How is prune juice produced?

Introduction

Prune juice is a popular beverage made from dried plums, also known as prunes. It has a unique sweet yet tart flavor and is known for its potential health benefits. Prune juice production involves multiple steps, from growing and harvesting plums to drying them into prunes and finally extracting the prune juice. In this article, we will explore the detailed process of how prune juice is made.

Growing Plums

Most prune juice sold commercially is made from a variety of plums known as Prunus domestica. The majority of plums used for prune production are grown in California, as the state provides an ideal climate for plum cultivation.

There are over 2,000 plum varieties, but the main types used for prune production include French, Imperial, Sugar, and Moyer. These varieties are preferred for their high sugar content, which aids in the drying process. Plums are grown on orchards, with trees typically spaced 15-20 feet apart.

It takes approximately 4-7 years for plum trees to reach maturity and begin fruiting. Once mature, trees are pruned and fertilized annually to promote fruit production. The trees blossom in early spring, and plums are ready for harvest in late summer. Plums are handpicked when they reach optimum ripeness and sweetness.

Drying Plums into Prunes

After being harvested, plums undergo a process known as dehydration to be turned into prunes. There are several methods used to dehydrate plums:

Sun Drying

This traditional method involves spreading harvested plums out on trays under the sun for 2-3 weeks. The plums are turned periodically to ensure even drying. Sun drying causes the plums to lose approximately 80% of their moisture content, concentrating the sugars and resulting in prunes.

Hot Air Dehydration

Plums are placed on perforated trays in large dehydration chambers and exposed to streams of hot, dry air for 18-36 hours. Temperature and air flow are controlled to optimize moisture removal. This is a faster and more efficient method than sun drying.

Continuous Tunnel Dehydration

In large commercial productions, plums move on conveyor belts through long insulated tunnels while warm air circulates to dehydrate the fruit. Tunnel temperatures reach 165°F-185°F to facilitate quick moisture removal. The fruit emerges shriveled and condensed into prunes.

Once dehydrated, prunes are graded based on size, inspected for quality, and prepared for packaging. The best prunes are reserved for prune juice manufacturing.

Extraction of Prune Juice

There are two main methods used to extract juice from prunes:

Hot Water Extraction

Prunes are soaked and cooked in hot water, usually around 190°F, for several hours, allowing the juice to infuse into the water. The softened prunes are then pressed to squeeze out the liquid. The extracted juice contains suspended pulp and solids. It is filtered, pasteurized, and homogenized. The solution is concentrated under vacuum conditions to intensify flavors before being bottled.

Cold Pressed Extraction

Prunes are soaked overnight in water and then ground into a pulp. The pulp is pressed through a filter which squeezes out the juice while leaving behind most of the solids. The filtered juice is pasteurized and bottled. This cold pressing preserves more of the raw fruit flavor. However, the yield is lower.

Ingredients in Prune Juice

The main ingredients in prune juice are:

Ingredient	Role
Prune juice concentrate	Provides signature prune flavor, natural sugar, and essential nutrients
Water	Rehydrates the concentrate into liquid juice form
Potassium sorbate	Preservative to inhibit mold and bacteria growth
Ascorbic acid	Vitamin C added to boost the nutrient profile

Other optional ingredients like viscosity stabilizers, natural flavors, and citric acid may be added. The juice concentrate usually constitutes around 70% of the final product.

Nutritional Content in Prune Juice

Prune juice is packed with beneficial nutrients and minerals:

Nutrient	Per 8 oz Serving
Calories	182
Total Carbohydrates	45g
Dietary Fiber	3g
Protein	1g
Vitamin A	2% DV
Vitamin C	3% DV
Iron	3% DV
Potassium	8% DV
Copper	6% DV
Manganese	4% DV

DV = Daily Value

Prune juice is high in antioxidants, particularly polyphenols, which can help reduce inflammation and protect cells from damage. It contains the minerals potassium and copper which are important for heart health, nerve transmission, immunity, and metabolism. The juice is also a good source of vitamin C and fiber.

Health Benefits of Prune Juice

Some of the key health benefits associated with drinking prune juice include:

• Relieving Constipation – Prune juice is widely used as a home remedy for constipation, owing to its laxative effects. The high fiber and sorbitol content add bulk to stools and draw water into the intestines, stimulating bowel movements.
• Supporting Bone Health – The potassium, vitamin K, and polyphenols in prune juice promote bone strength and density, reducing risk of osteoporosis.
• Aiding Blood Circulation – Iron, copper, and vitamin C in prune juice facilitate red blood cell formation and improve blood flow.
• Lowering Blood Pressure – With high potassium levels, prune juice can help vasodilate blood vessels and counteract sodium effects, lowering blood pressure.
• Controlling Blood Sugar – Despite its sweet taste, studies show prune juice has a low glycemic index that does not spike blood sugar levels.
• Boosting Immunity – The antioxidants and vitamin C content of prune juice enhance the body’s immune defenses.

However, prune juice is high in natural sugar so intake should be moderated for people with diabetes or those watching their sugar intake. Some also complain of gastrointestinal side effects like gas or diarrhea if consuming too much. Overall, prune juice is a healthy beverage when enjoyed in moderation.

How to Select Prune Juice

When buying prune juice, look for:

• 100% pure or concentrated prune juice, without added fillers or unnecessary ingredients
• Juice made from whole prunes, not extracts or powders
• Bottles stored in dark glass to protect against light damage
• USDA Organic certification or indication that no preservatives/additives are used
• Refrigerate after opening for maximum freshness

Avoid prune juice products with added sweeteners. Check the ingredient list for any additives or preservatives you want to avoid.

How to Enjoy Prune Juice

Prune juice has a unique sweet-tart taste. Here are some tips for enjoying it:

• Drink chilled from the fridge for a refreshing beverage
• Pour over ice cubes in a glass and enjoy slowly like a fine wine
• Mix with soda water or sparkling water for a bubbly drink
• Blend with Greek yogurt, cinnamon, and ice for a smoothie
• Use as a base for cocktails, combined with vodka or rum
• Drizzle over oatmeal or pancakes instead of syrup
• Substitute for oil or butter in baking recipes like cakes and muffins

Start with 4-8 oz serving and adjust amount based on your taste preferences. The tart, deep flavor profile makes prune juice an intriguing ingredient.

Conclusion

Prune juice is made through a complex process that starts with cultivating plums and dehydrating them into prunes before extracting the nutrient-rich juice. The final product delivers a concentrated source of antioxidants, potassium, vitamin C and fiber that can provide constipation relief, improve bone health, lower blood pressure and cholesterol, and boost immunity. When buying and enjoying prune juice, look for 100% pure, additive-free varieties and experiment with different serving methods. In moderation, this unique beverage can be a great addition to a healthy diet.