SOYA LECITHINS QUALITY CONTROL USING THE NMR PULSE METHOD

Soya lecithins are leaders in the global lecithin market not only in terms of production, but also in terms of consumption in various sectors of the food industry, due to the uniqueness of their technological and physiologically functional properties. Production of domestic lecithin is increasing rapidly, it has a high export potential. Development of operational methods for controlling their quality using modern analytical instruments that ensure accuracy and reproducibility of the results is relevant today. The most promising methods are the ones for assessing the quality of oilseed raw materials and products of its processing, including lecithins, based on the NMR pulsed method.
The aim of the research is to develop a method for determining the acid number (AN) of liquid soya lecithins using a NMR pulsed method. It has been shown that for the development of a method for determining the AN of liquid soya lecithins, it is necessary to carry out special sample preparation of the sample taking into account the parameters specified for soya lecithins, namely, the ratio of the system «soya lecithin - carbon tetrachloride (CCl4) - NaOH solution» should be equal to 1.0: 3.0: 0.6 ( by weight), and the duration of active contacting of the specified system should be at least 1.5 minutes The indicated sample preparation of samples of liquid soya lecithins will allow obtaining accurate and reproducible results of measuring the amplitude of NMR signals of soap protons, which is an analytical parameter characterizing the content of lipids exhibiting acidic properties in lecithin. Method for determining the AN of liquid soya lecithins based on the NMR pulsed method has been developed using the revealed dependence of the analytical parameter on the values of the AN of liquid soya lecithins, which is characterized by a high correlation coefficient (0.9943).

liquid soya lecithins, quality control, NMR pulsed method, acid number, amplitude of NMR signals of soap protons

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