An overview of anti-nutritional factors in food

Anti-nutritional factors are the compounds found in most food substances which are poisonous to humans or in some ways limit the availability of nutrient to the body. Anti-nutritional factors are present in different food substances in varying amounts, depending on the kind of food. Many anti-nutrients (oxalate, phytate, etc.) and toxic substances (cyanide, nitrate, phenols, etc.) are present in many plants and vegetables. Anti-nutrients in foods are responsible for deleterious effects related to the absorption of nutrients and micronutrients. However, some anti-nutrients may exert beneficial health effects at low concentrations. For example, phytic acid, lectins, tannins, saponins, amylase inhibitors and protease inhibitors have been shown to reduce the availability of nutrients and cause growth inhibition. However, when used at low levels phytate, lectin, tannins, amylase inhibitors and saponins have also been shown to reduce the blood glucose and insulin responses to starchy foods and/or the plasma cholesterol and triglyceride. Anti-nutrients are chemical substances which reduces the maximum utilization of nutrients especially proteins, vitamins, and minerals, thus preventing optimal exploitation of the nutrients present in a food and decreasing the nutritive value. Anti-nutrients can be divided into two groups: heat-stable group-phytic acid, tannins, alkaloids, saponins, non-protein amino acids etc. and heat labile group include lectins, cynogenic glycosides, protease inhibitors and Toxic amino acids etc. Due to the presence of several anti-nutritional factors, legumes possess low protein digestibility. Most of the toxic and anti-nutrient effects of these compounds in plants could be removed by several processing methods such as soaking, germination, boiling, autoclaving, fermentation, genetic manipulation and other processing methods, but extensive research is still needed to discover elimination methods for heat stable anti-nutrients present in various food without altering the nutritional value of food.