There’s a lot more to making juice than simply squeezing some citrus. Fruit juices have come under fire in recent years for a high sugar content, but scientists say the whole picture is not so clear cut.
They found that, although juices reduced the level of carotenoids, vitamin C and flavornoids present, they improved bioaccessibility (how much the body can absorb and use). But that’s not the whole story.
A shocking investigation has revealed that some of the best known brands of apple juice contain arsenic.
American apple juice is made from apple concentrate, 60% of which is imported from China. Other countries may use pesticides that contain arsenic, a heavy metal known to cause cancer and heart disease.
Findings of a Consumer Reports investigation about arsenic and lead levels in apple juice and grape juice have prompted the organization to call for government standards to limit consumers’ exposure to these toxins.
Weaning populations off fruit juice may be difficult. Market research firm Mintel says 83 percent of us drink fruit juice at least once a week, while 76 percent believe fruit juice to be healthy.
Ever wonder why commercial orange juice–even the premium, not-from-concentrate, “100-percent pure” juice kind–tastes the same each time you buy it, but doesn’t taste exactly like a freshly peeled orange?
As part of the mass-production process, big-name brands like Tropicana, Minute Maid, Simply Orange, and Florida’s Natural add artificial flavouring in order to make sure your juice tastes consistent from carton to carton–and to make sure it tastes like oranges.
“It really rocks people’s world to learn that most orange juice is not a fresh product,” says Alisa Hamilton, author of “Squeezed: What You Don’t Want to Know About Orange Juice“
Oranges and their products are rich sources of carotenoids (antioxidants, and a precursor to vitamin A); flavonoids (thought to have antioxidant effects) and vitamin C. They also contain lutein and zeaxanthin, compounds believed to play an important role in preventing age-related macular degeneration (loss of vision) and cognitive impairment in the elderly.
“Consumers perceive orange juice as a healthy and natural source of vitamins and other health promoting nutrients, resulting in an increasing worldwide demand and production,” wrote Ralf Schweiggert, one of the authors in the study published in the Journal of Agricultural and Food Chemistry. “Additionally, the convenient packaging and long shelf life of juices are advantageous compared to fresh fruit.
“Recent intervention studies demonstrated the health benefits of long-term orange juice consumption, such as an increased total antioxidant status, lower total cholesterol levels, and the prevention of endotoxin increases after meals high in fat and carbohydrate.
“However, greater consumption of orange juice has also been criticized because of its high intrinsic sugar level, being associated with a higher risk of type 2 diabetes and cardiovascular diseases.”
Should we concentrate on juice?
Too many natural sugars from fruit without fiber to slow the digestion and absorption down will cause a spike in blood glucose. The pancreas secretes insulin to push glucose into the cells, and when the pancreas overcompensates as a result of a glucose spike, blood sugar will drop.
Overtime, if your pancreas secrets too much insulin often, your cells will stop responding, leading to a condition known as insulin resistance. Fruit juices alone won’t cause insulin resistance, but considering that most Americans eat more sugar and refined carbs than they should and not enough fiber, those juicing should ensure they consume as much fiber as they can if they overconsume refined processed foods.
The study analysed five different orange product types: fresh unprocessed orange segments, homogenized segments (puree), freshly squeezed juice, pasteurized juice, and flash-pasteurized juice.
Orange juice (fresh and pasteurized) showed ‘slightly diminished’ carotenoid and vitamin C levels, by 3-18%. Flavonoid and dietary fiber levels were decreased to approximately one-tenth upon dejuicing.
However, carotenoid bioaccessibility — how easily the body can absorb the nutrients – was enhanced from 10.8% in oranges to 28.3% in freshly squeezed orange juice. Flavonoid bioaccessibility was boosted almost five-fold to 96.5%.
The bioflavonoid hesperidin remained similar across all test foods.
“The lower flavonoid levels in orange juices as compared to orange segments might be less relevant regarding their intestinal absorption, because low flavonoid solubility in the digestive fluids is considered to be the limiting factor.”
Orange juice makes a good example of the health difference when you focus on the issue of its pulp. The white pulpy part of the orange is the primary source of its flavonoids. The juicy orange-colored sections of the orange contain most of its vitamin C.
In the body, flavonoids and vitamin C often work together, and support health through their interaction. When the pulpy white part of the orange is removed in the processing of orange juice, the flavonoids in the orange are lost in the process.
This loss of flavonoids is one of the many reasons for eating the orange in its whole food form (even if you only end up eating a little bit of the white pulpy part). Although many commercial products will say “pulp added” on their labels, the “pulp added” many not even be the original pulp found in the whole fruit, and it is highly unlikely to be added back in the amount removed.
Researchers add that mashing orange segments did not alter carotenoid bioaccessability, suggesting that processing fiber is more significant.
“In contrast to dejuicing, homogenization of orange segments to a puree did not enhance carotenoid bioaccessability. This indicates a minor role of cell disruption and comminution, compared to the removal of fibers in orange products.”