The Scientific Secret of Garlic

by Lynn Parrucci

Often called the "stinking rose," garlic is among the most ancient of cultivated plants, and its pungent odor has given it a legendary reputation. Through the annals of culinary history and folklore, garlic (Allium sativum) has been credited not only as an aphrodisiac, but also as a tonic to embolden soldiers and to ward off vampires, worms, tumors and the common cold.

Garlic lovers would certainly agree that store-bought garlic powder or garlic salt provide a superficial, monotonous culinary experience compared with the bountiful flavors inherent in a clove of fresh garlic. Knowing the plant's scientific secret allows cooks to creatively manipulate elegant nuances of flavor, bringing a rich diversity to their cooking.

Many plants, including garlic, protect themselves from bacteria, insects and animals by producing odoriferous compounds. But whole garlic cloves are relatively odorless. The key to garlic's aromatic magic lies within the plant's cell walls, and once these cell membranes are ruptured, the power is unleashed. The process is like assembling a puzzle. Inside each garlic cell lies one piece of the puzzle, an odorless molecule call alliin. Outside the cell, between the individual cell walls, lies the other puzzle piece, an enzyme called alliinase. Enzymes are specialized proteins shaped in such a way that they lock with other molecules in a fixed position. Once a molecule is held by an enzyme, it is more likely to undergo specific chemical reactions

As garlic is chopped into fine pieces, more and more cell walls are broken, allowing more alliin molecules to meet alliinase. When these puzzle pieces lock together, a complex series of reactions is triggered. The alliin molecule is broken into several new molecules with different properties, but the alliinase molecules catalyze many reactions without undergoing any changes themselves. One of the molecules produced by the enzymatic reactions is the primary source of garlic's odor.

Chopped raw, garlic has a pungent taste and odor. But when whole cloves are simmered or roasted, the heat transforms the alliin into new, larger molecules before they meet the alliinase. This new structure gives the garlic a soft, sweet buttery flavor that surprises many first-time eaters. Somewhere between finely chopped and whole there exists a wealth of opportunities to vary garlic's flavor-from slicing, smashing and quartering to fusing with oil.

While garlic is thought to have been first discovered in Siberia, its culture is widely spread and is popularly used in Indian, Asian, Middle Eastern, Mediterranean, European and American cuisine.

Below are adaptations of two pasta recipes in which fused garlic is used as a base for a delicate anchovy paste. Herbs and spices are added to the paste to give the sauce a distinct flavor. The original recipes from the Umbria and Calabria-Lucania regions of Italy can be found in a cookbook by Ada Boni entitled Italian Regional Cooking. The Umbria variation produces a fresh mint flavor enhanced by capers. The Calabria-Lucania version is boldly influenced by spicy chili powder and bread crumbs. Either of these sauces can be complemented by hearty vegetables such as asparagus, portabella mushrooms or sun dried tomatoes.

To learn more about garlic, visit the Carnegie Science Center's Kitchen Theater. For information about garlic festivals, recipes and planting, visit the Garlic Page website at, or search for "stinking rose" on any search engine.

Lynn Parrucci is program coordinator at the Science Center's Kitchen Theater. Botanist Sue Thompson also contributed to this article.


Bring large pot of water to boil and add pasta. Cover, bring water back to boil, stirring occasionally with large fork. Cook briskly until tender but firm.

Meanwhile, heat oil in saute pan. Add garlic and saute until golden brown, then remove from oil. Add anchovies and cover immediately to avoid spattering hot oil. Wait a few seconds until spattering stops. Remove lid and stir until anchovies dissolve into paste. Add cracked pepper to taste. Remove pan from heat. Drain pasta and pour onto heated dish. Add anchovy paste and toss with either of the variations below.



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Visit the Kitchen Theater at Carnegie Science Center to learn more about the science of cooking, and get a taste of what we're cooking and a recipe to take home. For a schedule of daily cooking shows, check the schedule board in the Science Center lobby on the day of your visit, or call 237-3400. Be sure to ask if there is a guest chef appearing. The Kitchen Theater at Carnegie Science Center is sponsored by the Jewish Healthcare Foundation.