A Handy method of Bleaching Yellow Fat from the Seeds of Meetha Jaal (Peelu)

The inedible fat from the seeds of Meetha Jaal (Salvadora oleoides) is yellow in colour which is sometimes objectionable from industrial point of view. The fats are generally bleached to get rid of their undesirable colours. This is because, not only that white colour is preferred in many applications, it is also convenient to give any desired colour if the material is white. A simple method has, therefore, been standardised for bleaching of yellow fat from the seeds of Meetha Jaal. The pulverized sample of yellow fat was spread in a petri dish in thin layer and put under direct sunlight for two days with periodic turning of the layer upside down. The yellow colour of the fat attributable to the presence of carotenoides) was completely bleached (no absorption in visible region), yielding a snow-white fat.

Meetha Jaal is an important plant of the desert and occurs widely in western Rajasthan and the dry region of Gujarat. Leaves of Meetha Jaal are used as fodder for animals, particularly for the camels. Fruits of Meetha Jaal, commonly known as Peelu, are edible and the seeds contain 40-50 inedible fat which can be used in soap industry and is considered a potential industrial substitute of coconut oil. The fat can also be used for making candles. But the commercial utilization of seeds of the fruits, in general, for fat has not been possible so far due to uneconomic collection of the fruits if only the fat has to be obtained from the seeds of the fruits. The production of fruits is profuse and the average fruit production has been found to be 30kg per tree in good fruiting season and a good tree in good fruiting season can afford even upto a quintal of fruits. The small size fruits are perishable in nature and are available only for a short duration of say, 15 to 20 days in May. As we have successfully prepared value-added products (Peelu squash and Peelu jam), at CAZRI, Jodhpur, from 'Peelu' (fruits of S. oleoides), enabling availability of the seeds as a by-product from which the fat can be cost-effectively extracted, the bleached snow-white fat can be conveniently used in soap and industry candle. The advantage of bleached fat is that different desired colouration can be converiently imparted to various industrial products such as soaps and candles.

Though the potential estimate of availability of seeds is about 47,000 tonnes, it seems that the target has never been practically realized despite luxurious growth, profuse fruiting and considerable wide cover of the plant. Every year, lots of Peelu fruits go waste as only small amount of the total production of the fruits is consumed by the local people. Value addition such as production of Peelu squash and Peelu jam makes seeds available as a product 40-50% inedible fat of industrial importance; the remaining seed-cake method can be used as animal feed since it has about 27% of crude protein). The handy bleaching method of turning yellowish' fat to snow-white fat, along with other benefits, make Meetha Jaal an important multipurpose economic plant of the desert small industrial units where Meetha Jaal is widely available.

Source: Invention Intelligence, July - August 2007