Aussie soldier essentials

Australian defence scientists are developing a dark chocolate for soldiers that does not melt in extreme desert heat and lasts for years.

While normal chocolate melts at around 25 to 30 degrees Celsius, the Defence Science and Technology Organisation (DSTO) says the new chocolate will be expected to keep its shape despite extended periods at over 49C.

DSTO food technologist Dr Lan Bui says the research team is substituting existing fats in the chocolate with other fats that have higher melting points to reduce the chance of the chocolate melting.

Combat ration packs must supply soldiers with their daily nutrition needs without weighing too much, yet be varied to make the daily menu interesting. Soldiers' chocolate is fortified with vitamins A, C and B1 (thiamine) but extreme heat or humidity can melt it, change its texture and flavour, and reduce the stability and effectiveness of its vitamins.

"Ration chocolate has a longer shelf life, is more stable compared to other chocolate and is also fortified with vitamins," DSTO food technologist Dr Bui said. "It's a bit firmer but the flavour is nice."

The researchers are also developing ways to keep the vitamins in the chocolate fresh until it is eaten, possibly years later.

Dr Bui, who is based in Scottsdale, Tasmania, says they are working with university researchers and the food industry to micro-encapsulate vitamins in hydrocolloids, such as gum arabic.

She says the coating keeps out heat, humidity, moisture and oxygen, and allows the vitamins to be slowly released into the body. Another part of the research is making sure the chocolate's flavour lasts longer.

Dr Bui says the aim is to ensure the coated vitamins and flavour stay stable up to 48C. She says sensory evaluations suggest the new chocolate still tastes, looks and feels good in the mouth.

The team is also developing less permeable packaging to help extend the chocolate's shelf life.