Investigation on the Utilization Possibility of Orange (Citrus sinensis var. Valencia) Oil Extracted by Microwave Pretreatment-Improved Steam Distillation as Natural Flavoring Agent Based on its Characteristics Analysis

Abstract

The main objective of the present study was to determine some of the physical, chemical and sensory characteristics of essential oil extracted from orange peel using microwave pretreatment-improved steam distillation method in order to utilize it as a natural flavoring agent. Microwave pretreatment of orange peel preceded steam distillation process, which carried out under a set of defined conditions. Scanning electron microscopy (SEM) of orange peel undergone 15 seconds with a temperature of 60°C (320W) microwave pretreatment was used to study the potential of this pretreatment. With GC and GC-MS, the quantity and quality of the oil compounds were characterized in particular of which relative to the flavor. Sensory evaluation was determined by a panel of experienced people and consumer evaluation. Comparisons were made to orange oil provided in literature in terms of yield, physical, chemical and sensory characteristics. The study showed an effective commercially and environmentally friendly technique termed as microwave pretreatment-improved steam distillation method. SEM images provided evidence as to a greatly expand in the oil glands by microwave pretreatment without any rupture which subsequently correlated with extraction time reduction. Moreover, the set of defined conditions that applied in the steam distillation step considerably maintained the chemical and sensory properties of the oil distilled. The extracted oil possesses physical, chemical and sensory characteristics that offer this oil special interest as a natural flavoring agent. Further, the productivity was 0.52% and it was useful to add a small amount of this oil (0.2%) for adding orange flavor as it in original fruit. Based on orange oil flavor profile characterized by GC-MS and sensory evaluation, flavor compounds deterioration, development boiled odor and off-flavor compounds were prevented due to the adjustment in the extraction process. Orange peel oil steam distilled was highly appealing in flavor and overall acceptability.