Založba Univerze v Ljubljani / University of Ljubljana Press
Doi
Abstract
The aim of the investigation was to get an orientation on the concentrations of vitamin A in livers of different animal specieses in Slovenia. Liver samples from calves (5), cattle (5), chickens (7) and pigs (6) were analyzed. For determination of vitamin A, HPLC method was used after saponification and extraction of samples. It was possible to separate all-trans-retinol from other isomers. UV-detector at 328 nm was used for detection. Average concentrations of all-trans-retinol in liver (mg/100 g) were as follows: calf 5.6, cattle 25.9, chicken 14.0 and pig 15.0. Mean values of vitamin A in 100 g servings of animal livers were 4-fold to 25-fold of the RDA that depend on sort of liver, age, and sex of human. From nutritional point of view liver is a very rich source of vitamin A. Pregnant women should avoid liver with high vitamin A content, because of teratogenicity of high doses of vitamin A. Even few high doses of vitamin A can cause malformation of the fetus, especially in the first trimester of pregnancy. In other consumers some risk exist only at high and very frequently intake of liver.Namen raziskave je bil dobiti orientacijsko oceno o koncentracijah vitamina A v jetrih različnih vrst domačih živali v Sloveniji. Analizirali smo jetra telet (n=5), govedi (n=5), piščancev (n=7) in prašičev (n=6).Po umiljenju in ekstrakciji je sledila določitev vitamina A s HPLC metodo. Sistem HPLC omogoča ločitev all-trans-retinola od ostalih izomer vitamina A. Detekcija je potekala z UV-detektorjem pri valovni dolžini 328 nm. V telečjih jetrih je bila povprečna koncentracija all-trans-retinola 5,6 mg/100g jeter, v govejih 25,9 mg/100 g, v piščančjih 14,0 mg/100 g in v svinjskih 15,0 mg/100 g. Srednje vrednosti vitamina A, preračunano na 100 g praženih jeter, so bile 4-krat do 25-krat večje od priporočil za dnevno oskrbo (RDA), odvisno od vrste jeter, starosti ter spola oseb. S prehranskega stališča so jetra zelo bogat vir vitamina A. Večja količina zaužitega vitamina A je lahko teratogena za zarodek, zato naj bi se nosečnice jetrom z veliko vitamina A izogibale. Že nekaj povišanih vnosov vitamina A lahko pri nosečnicah povzroči razvojne anomalije zarodka, posebej v prvem trimesečju. Pri ostalih porabnikih tega živila obstaja nevarnost le, če so količine zaužitih jeter zelo velike in je njihovo uživanje zelo pogosto
