ENCAPSULATION, ANALYSIS AND STABILITY OF ORANGE PEEL OIL (FLAVOR, CITRUS, KINETICS)

Encapsulation of orange peel oil using dextrinized starch was done by spray drying process. Microcapsules containing 13 to 16% oil with an average diameter of 25 (mu) were obtained.;Relevant chemical and instrumental methods for the analyses of the microcapsules have been standardized. These analyses include moisture, total oil, surface oil and peroxide value determination. A new gas chromatographic method for total oil determination has been standardized. This method offers advantages over the conventional steam distillation method in terms of reduced analysis time, quantitation of individual flavor components and absence of thermally induced artifact formation.;Oxidation of orange peel oil has been shown to follow pseudo first order kinetics past the induction period with respect to limonene-1,2-epoxide formation and oxygen absorption rate. Limonene-1,2-epoxide and carvone have been positively identified as to oxidation products of limonene via combined gas chromatography-mass spectrometry.;Oxidation of orange peel oil in the microcapsules follow zero order kinetics with respect to limonene-1,2-epoxide formation, carvone formation and oxygen absorption. Sensory evaluation coupled with gas chromatographic analysis, during accelerated shelf life testing, revealed that when limonene-1,2-epoxide or carvone reached 2-4 mg/g oil concentration the samples had an unacceptable oxidized flavor. Overall, the more dextrinized starches offered enhanced protection to the oil against oxidation. A linear relationship was found to exist between the log (rate) for the formation of limonene-1,2-epoxide and carvone as a function of reducing sugar content of the dextrinized starch.;Scanning electron microscopic examination of the microcapsules did not reveal major differences in the morphologies of the various samples. Samples stored at higher relative humidities exhibited varying degrees of structural change.