The high rate of adulteration of the oil and cheating on weight is because "coconut oil is a preferred medium of cooking and Keralites are ready to pay a premium for it," the study conducted by PT Thomas and RK Singh says.

A study conducted by the Post Harvest Technology Centre of the Indian Institute of Technology, Kharagpur found that consumers in Thiruvananthapuram and Kozhikode preferred coconut oil over other edible oils. The percentage of coconut oil users was 60 per cent compared to the 18 per cent for suffola and 15 per cent for palmolein. This is an indication of the edible oil consumption pattern for the entire state of Kerala.

For the Coconut DevelopmentBoard study, two districts and one corporation area from Central Kerala were chosen. Three-hundred samples of coconut oil sold loose and weighing 500 gms each were bought in these sample areas. In 60 per cent of the cases, the samples were short of their actual weight by 10 to 100 gms even as in some cases the weight exceeded the indicated 500 gms, the study results showed.

The study also found that 14 per cent of the samples were adulterated with the most common adulterant being palmolein. The Prevention of Food Adulteration Rules, 1955, specify that coconut oil should be free of rancidity, suspended particles, separated water, added colouring and flavouring or mineral oil.

However, retail traders have found the similarities between the prescribed qualities of the two edible oils a convenient tool for adulterating coconut oil with the much cheaper palmolein. The prescribed qualities of coconut oil are: acid value should not exceed 6 per cent, unsaponifiable matter should not exceed 1 per cent, polenskevalue not less than 13.0, iodine value 7.5 to 10.0, refractive index 1.449 and butyro refractometer reading at 40 degree Celsius should be 34.0 to 35.5.

The study found that the price factor played a key role in the rate of adulteration of coconut oil. Even though Keralites are ready to pay a premium for coconut oil, the demand for the oil as dietary oil is inelastic only up to a particular price range -- between Rs 45 and 55 per kg.

When the price of coconut oil exceeds this level, consumers are forced to shift their preferences. This is also the opportunity for traders to use cheap palmolien for adulterating coconut oil. Palmolein is obtained by fractionation of palm oil.

The study finds that apart from coconut oil, dessicated coconut powder sold in the market is also adulterated. The dessicated coconut powder industry is growing fast in South India and there are more than 60 units manufacturing coconut powder. Often rice and tapioca powders are found in dessicated coconut against the standardsprescribed by Agmark and Bureau of Indian Standards.

The study has called for effective state intervention to ensure that only quality coconut oil is sold in the state. Strict enforcement of the Edible Oils Packing (Regulation) Order, 1998 under section 3 of the Essential Commodities Act with a mandate that all edible oils in the country be sold in packed forms is the case in point.

There is also an appeal to raise consumer awareness. The arrival of branded coconut oil in the market is a good development towards this end, the study said. Until recently there were only three or four brands of edible coconut oil in the market. However, the scene is changing and now there are 80 brands available in the market.