Simultaneous determination of moisture and oil content in oilseeds by pulsed nuclear magnetic resonance

Pulsed nuclear magnetic resonance technique using Carr-Purcell-Meiboom-Gill (CPMG) sequence has been used for simultaneous determination of moisture and oil content in rapeseed-mustard. This method involves sampling the free induction decay (FID) following 90° pulse in the CPMG sequence and resolving the trace of the amplitude of the CPMG echo signals into exponentially decaying liquid components of oilseeds. The data show that water in oilseeds generally exists in 2 phases and the relatively slow decaying component disappears around moisture content of 7% and below. The moisture and oil content have been determined by the method for 34 samples of 5 different varieties of seeds at varying moisture levels (∼3% to 22%). The measured moisture and oil content have been compared with the values obtained by the oven drying method and earlier known FID method of pulsed nuclear magnetic resonance (NMR) respectively, and the agreement is fairly good for rapid estimation with standard deviation of 0.70% for oil content and 0.99% for moisture content. This is a rapid and nondestructive method for determination of both moisture and oil content without weighing and drying the seeds and also seems suitable for other matrix samples.