Degradation of phytate in the gut of pigs--pathway of gastro-intestinal inositol phosphate hydrolysis and enzymes involved.

The present study gives an overview on the whole mechanism of phytate degradation in the gut and the enzymes involved. Based on the similarity of the human and pigs gut, the study was carried out in pigs as model for humans. To differentiate between intrinsic feed phytases and endogenous phytases hydrolysing phytate in the gut, two diets, one high (control diet) and the other one very low in intrinsic feed phytases (phytase inactivated diet) were applied. In the chyme of stomach, small intestine and colon inositol phosphate isomers and activities of phytases and alkaline phosphatases were determined. In parallel total tract phytate degradation and apparent phosphorus digestibility were assessed. In the stomach chyme of pigs fed the control diet, comparable high phytase activity and strong phytate degradation were observed. The predominant phytate hydrolysis products were inositol phosphates, typically formed by plant phytases. For the phytase inactivated diet, comparable very low phytase activity and almost no phytate degradation in the stomach were determined. In the small intestine and colon, high activity of alkaline phosphatases and low activity of phytases were observed, irrespective of the diet fed. In the colon, stronger phytate degradation for the phytase inactivated diet than for the control diet was detected. Phytate degradation throughout the whole gut was nearly complete and very similar for both diets while the apparent availability of total phosphorus was significantly higher for the pigs fed the control diet than the phytase inactivated diet. The pathway of inositol phosphate hydrolysis in the gut has been elucidated.

[Reduction of lead content and other elements in wine using pectic acid]. / Verminderung des Gehaltes von Blei und anderen Elementen in Wein mit Hilfe von Pectinsäure.

A procedure for reducing the Pb content in wines containing high levels of Pb is described. The reduction of Pb by means of pectic acid (PA) depends on the quality grade of the wine. In "Auslese" (wine A) 6250 mg PA/l diminished Pb content in 24 h from 0.88 mg/l to 0.28 mg/l; in "Spätlese" (wine B) from 0.83 mg/l to 0.06 mg/l. Under the same conditions the content of Fe, Zn, Cu decreased in wine A from 8.85 mg/l to 7.05 mg/l, from 4.75 mg/l to 1.25 mg/l, from 0.67 mg/l to 0.57 mg/l and in wine B from 6.70 mg/l to 5.41 mg/l, from 1.17 mg/l to 0.28 mg, 0.46 mg/l to 0.28 mg/l, respectively. PA is removed almost quantitatively by filtration. Sensory properties of treated wines were unchanged with concentrations of PA of 750 mg and 1500 mg/l. A slight effect on taste at 6250 mg PA/l wine cannot be excluded. On account of its high affinity to Pb, PA will probably remove Pb from other liquid foods as well.

[Determination of the bioavailability of cadmium in mushrooms in a feeding experiment with rats; relevance for man]. / Bestimmung der Bioverfügbarkeit von Cadmium in Pilzen durch Fütterungsversuche mit Ratten; Relevanz für den Menschen.

A pulverized mixture of Agaricus species known to accumulate cadmium, mixed 15:85 with standard rat diet, was fed to a group of growing rats. The mixture contained 3.87 micrograms Cd/g dry weight. A control group received the standard rat diet alone (0.08 microgram Cd/g). During the feeding period of 6 weeks the animals of both groups excreted about 90% of the ingested cadmium in the faeces. In comparison to the control group, the experimental group accumulated much more cadmium in liver, kidneys, and remaining carcass. While it is concluded that the bioavailability of cadmium contained in mushrooms is not less than that of cadmium contained in other feeds and foods, most mushroom species do not contain more cadmium than other vegetables. In humans the average cadmium intake from the total diet is considerably below the tolerable level. Generalized warnings against consumption of mushrooms are therefore not considered necessary.