Encapsulation of Food Antioxidants as Potential

Functional Food Ingredients

Amyl Ghanem Ph.D. P.Eng.Chemical EngineeringDalhousie University

Health benefits of plant polyphenols

– Plant polyphenols possess a high spectrum of antioxidant, anti inflammatory anti bacterial and antiviral functions.

– Research suggests that plant polyphenols can slow the progression of certain cancers, reduce risk of cardiovascular disease, neurodegenerative disease, diabetes, osteoporosis etc.

Challenges

• Concentrations that are effective in vitro are often an order of magnitude higher than in vivo.

• Low bioavailability of polyphenols• small proportion of the molecules ingested orally actually

make it into bloodstream • short gastric residence time, low solubility/permeability in

the gut or degradation due to enzymes, pH etc. in the GI tract.

• Instability of molecules during food processing and storage • degradation due to exposure to light, oxygen, temperature.

Objective: • Protect the core/active material from degradation in storage, processing or

active conditions• Improve bioavailability, cell uptake of core/active material• Act as a slow release reservoir• Improve solubility of core/active material• target delivery of core/active material to a specific location

“Microencapsulation*”Technically the formation of a wall material around a core/active material to make a capsule, on the scale of 1-1000 microns. However this term has come to encompass “entrapment” as well, Which includes the distribution of the core/active material within a matrix:

wallCore/active

matrix

active

*Nanoencapsulation appliessimilarly to a nano-size range

Encapsulate or entrap plant extracts in microparticles/nanoparticles

• Achieve high concentration of active molecules in small volume.

• Matrix material would stabilize polyphenols during storage and processing.

• Matrix material could be used to improve bioavailability.• Applications exist in food, pharmaceutical and cosmetics

industries.• Aim for particle size range < 30 mm or even lower not affect

texture or clarity.

My background:Entrapment of molecules for Drug Delivery Systems

Aicello Japan

Purpose: to understand and manipulate the fate of drugs in humans.• Controlled release• Tissue targeting

Designed to release drug in the small intestine

Encapsulation Methods

–Spray dryingWidely used in the Food IndustryCommon wall materials:

• Modified starch• Maltodextrin• Gum Arabic

Spherical particles10-100 mmLimitations: wall materials, high T

Lane et al, Agricultural and Food Chemistry2008:11251-11261

Freeze-DryingDehydration process good for heat sensitive materialsActive material and matrix material in solutionResults in powder of “uncertain form”Great potential to combine with other methods

Cloudberry extract with Maltodextin

– Ionic interactions: Coacervation, Gelation

Active molecule + matrix material

Counter ion solution

Microcapsules withentrapped active molecule

Gel in solution deposits around the active ingredient which is suspended• Gelatin• Calcium alginate• ChitosanConsidered expensive but does not involve high temperatures or solvents.Control sizes from nano to micron sized

-Liposomes

Lipid bilayer membrane encapsulating an aqueous phase

Formed from phospholipids utilizing hydrophobic/hydrophilic interactions

Formed by: thin film evaporation, sonication, reverse phase evaporation,melting, freeze thawing, extrusion

A lot of literature on this techniqueShown to improve bioavailability and targetingOften low entrapment efficiency and loading Rapid release of active materialCan be improved by coatings

Fang and Bandhari, Trends in Food Science and Technology 21(2010) 510-523

– Inclusion Complex• Using cyclodextrin as an encapsulating material• Hydrophobic/hydrophilic areas helps to improve the water solubility of

molecules.

– Emulsification• Active material dispersed into matrix/wall material • emulsified and cooled; Or• evaporation of internal phase• Lipids, hydrophilic polymers such as gelatin, glucan or agarose

– Thermal gelation– Supercritical fluid– Combinations of techniques, crosslinking, coatings

etc.

Fang and Bandhari, Trends in Food Science and Technology 21(2010) 510-523

• Matrix material: chitosan

• Active material– BSA (sample protein)– Glucose oxidase (sample enzyme)– Cladribine, adenosine (nucleotides, anticancer drug)– bFGF (growth factor)

• Methods:– Complex coacervation of CH and TPP– Crosslinking with gluteraldehyde, glyoxal, genipin)

My background:Entrapment of molecules for Drug Delivery Systems

Chitosan Nanoparticles (CH NP)

Unmodified chitosan loaded with 100 ng of bFGF

87,000 x magnification (157 nm 23)

N-succinyl Chitosan, unloaded, dried

Magnification 16,500 ×(642 nm 90)

Unmodified, unloaded CHNanoparticles (112 nm 13)

Particle Properties

• Sizes: Microparticles and Nanoparticles– 100-150 nm when dried (swell to 500 nm)– Smooth spherical morphology– Some aggregation observed

• Good loading efficiencies– 70% for cladribine (anticancer drug)– 50% for bFGF (growth factor)

• Can manipulate to modify behaviour– Crosslinking (ionic, glyoxal, genipin)– Modification (N-succinyl chitosan)

Overall release from crosslinked Cladribine-loaded nanoparticles into PBS, pH 7.4.

Domaratzki, A and Ghanem, A. Journal Applied Polymer Science 2013, 128: 2173–2179

0

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0 20 40 60 80 100 120

Time (h)

Cum

ulat

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CdA

Rel

ease

(%)

Genipin Crosslinked (2 h, 0.1 mg/mL genipin)

Glyoxal Crosslinked (2 h, 50 mg/mL glyoxal)

No entrapment

18

Controlled Release

bFGF release from nanoparticles into PBS, pH 7.4

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bF

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CH

CH+heparin

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chitosan

+heparin

N succinyl chitosan

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Examples of Polyphenol Entrapment

Encapsulation of anthocyanin extract from jabuticaba and storage stability

Extracts by supercritical CO2, compared storage conditions of 3 systems

at 14 days:

EncapsulationEfficiency

Degradation 25 oC light

Degradation 25 oC No light

Degradation 4oNo light

Free anthocyanin

- 60% ~50% ~50%

Polyethylene glycol

79.78% 60 30 ~0

Ca-alginate system

98.67% 25 20 ~0

Both encapsulated systems were more stable under light and temperature

Santos et al, Food Research International, 2013:617-624

Spray drying of blueberry extract• Freeze dried blueberry, and blueberry pomace extracted into acetone (A), ethanol

(E) or methanol (M) • Spray dried with whey protein or gum arabic• Subjected to in vitro digestion model

EncapsulationEfficiency(TPC)

Antioxidant activity during digestion(Frap % 2hours)

Antioxidant activity during digestion(Frap %4hours)

Gum Arabic AEM

6810695

~658790

~30%3530

Whey ProteinAEM

53137102

658585

558085

Flores et al, Food Chemistry, 2014:272-278

No comparison to Free extractHowever they did show that WPI preserved antioxidant activity during simulated digestion

• Currently investigating extraction of blueberry polyphenols and encapsulation by spray drying and freeze drying

• Steps: what concentration can be achieved in the extract? • Recommend a combination of methods to achieve high

entrapment, stability and bioavailability• Main variables would include material(s), extraction

method for polyphenols, encapsulation• Encapsulation facilities

– spray drying, freeze drying, liposome formation, coacervation

Possible applications to Haskap

References• Encapsulation of Natural Polyphenolic Compounds: A Review. Munin, A.

and Edwards-Levy, F. Pharmaceutics. 2011:793-829.• Encapsulation of Polyphenol- a Review. Fang, Z and Bhandari, B. Trends in

Food Science and Technology 2010:510-523.