Fytinezuur

Fytinezuur, also known as phytic acid, is the principal storage form of phosphorus in seeds and grains. Chemically, it is myo-inositol hexakisphosphate (IP6), a phosphorylated molecule that can bind minerals through its six phosphate groups.

Fytinezuur occurs mainly in the bran, hulls, and germ of seeds, and is abundant in cereals, legumes, nuts, and oilseeds. Its content varies by species, cultivar, and processing. In foods, it forms complexes with minerals such as iron, zinc, calcium, and magnesium, reducing their solubility and bioavailability in the human gut.

Humans have limited endogenous phytase activity, so phytate is poorly digested; some degradation occurs via gut microbiota. Processing methods such as soaking, sprouting (germination), fermentation, and the use of microbial phytase can reduce phytate levels and improve mineral absorption. Cooking alone has limited effect.

Nutrition-wise, fytinezuur is often labeled an anti-nutrient because of its mineral-binding properties, which can contribute to mineral deficiencies when intake of absorbable minerals is marginal. Conversely, phytic acid also exhibits antioxidant properties and has been studied for potential protective effects against certain diseases in laboratory and some animal studies; evidence in humans is not yet conclusive.

Industrially, fytinezuur is considered in animal feeds and food processing; adding phytase to feeds can improve phosphorus utilization and reduce environmental phosphorus excretion. Phytate content decreases with milling and processing that remove bran.