Improving Oxidative Stability of Polyphenolic Fraction of Apple Pomace by Encapsulation Using Naturally Occurring Polymers

Abstract

Polyphenolic compounds with relatively high antioxidant activity obtained from subcritical water extraction of apple pomace were assessed for encapsulation by spray drying technique, making use of polymeric substances co-extracted with the polyphenolic compounds. Comparative assessments were carried out of the directly encapsulated subcritical water extract (SWE) products with particles formed when encapsulated with the addition of hydroxyl propyl-β-Cyclodextrin (SWE + HPβ-CD). The powders were characterized for their physico-chemical properties such as, moisture content, density, particle size, hygroscopicity to assess their suitability within cosmetic formulations. The SWE and SWE + HPβ-CD encapsulated products resulted in different physical properties. Although the particle size was less than 4 μm for both products, the direct encapsulation (SWE) was highly hygroscopic and this property was significantly reduced with addition of HPβ-Cyclodextrin (SWE + HPβ-CD). Scanning electron microscopy (SEM) and Fourier Transform Infra-red (FT-IR) spectroscopic were employed to analyse the micronised powders to support evidence of encapsulation. Both techniques revealed the interaction between compounds in extract and the carrier HPβ-Cyclodextrin suggesting successful encapsulation. The effect of storage conditions on retention of antioxidant activity of the subcritical water extract was evaluated within 35 days for extracts with and without the carrier HPβ-Cyclodextrin. Hydroxyl propyl-β-Cyclodextrin offered protection against degradation of antioxidant compounds thereby potentially extending the shelf-life and making the encapsulated powder suitable for incorporation in cosmetic and pharmaceutical applications.

β-Cyclodextrin Inclusion Complexes with Catechol-Containing Antioxidants Protocatechuic Aldehyde and Protocatechuic Acid—An Atomistic Perspective on Structural and Thermodynamic Stabilities

“…The physicochemical properties of polyphenols (epicatechin, quercetin, CGA, PCAC, CFA, etc.) in plant extracts have been improved via CD inclusion complexation, for example, the thermal stability of H. sabdariffa L. anthocyanin extract by β-CD [31], the water solubility of propolis extract by β-CD [32], the thermal stability and antioxidant of St. John's wort extract by β-CD [33], and the oxidative stability of apple pomace extract by hydroxypropyl-β-CD (HP-β-CD) [34].…”

Citrus Peel Extracts for Industrial-Scale Production of Bio-Based Active Food Packaging

“…The SEM images show how the natural powder extracts are characterized by an amorphous and irregular shape, while after the spray-drying process with β-CD, the particles present a spherical shape and smooth surface, which is a typical feature of microparticles obtained by this encapsulation technique [ 35 , 36 ]. Although some particles present a “flat ball” effect, probably due to air bubbles originally generated during homogenization or atomization [ 16 ], no surface fractures are visibly confirming the successful encapsulation of citrus extracts with β-CD.…”