‘Cool’ research to keep food fresh

RETAINING food quality from field to fork is a challenge, but researchers at the University of Nottingham Malaysia have developed a way to preserve them without compromising taste and features.

The Nottingham team discovered that by drying lemon myrtle leaves at a low temperature of 20°C under controlled humidity, it enables the plant’s colour and bioactive ingredient called citral to be significantly retained compared with conventional methods at 60°C.

The team, led by Chemical and Process Engineering Professor Dr Law Chung Lim since 2006, has used the technique to process various products like edible birds nests, cocoa beans, fruits jackfruit, apple, pear, mango and papaya) and herbs

and mushrooms).

For the dried cocoa beans, the team found that the flavour is well preserved, even after they have been roasted.

“The team has discovered that lowtemperature drying is an effective way to retain bioactive ingredients and key nutrients in processed products.

“How the food looks is a key part in the selection process of the food industry as it gives a strong indication on the quality of the product and how it tastes,” said Law.

“Furthermore, the retention of bioactive ingredients can define the quality of the food product, so the selection of appropriate processing techniques is important.”

He said besides retaining the bioactive ingredients, the technique could also preserve colour by eliminating or minimising chemical reactions triggered by harsh processing conditions, such as high temperature.

“The low-temperature drying technique we tested can help to minimise harvest loss, giving an effective process for drying products that retains colour and quality while extending shelf life. It allows post-harvest crops to be maximised.”