Micro-fibres eyed as future functional ingredients

Writing in the Journal of Food Science, researchers from China's National Chiayi University report that high-pressure micronisation of orange fibre at five per cent level might positively affect intestinal function and health.

"Our results also demonstrated that particle size might not be the only factor affecting the characteristics and physiological functions of fibres while the ways of processing and their related particle size were also crucial to their physiological benefits," wrote the authors.

"This study gives some hints for different potential applications of micron technology in food industry and offers the industries some opportunities to develop new formulations of fibre-rich functional foods."

Insoluble fibre contains cellulose, hemicellulose and lignin and cannot be dissolved in water, unlike soluble fibre.

It is found in wheat or cereal bran and in most vegetables and fruits.

Consumption of insoluble fibre has previously been associated with a reduced risk of obesity and diabetes.

The researchers using a jet-milling and high pressure micronisation process to reduce the particle size of the insoluble fiber fraction (IFF) from Citrus sinensis L. cv.

Liucheng (Liucheng sweet orange, LSO).

They then fed the micronised fibres, with a particles size range of 6.3 to 11.4 micrometres, to hamsters and measured changes in gut health parameters.

Lead author S.-C. Wu reports that significant reductions in ammonia concentration in the cecum (37 per cent reduction), increased in faecal moisture of 164 per cent, and decreases in mucinase enzymes (28.5 per cent less) in faeces were observed.

"These findings suggested that the incorporation of micronized IFF into diet at five per cent level might exert a favorable effect on improving intestinal function and health," wrote Wu.

Despite this study being performed on hamsters, and therefore not directly translated to human, the authors suggest that the process of reducing the particle size of the insoluble fibre and applying it in functional foods, could lead to direct benefits for the food industry.

"The successful improvement in the functions of the IFF would give useful hints on the use of micron technology in food industry, and would also profit the fibre-rich food development, juice industry, and environment," wrote the researchers.

Source: Journal of Food Science Volume 72, Number 8, Pages S618-S621, doi:10.1111/j.1750-3841.2007.00489.x "Particle Size Reduction Effectively Enhances the Intestinal Health-Promotion Ability of an Orange Insoluble Fiber in Hamsters" Authors: S.-C. Wu, P.-J. Chien, M.-H. Lee, C.-F.

Chau