It is well known that heat destroys of the antioxidant potential of most berries, making canned and juicing that involve friction and heat a poor choice to maximize their antioxidant potential.
While intake of raw, fresh, blueberries could be connected with many health benefits - including improved cognitive features, lesser threat of heart disease and less inflammation, thanks to their very high content in highly effective polyphenolic compounds; researched now know that a freshly cooked blueberry does not have the same advantages.
Writing in the Journal of Agricultural and Food Chemistry, researchers described that some techniques of processing, such as conventional juicing and canning, are understood to lesser polyphenol levels by between 22% and to 81%. Nevertheless, the team noted that no studies have actually tested whether using blueberries in muffins, pies or breads affects their polyphenol content.
Led by Ana Rodriguez-Mateos from the University of Dusseldorf, Germany, the study team decided to check the stability of these health-promoting compounds during cooking, proofing (when the dough increases before food cooking) and baking.
"Due to their possible health benefits, a better understanding of the impact of processing is important to maximize the retention of these phytochemicals in berry-containing-products," claimed the analysts, who discovered that all three procedures had mixed results on blueberries' polyphenols including anthocyanin, procyanidin, quercetin and phenolic acids.
Just 300 grams of blueberries is associated with an 18% decrease in DNA damage to blood cells due to oxidative stress. The benefits of blueberry consumption has been demonstrated in several nutrition studies, more specifically the cardio-protective benefits derived from their high polyphenol content.
Berries, and the polyphenols they contain, have previously been reported to have blood sugar management activity, linked to both an inhibition of the digestion of carbohydrate rich foods (for example, by inhibiting starch digesting enzymes alpha-amylase and glucoamylase ), as well as reducing the absorption of carbohydrates in the gut.
The majority of the science, however, has been unsuccessful in testing the depletion of polyphenols in specific processed foods.
Rodriguez-Mateos and her associates uncovered that anthocyanin levels dropped by 10 % to 21 %, while degrees of smaller procyanidin oligomers obtained an improvement and those of the larger ones fell as well. Phenolic acid levels were found to increase while various other substances such as quercetin remained consistent.
The group recommended that the good retention of polyphenols observed in their research may be because of the use of yeast, which may serve as a stabilising agent throughout baking.
Journal of Agricultural and Food Chemistry
Mae Chan holds degrees in both physiology and nutritional sciences. She is also blogger and and technology enthusiast with a passion for disseminating information about health.