Fortifying dried fruit pieces like apple with green tea extracts may boost the antioxidant content of the finished product by four-fold, suggests a joint study from the US and Italy.
Addition of the green tea extract to dried apple pieces also did not affect the colour of the fortified product, with the green tea compounds potentially preventing undesirable browning, according to new findings published in the Journal of Food Science.
“The novel green tea-apple product would be advantageous for two reasons,” wrote the researchers from the University of Milan and the University of Georgia. “[Firstly,] from an economic point of view, it would provide a greater variety of dehydrated apple products available in the marketplace, and [secondly] from a nutritional perspective, since apple consumption is very high throughout the world, this novel product could offer consumers a simple opportunity for regular consumption.”
According to recent report from Frost & Sullivan, the market for green tea extracts, currently worth around $44m (€29.7m), is expected to grow by more than 13 per cent over the next seven years.
The F&S analysts state that science is the reason for the ingredient's growing popularity, and that it is generally accepted that green tea has a beneficial role in reducing Alzheimer's, certain cancers, cardiovascular and oral health.
Led by Vera Lavelli, the researchers fortified dried apple pieces with green tea extract (Java Green Tea, Twinings of London) at a level equivalent to the green tea catechin content of four cups of green tea.
Antioxidant levels, measured using the ferric reducing/antioxidant power (FRAP) and 2,2-diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl radical (DPPH) scavenging capacity assays, showed a four-fold increase, compared to non-fortified apple pieces, said the researchers.
Furthermore, these antioxidant levels remained almost unchanged during storage at 30 °C for one month. “The GT-fortified product retained 80 and 100 per cent of the initial contents of the monomeric flavan 3-ols and total procyanidins, respectively,” said the researchers.
In terms of the appearance of the apple pieces, the researchers note that the colours of the green tea-fortified product and a commercially available dehydrated apple product were similar.
“Results highlighted some advantages of using dehydrated apples as a target for green tea fortification, which deserve further trials to investigate potential applications for fortification of other dehydrated fruits,” they concluded.
Source: Journal of Food Science
Published online ahead of print, doi: 10.1111/j.1750-3841.2009.01489.x
"Formulation of a Dry Green Tea-Apple Product: Study on Antioxidant and Color Stability"
Authors: V. Lavelli, C. Vantaggi, M. Corey, W. Kerr