Antinutritional factors and their detoxification in pulses – A review

Pulses are relatively a cheaper source of protein than milk, cheese, cashew, almond, meat and fish etc., hence valuable for developing countries. The seeds of pulses are most commonly eaten can be economically stored well for future use. The food values of seeds of pulses is high, have about the some calorific value per unit weight as cereals and are fair sources of some vitamins and minerals. Their protein contents are generally about double that of most cereals. Consumption of pulses is highest in India as compared to other pulses growing countries due to low purchasing power and religious restrictions on non-vegetarian diet. Pulses contain about 18.0 to 32.0% protein and about 1 to 5% fat. Pulses are considerably richer in calcium than most cereals and contain about 100 to 200 mg of calcium per 100 g of grain. They are also considerably rich in iron, thiamine, riboflavin and nicotinic acid as compared to cereals. Young sprouts of pulses like mungbean, mothbean and chickpea are popular foods in some places. Pulses contain several anti-nutritional factors, such as trypsin and chymotrypsin inhibitors, lectins, polyphenols, flatulence factors, lathyrogens, saponins, antihistamines and allergens. The protease inhibitors, lectins and other antinutrients cause toxicity. Heat treatment has been well established to destroy proteinaceous antinutrients, such as protease inhibitors and lectins, but heat treatment destroys some of the amino acids and vitamins as well. For maintaining the nutritional value of food, it is necessary that heating temperature and length of processing do not exceed the optimum temperature required to eliminate the effect of inhibitors. Proteins in pulses are known to interact with lipids, tannins, phytates, flavor compounds and pigments. These interactions occur when pulses are processed and converted into products. It decreases the bioavailability of proteins. Similarly, tannins and phytates interact with minerals and vitamins resulting in a decrease in their bioavailability. Thus, bioavailability of nutrients depends not only on their content in the seed, but also on the interaction of nutrients under various processing conditions. The pulses are subjected to various processing techniques like milling, dehulling, soaking, germination, fermentation and cooking. These processing techniques not only save time, energy and fuel but have several nutritional advantages and produce edible products having a higher nutritional value and lower toxic compound. The degrees of elimination of toxic compound depend on type of pulses and the processing technique.