Standard Methods for the Analysis of Oils, Fats and Derivatives

TLDR

The standard applies to oleaginous seeds and fruits that yield fully liquid oil at the measuring temperature (~200 °C) and excludes those that remain solid at 20 °C, such as shea nut, palm kernel, and cocoa. It provides a rapid method for determining the oil content of such oleaginous seeds and fruits. The method measures hydrogen‑containing liquid compounds by low‑resolution NMR after drying the sample at 103 ± 2 °C, correcting for solid residues, using a continuous‑wave NMR spectrometer, appropriate measuring tubes, and reference reagents from the same seed variety.

Abstract

This Standard describes a quick method for the determination of oil content of oleaginous seeds and fruits. FIELD OF APPLICATIONThis Standard is applicable to oleaginous seeds and fruits giving an entirely liquid oil at the measuring temperature (basically 200C), It is not applicable, under current conditions of application, to seeds and fruits which do not give an entirely liquid oil at 20°C (shea nut, palm kernel, cocoa,...). DEFINITIONIn this.Standard the oil is the whole of the organic substances contained in the oleaginous seeds and fruits which are liquid at the measuring temperature (basically 20°C). PRINCIPLEDetermination by low resolution nuclear magnetic resonance (NMR) of liquid compounds containing hydrogen content in oleaginous seeds and fruits (mainly kernels and pips) which have been previously dehydrated by drying at 103 ± 2°C, applying a correction for the response of solids (cakes).N.B.In the following text of this Standard the word "seeds" is used for seeds as well as kernels and pips. APPARATUS5.1.Continuous wave low resolution NMR spectrometer (Note 1) 5.2.Measuring tubes to fit the apparatus 5.1.and of maximum áapacity, made of a non-conductive, non-magnetic material containing no hydrogen (e.g.glass, polytetrafluoroethylene) 5.3.Desiccator 6. REAGENTS 6.1.Crude oil from seeds of the sane variety and origin as the seeds to be analysed, extracted according to method 1• 122., less than one month in advance, and protected from autoxidation 6.2.Cake from seeds of the sane variety and origin as the seeds to be analysed, freed from fat according to method 1.122.less than one month in advance and dried at 103 5 2°C according to method 1.121. PROCEDURE Preparation of the SampleWeigh exactly a quantity of seeds at least equal to 20 g and sufficient to fill a measu- ring tube (5.2.) and dry it according to method 1.121.(Note 2).Determine the water content.