Gedroogde pruimen als conserveermiddel en tegen botontkalking*
Uit twee studies blijken de grote voordelen van gedroogde
pruimen. Uit de ene studie blijkt dat gedroogde pruimen een uitstekend en natuurlijk conserveermiddel van vlees en vleeswaren is. In de andere studie, weliswaar met muizen blijkt dat de bioactieve stoffen in gedroogde pruimen zorgen voor aanmaak van nieuwe botcellen en het ontstekingscytokine, TNFα doen neutraliseren waardoor het ontstekingsproces wordt afgeremd.
Dried Plums: An Effective Natural Alternative to Synthetic Preservatives
Dried plums (prunes) are just as effective as synthetic preservatives at preventing the oxidative deterioration of ready-to-eat meat products, according to a study conducted by researchers from Venezuela's University of Oriente and Texas A&M University, and published in the Journal Food
Science.
The market for long-used synthetic preservatives such as butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT) continues to decline as consumers demand more natural food ingredients, while the market for natural antioxidant preservatives such as herb extracts or vitamins C and E continues to grow.
Researchers used raw pork pate to prepare sausages using a variety of preservative methods: 0.02 percent BHA/BHT, 3 or 6 percent dried plum puree, 3 or 6 percent dried plum and apple puree, or a control sausage with no preservative at all. The sausages were then refrigerated raw; cooked, vacuum packed and then refrigerated; or cooked, vacuum packed and then
frozen.
At both concentrations, dried plum was as effective at preserving the cooked sausages as BHA/BHT. At 6 percent, it was actually more effective at preventing the oxidation of fats in refrigerated meat. This concentration caused noticeable discoloration of the sausage, however - increased yellowness for both purees, as well as increased redness for the dried plum-only puree.
Trained taste testers concluded that the purees masked the flavors of pork fat and sage, as well as spicy or peppery flavors. The purees increased the sausages' sweetness, and decreased their saltiness and bitterness. At concentrations of 3 percent however, these flavor changes were not
objectionable.
"Overall, pork sausage with 3 percent dried plum puree or dried plum and apple puree was as acceptable to consumers as the control or those patties with BHA/BHT," the researchers wrote. They suggested that dried plum could also function as a preservative in other pre-prepared meat products, such as roast beef or ham.
The study was funded by Texas AgriLife Research and the California Dried Plum Board.
Polyphenols in Dried Plums Reduce Risk of Osteoporosis
The naturally occurring polyphenols in dried plums (prunes) may encourage bone formation and reduce the risk of osteoporosis, according to a study conducted by researchers from Oklahoma State University and the University of Oklahoma Health Sciences, and published in the Journal of Nutritional Biochemistry.
Polyphenols are naturally occurring plant compounds known to have antioxidant and other health benefits.
Researchers incubated mouse cells in concentrations of zero, five, 10 and 20 micrograms per milliliter of dried plum polyphenols. Twenty-four hours later, some of the cells were treated with 1.0 nanograms per milliliter of tumor necrosis factor-alpha (TNF-alpha).
TNF-alpha is a chemical, naturally produced by the body that is known to inhibit the activity of bone-building osteoblast cells.
Both in the presence and absence of TNF-alpha, the dried plum polyphenols caused mouse cells to produce more chemicals linked to the process of bone formation. The polyphenols also counteracted the negative effects of TNF-alpha on the
cells.
"We have demonstrated that dried plum polyphenols effectively enhance osteoblast activity and mineralization under normal and inflammatory conditions," the researchers wrote. "The findings of this study suggest that the polyphenols in dried plum are at least in part responsible for the anabolic effects of dried plums reported in previous animal studies."
Prior studies have shown that dried plums, and particularly the polyphenols from dried plums, have benefits for bone health, but little research has previously been conducted into the mechanisms by which this effect
operates.
And estimated 75 million people in the United States, Europe and Japan suffer from osteoporosis. Many of these are treated using drugs with the potential for long-term side effects.
"It is possible that dietary consumption of dried plums could serve as a source of polyphenolic compounds that favorably modulate both bone formation and resorption, and provide a natural alternative for individuals at risk of osteoporosis," the researchers
wrote. (Januari
2009)
