THE ANALYSIS FOR INOSITOL PHOSPHATE FORMS IN FEED INGREDIENTS

Limited data are available on the content of inositol phosphates in fe ed ingredients. The doubtfulness over the identity and literature valu es of the inositol hexaphosphate (phytate) analysed in feed ingredient s by the classical iron precipitation method prompted the analysis for inositol phosphates in some feed ingredients using a modified high-pe rformance liquid chromatography method. The inositol phosphates analys ed were inositol triphosphate (IP3), inositol tetraphosphate (IP4), in ositol pentaphosphate (IP5) and inositol hexaphosphate (IP6). At least 97% of the inositol phosphates in grains occurred as IP6 and the rema inder as IP5. In milled products the relative percentage of IP5 was hi gher (up to 14.5% in wheat bran) but the overall IP6 relative percenta ge was still high (more than 82%). IP3 and IP4 were not present in gra ins, and their amounts were very low when present in their milling or processed fractions. The absolute IP6 content was highest in rice bran and wheat bran at 68.31 and 47.63 g kg(-1), respectively. The results indicate that processed plant products may contain hydrolysis product s of IP5 and IP6. These products contain greater percentages of IP3, I P4 and IP5 than in grains or milling products. (C) 1998 SCI.