A team of scientists from the Agricultural Research Service of the United States Department of Agriculture, led by Dr. Lisa Dean, has developed a milk chocolate with peanut skin that is cheaper and has a sweeter flavour and at least as many antioxidant properties as dark chocolate.
The study, which was presented this August at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo, states that thousands of tonnes of peanut shells are discarded every year, which is a shame since they contain 15% phenolic compounds by weight with high potential for antioxidant bioactivity.
In order to make milk chocolate fortified with antioxidants, Dean and her team ground the peanut skins into powder and extracted the polyphenols with 70% ethanol. Later, they combined this powder with maltodextrin to facilitate its incorporation into the chocolate.
From here, the goal was to ensure that this phenolic powder did not alter the usual flavour of milk chocolate. For this, they conducted different tests with samples that contained from 0.1% to 8.1% of phenol concentrations, reaching the conclusion that up to 0.8% is undetectable on the palate.
Although these results are very promising, this chocolate is not yet on the market. And since peanuts are allergenic, researchers are also going to explore the use of coffee grounds, tea leaves and other food waste.