Recent Developments on Emulsification Techniques: Formulation of - PowerPoint PPT Presentation

Recent Developments on Emulsification Techniques: Formulation of Nanoscale Antioxidant Food Materials Antioxidant Food Materials Mitsutoshi Nakajima 1 2 Mitsutoshi Nakajima 1,2 , Marcos A. Neves 1,2 , Isao Kobayashi 2 1 Allience for Research on North Africa (ARENA), University of Tsukuba, Japan U i it f T k b J 2 National Food Research Institute, NARO, Japan Japan-New Zealand Joint Workshop on “Functional Foods” Tokyo (October 11 th , 2010) 1

Contents Introduction Emulsification processes Formulation of monodisperse emulsions using Microchannel emulsification  -carotene nanoemulsions passing through an in vitro digestion model g Food nanoemulsions containing bioactive compounds compounds Investigation of functional molecules from medicinal plants di i l l t Food nanotechnology Project

Introduction “Small, spherical droplets of one of two immiscible Emulsion liquids in the continuous phase of another” q p Classification Emulsifier Oil Water Nano-emulsion Macro-emulsion Bioactive (0.5-100  m)  (<500 nm) ( ) ( ) compound d Food Formulation Using Oil-in-Water Emulsions Food Formulation Using Oil-in-Water Emulsions  Increased bioavailability  Lipophilic bioactive compounds dissolved in oil  Wide application in food industry  Water dispersible system

Comparison of emulsification processes Relation between the type of process and size distribution Relation between the type of process and size distribution 10 -1  m 10 2  m 10 3  m 1  m 10  m 10 1 10 2 10 3 1 10 Size Size distribution distribution Conventional equipment Conventional equipment Colloidal mill （ Upper right fig. ） Wide High speed blender High speed blender （ higher than 30% ） High pressure homogenizer （ Lower right fig. ） Membrane emulsification Narrow （ around 10% ） （ d 10% ） Microchannel (MC) emulsification ( ) Hi hl Highly narrow （ lower than 5% ）

Protein-stabilized* O/W emulsions prepared by different methods prepared by different methods MC emulsification Homogenization (Straight-through MC) (Polytron) 100  m 100  m * Bovine serum albumin (1 wt%)

Microchannel emulsification Droplet generation Uniform droplets ( d : 1  m to 100  m) ( d av : 1  m to 100  m) Continuous Dispersed phase phase MC Terrace Terrace Droplets ・ Very mild droplet generation by spontaneous transformation y p of a dispersed phase that passed through MCs ・ Controllable generation of Controllable generation of uniform droplets with CV of less than 5% ・ MC array devices consisting of many MCs (>100)

Emulsification using straight-through MC arrays Major features Major features Symmetric type Symmetric type Obl Oblong MC MC ・ High-performance production of monodisperse (2 to 15  m-diam.) emulsions due to highly integrated MCs (Droplet productivity ： 10 to 2,000 L/(m 2 h)) (Droplet productivity ： 10 to 2,000 L/(m h)) ・ Stable generation of highly uniform droplets Kobayashi et al ., AIChE J ., 2002 y of low viscosity using asymmetric straight- of low viscosity using asymmetric straight through MCs Asymmetric type Asymmetric type Mi Microslot l t Asymmetric type Asymmetric type Symmetric type Symmetric type Symmetric type Symmetric type Asymmetric type Asymmetric type Aqueous q Aqueous q Microhole Microhole (10  m-diam.) solution solution Droplets Droplets (Soybean oil) (Decane) 100  m 100  m 100 mm 100 mm Kobayashi et al ., Langmuir , 2005

High-performance production of O/W emulsion using asymmetric straight-through MC array (WMS2-2) y g g y ( )  Continuous phase: Milli-Q water with 0.3wt% SDS  Dispersed phase ： Refined soybean oil spe sed p ase e ed soybea o 200  m  Flow rate of dispersed phase: 10 mL h -1 Highly uniform oil droplets with an average diameter of about 30  m were Highly uniform oil droplets with an average diameter of about 30  m were generated at a high dispersed-phase flux (100 L m -2 h -1 ). Kobayashi et al ., MicroTAS2007

Effect of aspect ratio of oblong MCs ( R MC ) ( w s MC : ~10  m, R MC : w l MC / w s MC )  ( , s,MC ) s,MC MC l,MC  Refined soybean oil-in-Milli-Q water with 1.0 wt% SDS system Continuous expansion Generation of Continuous expansion Generation of Stable generation of Stable generation of polydisperse droplets of dispersed phase monodisperse droplets 1 0 mL h -1 Q : 1 0 mL h -1 Q d : 1.0 mL h 1 1.0 mL h 1 1 0 mL h -1 R R MC : 3.8 : 3 8 1.0 mL h R R MC : 1.9 : 1 9 R R MC : 2.7 : 2 7   w w l,MC w s,MC 100  m 100  m 100  m * Q d : Flow rate of dispersed phase d av : 41.9  m CV: 1.9% Oblong straight-through MCs with R MC over a threshold value of about 3 are needed for stably generating uniform droplets stably generating uniform droplets. Kobayashi et al ., J. Colloid Interface Sci. (2004)

Droplet generation process calculated using CFD (Oblong straight-through MC, R MC : 2) ( g g g ) MC (a) 0 ms (a) 0 ms (b) 20.2 ms (b) 20.2 ms (c) 36.5 ms (c) 36.5 ms (d) 48.8 ms (d) 48.8 ms 20  m 2 Water Channel Channel exit Soybean oil Z Y Y X X

Droplet generation process calculated using CFD ( (Oblong straight-through MC, R MC : 4) g g g ) MC  Flow velocity of the dispersed phase at the MC inlet ( U d,MC ): 1.0 mm/s (a) 0 0000 s (a) 0.0000 s (b) 0 0201 s (b) 0.0201 s (c) 0.0362 s (c) 0 0362 s (d) 0.0395 s (d) 0 0395 s 20  m 2 Water Neck Droplet Soybean oil Z Y Y X X Sufficient space for the continuous phase at the MC outlet must be kept Sufficient space for the continuous phase at the MC outlet must be kept to achieve successful droplet generation.

Applications of MC emulsification W/O/W emulsions Giant vescicles Solid microparticles Gel microparticles (Kobayashi et al ., 2005) (kuroiwa et al ., 2008) (Sugiura et al ., 2000) (Kawakatsu et al ., 1999) 40  m 50  m Coaservate Nanoparticle stabilized O/W emulsions stabilized by microcapsules microcapsules O/W emulsions O/W emulsions modified lecithin and chitosan modified lecithin and chitosan (Nakagawa et al ., 2004) (Xu et al ., 2005) (Chuah et al ., 2009) 50  m 100  m 10  m

F F Formulation and characterization Formulation and characterization l ti l ti d d h h t t i i ti ti of oil of oil in of oil of oil-in in-water emulsions in water emulsions water emulsions water emulsions containing bioactive compounds containing bioactive compounds To develop a method efficient to Approach: produce monodisperse emulsions with antioxidant food materials, and evaluate their stability evaluate their stability

Bioactive food compounds  Palm oil Palm oil Functional compound  -carotene (C 40 H 56 )  ( 56 ) Oil palm fruit p Palm oil 40  Fish oil Fish oil Functional compounds O OH  -Linolenic Acid (ALA) (18:3  -3)  -Linolenic Acid (ALA) (18:3  -3) O Fish oil Atlantic Menhaden OH Eicosapentaenoic Acid (EPA) (20:5  -3) ( Brevoortia tyrannus ) ( y ) O OH Docosahexaenoic Acid (DHA) (22:6  -3) Omega-3 polyunsaturated fatty acids (  -3 PUFAs)

Methodology Disperse phase: Disperse phase: Red palm Superolein + PUFA (45 g/L) Continuous phase: Water +  Lactoglobulin (1wt%) + Continuous phase: Water +  -Lactoglobulin (1wt%) + Continuous phase: Continuous phase: Sucrose laurate (L-1695) (1wt%)  -carotene rich  Palm oil PUFA O/W emulsion  260 mg  -carotene/L Water + emulsifiers Scheme of microchannel (MC) emulsification process

Experimental setup for MC emulsification video video camera syringe pumps microscope O/W emulsion MC emulsification module MC emulsification module

Microchannel plate  Asymmetric Straight Through (AST) Asymmetric Straight Through (AST) T Top view i Alternate vertical-horizontal slits Silicon fabricated Hydrophilic (surface oxidized) Specification: WMS 1-4 Dimensions: Diameter: 10  m Diameter 10 m Slit: - longer line: 50  m Cross-sectional view - shorter line:10  m shorter line:10  m Number of channels:  23, 400 Active area: 1 x 10 –4 m 2 Active area: 1 x 10 m

Results  Emulsification at various Emulsification at various levels of oil flux levels of oil flux using using  -carotene rich  carotene rich carotene rich palm oil carotene rich palm oil palm oil loaded with PUFAs palm oil loaded with PUFAs loaded with PUFAs loaded with PUFAs 50  m 50  m Oil flux: 10 L/(m 2 ·h) Oil flux: 80 L/(m 2 ·h) d av = 27.6  m d av = 33.7  m d 27 6 d 33 7 CV = 3.3 % CV = 15.1 % Images of PUFA-loaded droplets formed using the AST MC plate at various oil fluxes (in both cases the continuous phase flow rate was 10 mL · h -1 ) Neves et al ., Food Biophysics 2008

Conclusions (1)  Monodisperse PUFA-loaded emulsions containing  -  M di PUFA l d d l i t i i carotene were obtained successfully by Microchannel emulsification.  Increasing the oil flux above 40 Lm -2 h -1 , polydisperse droplets with high coefficient of variation were produced.  The emulsions formed were nearly stable for 3 weeks without coalescence or phase separation.  Monodispersed droplets and droplet size are of essential importance because of its great influence on physical importance because of its great influence on physical stability.