Selection of moderate refining process for gardenia fruit oil based on SPE-HPLC-UV analysis of phytonutrients

Gardenia fruit oil (GFO) is a new emerging edible woody oil with few investigations of its’ refinement process. In this study, different degumming, deacidification and bleaching technologies were introduced for realizing moderate refining of the GFO based on the preservation of bioactive micronutrients. Firstly, a simple multi-stage solid phase extraction (SPE) combined with a lab- affordable HPLC-UV instrument was developed for determinations of several vital biological constituents, such as crocetin, geniposide, polyphenols, phytosterols and squalene in the GFO. Satisfactory limit of detection (LOD), limit of quantification (LOQ), recovery, intra-day and inter-day precision were obtained. Subsequently, changes of those phytochemicals during three types of degumming, followed by three kinds of deacidification and then three ways of bleaching were investigated, offering insightful suggestions for achieving moderate refining of the GFO. Finally, the refined GFO might be suggested as a potential functional edible oil with valuable micronutrients. To our knowledge, this is the first study investigating moderate refinement techniques for GFO, as well as developing novel methods for phytonutrients analysis in the GFO.