Effect of water-soluble oxalates in Amaranthus spp. leaves on the absorption of milk calcium.

1. Amaranthus spp. leaves contain high amounts of oxalates which affect the calcium absorption.

A simple method for estimation of thiamine in foods using base-exchange on sand instead of Decalso.

Sea-sand obtained from two different areas (Madras and Bombay) in India showed that sand of 50-80 mesh from Madras had a satisfactory capacity to adsorb thiamine, and that the elution of the adsorbed vitamin was quantitative. With Bombay sand, however, the elution of the vitamin was not efficient. A few simple methods that can be used for testing sands from different areas for their efficacy as base-exchangers were described, and details were given of a method for the estimation of thiamine in cereals and legumes using sea-sand in place of Decalso for the removal of the interfering substances from the food extracts.

Folic acid conjugase from plasma. III. Use of the enzyme in the estimation of folate activity in foods.

A convenient method for the estimation of food folates using human plasma as a source of folic acid conjugase has been standardized. Bovine, goat and dog plasma could not be used for the purpose because of low enzyme activity and slow reaction rates. Human plasma conjugase released food folates from conjugated forms over a pH range of 4.

Folic acid conjugase from plasma. II. Studies on the source of the enzyme in blood.

Following the administration of carbon tetrachloride to rats, the liver conjugase level decreased with 4 hours and continued to be low till 24 hours. Plasma conjugase did not change till 6 hours after administration, but at 24 hours showed a significant increase. Histological examination of the livers revealed liver damage even by 6 hours following carbon tetrachloride administration.

Folic acid conjugase from Plasma. I. Partial purification and properties.

Human plasma conjugase was partially purified by ammonium sulphate and DEAE-cellulose column fractionation. The pH optimum was found to be 4.5.