Shampoo strips hair of the natural oils and grease that help smells cling to strands. That means the pleasant odors of shampoo and conditioner tends to disappear within a few hours.

But researchers have developed technology that binds fragrances from shampoo to the surface of hair so that the smell is gradually released.

Andreas Herrmann, a chemist at fragrance firm Firmenich, worked with the Swiss Federal Institute of Technology on the breakthrough.

The researchers packaged the fragrance inside capsules* that were many times smaller than the width of a human hair. Then, to get them to stick to hair, they studded the capsules with short fragments of protein.

The fragrance is released over 24 hours as the capsules burst gradually. Herrmann said the capsules do not change the way hair feels but further testing would be needed to ensure they do not affect combing or drying. (SD-Agencies)