Reaching for Raspberries

Raspberries are the edible fruits of several species in the genus Rubus. They belong to the Rosaceae family, which includes strawberriesblackberries, plumsapricotspeachescherriesquinces, apples, nectarines, almonds,  pears, and ornamental trees and shrubs (such as roses, meadowsweets, photinias, firethorns, rowans, and hawthorns). Within the raspberry family there are two major types, the red raspberry and the black raspberry. There is also a purple raspberry which is a cross between the red and black raspberries and a yellow raspberry which is a genetic mutation that occurs in red raspberries. Among these types there are 200 different varieties of raspberries.

Wild raspberries grow on at least five continents, and there is a great deal of diversity in raspberry species. Some arctic species of raspberry are native to Alaska, the Aleutian Islands, and northern Asia; other species are native to eastern Asia and the Hawaiian islands; still others are native to Europe or to North America. The red raspberry may have been brought to North America by prehistoric people who crossed the Bering Straight and then introduced them to North America, although the wild black raspberry is believed to be native to the western hemisphere.

Archaeological evidence shows that Paleolithic humans ate raspberries, and they have been a part of the human diet ever since. There is evidence of their first cultivation dating back about 2,000 years in Europe, making raspberries one of the earliest berry crops.

In the Hellenistic period (323 BC–31 BC), raspberries were associated with fertility. In Greek mythology, the berries were once white but when Zeus’ nursemaid, Ida, pricked her finger on a thorn, it stained the berries red and they have remained so ever since. The scientific name for red raspberries, Rubus idaeus, means literally “bramble bush of Ida”, both for the nursemaid and the mountain where they grew on the island of Crete.

Roman writer Rutilius Taurus Aemilianus Palladius mentions raspberries in his book on agriculture, Opus agriculturae, sometimes known as De re rustica.

Raspberry plants were valued for their sweet berries, but even more for their leaves, which people have long used as medicine.  People still use the leaves in herbal teas or infusions to sooth the digestive system and to help soothe menstrual cramps. The popularity of raspberries as food and medicine continued well into the middle ages, when its juice was also used as a red stain in art work.

The 13th-century English king, Edward I, encouraged the cultivation of raspberries throughout England.

European settlers brought raspberry canes with them to America and continued their cultivation. They also crossed the red raspberries with the native black raspberries. By 1771, William Price sold the first cultivated stock in Virginia. George Washington cultivated raspberries at Mount Vernon. After 1755, Henry Laurens, who lived in Charleston, South Carolina and served as a President of the Continental Congress, introduced olives, limes, ginger, everbearing strawberry, red raspberry, and blue grapes into the United States. By the time of the Civil War, there were at least 40 known varieties of raspberries in North America.

Today, raspberries rank high on the list of the world’s most popular berries. Among the 400,000 metric tons of raspberries produced worldwide, Russia, the United States, Serbia, Poland, and Chile rank among the top producers. Raspberries are grown commercially in most of the United States, but the state of Washington has a perfect growing climate for the berries and leads the way with 70 million tons per year in production. Raspberries are also an important crop in Oregon, California, and much of the Midwest. Raspberries will actually grow as far north as the Arctic circle and can be grown even in tropical regions, though they prefer a cooler climate. Well over 500 organic farms in the U.S. are now certified for organic raspberry production, and raspberries rank as the third most popular fresh-use berry in the U.S. following strawberries and blueberries. The United States also imports about 15,000 metric tons of raspberries from Mexico.

Raspberries have high levels of phenolic flavonoid phytochemicals such as anthocyanins, ellagic acid (tannin), quercetin, gallic acid, cyanidins, pelargonidins, catechins, kaempferol and salicylic acid. Gallic acid in raspberries is an antioxidant, has antimicrobial properties, and helps regulate cellular communication. Pelargonidin in raspberries acts as an antioxidant and protects your body’s cells from dangerous free radicals, keeps your heart healthy, and prevents cancer, diabetes, and neurodegenerative disorders. Proanthocyanidins in raspberries improve insulin sensitivity and reduce free radical formation and the signs and symptoms of chronic age-related disorders. Catechins in raspberries are potent antioxidants that can prevent tumor blood vessel growth, protect against the development of atherosclerotic plaque buildups in arteries, help promote anti-diabetic effects in insulin resistance, and provide significant protection against Parkinson’s and Alzheimer’s diseases. The antioxidant compounds in these berries have potential health benefits against cancer, aging, inflammation, and neuro-degenerative diseases. Raspberries can:

  1. Fight free radicals. Fresh raspberries are an excellent source of vitamin C, which is a powerful natural antioxidant. Just 100 grams of raspberries provides 26.2 milligrams or 44% of the Daily Value (DV) of vitamin C, which helps your body develop resistance against infectious agents, counter inflammation, and scavenge harmful free radicals. Raspberries are also high in manganese, which your body uses as a co-factor for the antioxidant enzyme, superoxide dismutase. They are also also rich in several flavonoid poly phenolic antioxidants such as lutein, zea-xanthin, and beta-carotene in small amounts. Ellagic acid in raspberries directly inhibits the DNA binding of certain carcinogens, and acts as an antioxidant by reducing oxidative stress. Altogether, these compounds help act as protective scavengers against oxygen-derived free radicals and reactive oxygen species (ROS) that play a role in aging and various disease processes.
  2. Fight inflammationThe phytochemical ellagic acid in raspberries is a powerful anti-inflammatory compound. It helps prevent overactivity of certain pro-inflammatory enzymes (including cyclo-oxygenase 2, or COX-2) as well as their overproduction. Ellagic acid can reduce chronic inflammation, including that associated with Crohn’s disease.
  3. Prevent obesity. Raspberry ketone (also called rheosmin) is a compound that naturally occurs in raspberries, and in some other plants. The chemical name for raspberry ketone is 4-(4-hydroxyphenyl) butan-2-one. Researchers are equally familiar with raspberry ketone under the name of rheosmin, and since 1965, it’s been included on the Food and Drug Administration’s (FDA’s) Generally Recognized As Safe (GRAS) list as an approved food additive. The primary use of rheosmin as a food additive for flavor and aroma. The rheosmin found in raspberries can increase metabolism in your fat cells by increasing enzyme activity, oxygen consumption, and heat production in certain types of fat cells. By boosting fat metabolism in this way, you may be less likely to deposit fat in your fat cells, and you may be able to use up some of the fat that is stored there. By improving your fat cell metabolism, you may also be able to reduce the number of pro-inflammatory messaging molecules that are produced by your fat cells. As a result, you may be less likely to experience some of the inflammation-based problems that typically accompany obesity. In addition to these benefits, rheosmin found in raspberries can also decrease activity of a fat-digesting enzyme called pancreatic lipase that is produced by your pancreas. By decreasing the activity of this enzyme, you may digest and absorb less fat, which is another potential plus when trying to deal with the consequences obesity.
  4. Regulate blood sugar and blood fatTiliroside, a type of flavonoid (called a glycosidic flavonoid) in raspberries, activates a special hormone called adiponectin that is produced by your fat cells. (The “adipo” part of this word means “fat,” which is also why your fat cells are also called “adipocytes.”) In obese people with type 2 diabates, adiponectin is not produced in sufficient amounts or, if adequately produced, remains too inactive, which makes them unable to regulate their blood sugar and blood fats. By activating adiponectin, the tiliroside in raspberries can help improve insulin balance, blood sugar balance, and blood fat balance in obese persons with type 2 diabetes. Raspberries can also block the activity of alpha-glucosidase, a starch-digesting enzyme that increases the breakdown of starches into sugars. These sugars get absorbed up into the bloodstream and can cause excessively high levels of blood sugar following a meal. (This process is called postprandial hyperglycemia.) By blocking activity of alpha-glucosidase, raspberries may make it possible for people with type 2 diabetes (or obese persons experiencing problems with blood sugar regulation) to better manage their blood sugar levels. Xylitol, a low-calorie sugar alcohol in raspberries, absorbs more slowly in your intestines than sugar and does not contribute to blood sugar fluctuations.
  5. Fight cancerChronic oxidative stress and chronic inflammation can combine to trigger the development of cancer cells in a variety of human tissues. By providing a rich supply of antioxidants, raspberries can help lower your risk of oxidative stress, and by providing a rich supply of anti-inflammatory nutrients, raspberries can help lower the risk of excessive inflammation. When combined, these results mean decreased risk of cancer formation, especially in the breast, cervix, colon, esophagus, and prostate. The phytochemicals in raspberries like ellagitannins may be able to decrease cancer cell numbers by sending signals that encourage the cancer cells to being a cycle of programmed cell death (apoptosis). This signaling is likely to involve the p53 protein that is typically classified as a tumor suppressor protein. The phytochemicals in raspberries may use a protein complex called nuclear factor kappa B (NFkB) to trigger signals that encourage non-cancerous cells to remain non-cancerous.
  6. Promote bone and blood health. Raspberries are a good source of vitamin K, offering 10% of the DV in 100 grams. Your body uses vitamin K for blood clotting and to aid the absorption of calcium.

Raspberries are low in calories and saturated fats, but are rich source of fiber and antioxidants: 100 grams of raspberries contain just 52 calories but provide 6.5 g of fiber (16% of Daily Value).

Nutrients in 100 Grams Raw Raspberries (Rubus idaeus

Nutrient

Amount

Daily Value

vitamin C

26.2 mg

44%

manganese

0.67 mg

34%

fiber

6.5 g

26%

vitamin K

7.8 µg

10%

biotin

1.8 µg

5.1%

folate

21 µg

5%

magnesium

22 mg

5%

carbohydrates

11.94 g

4%

vitamin E

0.97 mg

4%

potassium

151 mg

4%

copper

0.09 mg

4%

iron

0.69 mg

4%

niacin

0.598 mg

3%

pantothenic acid

0.3 mg

3%

phosphorus

29 mg

3%

zinc

0.42 mg

3%

vitamin B6

0.1 mg

3%

Calories

52

2.6%

protein

1.2 g

2%

riboflavin

0.038 mg

2%

thiamine

0.032 mg

2%

calcium

25 mg

2%

fat

0.65 g

1%

vitamin A

33 IU

1%

sodium

1 mg

0.04%

selenium

0.2 µg

0.5%

cholesterol

0 mg

0%

beta-carotene

12 µg

alpha-carotene

16 µg

lutein-zeaxanthin

136 µg

In the United States, raspberries fresh and plentiful from mid-summer through early fall. If you are lucky enough to grow your own raspberries (or you know where they grow in the wild), harvest them when they come off the receptacle easily and have turned to deep color (red, black, purple, or golden yellow, depending on the species and cultivar).

In the store or at the farmers market, select berries that are firm, plump, deep in color, and free of sand and mold. Avoid those that appear soft, mushy, moldy, dull, sunken, flattened, bruised or discolored patches. If you are buying berries prepackaged in a container, make sure that they are not packed too tightly, since this may cause them to become crushed and damaged, and that the container has no signs of stains or moisture, indications of possible spoilage.

Raspberries are highly perishable. If you do not plan to eat your raspberries immediately, remove any berries that are molded or spoiled so that they will not contaminate the others. Place the unwashed berries in their original container or spread them out on a paper towel inside of a container that has a lid and can be sealed, and place them in the refrigerator, where they will keep fresh for only one or two days. Do not leave raspberries at room temperature any longer than necessary (one to two hours), and avoid placing them directly in strong sunlight.

Raspberries freeze very well. Wash them gently using the low pressure of the sink sprayer so that they will maintain their delicate shape and then pat dry. Arrange them in a single layer on a flat pan or cookie sheet and place them in the freezer. After they are frozen, transfer the berries to a freezer container that can be sealed and return them to the freezer where they will keep for up to one year.

As raspberries are very delicate, wash them very gently, using the light pressure of the sink sprayer if possible, or dip them in cold water in a large bowl for few seconds and swish gently few times to remove any sand and insecticide residues. Gently pat them dry using paper towel or cloth. This method will help bring them to normal room temperature, and so also increases their flavor and enriches the taste. Wash them right before eating or preparing a recipe so that they do not become water-soaked and are not left at room temperature for too long. Do not use any berries that are overly soft and mushy unless you will be pureeing them or blending them.

Here are some serving tips:

  • Enjoy fresh raspberries as a snack between meals.
  • Add fresh raspberries to fruit salads or green salads, especially when dressed with balsamic vinegar.
  • Add raspberries to pastries. 
  • Add raspberries to non-dairy ice cream, shakes, smoothies, or yogurts.
  • Mix fresh raspberries in with porridge (oat, millet, etc.) for a breakfast treat.
  • Mix raspberries with plain soy yogurt, agave syrup, and freshly chopped spearmint, and eat it as-is or use it to top top waffles or pancakes.
  • Make a raspberry coulis to serve over savory dishes like chickpea cutlets or sweet desserts.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s