Researchers have developed novel black raspberry-based functional foods that can withstand the rigors of a large-scale cancer prevention trial.

Black raspberries- not to be confused with the more recognizable red variety - have piqued the interest of cancer scientists in the last decade due to research showing they have distinct antioxidant and anti-inflammatory properties that appear to inhibit tumour growth.

But the berries are only grown in a few places around the US, and like many of their berry cousins, must be refrigerated and eaten within a few days of picking.

"We set out to create a product that had the same level of quality and stability you would find in a pharmaceutical medicine, but that was 100 percent fruit, simple to take and retained high levels of chemopreventive bioactives," said Yael Vodovotz, PhD, a food scientist with The Ohio State University Department of Food Science and Technology, said.

The result was two different formulations - gummy candies and a concentrated fruit juice (nectar) - each roughly equal to a cup of fresh berries. Both formulations were created by freeze drying the berries, which helped preserve the essential nutrients, and then grinding the whole berry - fiber, seeds and fuzz - into a fine powder.

The black raspberry formulations are currently being used in a clinical study of men with prostate cancer undergoing surgery.

The researchers hope to see if the black raspberry preparations, coupled with different types of diets, can improve post-surgery outcomes versus a control group of men with diet interventions only.

The study was published in the journal of Agriculture and Food Chemistry.