By Dom Castaldo, Ph.D.
The produce sections in northern Illinois supermarkets are becoming crowded. Unfamiliar fruits and vegetables are joining potatoes, cabbage and tomatoes.
The expanded selection of food is largely the result of increased global trade. For example, many older northern Illinoisans remember that when they were younger, watermelon or cantaloupe were only available in local grocery stores in the summer. Now, they can buy fresh melon — as well as corn on the cob, peaches and yellow squash — all year long. In addition, they can now enjoy fruits and vegetables that were unheard of when they were children. Although some of these foods are imported, many are grown in the U.S.
Many northern Illinois consumers have tried — and liked — the following exotic foods, but they don’t know much about them. Others are waiting for feedback from their relatives and friends before experimenting with these foods.
Consumers who desire spicy snacks enjoy wasabi. Wasabi is a member of the Brassicaceae family, which also includes cabbage, mustard and horseradish. Unlike cabbage and mustard, wasabi is sometimes difficult to grow. Therefore, authentic wasabi paste and powder is expensive.
The plant’s roots are ground into a paste and used as a condiment for other foods, such as fish or rice, in a manner similar to how horseradish and hot mustard are used. The paste can be dried and dusted on dried green peas, peanuts or soybeans. Volatile allylisothiocyanate — not to be confused with capsucin, which is found in chili pepper — is the compound that gives wasabi its hot flavor. Researchers have reported that this compound has antimicrobial properties, making it a potential food preservative. Also unlike capsaicin, the allylisothiocyanate in wasabi degrades quickly when fresh wasabi root is ground.
Kiwifruit has been available in northern Illinois supermarkets for many years. However, many have not yet eaten this small, hairy, oval kiwifruit.
Although kiwifruit is associated with New Zealand, kiwifruit traces its roots to northern and eastern China. In 1906, Mary Fraser brought kiwifruit seeds to New Zealand. Eventually, kiwifruits were shipped to other parts of the world. Today, commercial kiwifruit farms operate in the U.S. — California, Texas and Florida — South Africa, Japan, Italy, Greece, France, Canada and Chile. Kiwifruit vines can withstand temperatures as low as 10 degrees Fahrenheit.
The name “kiwifruit” was developed in the early 1960s. Kiwifruit has been called Chinese gooseberry, Macaque peach, vine pear and hairy bush fruit during its history.
Kiwifruit vines are diecious. This means a male vine and a female vine are needed to produce fruit. Only female vines produce fruit. Most kiwifruit growers cross two varieties to produce fruit with desired characteristics. Kiwifruit vines require large volumes of water and fertilizer with a high nitrogen concentration.
The flesh of kiwifruit is usually bright green, but varieties that produce kiwifruit with off-white and yellow flesh are available. The flavor of the flesh is described as sweet, tart or bitter. Some people claim kiwifruit has a slight strawberry flavor. Kiwifruits are rich in potassium, vitamin C and vitamin A. The seeds contain the essential fat linoleic acid. Some health experts claim the fiber content of kiwifruit reduces the risk of colon cancer and may benefit asthmatic children. However, other experts warn that some people are allergic to kiwifruits. A protein-dissolving enzyme actinidin makes raw kiwifruit undesirable in desserts containing milk or dairy products.
A native of southern India and Sri Lanka, carambola is more commonly known as “star fruit” because of its prominent longitudinal ribs. When the oval fruit is cut horizontally, the slices have a star shape — hence the name “star fruit.” The first carambola fruits were brought to Florida in the 1870s but were used as ornaments. Later, consumers discovered they were a versatile food.
The flavor of the fruit ranges from sour to slightly sweet. The sour taste is the result of a combination of acids including oxalic, tartaric, citric and fumaric acids. Green fruits tend to have a slightly higher acid concentration than yellow fruit. Carambola fruit contains less than 4 percent sugar. When picked early, carambola ripen slowly — in two to three weeks. When ripe, the fruit has a bright yellow or green color. Ripe fruit is easily damaged and must be handled gently. Consumers slice and eat carambola or add slices to salads and soups. Cooking carambola, especially in high-sugar syrups, often causes the skin to become tough.
According to Purdue University scientists, a 100-gram portion of carambola contains 36 calories and less than 1 gram of protein. The vitamin C content ranges from 26-53 mg per 100 grams of fresh fruit. It also contains measurable amounts of iron, thiamin, riboflavin and niacin.
A warm-climate fruit, longan berries — also known as “dragon’s eye” — originated in southern China. Longan trees produce the fruits in drooping clusters. Longan berries are round and 0.5-1 inch in diameter, possess a juicy, musty-sweet tasting flesh covered with a yellow-brown to red-brown rind. The single round seed in each berry is jet black with a white spot, giving it the appearance of an eye.
Longan berries are eaten fresh or dried over a wood fire, which gives them a smoky flavor. They can be frozen, and their rind prevents them from degrading when they thaw.
Fresh longan berries contain approximately 82 percent water and 60 calories of energy per 100 mg, according to Purdue University researchers. One hundred grams of fresh longan fruit also contains approximately 16 g total carbohydrates and 1.2 mg of iron. Practitioners of traditional Asian medicine regard longan fruit as an antidote for some poisons and a treatment for insomnia.
Longan trees thrive in rich, sandy loam soils. The tree cannot survive heavy frost. Although native to southern China, longan trees also grow in southern Florida. Few diseases or insect pests damage longan trees.
Muscovado is a type of unrefined brown cane sugar that possesses a strong molasses flavor. Muscovado is coarser and stickier than other types of brown sugar. It is popular in the south Pacific and the Caribbean for making rum and sweetening coffee, tea and other beverages. Filipinos snack on granules of muscovado. Muscovado can withstand high cooking temperatures and have a long shelf life.
Muscovado contains approximately 80 percent sucrose and 275 calories per 100 grams. (Refined cane sugar contains 400 calories per 100 grams.) Muscovado also contains approximately 85 mg of calcium, 25 mg of magnesium, 100 mg of potassium, 1.3 mg of iron and 4 milligrams of phosphorus.
Native to the Andes Mountains in South America, cherimoya is now grown in many parts of the world, including southern California. Also called the custard apple, the cherimoya is a green-skin, heart-shaped fruit, produced on a fast-growing evergreen tree.
Ripe cherimoya fruits have a dark brown skin and a white, creamy flesh. The toxic black seeds must be removed before eating the flesh. Ground cherimoya seeds are an effective insecticide. Some people describe the flavor of cherimoya flesh as a blend of banana and pineapple with a hint of mango.
Most people eat cherimoya raw. Cooking destroys the flavor and texture. It is frequently served chilled but can be incorporated into fruit salads, ice cream or cookies. It can be stored briefly in a refrigerator or frozen. One hundred grams of cherimoya fresh flesh contains 74 grams of water and 94 calories.
Although tomatillos are often mistaken for small tomatoes, the plants that bear the two vegetables belong to different genus and species. However, both plants are in the same family, which also includes the poisonous nightshade plant.
Tomatillos feature a paper-thin husk that consumers must remove before they eat them. Also, most recipes require tomatillos to be cooked to soften the skin and improve their flavor. They are often added to sauces and salsa.
Because tomatillo flowers do not self-pollinate, two or more plants are required to produce fruit. The red and purple varieties are sweeter than the green and yellow varieties, which tend to taste tarter than the red and purple varieties. Removing the husk increases the amount of time tomatillos can be stored in the refrigerator. Tomatillos can also be frozen.
Some of the exotic foods mentioned above may not be available in all northern Illinois grocery stores and supermarkets. However, many produce managers are happy to order them at a customer’s request. Many exotic fruits and vegetables are also available on the Internet.
Dr. Dom Castaldo is a biology instructor at Sauk Valley Community College in Dixon, Ill. He lives in Mt. Morris and can be contacted via e-mail at firstname.lastname@example.org.
From the Jan. 4-10, 2012, issue