Food for thought: When is a nut not a nut

Published 8:00 am Wednesday, September 29, 2010

Recently, a friend of Ben Ben’s from Atlanta who is a horticulturalist stopped by the shop and had a conversation with Rhonda about pine nuts. We were making pesto that day. “Where do they come from?” he asked. “They come from inside the pine cone,” Rhonda responded. After much debate Rhonda asked if we could google the answer. She was correct!

Very few fruit, vegetables or spice plants were known to more than one continent before the spice trade and discovery of the New World. Cereals and legumes hold the same truth. Not so, however, for nuts. Pine, walnut, chestnut, oak and hazelnut trees all have both New and Old World representatives. Why? Because they existed long before Europe and North America divided some 60 million years ago. The world wide distribution of many nut trees is a mark of their great antiquity.

From the beginning, the English word nut meant an edible kernel surrounded by a hard shell. Today botanists have designated the word to refer specifically to one-seeded fruits with a tough, dry fruit layer rather than a fleshy one. With such a strict definition, only beechnuts, hazelnuts, acorns and sweet chestnuts qualify as true nuts because they are a composite of the seed and fruit, where the fruit does not open to release the seed.

There exists a wide variety of dried seeds and fruits that we refer to as nuts. For the most part these “nuts” are a drupe – a fruit in which an outer fleshy part surrounds a shell with a seed inside. Examples include: almonds, cashews, coconut, hickory, pecans, pistachios and walnuts.

Almonds and walnuts actually correspond to the stones of the peach or plum. The cashew is related to poison ivy and thus, we never see cashews for sale in their shell. The irritating oil in the shell must be destroyed by heating before the seed can be extracted. This oil is eventually used in products such as paint and varnish. One of the oldest food plants, the coconut palm originates in Malaysia. Over its approximate 70 year lifespan, this prolific tree yields thousands of coconuts. This “nut” has been known to survive flotation across entire oceans; mere speculation to its abundance in native lands?

There are 17 varieties of hickory trees, 13 of which are native to the United States. The hickory tree is in the walnut family, and although little cultivated, all varieties bear “nuts;” the most popular “nut” being the pecan. In 1846/47 a slave named Antoine seriously improved pecan breeding by working different grafts onto root stocks. He propagated a variety known as “Centennial” on 16 trees of Louisiana’s Oak Alley plantation.

Historically, the true nut acorn, borne by the oak tree was used as a pseudocereal. Although it has fallen somewhat in esteem for humans, it is a prized food source for pigs, squirrels, jays and other wildlife. Acorns have been used in Spain as a food source for the prized Iberian pig for centuries. The treasured jamon Serrano is priced according to the ratio of acorns in the animal’s diet. The king of all hams, the first “jamones ibericos” were released for sale in the United States in December 2007. Basic jamon iberico is priced upward of $64 a pound with the prized iberico de bellota $200 and above.

Nutritionally nuts contain the essential fatty acids and linolenic acids, and the fats in nuts for the most part are unsaturated fats. Nuts are also good sources of vitamins E and B2 (riboflavin, an antioxidant), and are rich in protein, folate, fiber and the essential minerals such as magnesium, phosphorus, potassium, copper and selenium.

Because of a high fat content, nuts are especially vulnerable to rancidity. For that reason it is best to store them in an airtight container in a cool place. Shelled nuts can be refrigerated up to 4 months, frozen up to 6 months.

So what about the pine nut? Residing inside the pine cone, each “seed” must be hand extracted. This labor intensive process is what makes these nuts so expensive. So the next time you are in the mood for a faux nut dish, stop by the pasta shop and try our Grilled Chicken Breast and Pesto Lasagna. It is seven layers of deliciousness and is our horticultural friend Joe’s favorite!

— Cindy Shultz is the owner and chef at Cindy Lutini’s Pasta for Life. She holds a B.A. from the University of North Carolina at Chapel Hill and an M.A. from John Carroll University.