University of Chicago, who said: "Whenever I'm tempted to exercise, I lie down until the urge passes."
A fairly simple exercise in looking for adulterants in food products can be carried out by taking a small sample of crab, lobster, or shrimp paste, stirring it vigorously in very warm water, and then pouring it through a fine meshed sieve. This process may need to be repeated several times. Place the residue in a small plastic Petri dish with some distilled water. As you examine this material, you may find small bits of crustacean shell, but there's a fair chance that you will also find some fish scales and tiny bits of fish bone. It is interesting to check the label to see if the manufacturer has included the information that fish have also been used in the production of the paste, and if you get lucky, you might even find a label that tells you which kinds of fish which makes identifying the scales, considerably easier.
Tomato products are interesting in quite a different respect in that they can provide clues to the use of overripe fruit or fruit that has been processed in less than hygienic conditions. Tomatoes are exceptionally vulnerable to molds and, as a consequence, virtually every tomato product will contain fungal filaments or hyphae. An excess of such fungal growth can effect both texture, and more importantly, flavor. So, here's a good place to look for fungal filaments. (Say that fast 21 times in a row.) Food scientists have developed quantitative techniques for determining when overripe or otherwise unsuitable tomatoes have been used in a particular product.
As significant percentages of people in industrialized nations move toward obesity, there has developed an increasing demand for food with fewer calories. (What? Me, overweight? Why I'm at my perfect weight, if I were 7 foot 11 inches tall. I'm just a little short for my weight.) So, interestingly, here's an instance where people want adulterants in their food and, in this case, gums and gum extracts. Food gums are thickeners and are readily available in nature. Agar, which is derived from kelp, is a common additive as are other dried secretions from a variety of plants, such as, acacia, tragacanth, Irish moss, pectin from fruits, and certain types of cellulose extracts. Iodine solution, Congo red, and Toluidine blue are often used to identify various gums and extracts. Gums and gum extracts are added to sauce mixes, dried soups, instant coffee, instant tea, many types of medications and all those wonderful desserts which come out of a box.
Another interesting food to examine under the microscope is honey in which you will certainly find pollen grains. If you don't find pollen, then it's very likely that it isn't honey. There are, of course, specialty types and the producers will tell you on the label that it's clover honey, alfalfa honey, orange blossom honey, lavender honey, sage honey, or tuna honey (just kidding about this last one!—Yeech!) We also have had a honey labeled as mountain flower honey. Other kinds of pollens which can be found in honey include those from coniferous trees. Being a great fan of neither bees (I'm highly allergic to their stings) nor honey, I can't claim any expertise, but I suspect that this pollen is not something which bees actively collect, but rather that it drifts in such large quantities, that bits of it get picked up by the bees when collecting from nearby flowers. I suppose I could look this up on the web or, being old-fashioned, in a book, but I'm lazy and I'm sure that if I'm wrong, some kind soul will correct me.
This natural world is no respecter of our moral views and you may even find rape seed in some samples of honey. Apple, buttercup, dandelion, buckwheat, and even sunflower pollen may show up in samples of honey. In any case, the designations provided by the producer regarding the type may be very helpful in picking out the particular kinds of pollen.
I mentioned tea earlier and here we will consider genuine tea and not herbal teas. Take the dregs from a good pot of strong tea and rub a few between your thumb and index finger. Tea leaves have a distinctive leathery feel to them and if you don't notice this, then you have a hint at least that there may be something other than tea in your tea.
Tea is especially interesting as a test subject, since it has some distinctive morphological features which provide us with a modern, scientific version of "reading" tea leaves. The first of these features is stone cells or idioblasts which are most abundant in the area of the central rib of the leaf. These cells are very large with very thick cell walls and irregular indentations. You will, of course, have to cut some fairly thin sections of the leaves to observe these cells. The second distinctive feature is the idiosyncratic structure of the hairs on the leaves. Younger leaves have numerous hairs and, in the older leaves, they are sparse, but with a bit of searching, can be found. The hair tapers down in a straight line, but then the base veers off at a sharp angle. The third distinctive feature is crystalline rosettes which can be abundant and will show up under polarization.
If the tea is a fragrant one, then you may find flowers, such as, jasmine which have been added to create a delicate bouquet. If it is a flavored tea, then you may find leaves of other plants, such as the various types of mint. Cheap teas may contain significant quantities of tea stems which will effect the quality.
Today when tea, coffee and spices can be produced in enormous quantities, large scale adulteration of these products is rare. However, in the past when such items were sometimes scare, difficult to obtain, and relatively expensive, adulteration was a common practice. 150 years ago, food testing was virtually non-existent and merchants were often unscrupulous in their desire to make enough money to move into the middle class (some forms of historical dialectic never seem to change, and, no, I'm not a Marxist.)
Often tea was treated with various compounds to give it a more pleasing and more distinctive color which, as a side benefit, helped disguise various sorts of leaves that were something quite other than tea leaves. In earlier times, in major tea-consuming countries, used tea leaves were collected, dried, treated and re-sold as the genuine article. As you can imagine, such a product must have been a pale imitation indeed.
But, even worse, starches and minerals were added in order to increase the weight and reduce the quantity of actual, precious tea leaves. Ground chalk, soapstone, and even sand were added to increase weight. In addition 20 or so different kinds of leaves from other plants ranging from acacia to willow were often added to create bulk. So, as my old Latin teacher used to say—the emperor likes caviar—Caveat emptor!
Similar cautions can be offered in relation to coffee which has a long, complex, and interesting social history. Originally a native plant in East Africa, it was introduced into the Mideast in the 1400s and coffee soon became the most popular beverage in spite of prohibitions by Islamic priests. In the late 1600s, the Dutch introduced this plant into Java and northern South America and it quickly became cultivated in many tropical parts of the world. However, as demand grew, supplies were not always stable and prices to coffee brokers varied dramatically. This led to two strategies: 1) the use of a wide variety of adulterants and 2) the development of coffee substitutes.
Sometimes coffee was adulterated with coffee, that is, the hulls were ground and used to add bulk. It is, of course, easier by far to hide adulterants in ground coffee where they can be detected only by microscopic examination. And you'd be surprised what got added into "100% pure ground coffee":
1) Grain—wheat, rye, corn, barley and brans from such grains. Even bread was used as an adulterant.
2) Legumes—soy beans, chick peas, peanuts, and yes, sometimes even the ground shells.
3) Roots—Chicory—especially chicory—, carrots, beets, turnips, radishes, and dandelions—I have enough dandelions in my yard right now, if someone wants to dig up the roots, roast them and grind them, to produce at least a ton of faux-coffee.
4) Fruits—Dry your favorite fruit, grind it up, and you may well find that it was used in "coffee". Sometimes, also seeds were used. Imagine that you're a vintner and someone offers to pay you for the waste mash after you've spent all day stomping the grapes to make a subtle, but saucy, even slightly arrogant Chateau-Neuf-de-Mom with a hint of walnut, a slight overbite of cherry wood, a soupcon of chocolate, and tang of peach with a mixed bouquet of white roses and Brussell sprouts. So, the coffee broker buys the dregs, dries them out, grinds them up, and—voila!—you have Coffee-Neuf-de-Mom. Dried bananas, pears and prunes have all been used as adulterants along with ground acorns and date pits.
Coffee substitutes were honest, at least, in the respect of not pretending to contain coffee—a little less honest perhaps in claiming myriad health benefits provided by these ersatz coffees. Many of them were given exotic names, especially the German and French varieties, whereas the names of the American brands tended to be more prosaic and emphasize that they were "hygienic" or good for the nerves. Most of these substitutes consisted primarily of roasted cereal grains with some bits of roots, fruits, and legumes thrown in here and there. One was made just of dried figs and chicory—Ugh!
Since I mentioned wines, let me just say a few words about these Dionysian nectars. Anyone who has had the misfortune of drinking a truly wretched bottle of wine, immediately suspects that the prime adulterant is vinegar. There is a great deal of snobbery associated with wines and an expensive wine is not necessarily a good wine. However, a very cheap wine is a very cheap wine. Nearly 40 years ago, my wife and I and fellow graduate students used to buy California burgundy for $1.49 a gallon! This fitted only the loosest definition of "wine"—it contained fermented grapes and alcohol. Nonetheless, it contributed to generating many intense philosophical discussions which were at least as important and stimulating as the seminars we were taking. Glorious days—when one is young, poor, highly energetic, and slightly silly. The French, in particular, have been quite strict about regulating their wines, and, with good reason. A decade or so ago, there was an enormous scandal centered on Italian wines, some of which were found to be "synthetic", that is, they contained no fermented grape juice. Oh, yes, there was alcohol in them. When you find a wine label that states "fortified", it's best not to buy it. What that means is that grain alcohol has been added to get the strength up. But this Italian stuff had cattle blood in it and chemicals for flavor and color—in other words, a first-rate hoax and abomination. The analysis of wines, however, depends much more upon chemistry than microscopy, although there is an interesting aside. Some wines will "throw off" wine sugar crystals and these may be found at the bottom of a bottle. The wine that produced them may not be especially good, but the crystals themselves are quite elegant and well worth isolating and mounting.
Once one gets started on this path of examining items in one's kitchen, there is almost no end to the kinds of investigations one can carry out. The ordinary table seasoning, pepper, comes in a great variety of types and sometimes contains things other than pepper. One kind of experiment which you can readily carry out is to buy a small jar of mixed peppercorns which contains brown, green, red, and black peppercorns. Separate out a few of each type from the mixture and soak those of each type in a separate small dish of water and then carefully cut some thin sections. Under the microscope, compare and contrast the different types. Next, put some of the mixture of peppercorns in a pepper mill and grind a bit of the material, place in a drop of water on a slide and see if you can now distinguish the various types. Herbal teas, cooking herbs, medicinal herbs from capsules from the drug store—these too can provide material for many hours of interesting investigations.
A last word: when you leave your lab, forget all of your analyses and trust your palate; otherwise you'll starve to death.
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