INDONESIAN JOURNAL OF PHARMACY
Vol 13 No 1, 2002

ESTIMATION OF PROTEIN CONCENTRATION IN FOOD BY TOTAL NITROGEN AND AMINO ACID ANALYSES

Sumarno . (Departement of Chemistry Faculty of Pharmacy Universitas Gadjah Mada Yogyakarta)
Sri Noegrohati (Departement of Chemistry Faculty of Pharmacy Universitas Gadjah Mada Yogyakarta)
Narsito . (Departement of Chemistry Faculty of Sciences and Mathematics Universitas Gadjah Mada Yogyakarta)
Iip Izul Falah (Departement of Chemistry Faculty of Sciences and Mathematics Universitas Gadjah Mada Yogyakarta)



Article Info

Publish Date
01 Jan 2005

Abstract

Since protein is the principal constituent of biological organs, a continuous supply is needed in food for growth and repair. Protein quality in food is determined by its assortment of amino acids, whether it is essentially needed or not. The aim of this study is to develop an accurate and precise simple method of protein estimation for food and feed. The validity of simple protein estimation by multiplying the N-total concentration with a constant factor: of 6.25, should be clarified. Protein could be estimated more specifically by summing up the determined amino acids. In this study, the amino acids of some substantially high protein food were analysed by HPLC-ninhydrin, HPLC-o-phthalaldehyde, and HPLC-dansyl techniques, by gas chromatograph after derivation with TFA-butanol, and by formol titration. Method based on HPLC-ninhydrin techniques shows significant correlation (r=0-9992) with its amino acids content and N-total content. The protein as amino acids - N-total conversion factor obtained was 6.95 for N-total content less than 15.5%, and 8.59 for N-total content higher than 15.5%.Key words: food, protein and analytical methods

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Journal Info

Abbrev

3

Publisher

Subject

Medicine & Pharmacology

Description

Indonesian Journal of Pharmacy (ISSN-e: 2338-9486, ISSN-p: 2338-9427), formerly Majalah Farmasi Indonesia (ISSN: 0126-1037). The journal had been established in 1972, and online publication was begun in 2008. Since 2012, the journal has been published in English by Faculty of Pharmacy Universitas ...