Analytical techniques to recognize inclusion complexes formation involving monoterpenes and cyclodextrins: A study case with (-) borneol, a food ingredient

Food Chem. 2021 Mar 1:339:127791. doi: 10.1016/j.foodchem.2020.127791. Epub 2020 Aug 9.

Abstract

Monoterpenes are non-polar secondary metabolites widely used by industry due to their excellent therapeutic, food-ingredient and cosmetic properties. However, their low solubility in water limits their use. In this sense, cyclodextrins (CDs) have been widely used to solve these technological challenges. Thus, this study aims to use (-)-borneol as a monoterpene model to prepare inclusion complexes between β-CD and hydroxypropyl-β-CD (HP-β-CD) through different ways and characterize them in order to choose the best inclusion method to improve physicochemical properties of monoterpenes. To achieve this goal, the samples were prepared by physical mixture (PM), paste complex (PA) and freeze-drying complex (FD) and then, extensively characterized by thermal analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy, size particle, X-ray diffraction and nuclear magnetic resonance. The physicochemical results showed that freeze-drying was more effective to form inclusion complexes between (-)-borneol with both CDs. This research highlights the importance of recognizing the best method to prepare inclusion complexes, including food additives as (-)-borneol, to achieve better results in food preparations.

Keywords: (–)-borneol; Cyclodextrins; Food ingredient; Inclusion complexes; Monoterpene.

MeSH terms

  • 2-Hydroxypropyl-beta-cyclodextrin / chemistry
  • Calorimetry, Differential Scanning
  • Camphanes / chemistry*
  • Food Ingredients
  • Freeze Drying / methods
  • Magnetic Resonance Spectroscopy
  • Microscopy, Electron, Scanning
  • Monoterpenes / chemistry
  • Particle Size
  • Solubility
  • Spectroscopy, Fourier Transform Infrared / methods
  • X-Ray Diffraction
  • beta-Cyclodextrins / chemistry*

Substances

  • Camphanes
  • Food Ingredients
  • Monoterpenes
  • beta-Cyclodextrins
  • 2-Hydroxypropyl-beta-cyclodextrin
  • isoborneol