Does fresh juice lose nutrients over time?
Juicing fresh fruits and vegetables into nutrient-rich beverages has become an increasingly popular health trend. Proponents claim that drinking fresh juice provides a concentrated dose of vitamins, minerals and antioxidants. However, there are concerns that the nutrients in fresh juice may degrade over time. This article examines whether fresh juice loses nutrients after it has been made and provides tips for maximizing nutrition when making and storing juice.
How Juicing Affects Nutrients
When you juice fresh produce, the process ruptures cell walls and releases nutrients into an aqueous solution. This allows you to consume the vitamins, minerals, and phytochemicals in their raw, natural state. However, once these nutrients are exposed to air, heat, and light, they begin to degrade through oxidation and enzymatic breakdown. Over time, some nutrients like vitamin C and phytochemicals can be completely destroyed.
Juicing removes the produce’s natural fiber content, which also eliminates a protective barrier for the nutrients. Without intact cell walls, the nutrients are more exposed to environmental degrading factors.
Finally, juicing concentrates the natural sugars in produce. This gives a boost of carbohydrates but creates an environment conducive to microbial growth. Spoilage microorganisms can further damage nutrients as juice starts to ferment.
Nutrient Loss Over Time
So how quickly do nutrients actually breakdown in fresh juice? This depends on the specific nutrient, storage conditions like temperature and light exposure, and properties of the juice like acidity.
In general, most minerals like potassium, calcium, iron and zinc remain stable in juice over time. Fat-soluble vitamins like A, E, D, and K are also relatively shelf-stable.
However, water-soluble vitamins are more sensitive. Vitamin C in particular degrades rapidly, especially when exposed to air, light, and heat. One study found a 24% loss of vitamin C in orange juice stored at room temperature for 6 days. Refrigeration helps slow degradation. Still, substantial Vitamin C loss can occur in just a few days. Other water-soluble B vitamins like folate and thiamine are also vulnerable to breakdown.
| Nutrient | Loss at Room Temperature | Loss Refrigerated |
|---|---|---|
| Vitamin C | 70% | 50% |
| Folate | 5-10% | Minimal |
| Vitamin A | Minimal | Minimal |
Phytochemicals like polyphenols and carotenoids also break down over time, especially when exposed to heat and light. One study found the carotenoid compounds in carrot juice declined by 13-28% after 8 weeks refrigerated storage.
Tips to Maximize Nutrition
To get the most nutritional bang for your buck when juicing, follow these tips:
- Use produce at peak ripeness
- Wash thoroughly but don’t soak produce
- Juice right before drinking
- Store juice in airtight, opaque containers
- Refrigerate juice immediately
- Drink juice as soon as possible, within 1-2 days
- Add a squeeze of lemon juice to help preserve vitamin C and slow microbial growth
How Juicing Compares to Whole Produce
It’s also important to note that while juice offers a convenient way to increase your produce intake, it may not provide the full spectrum of nutrients available from whole fruits and vegetables.
Some studies have found that polyphenols and carotenoids are more bioavailable from whole produce compared to juice. The fiber content of whole produce also provides important benefits like improved gut health and blood sugar regulation.
For a given amount of produce, juice ends up containing only a fraction of the overall nutrients. One analysis found that 240 mL of juice made from 480 grams of fruit or vegetables only provided 22% of polyphenols, 17% of carotenoids, and 43% of vitamins.
| Nutrient | Whole Produce | Juice from 480g Produce |
|---|---|---|
| Polyphenols | 100% | 22% |
| Carotenoids | 100% | 17% |
| Vitamins | 100% | 43% |
For maximum nutrition, eating whole fruits and vegetables in their entirety should be prioritized. But juicing can be a tasty way to supplement your produce intake, especially if you use juices immediately after making them.
Conclusion
Fresh juice provides an easy way to ingest a concentrated dose of nutrients from fruits and vegetables. However, juicing ruptures cell walls and exposes nutrients to degradation over time. Water-soluble vitamins like C and phytochemicals are particularly prone to breakdown, especially when juice is stored at warmer temperatures and exposed to air and light.
To maximize nutrition, drink juice as soon as possible after juicing. Refrigerate juices immediately in opaque, airtight containers and consume within 1-2 days. Adding lemon juice can also help preserve nutrients. Keep in mind that juice generally contains a lower amount of overall nutrients compared to the whole produce. For the full spectrum of benefits, continue emphasizing whole fruits and vegetables in your diet.