Studies on the Effect of Germination on the Phosphorus Values of Some Common Indian Pulses

Abstract

12) observed that phytic acid phosphorus is nutritionally less available than inorganic phosphorus. Bruce and Callow ( 3 ) are of the opinion that hydrolysis of phytic acid to inositol and phosphoric acid is a necessary step for the absorption of phosphorus and that this is accomplished by phytase present either in the food or in the gastro-intestinal tract. Phytase has been shown t o be present in the intestine of rats (17). An acid phytase, possibly bacterial in origin, has been shown to be present in the human feces (8). Nicolaysan and Njaa (16) showed a distinct depression of calcium absorption in rats and pigs b y diets rich in phytic acid. Courtois and Valentino (9) and Boutwell, Geyer, Halverson, and Hart (2), however, observed that the presence or absence of phytase in food had no effect on the availability of phytin phosphorus. Boutwell et al.( 2 ) further observed that vitamin D makes phytin phosphorus in wheat bran completely available to rats. Pulses are rich in phytin. It was of interest to ascertain whether the phytin content and water soluble inorganic phosphorus content change during the process of germination. The present paper presents the results of such a study carried out with 8 species of pulses. METHODOLOGYThe terms used in this paper are those which are defined by specified analytical procedures. Water soluble inorganic phosphorus is that which is extracted as phosphate by water alone and determined colorirnetrically by the method of Fiske and Subbarow (10). Phytin phosphorus was determined by extracting the phytin with N/2 hydrochloric acid, precipitation thereof as the ferric salt, and determining the phosphate liberated by digesting the precipitate with sulfuric and perchloric acids. This method is that described by RIcCance and Widdowson (12). Total phosphorus is that which is determined as phosphate after digestion of the whole dry plant material with sulfuric and perchloric acids. E X P E R I M E N T A L Germination of the seedlings. One g. of healthy pulse was weighed and kept in dry clean petri dishes; 2 cc. of redistilled water was added on the first day and 0.5 to 1 cc. water was added from the second day. The dishes were kept away from direct sunlight.Estimation of total phosphorus. One g. of pure dry seeds was digested with 20 cc. of sulfuric acid and perchloric acid mixture (10 : 1). The digest was diluted to 100 cc.; 5 cc. aliquot was neutralized, 0.12 cc. of 10 N. sulfuric acid was added and the volume made up to 25 cc. Total phosphorus was estimated in the solution by the method of Fiske and Subbarow (10).Estimation of phytin phosphorus and water soluble inorganic phosphorus. One g. of powdered dried pulse was crushed with water and made up to 2.5 cc. F i r e cc. of this extract mas used for the estimation of water soluble inorganic phosphorus. Concen- 223

Effects of domestic preparation of cereals and legumes on ionisable iron

“…Reduction in phytin P and increase in ascorbic acid during germination has been reported earlier. 14,15 In the present study, germination beyond 48 h was accompanied by a reduction in phytin P and an increase in ascorbic acid content of the seeds both before and after decortication. However, the increase in ionisable iron was observed only in whole seeds.…”