Steam Treated Soya Dhal (Pulse) for human consumption & for social nutrition programmes

Soyabean, though a superb source of protein, cannot be eaten raw because of the presence of anti-nutritive factors which are physiologically alive. The unpopularity of soyabean in this country is due to the fact that it requires elaborate pre-treatment to inactivate such enzymes.

As you are very well aware, the following are the major drawbacks of unprocessed soyadhal :

1. Rancidity :
Oxidative rancidity is commonly observed in all fats and oils. The oxidation takes place at the unsaturated linkage. The addition of oxygen to the unsaturated linkage results in the formation of peroxide, which on decomposition, yields aldehydes and ketones having pronounced off flavour. The enzymes like lipase and lipoxigenase present in unprocessed soyadhal are responsible for the characteristic off flavours and bitter taste. They promote the hydrolysis of fat, releasing free fatty acids which cause rancidity.

2. Trypsin Inhibitors :
The hyperactive pancreas of human body secretes trypsin which is necessary for hudrolysing and digesting protein modules. Unprocessed soyadhal, like any other legume or pulse, contains trypsin inhibitors which prevent the function of trypsin. This results in endogeneous loss of essential amino acids in response to the stimulatory effects of the inhibitors, causing poor utilization of proteins.

3. Haemogglutinins & Urease :
Unprocessed soyadhal also contains undesirable enzymes like haemogglutinis and Urease. Haemogglutinis cause thumping of red blood corpuscles and urease converts urea into ammonia, both of which are toxic.

The presence of anti-nutritional factors prevented the popular use of unprocessed soyadhal, by causing metabolic disturbances and poor performance of proteins.

However, under careful processing conditions, which control the four important variables like time, pressure, temperature & moisture, all the anti-metabolities in raw soyadhal can be completely destroyed without causing the solidification of proteins and without making the de-naturation of amino acids. Varying degrees of moist and dry heat treatment of soyabean will progressively raise the protein efficiency and lower the Nitrogen solubility index.

Soyabean processing also removes oilgosaccarides, some of which are believed to be responsible for the production of intestinal gas.

Only after the above detailed processing, soya dhal will be fit for human consumption. 

Properly processed soya dhal is prepared by the Company by using the following methods :

We are not activating more than 90% of these anti-nutritional elements. This is due to the fact that in case Soya Dhal is over-cooked, there is also a possibility of ‘Millard reaction’, linking proteins with Carbohydrates to form a complex which cannot be digested by the human body. 

Similarly Lysine, one of the essential amino acids is highly susceptible to heat de-gradation and the bio-availability of Lysine may decrease by over-cooking. Hence we have optimized the above process parameters. 

Other quality parameters

Note on the Colour of Steam Treated Soyadhal :

Raw soya dhal is having bright yellow colour. However, it is un-fit for child feeding programmes due to the presence of Enzymes, Bitterness, Off flavour and Anti-nutritional elements like trypsin inhibitors, lipoxygenase, haemogglutinins & urease.

Steam Treated soyadhal becomes a dull coloured dhal after thorough cooking & drying. However, it is having pleasant aroma, nutty flavour & good taste. It is most suitable for Human consumption in general & for Child Feeding programmes in particular.