The annatto plant ( Bixa orellana), also known as Kurangumanjal or Kungumachedi in Malayalam, could soon be a money-spinner for farmers in Kerala.

Scientists at the Department of Botany, University of Kerala, have developed methods for commercial cultivation of the plant that has emerged as a potential candidate for commercial production of food-grade natural dye.

A woody shrub cultivated in tropical and subtropical regions, annatto is chiefly valued for the red dye present on the seed surface. The exotic species that was introduced to Kerala as an ornamental plant is now a naturalised plant.

Natural substitute

According to E.A. Siril, Assistant Professor, Department of Botany, University of Kerala, increasing awareness about the health hazards posed by chemical colouring agents used in food products has triggered a global search for safe natural substitutes.

Annatto is widely used in the food processing sector and is one of the 13 food dyes approved by the US-Food and Drug Administration. Dr. Siril won the Dr. S. Vasudev Award at the ongoing Kerala Science Congress for his work on propagating annatto.

Dr. Siril told The Hindu that the dye was also being tested for use in the drugs and cosmetics industries. Aqueous or alkaline extracts of B.orellana are extensively used to colour cheese, ice-cream and other dairy products, alcoholic and non-alcoholic beverages, baked foods, meat and fish products, snacks, and gravies.

Two pigments

The presence of two pigments, bixin and norbixin, is responsible for the red colour of annatto seeds. Brazil is the world’s largest producer of annatto seeds, followed by Peru. The annual global production of annatto seeds is estimated to be 14,500 tonnes.

Dr. Siril said the unavailability of superior planting material was hindering mass cultivation of Bixa orellana in Kerala. “My objective was to evolve suitable methods to produce high quality planting materials to promote the plant as a cultivated crop rather than an ornamental shrub.”

Over a period of three years, Dr. Siril’s team developed a method for clonal propagation of superior germplasm and standardised breeding parameters. The team also carried out tests for genetic improvement of B.orellana, identified its variants with distinct genetic base and developed treatment methods to improve seed germination.

High-yielding variants

Dr. Siril stresses the need to undertake an exploration survey targeting high-yielding varieties of B.orellana. He advocates a collaborative approach with institutions in neighbouring States.

He feels that the clonal propagation method could be further refined to enhance efficiency. He also sees the need to employ cell culture technology for production of bixin.

Dr. Siril says the adoption of the techniques developed by his team could make the cultivation of annatto a profitable venture and help reduce the demand for synthetic colorants harmful for human health.