Bioavailability of phytic acid–phosphorus and magnesium from lentils ( Lens culinaris m.) in growing rats: Influence of thermal treatment and vitamin-mineral supplementation

We sought to improve the nutritive utilization of Lens culinaris M. variety vulgaris cultivar Magda-20 in growing rats by autoclaving the lentil seeds at 120°C for 30 min at an internal pressure of 1 atm and by supplementing the rats with a vitamin-mineral premix. Nutritional assessment was based on chemical analysis of total phosphorus, free phosphorus, phytate, magnesium, neutral detergent fiber, and acid detergent fiber contents of the lentils and the digestive and metabolic use of phosphorus and magnesium by the growing rats. The net absorption of phosphorus was greater than the amount of non-phytate phosphorus ingested by the animals fed diets of raw and autoclaved lentil flours. Vitamin-mineral supplementation of raw and autoclaved lentil flour resulted in a significant increase in dietary intake and net absorption of phosphorus and magnesium. For all of the experimental diets tested, there was a direct correlation between phosphorus or magnesium balance and weight gain ( r = 0.91 and 0.80, respectively) and between phosphorus or magnesium balance and nitrogen balance ( r = 0.91 and 0.87, respectively). Part of the phytate-phosphorus from raw and autoclaved lentil flour was available during digestion, and hardly any phytate was detected in the feces. Supplementation of raw lentil flour with a vitamin-mineral premix was the most effective treatment for increasing daily food intake, body weight gain, and nutritive use of phosphorus and magnesium.