To overcome the problems of incomplete flavor components from Piper nigrum extract and the Piper nigrum product easy deterioration in the storage process, microcapsules of the whole Piper nigrum were prepared by spray-drying combined with enzymatic hydrolysis. Under the best conditions for the microencapsulation obtained by the response surface methodology, which have been determined as the ratio of core and wall material (1:0.2, w/w), proportion of wall materials (starch sodium octenyl succinate : maltodextrin : xanthan gum) (1:1:0.2, w/w/w), wall material concentration (11%, w/v) and inlet air temperature (180°C), the embedding rate of the prepared Piper nigrum microcapsules reached 90.21%. Fourier transform infrared spectroscopy, scanning electron microscopy and particle size distribution studies established that the Piper nigrum powder was entrapped within the microcapsules, which had intact morphology and uniform particle size distribution. Besides, gas chromatography-mass spectrometry analysis demonstrated that the prepared Piper nigrum microcapsules could preserve the major of the volatile aroma components of Piper nigrum, carene, D-limonene, α-phellandrene, and (-)-β-pinene. The obtained results showed that the microcapsules might contribute to the development of preserving original flavor from Piper nigrum and have potential applications in the commodity market.
Keywords: Piper nigrum; enzymatic hydrolysis; microencapsulation; response surface methodology; spray drying.