Plants on your plate: Rhubarb

by Denise Sullivan,
​Nutrition & Health Education Specialist, MU Extension-Jackson County

            The month’s plant is another example that begs the question ‘is it a vegetable or fruit’? Botanically speaking, rhubarb is a considered a vegetable, though it is more commonly used as a fruit in culinary preparations such as desserts or sweet spreads -- with a fair amount of sugar added. To add to the confusion, in 1947 the U.S. Customs court in Buffalo, N.Y., legally classified rhubarb as fruit.
            Though the origin of rhubarb is uncertain, it was commonly used in Asia over 2,000 years ago for its medicinal qualities. It was not until the 18th century that rhubarb was grown for culinary purposes in Britain and America. Rhubarb is a perennial plant in the Polygonaceae family, more commonly known as buckwheat. Rhubarb leaves contain a toxic compound that acts as a natural insecticide. This is the reason that the leaves are not fit for human consumption and only the rhubarb stalk is edible. Rhubarb ranges in color from light green to deep red depending on the variety, with a texture that is resemblant of celery. Typically, the deeper red a rhubarb stalk is, the less tart it will be.
            Rhubarb is a nutrition powerhouse, with over 40 nutrient compounds present. A 1 cup serving provides about 25% of the daily value of Vitamin K, as well as Vitamins A and C, potassium, and dietary fiber, with under 30 calories. The high level of vitamin K should be considered by anyone on blood thinners, as it can intensify the effects of the medication. Beyond the vitamins and minerals, numerous phytochemicals provide additional health benefits including anti-inflammation and aiding in the prevention of cardiovascular disease and cancer. Rhubarb also contains about 15% of the daily value of calcium, however not in a form that is readily absorbed by the body. Calcium oxalate, the form found in rhubarb, may lead to the buildup of oxalate crystals in different organs, including the kidneys, which can increase risk of kidney stones.
            Rhubarb’s high acidity, which is atypical for vegetables, is mostly due to malic acid. Malic acid is one of the most abundant acids in plants and contributes to the sour taste of many fruits and vegetables. For this reason, rhubarb can be safely processed as a high acid food using a boiling water bath process, as opposed to the pressure canned process required for most vegetables.
            Rhubarb’s tart flavor requires a sweet helper and strawberries are a popular choice (and a personal favorite of mine) but the use of blueberries in the recipe below results in an exquisite blend of colors, flavors, and textures.


Rhubarb & Blueberry Crisp
(makes 9 servings)
 
Topping
1/4 cup packed brown sugar
1/2 cup all-purpose flour
1/2 cup old fashioned rolled oats
2 tablespoons ground flax seed
1/4 cup margarine or butter, melted
 
Fruit Filling
3 cups chopped rhubarb
3 cups blueberries
2 tablespoons cornstarch
1/2 cup sugar
1 teaspoon cinnamon
1 cup 100% apple juice
1 teaspoon vanilla
 
Directions

1. Wash hands with soap and water.
2. Preheat oven to 350 degrees F.
3. In a medium bowl, stir together brown sugar, flour, oats, and flax seed. Mix in the margarine or butter and set aside.
4. Spread the rhubarb and blueberries in an 8x8-inch baking dish and set aside.
5. In a medium saucepan, mix cornstarch, sugar, and cinnamon until combined. Stir in the juice and cook over medium heat, stirring all the time, until the mixture has thickened. Turn off the heat.
6. Stir in vanilla and pour the mixture over the rhubarb and blueberries.
7. Crumble oat mixture on top of the fruit.
8. Bake for 45 minutes or until topping is browned and fruit is bubbling at edges. Serve warm or cold.

 
Nutrition information: Calories: 185, Total Fat: 6.7g, Saturated Fat: .9g, Sodium: 65mg, Carbohydrates: 31g, Fiber: 3.5g, Protein: 2.5g
 
Recipe adapted from MyPlate Kitchen, analyzed by verywellfit.com