Enhancing extraction processes in the food industry edited by nikolai lebovka, eugene vorobiev, and farid chemat

Contemporary Food EngineeringSeries Editor Professor Da-Wen Sun, Director Food Refrigeration & Computerized Food Technology National University of Ireland, Dublin University College Dubl

Enhancing Extraction Processes in the

Food Industry

Contemporary Food Engineering

Series Editor

Professor Da-Wen Sun, Director

Food Refrigeration & Computerized Food Technology National University of Ireland, Dublin (University College Dublin) Dublin, Ireland http://www.ucd.ie/sun/

Advances in Food Extrusion Technology, edited by Medeni Maskan and Aylin Altan (2011) Enhancing Extraction Processes in the Food Industry, edited by Nikolai Lebovka, Eugene Vorobiev, and Farid Chemat (2011)

Emerging Technologies for Food Quality and Food Safety Evaluation,

edited by Yong-Jin Cho and Sukwon Kang (2011)

Food Process Engineering Operations, edited by George D Saravacos and

Mathematical Modeling of Food Processing, edited by Mohammed M Farid (2009)

Engineering Aspects of Milk and Dairy Products, edited by Jane Sélia dos Reis Coimbra and José A Teixeira (2009)

Innovation in Food Engineering: New Techniques and Products, edited by Maria Laura Passos and Claudio P Ribeiro (2009)

Processing Effects on Safety and Quality of Foods, edited by Enrique Ortega-Rivas (2009) Engineering Aspects of Thermal Food Processing, edited by Ricardo Simpson (2009) Ultraviolet Light in Food Technology: Principles and Applications, Tatiana N Koutchma, Larry J Forney, and Carmen I Moraru (2009)

Advances in Deep-Fat Frying of Foods, edited by Serpil Sahin and Servet Gülüm Sumnu (2009)

Extracting Bioactive Compounds for Food Products: Theory and Applications,

edited by M Angela A Meireles (2009)

Advances in Food Dehydration, edited by Cristina Ratti (2009)

Optimization in Food Engineering, edited by Ferruh Erdoˇgdu (2009)

Optical Monitoring of Fresh and Processed Agricultural Crops, edited by Manuela Zude (2009) Food Engineering Aspects of Baking Sweet Goods, edited by Servet Gülüm Sumnu and Serpil Sahin (2008)

Computational Fluid Dynamics in Food Processing, edited by Da-Wen Sun (2007)

Enhancing Extraction Processes in the

Food Industry

Edited by

Nikolai Lebovka Eugene Vorobiev Farid Chemat

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Contents

List of Figures vii

List of Tables xvii

Series Preface xxi

Preface xxiii

Acknowledgments xxv

Series Editor xxvii

Editors xxix

Contributors xxxi

Abbreviations xxxv

Chapter 1 Introduction to Extraction in Food Processing 1

Philip J Lloyd and Jessy van Wyk Chapter 2 Pulse Electric Field-Assisted Extraction 25

Eugene Vorobiev and Nikolai I Lebovka Chapter 3 Microwave-Assisted Extraction 85

María Dolores Luque de Castro and Feliciano Priego-Capote Chapter 4 Ultrasonically Assisted Diffusion Processes 123

Zbigniew J Dolatowski and Dariusz M Stasiak Chapter 5 Pulsed Electrical Discharges: Principles and Application to Extraction of Biocompounds 145

Nadia Boussetta, Thierry Reess, Eugene Vorobiev, and Jean- Louis Lanoisellé Chapter 6 Combined Extraction Techniques 173

Farid Chemat and Giancarlo Cravotto Chapter 7 Supercritical Fluid Extraction in Food Processing 195

Rakesh K Singh and Ramesh Y Avula Chapter 8 Pressurized Hot Water Extraction and Processing 223

Charlotta Turner and Elena Ibañez

Chapter 9 Instant Controlled Pressure Drop Technology in Plant

Extraction Processes 255

Karim Salim Allaf, Colette Besombes, Baya Berka,

Magdalena Kristiawan, Vaclav Sobolik, and

Chapter 11 Extrusion-Assisted Extraction: Alginate Extraction from

Macroalgae by Extrusion Process 323

Peggy Vauchel, Abdellah Arhaliass, Jack Legrand,

Régis Baron, and Raymond Kaas

Chapter 12 Gas-Assisted Mechanical Expression of Oilseeds 341

Paul Willems and André B de Haan

Chapter 13 Mechanochemically Assisted Extraction 361

Oleg I Lomovsky and Igor O Lomovsky

Chapter 14 Reverse Micellar Extraction of Bioactive Compounds for

Food Products 399

A B Hemavathi, H Umesh Hebbar, and

Karumanchi S. M. S. Raghavarao

Chapter 15 Aqueous Two-Phase Extraction of Enzymes for Food Processing 437

M C Madhusudhan, M C Lakshmi, and

Karumanchi S. M. S. Raghavarao

Chapter 16 Enzyme-Assisted Aqueous Extraction of Oilseeds 477

Stephanie Jung, Juliana Maria Leite Nobrega de Moura,

Kerry Alan Campbell, and Lawrence A Johnson

List of Figures

FIGURE 1.1 Solubility of caffeine in SC-CO2 and CO2–ethanol 4

FIGURE 1.2 Use of triangular coordinates 5

FIGURE 1.3 Solubility representation in a ternary diagram 6

FIGURE 1.4 Transfer of solute between two liquid phases 7

FIGURE 1.5 Extraction in a single stage 10

FIGURE 1.6 Differential extraction circuit 11

FIGURE 1.7 Batch countercurrent operation 12

FIGURE 1.8 Continuous countercurrent mixer–settler 13

FIGURE 1.9 Elevation view of a settler, showing weir arrangement to separate phases 14

FIGURE 1.10 Extraction column operated with the solvent phase continuous 15

FIGURE 1.11 Graphical estimation of number of countercurrent stages 16

FIGURE 1.12 Graphical estimation of number of countercurrent stages where extract and raffinate are mutually insoluble (McCabe–Thiele diagram) 17

FIGURE 2.1 The PEF-assisted technique 26

FIGURE 2.2 Electrophysical schema of a cell Here R is the radius of the cell; d is the membrane width; θ is the angle between the external field E and radius vector r at the surface of membrane; C is the membrane capacitance; and σm, σ, and σdare the electrical conductivities of the membrane, extracellular medium, and cytoplasm, respectively 29

FIGURE 2.3 Electroporation factor e versus σ/σi (Equation 2.2) The curves, k = σd/σi, were obtained from Equations 2.2 through 2.3 at R = 50 μm (for plant tissues) Curve 1 was calculated for σm = 3 ×10–7 S/m, σd = 0.3 S/m, and R = 5 μm (for microbial cell) 31

FIGURE 2.4 Estimation of electrical conductivity disintegration index ZC from (a) PEF treatment time tPEF and (b) frequency f dependencies of tissue electrical conductivity σ 33

FIGURE 2.5 Dependencies of ZC versus ZD and ZC versus ZA for potato

and apple, respectively The pulse protocols were as follows: E = 400 V/cm,

ti = 10–4 s (potato) and E ≈ 300 V/cm, ti = 10–4 s (apple) The dashed lines

correspond to the least square fitting of the experimental data to power

equations Z Z m

C = DD and Z Z m

C = AA with mD = 1.68 ± 0.04 for potato and

mA = 3.77 ± 0.26 for apple 37

FIGURE 2.6 Characteristic time τ versus electric field strength E

for different vegetable and fruit samples Data were obtained from the

measurements of acoustic disintegration index of PEF-treated samples in

tap water (Compiled from data presented in Grimi, N., PhD dissertation,

University of the Technology of Compiègne, Compiègne, 2009.) The inset

shows schematic Z versus t dependence; here τ is the characteristic damage

time, defined as the time necessary for half-damage of material (i.e., Z = 0.5) 39

FIGURE 2.7 The typical PEF protocol Bipolar square waveform pulses are

presented A series of N pulses (train) is shown Each separate train consists

of n pulses with pulse duration ti, pause between pulses Δt, and pause Δtt

after each train The total time of PEF treatment is regulated by variation of

the number of series N and is calculated as tPEF = nNti 41

FIGURE 2.8 Power consumption Q (ZC= 0.8) versus electric field strength

E at different values of k = σi/σd: (a) results of Monte Carlo simulations and (b) experimentally estimated values for potato and orange 44

FIGURE 2.9 Correlations between characteristic damage time τ and power

consumption Q for different fruit and vegetable tissues The value of Q

was estimated at a relatively high level of disintegration (ZC = 0.8) for PEF

treatment at E = 400 V/cm with 1000 μs bipolar pulses of near-rectangular shape 44

FIGURE 2.10 Arrhenius plots of the effective diffusion coefficient Deff for the untreated and PEF-pretreated sugar beet slices 48

FIGURE 2.11 Temperature dependencies of diffusion juice purity P and

sucrose concentration S in experiment with untreated and PEF-treated sugar beet cossettes PEF treatment was done at E = 600 V/cm; the pulse duration

ti was 100 μs; and the total time of PEF treatment tPEF was 50 ms, which

corresponded to 5.4 kW·h/t of power consumption 48

FIGURE 2.12 The electrical conductivity disintegration index ZC versus

effective PEF treatment time (tPEF) and thermal treatment time (tT) at

different temperatures T Cs is the surfactant concentration (wt.%) PEF

treatment was done at electric field strength E = 5 kV/cm and pulse duration

ti = 10−3 s 61

FIGURE 2.13 (a) A scheme and (b) a photo of a pilot belt press recently

used for PEF-assisted expression from the sugar beets 65

FIGURE 2.14 The colinear treatment chamber used at a pilot plant for

PEF processing of red grapes (a) The treatment chamber consisted of

three cylindrical electrodes (stainless steel) separated by two methacrylate

insulators The central electrode was connected to high voltage and two

others were grounded (b) The distribution of the electric field strength E

was not uniform An example of E distribution simulated by method of finite elements for 14.2 kV input voltage is shown The value of E changes from the

weakest (1 kV/cm) to the strongest (7 kV/cm) 66

FIGURE 3.1 Major components of a typical multimode microwave system 91 FIGURE 3.2 Commercially available closed-vessel systems from (a) CEM

Corporation and (b) Milestone 93

FIGURE 3.3 (a) Assembly for the simultaneous treatment of up to 6

samples 1–8, open–close valves; AAS, atomic absorption spectrometer;

CT, sample collector tube; FS, flowing sample collector; R, recorder

(b) Online development of leaching, liquid–liquid extraction, and sorption/

cleanup with manual transportation to the GC–MS equipment IV, injection valve; PS, membrane phase separator; W, waste; XAD–2, sorbent material (c) Schematic depiction of the continuous microwave system 98

FIGURE 3.4 (a) Dynamic focused microwave-assisted extractor (b)

Experimental setup used to integrate microwave-assisted extraction with the subsequent steps of the analytical process Leaching: CT, controller; ER,

extract reservoir; MD, microwave digestor; R, refrigerant; S, sample; TCPP, two-channel piston pump; WR, water reservoir Clean up–preconcentration:

A, air; B, buffer; E, elution direction; EL, elution loop; F, filter; M,

methanol; MC, microcolumn; PP, peristaltic pump; R, retention direction;

SV, switching valve; VI, injection valve; W, waste Individual separation–

detection; AC, analytical column; DAD, diode array detector; HPIV,

high-pressure injection valve; SR, solvent reservoirs 100

FIGURE 3.5 (a) Comparison of the performance of a conventional Soxhlet

extractor and (b) the early prototype of focused microwave-assisted Soxhlet extractor from Prolabo 101

FIGURE 3.6 Scheme of a glass system used for atmospheric pressure

microwave-assisted liquid–liquid extraction 106

FIGURE 3.7 Extraction kinetics of fat from bakery products as performed

by (a) FMASE (solid line) and without microwave assistance (dashed line)

and (b) with the classic Soxhlet technique for the same target sample 109

FIGURE 4.1 Cavitation phenomenon at the solid phase boundary 129 FIGURE 4.2 Principle of ultrasound-aided leaching (S, solid; A, solid

matrix; i, solute; B, solvent; M, mixture; E, extract; R, residue) 130

FIGURE 4.3 Principle of ultrasonically assisted drying process 136 FIGURE 4.4 Diagram showing the principles behind extractors equipped

with ultrasound: (a) with belt (bucket) conveyor and (b) with screw conveyor 138

FIGURE 5.1 Experimental setup devoted to physical studies of discharges

in water gaps (Electrical Engineering Laboratory of Pau University) H.V.,

high voltage; O.F., optic fiber 147

FIGURE 5.2 I.C records in frame mode, associated voltage, and UV light

records (electrode radius = 200 μm, water gap = 28 mm, U = 30 kV) 149

FIGURE 5.3 Typical I.C records showing the development of bubbles into

water (electrode radius = 1 mm, water gap = 10 mm, Umax= 19.5 kV; t1 =

137 μs, t2 = 246 μs, t3= 350 μs, t4= 523 μs, t5 = 630 μs, and t6 = 746 μs) 150

FIGURE 5.4 Example of (a) pressure versus time curve and (b) its

associated Fourier transform 151

FIGURE 5.5 Conductivity disintegration index Z versus number of

HPH passes Nh at different pressures P for yeast suspensions (a) without

pretreatment, Zi = 0, and (b) with discharges pretreatment (PAED), Zi =

0.15 ± 0.05 154

FIGURE 5.6 Yield of solute during extraction from slices treated at 40 kV

and different numbers of discharges 155

FIGURE 5.7 Optimization of oil extraction from linseed meal by PAED 158 FIGURE 5.8 Effect of extraction temperature on yield of solutes of fresh

grape pomace Dashed lines followed by bold solid lines (solid marks)

represent the yield of solutes for grape pomace with PAED extraction (PAED

treatment conditions: delectrodes = 5 mm, U = 40 kV, N = 80 pulses, ti = 10 μs) Nonbold lines (open marks) correspond to experiments without PAED 159

FIGURE 5.9 Total polyphenol content C versus extraction time t for

untreated and PEF-treated grape skins at T = 20°C (PEF treatment: E =

1300 V/cm, tt = 1 s PAED treatment: delectrodes = 10 mm, U = 40 kV, tt = 120 s) 161

FIGURE 5.10 HPLC profiles from the extracts obtained at 20°C after 60

min of extraction for untreated, PEF-treated, and PAED-treated grape skins

Identified compounds are (a) catechin, (b) epicatechin, (c)

quercetin-3-O-glucoside, and (d) kaempferol-3-O-glucoside (PEF treatment: E = 1300 V/ cm,

tt =1 s PAED treatment: delectrodes = 10 mm, U = 40 kV, tt =120 s) 162

FIGURE 5.11 PAED treatment apparatus used (a) at a laboratory scale and

(b) at a semipilot scale 165

FIGURE 5.12 Effects of the treatment energy on the contents of (a) total

polyphenols and (b) antioxidant activity at the semipilot scale 166

FIGURE 6.1 Acoustically aided filtration 177 FIGURE 6.2 MWs combination with Soxhlet extraction 179 FIGURE 6.3 Conventional Clevenger, combined MW Clevenger, and an

“upside-down” MW alembic for extraction of essential oils 180

FIGURE 6.4 Simultaneous US–MW-assisted extraction of plant material 184 FIGURE 6.5 US-assisted extraction in flow reactor 186

FIGURE 6.6 Combined MWs and instantaneous controlled pressure drop

process: (1) MW autoclave; (2) vacuum tank with cooling water jacket;

(3) controlled instant pressure-drop valve; (4) extract container; (F1) cooling water flow 187

FIGURE 6.7 Combined US–SFE and cavitation bubble collapse near plant

material in supercritical CO2 188

FIGURE 7.1 Flow diagram of a supercritical fluid extraction (SFE) system 198 FIGURE 7.2 Schematic diagram of the pilot scale SFE unit 199 FIGURE 7.3 Scanning electron micrograph (×3000) of ground palm kernel: (A) before extraction, (B) after continuous extraction at 25 MPa, (C) after

pressure swing extraction at 25 MPa [a, oil; b, membrane; c, cell structure] 200

FIGURE 7.4 Differential scanning calorimetric melting thermograms

(10°C/min) of buffalo butter oil (BO) and its fractions (F1–F4) obtained at

different temperature and pressure conditions of SC-CO2 extraction 208

FIGURE 7.5 Differential scanning calorimetric crystallization

thermograms (10°C/min) of buffalo butter oil (BO) and its fractions

(F1– F4) obtained at different temperature and pressure conditions of

SC-CO2 extraction 209

FIGURE 8.1 Sites on a sample matrix particle where analytes can be found 226 FIGURE 8.2 Solubility parameter of water 227 FIGURE 8.3 SFE of chrysene from diesel soot, and hot ball model

including rapid fluid entry, reversible release (desorption), transport out of

matrix, and removal by fluid 228

FIGURE 8.4 Dielectric constant of water vs temperature and methanol/

water and acetonitrile/water mixtures at room temperature 229

FIGURE 8.5 UV and ECD chromatograms of a birch bark extract produced

by a 5-min extraction plus a 5-min hydrothermal treatment in water at 180°C 231

FIGURE 8.6 Schematic of a PHWE system 234 FIGURE 8.7 An example of a home-built dynamic PHWE system 237 FIGURE 8.8 Record of number of papers published vs years for PHWE

(search done in Web of Science Oct-10 using the keywords “hot water

extract* and food* OR agric*”/“subcrit* water extract* and food* OR agric*

OR plant*”) 239

FIGURE 8.9 Schematic layout of WEPO process 245 FIGURE 9.1 Paradoxical stage and “front progression” kinetics from coupled

transfers of heat and volatile compounds, in standard steam distillation 260

FIGURE 9.2 Instant controlled pressure drop (DIC) apparatus 261

FIGURE 9.3 Temperature and pressure of a DIC processing cycle: Ti is

initial temperature of the product, Tf denotes highest temperature of the

product: (a) sample at atmospheric pressure; (b) initial vacuum; (c) saturated steam injection to reach the selected pressure; (d) constant temperature

corresponding to saturated steam pressure; (e) abrupt pressure drop toward a vacuum; (f) vacuum; (g) release to atmospheric pressure 262

FIGURE 9.4 Pressure change in a multicycle DIC process 263 FIGURE 9.5 Experimental protocol for extracting and assessing essential

oils 267

FIGURE 9.6 Pareto charts of the number of cycles and operating time to

identify impacts of autovaporization and evaporation, respectively, on direct DIC extraction of essential oils from valerian root, lemongrass, chamomile, angelica seeds, thyme, and lavandin essential oils 272

FIGURE 9.7 Relative extraction rate of various compounds of lavandin

essential oils versus 20-s cycles (2, Eucalyptol [C10H18O]; 4, camphor

[C10H16O]; 9, α-terpineol [C10H18O]; 10, hexylisovalerate [C11H22O2]; 12,

lavandulyl acetate [C12H20O2]; 17, α-humulene [C15H24]; 21, τ-cadinol

[C15H26O]; 22, α-terpineol [C10H18O]) 278

FIGURE 9.8 Kinetics of hexane extraction of: (a) jatropha oil and

(b) rapeseed oil Untreated compared with DIC treated seeds (sample nos

1, 2, and 10) 287

FIGURE 9.9 Standardized Pareto chart from response surface method

experimental design for oil rapeseed oil yields 289

FIGURE 9.10 Solvent extraction of active molecules: (a) anthocyanins

from Algerian myrtle with DIC treatment at 0.28 MPa for 9 s; (b) flavonoids from Algerian buckthorn with DIC treatment at 0.5 MPa for 180 s, and

5 cycles; (c) flavonoids from Algerian myrtle with DIC treatment at 0.5 MPa for 180 s, and 5 cycles Unit 1: mg of equivalent delphinidine-3-glucocide

anthocyanins/g of Algerian myrtle dry matter; unit 2: mg of equivalent

kaempferol flavonoids/g of Algerian buckthorn dry matter; unit 3: mg of

equivalent myricetin flavonoids/g of Algerian myrtle dry matter 290

FIGURE 9.11 Pilot-scale DIC reactor TMDR0.3 (located in Queretaro,

Mexico) 295

FIGURE 9.12 Pilot-scale DIC reactor TADR0.25 (located in Alicante, Spain) 295 FIGURE 9.13 Industrial-scale DIC reactor TLDR0.5 (located in La

Rochelle, France) 296

FIGURE 10.1 (a) High pressure extraction equipment, (b) sample with

extraction solvent packed in flexible plastic bag, and (c) high pressure vessel 306

FIGURE 10.2 Comparison of DPPH and superoxide scavenging activity

from litchi fruit pericarp using conventional extraction (CE), ultrasonic

assisted extraction (UAE), and high pressure–assisted extraction (HPE) For each treatment, means in a row followed by different letters are significantly

different at P < 05 308

FIGURE 10.3 Total phenolic content and extraction yield from longan fruit

pericarp using various extraction times under 500 MPa, with 50% ethanol

and 1:50 (w/v) solid/liquid ratio at 30°C For each treatment, means in a row

followed by different letters were significantly different at P < 05 309

FIGURE 10.4 Phenolic contents of longan fruit obtained by high pressure–

assisted extract of longan (HPEL) and conventional assisted extract of longan (CEL) Values are means ± standard deviations of three replicate analyses 310

FIGURE 10.5 HPLC profile of corilagin obtained from longan fruit

pericarp extracted at different high pressures 310

FIGURE 10.6 Total antioxidant activity by phosphomolybdenum method of

HPEL compared to CEL and BHT Results are mean ± SD of three parallel measurements Higher absorbance value indicates higher antioxidant activity HPEL, high pressure–assisted extract of longan; CEL, convention-assisted

extract of longan; BHT, butylated hydroxy toluene 311

FIGURE 10.7 Comparison of DPPH radical scavenging activity from

longan fruit pericarp after application of conventional extraction (CE) and

different ultrahigh pressure–assisted extraction conditions (UHPE-200,

UHPE-300, UHPE-400, and UHPE-500 MPa) Different letters above bars

for the same concentration indicates significant differences among means of

treatments (P < 05) 313

FIGURE 10.8 Comparison of total antioxidant activity from longan fruit

pericarp after application of conventional extraction (CE) and different

ultrahigh pressure–assisted extraction (UHPE-200, UHPE-300, UHPE-400, and UHPE-500 MPa) Different letters above bars for the same concentration

indicates significant differences among means of treatments (P < 05) 314

FIGURE 10.9 Comparison of superoxide anion radical scavenging activity

from longan fruit pericarp after application of conventional extraction (CE) and different ultrahigh pressure–assisted extraction (UHPE-200, UHPE-300, UHPE-400, and UHPE-500 MPa) Different letters above bars for the same concentration indicates significant differences among means of treatments

(P < 05) 314

FIGURE 10.10 Comparison of tyrosinase inhibitory activity from longan

fruit pericarp after application of CE and different ultrahigh pressure–assisted extraction (UHPE-200, UHPE-300, UHPE-400, and UHPE-500 MPa) 315

FIGURE 10.11 Microscopy image of raw (left) and high pressure–treated

(300 MPa for 2 min, right) carrot tissues 319

FIGURE 11.1 Main elements of an extruder .324

FIGURE 11.2 Twin-screw configurations and screw element examples 325 FIGURE 11.3 Comparison of extraction yields and extraction times for

hemicellulose extraction from poplar wood in twin-screw extruder (TSE) and

in batch reactor 327

FIGURE 11.4 Schematic presentation of batch process steps for alginate

extraction 332

FIGURE 11.5 Screw profile Screw elements nomenclature: letters

correspond to the screw element type, and numbers correspond to the element length and pitch T2F, trapezoid groove transfer elements (direct pitch); C2F,

U groove transfer elements (direct pitch); C2FC, U groove reverse pitch

element; 100/50, 100-mm-long element with a 50 mm pitch 333

FIGURE 11.6 Reduced viscosity versus concentration curves (O)

high-viscosity commercial sodium alginate, (Δ) sodium alginate produced by

batch extraction, and (◻) sodium alginate produced by extrusion extraction (linear correlations are represented as a solid line) 336

FIGURE 12.1 Unit operations of various oil recovery technologies 342 FIGURE 12.2 Principle of GAME 344 FIGURE 12.3 CO2 content at 40°C at equilibrium for palm kernel (◻),

jatropha (○) and linseed (▵) oil Literature values for cocoa butter (Venter et al 2007) (◇), sesame (Bharath et al. 1992) (-), palm kernel (Bharath et al 1992)

(- -) and rapeseed (Klein and Schulz 1989) (····) oil are included for comparison 345

FIGURE 12.4 Viscosity for palm kernel (◻,-), jatropha (○,⋯) and linseed (▵,- -) oil at 40°C as function of CO2–pressure 346

FIGURE 12.5 Density of CO2 saturated palm kernel (◻), jatropha (○)

and linseed (▵) oil at 40°C as function of CO2–pressure and density of pure palm kernel (Acosta et al 1996) (-) and linseed oil (Acosta et al 1996) (⋯) as function of pressure 347

FIGURE 12.6 Schematic representation of a hydraulic press 348 FIGURE 12.7 Oil yield as function of the effective mechanical pressures

(Peff) at 40°C for different CO2 pressures for (a) sesame and (b) linseed:

PCO2 = 0 MPa (◻), 8 MPa (○), 10 MPa (▵), and 15 MPa (◇) Lines serve as

visual aid only 349

FIGURE 12.8 Oil yield as function of effective mechanical pressure for

(a) rapeseed (▴,▵) and palm kernel (◇), and (b) jatropha (stars) and jatropha dehulled (pentagrams) at 40°C with 0 MPa CO2 (closed) and 10 MPa CO2

(open) Lines serve as visual aid only 350

FIGURE 12.9 (a) Effective mechanical pressure for conventional expression

and GAME and compression rate as a function of time in four-stage pressing

experiments GA, gas assistance (b) Oil yield as a function of contact time of

CO2 in four-stage pressing, CO2 injection after the third stage 351

FIGURE 12.10 Yields for conventional, GAME, rupture, and entrainment

experiments for sesame (light) and linseed (dark) 353

FIGURE 12.11 Prediction of GAME yields (lines) based on conventional

yields (closed symbols) and solubility of CO2 (Bharath et al 1992; Willems 2007) Experimental GAME yields are also shown (a) Sesame (◼,◻,-) and

dehulled jatropha (●,○,···), (b) linseed (◆,◇,-) and hulled jatropha (▴,▵,⋯)

(Peff = 30 MPa, T = 40°C, PCO2 = 10 MPa) 354

FIGURE 12.12 Schematic of a two-stage extruder for GAME (www.sustoil org) 355

FIGURE 12.13 Predicted (a) pressure, (b) liquid content, and (c) viscosity

profiles for the cases studied (90 rpm) 356

FIGURE 13.1 Cross section along the culm of a herbaceous plant (rye) 369 FIGURE 13.2 Ultrafine cuts of the preparations of oil palm bunches The

preparations were fixed by osmic acid; the ultrafine cuts were stained by

uranyl acetate Notations are explained in the text Scale bars correspond to (a,c) 1 μm and (b,d–f) 2 μm 374

FIGURE 13.3 Mechanochemical treatment results in enzyme introduction

into the bulk of lignocellulose material and into reaction zone (to the right); for comparison, addition of the substrate to the aqueous enzyme solution

(to the left) 380

FIGURE 13.4 Comparison of the known methods of extraction by organic

solvents and mechanochemically assisted extraction 383

FIGURE 13.5 Hypericin content in the plant raw material versus time and

intensity of mechanical treatment in mill activator AGO-2 Acceleration of

milling bodies are 20, 40, and 60 g 384

FIGURE 13.6 Changes in activity of the cellulase under mechanical

treatment: (1) treatment of the preparation without a substrate and

(2) concurrent treatment of the preparation and microcrystalline cellulose 385

FIGURE 13.7 Dynamics of silicon dioxide dissolution for silicon dioxide

from mechanocomposite on the basis of green tea and silica gel: (1) activated silica gel, (2) concurrently activated silica gel, and tea powder (10:1), and

(3) activated silica gel in tea solution 387

FIGURE 13.8 HPLC chromatogram with electrochemical detection:

(a) reference sample prepared from the soluble forms of campesterol and

β-sitosterol, (b) product of the mechanochemical treatment of the raw

material in the presence of a soluble saccharide, and (c) product of the

mechanical treatment of the raw material without a saccharide 389

FIGURE 13.9 Chromatograms of the lappaconitine-containing

product of extraction for the cases of extraction by solvents (left) and

mechanochemically assisted extraction (right) 392

FIGURE 14.1 Solubilization of different biomolecules in reverse micelles:

(a) hydrophilic, (b) surface active, and (c) hydrophobic 401

FIGURE 14.2 Equilibrium phase diagram of AOT/isooctane/water 402 FIGURE 14.3 Methods of carrying out RME: (a) injection of aqueous

phase containing solute, (b) addition of dry powder, and (c) phase transfer 408

FIGURE 16.1 Schematic representation of (a) single-stage extraction and

(b) countercurrent multistage extraction 485

FIGURE 16.2 Flowchart of the steps involved in the integrated

protease-assisted aqueous extraction of extruded full-fat soybean flakes ET: extraction

tank (50°C, 1 h, pH 9); CT: cooling tank (10°C); DT: demulsification tank 65°C, 1.5 h, pH 9); DeT: decantation tank (4°C, 16 h); refrigerated storage (10°C, 16 h) 488

FIGURE 16.3 Flowchart for cream demulsification DT: demulsification

tank (65°C, 1.5 h, pH 9); DeT: decantation tank (4°C, 16 h) 489

FIGURE 16.4 Best extraction practices for (a) protease and (b) cellulase/

pectinase strategies in the EAEP of soybeans 491

FIGURE 16.5 Representation of oleosome and conformation of oleosin:

(a) transmission electron microscopy of oleosome, (b) model of oleosome

showing oleosins forming the outer surface of the oil body, and (c) model of the conformation of a maize oleosin 496

FIGURE 16.6 Extraction process flow diagram used for economic analysis

of AEP/EAEP 1Pretreatment steps: flour process and oil body process,

grinding; extrusion process, conditioning, flaking, then extrusion 2Extraction steps: flour process and extrusion process, agitation for 1 h at 50°C, pH 8

(flour) or 9 (extrudate); oil body process, incubation for 20 h at pH 4.5 with agitation 3Additives: for flour and extrusion process, sodium hydroxide;

for oil body process, hydrochloric acid, 0.4 M sucrose, and 0.5 M sodium

chloride 4Demulsification step was assumed to be 1 h agitation at pH 8 in

the presence of protease Protex 6L at a concentration of 0.5% (wt protease/

wt initial soybean mass) Aqueous fraction from demulsification is recycled

to extraction step as the enzyme source In the case of oil body extraction, no demulsification was conducted 507

FIGURE 16.7 Process diagram of skim treatment options to make soy

protein isolate (SPI) and/or soy protein concentrate (SPC) IEP: isoelectric

precipitation; UF: ultrafiltration 508

FIGURE 16.8 Integrated corn/soybean biorefinery concept 511

List of Tables

TABLE 1.1 Some Examples of Industrial Extraction Processes 3

TABLE 2.1 Main Historical Landmarks in the Progress of PEF Applications 27

TABLE 2.2 Tissue Characteristics for Different Fruits and Vegetables, Measured at a Temperature (T) of 293 K and a Frequency (f) of 1 kHz 30

TABLE 3.1 Dielectric Constant, Dipole Moment, and Temperature Reached by Various Solvents Upon Heating from Room Temperature Using Microwave Energy of 2450 MHz and 560 W for 1 min 90

TABLE 3.2 Summary of Recent Closed-Vessel Microwave-Assisted Devices and Their Most Salient Features 95

TABLE 3.3 Comparison of Extraction Time, Ethanol–Water Ratio, and Extractant Volume for the Isolation of Olive Phenols from Leaves with Different Methods Using Auxiliary Energies 112

TABLE 4.1 Major Applications of Ultrasounds in the Food Industry 127

TABLE 5.1 Values of the Constants in Peleg’s Model 160

TABLE 5.2 Typical Reaction Rate Constants for PAED Reactors 167

TABLE 6.1 Comparison of Innovative Extraction Techniques 175

TABLE 7.1 Critical Properties of Solvents Used in SFE 196

TABLE 7.2 Applications of SFE in Food Analysis 202

TABLE 7.3 Relative Extraction of Caryophyllene in Aromatic Plants (% of Total Distribution of Extract Content) 214

TABLE 9.1 Yield of Essential Oils Obtained Using DIC Extraction in Comparison with Conventional Hydrodistillation Process 270

TABLE 9.2 Yield of Essential Oils Obtained by DIC Extraction in Comparison with Conventional Steam Distillation and Hydrodistillation Processes 270

TABLE 9.3 Response Surface Methodology (RSM) Experimental Design of DIC Treatment of Lavandin at Moisture Wt = 20 g H2O/100 g Dry Material 271

TABLE 9.4 Independent Variables Used in RSM at a Fixed Steam Pressure Value with Dried Aromatic Plants 271

TABLE 9.5 Chemical Composition of Essential Oil Extracted from Algerian Myrtle Leaves Using Hydrodistillation (HD-EO) and Instant Controlled Pressure Drop (DIC-EO) 273

TABLE 9.6 Antioxidant Activity after Hydrodistillation of Untreated

and DIC-Treated Algerian Myrtle Leaves with an Initial Water Content

Maintained at 16.2 g H2O/100 g Dry Matter Obtained by Desorption 275

TABLE 9.7a Identification of Lavandin Essential Oil Compounds Extracted

TABLE 9.8 Experimental Data of Composite Central Design and Results of

Jatropha Oil Yield after a 2-h Extraction 286

TABLE 9.9 Experimental Data of Composite Central Design and Results of

Rapeseed Oil Yield after 2 h Extraction 288

TABLE 9.10 Solvent Extraction of Anthocyanins from Algerian Myrtle

Leaves: DIC-Treated and Untreated Samples 292

TABLE 9.11 Solvent Extraction of Flavonoids from Algerian Buckthorn:

DIC-Treated and Untreated Samples 293

TABLE 9.12 Solvent Extraction of Flavonoids from Algerian Myrtle

Leaves: DIC-Treated and Untreated Samples 294

TABLE 9.13 Energy Consumption of DIC Extraction (Case of Lavandin) 297 TABLE 10.1 Comparison of Extraction Yield, Extraction Time, and

Individual Flavonoid Content from Litchi Fruit Pericarp Obtained by

Conventional, Ultrasonic, and High Pressure (400 MPa) Extractions 307

TABLE 10.2 Antioxidant Activity of Extracts Obtained from Longan Fruit

Pericarp Using Different Extraction Methods 312

TABLE 10.3 Comparative Analysis of Extraction Yield and Total Phenolic

Content of Longan Fruit Pericarp Using Conventional (CE) and Different

Ultrahigh Pressure–Assisted Extractions (200, 300,

UHPE-400, and UHPE-500 MPa) 313

TABLE 10.4 Anticancer Activity of Extracts Obtained from Longan Fruit

Pericarp Using Different Extraction Methods 315

TABLE 10.5 Comparison of Extraction Yields of High Pressure–Assisted

Extraction with Other Extraction Methods 316

TABLE 11.1 Advantages and Limits of Reactive and Extractive Extrusion

Process 328

TABLE 11.2 Examples of Reactive Extrusion Applications and Associated

Benefits and Limits 329

TABLE 11.3 Comparison of Batch and Extrusion Processes for Alkaline

Extraction of Alginates from Laminaria digitata (Average Values of Triplicates) 335

TABLE 11.4 Intrinsic Viscosity and Average Molecular Weight of High-Viscosity Commercial Sodium Alginate and Sodium Alginate Produced by Batch and Extrusion Extractions 336

TABLE 12.1 Advantages and Disadvantages of Various Oil Production Processes 343

TABLE 12.2 Final Residual Liquid and Oil Contents for the Four Systems Investigated (90 rpm) 357

TABLE 14.1 Biomolecules of Food Application Studied Using RMS 414

TABLE 15.1 Components for the Formation of ATPSs 440

TABLE 15.2 Application of ATPE for Purification of Biomolecules 445

TABLE 15.3 Extractive Bioconversion of Enzymes 463

TABLE 16.1 Effects of Protease on Soybean Oil and Protein Extractabilities in Countercurrent Two-Stage and on Protein Recovery by Membrane Filtration and Isoelectric Precipitation 501

TABLE 16.2 Composition of Soybean-Insoluble Fractions Recovered after PAEP of Extruded Full-Fat Soybean Flakes and Hexane-Extracted Cakes from Various Oil-Bearing Materials 504

TABLE 16.3 Estimated Operating Costs and Product Selling Prices for Various Aqueous Extraction Processes for Soybeans 509

TABLE 16.4 Capital Expenditures and Annual Operating Costs for Different Extraction Processes 510

Series Preface

Food engineering is the multidisciplinary field of applied physical sciences bined with the knowledge of product properties Food engineers provide the technological knowledge transfer essential to the cost-effective production and commercialization of food products and services In particular, food engineers develop and design processes and equipment in order to convert raw agricultural materials and ingredients into safe, convenient, and nutritious consumer food prod-ucts However, food engineering topics are continuously undergoing changes to meet diverse consumer demands, and the subject is being rapidly developed to reflect market needs

com-In the development of food engineering, one of the many challenges is to employ modern tools and knowledge, such as computational materials science and nanotech-nology, to develop new products and processes Simultaneously, improving quality, safety, and security remains a critical issue in the study of food engineering New packaging materials and techniques are being developed to provide more protection

to foods, and novel preservation technologies are emerging to enhance food security and defense Additionally, process control and automation regularly appear among the top priorities identified in food engineering Advanced monitoring and control systems are developed to facilitate automation and flexible food manufacturing Furthermore, energy savings and minimization of environmental problems continue

to be important issues in food engineering, and significant progress is being made

in waste management, efficient utilization of energy, and reduction of effluents and emissions in food production

The Contemporary Food Engineering book series, which consists of edited

books, attempts to address some of the recent developments in food engineering Advances in classical unit operations in engineering related to food manufacturing are covered as well as such topics as progress in the transport and storage of liquid and solid foods; heating, chilling, and freezing of foods; mass transfer in foods; chemical and biochemical aspects of food engineering and the use of kinetic analy-sis; dehydration, thermal processing, nonthermal processing, extrusion, liquid food concentration, membrane processes, and applications of membranes in food process-ing; shelf-life, electronic indicators in inventory management, and sustainable tech-nologies in food processing; and packaging, cleaning, and sanitation These books are aimed at professional food scientists, academics researching food engineering problems, and graduate-level students

The editors of these books are leading engineers and scientists from all parts

of the world All of them were asked to present their books in such a manner as to address the market needs and pinpoint the cutting-edge technologies in food engi-neering Furthermore, all contributions are written by internationally renowned experts who have both academic and professional credentials All authors have attempted to provide critical, comprehensive, and readily accessible information on

the art and science of a relevant topic in each chapter, with reference lists for further information Therefore, each book can serve as an essential reference source to stu-dents and researchers in universities and research institutions.

Da-Wen Sun

Series Editor

Preface

Extraction has been used probably since the discovery of fire Egyptians and Phoenicians, Jews and Arabs, Indians and Chinese, Greeks and Romans, and even Mayans and Aztecs all utilized innovative extraction and distillation for processing

of perfumes or food Nowadays, we cannot find a production line in the food in dustry that does not use extraction processes (e.g., maceration, solvent extraction, steam distillation or hydrodistillation, cold pressing, squeezing, etc.) With the increasing energy costs and the drive to reduce carbon dioxide emissions, food industries are under a challenge to find new technologies in order to reduce energy consumption,

to meet legal requirements on emissions, product/process safety and control, and for cost reduction and increased quality as well as functionality For example, existing extraction technologies have considerable technological and scientific bottlenecks

to overcome, often requiring up to 50% of investments in a new plant and more than 70% of total process energy used in food industries These shortcomings have led to the consideration of the use of enhanced extraction techniques, which typi-cally require less solvent and energy, such as microwave extraction, supercritical fluid extraction, ultrasound extraction, flash distillation, and controlled pressure drop process

Although there are a number of books that explain the innovative unit operations

in food technology and describe how to conduct conventional extraction, there are few books that focus on understanding the actual instruments used in innovative and enhanced extraction This book was prepared by a team of chemists, biochemists, chemical engineers, physicians, and food technologists who have extensive personal experience in the research of innovative extraction techniques at the laboratory and industrial scales The book provides valuable information about the newly developed processes and methods for extraction

The book comprises a preface, a contributors list, and 16 chapters, which take the reader through accessible descriptions of enhanced extraction techniques and their applications in food laboratory and industry The book is addressed primarily

to science graduate students, chemists, and biochemists in industry and food quality control, as well as researchers and persons who participate in continuing education and research systems

Nikolai I Lebovka Eugene Vorobiev Farid Chemat

MATLAB® is a registered trademark of The MathWorks, Inc For product tion, please contact:

informa-The MathWorks, Inc

3 Apple Hill Drive

Acknowledgments

We thank all the authors who have collaborated in the writing of this book

Particular thanks are due to the Editor-in-Chief of the book series Contemporary

Food Engineering, Member of the Royal Irish Academy, Professor Da-Wen Sun for his kind advice and help during the preparation of this book

on vacuum cooling of cooked meats, pizza quality inspection

by computer vision and edible films for shelf-life extension of fruits and vegetables have especially been widely reported in national and international media The results

of his work have especially been published in over 500 papers, including about 250 peer-reviewed journal papers He has also edited 12 authoritative books According

to Thomson Scientific’s Essential Science IndicatorSM,updated as of July 1, 2010, based on data derived over a period of 10 years and 4 months (January 1, 2000, to April 30, 2010) from the ISI Web of Science, a total of 2,554 scientists are among the top 1% of the most frequently cited scientists in the category of Agricultural Sciences, and professor Sun tops the list with his ranking of 31

Sun received his BSc honors (first class), his MSc in mechanical engineering, and his PhD in chemical engineering in China before working in various universities

in Europe He became the first Chinese national to be permanently employed in an Irish university when he was appointed as college lecturer at the National University

of Ireland, Dublin (University College Dublin), in 1995, and was then continuously promoted in the shortest possible time to senior lecturer, associate professor, and full professor He is currently the professor of food and biosystems engineering and the director of the Food Refrigeration and Computerized Food Technology Research Group at the University College Dublin (UCD)

Sun has contributed significantly to the field of food engineering as a leading educator in this field He has trained many PhD students who have made their own contributions to the industry and academia He has also regularly given lectures on advances in food engineering in international academic institutions and delivered keynote speeches at international conferences As a recognized authority in food engineering, he has been conferred adjunct/visiting/consulting professorships from over 10 top universities in China, including Zhejiang University, Shanghai Jiaotong University, Harbin Institute of Technology, China Agricultural University, South China University of Technology, and Jiangnan University In recognition of his sig-nificant contributions to food engineering worldwide and for his outstanding lead-ership in this field, the International Commission of Agricultural and Biosystems Engineering (CIGR) awarded him the CIGR Merit Award in 2000 and again in 2006 The Institution of Mechanical Engineers (IMechE) based in the United Kingdom named him Food Engineer of the Year in 2004 In 2008, he was awarded the CIGR Recognition Award in honor of his distinguished achievements in the top 1% of

agricultural engineering scientists in the world In 2007, he was presented with the AFST(I) Fellow Award by the Association of Food Scientists and Technologists (India), and in 2010 he was presented with the CIGR Fellow Award The title of Fellow is the highest honor in CIGR and is conferred upon individuals who have made sustained, outstanding contributions worldwide.

Sun is a Fellow of the Institution of Agricultural Engineers and a Fellow of Engineers Ireland (the Institution of Engineers of Ireland) He has received numer-ous awards for teaching and research excellence, including the President’s Research Fellowship and the President’s Research Award of University College Dublin on

two occasions He is the editor-in-chief of Food and Bioprocess Technology—An

International Journal (Springer) (2010 Impact Factor = 3.576, ranked at the 4th

posi-tion among 126 food science and technology journals); the former editor of Journal

of Food Engineering (Elsevier); and an editorial board member for Journal of Food

Engineering (Elsevier), Journal of Food Process Engineering (Blackwell), Sensing

and Instrumentation for Food Quality and Safety (Springer), and Czech Journal of

Food Sciences He is a chartered engineer

On May 28, 2010, he was awarded membership of the Royal Irish Academy (RIA), which is the highest honor that can be attained by scholars and scientists working in Ireland, and at the 51st CIGR General Assembly held during the CIGR World Congress in Quebec City, Canada on June 13–17, 2010, he was elected incom-ing president of CIGR, and will become CIGR President in 2013–2014—the term of his CIGR presidency is six years, two years each for serving as incoming president, president, and past president

Editors

Nikolai I Lebovka was born in Kiev, Ukraine, in 1954

He  received his PhD in molecular physics from Taras Shevchenko National University of Kyiv (1986) and Dr Habil in physics of colloids from the Biocolloid Chemistry Institute, Ukraine (1995) He is currently head of the Physical Chemistry Department of the Biocolloid Chemistry Institute and professor of physics at Taras Shevchenko National University of Kiev He studies electric field–induced effects

in biological and food materials and is also active in the fields of colloids and biocolloids, theory and applications

of nanocomposites, computation physics, and theory and practice of percolation phenomena He has published more than 230 papers in peer-reviewed journals and several chapters in books, and was a member of the organiz-ing committee of several international conferences

Eugene Vorobiev is a full professor at the Chemical

Engineering Department and head of Laboratory for Industrial Technologies at the Université de Technologie de Compiègne (UTC), France He received his PhD in Food Engineering (1980, Ukraine) and his Dr Habil in Chemical Engineering (1997, France) His main research interests are focused on mass transfer phenomena, theory and practice

Agro-of solid–liquid separation, and innovative food technologies (especially electrotechnologies) He has published more than

200 peer-reviewed papers and is the author of 18 patents

He is a member of the editorial board of several journals

(Separation and Purification Technology, Food Engineering Reviews, Filtration)

and president of the Scientific Council of IFTS (“Institut de la Filtration et des Techniques Séparatives”) He was awarded the Gold Medal of the Filtration Society (2001) and is a Laureate of the Price for the innovative technique for the environment (Ademe, 2008) He acted as a chairman of several international conferences

Farid Chemat is a full professor of chemistry and

direc-tor of the Laboradirec-tory for Green Extraction Techniques of Natural Products (GREEN) at the Université d’Avignon

et des Pays de Vaucluse, France Born in Blida (1968), he received his PhD (1994) in innovative process engineering from the Institut National Polytechnique de Toulouse His main research interests are focused on innovative and sus-tainable extraction techniques (especially microwave, ultra-sound, and green solvents) for food, pharmaceutical, and

cosmetic applications His research activities are documented by more than 100 entific peer-reviewed papers and 6 patents He is coordinator of a new group named

sci-“France Eco-Extraction,” which deals with international dissemination of research and education on green extraction technologies

Contributors

Karim Salim Allaf

Department of Process Engineering

University of La Rochelle

La Rochelle, France

Tamara Sabrine Vicenta Allaf

Department of Process Engineering

Research and Development

Cherry Central Inc

Traverse City, Michigan

Chemical Engineering Department

University of Technology of Compiègne

Compiègne, France

Kerry Alan Campbell

Department of Chemical and Biological Engineering

Iowa State UniversityAmes, Iowa

Farid Chemat

UMR, INRA-UAPVUniversité d’Avignon et des Pays du Vaucluse

Mysore, India

A B Hemavathi

Department of Food EngineeringCentral Food Technological Research Institute

Mysore, India

Department of Nutrition and Dietetics

Universiti Putra Malaysia

Selangor, Malaysia

Yue Ming Jiang

South China Botanical Garden

Chinese Academy of Sciences

Guangzhou, People’s Republic of China

Department of Food Engineering

Central Food Technological Research

Juliana Maria Leite Nóbrega de Moura

Department of Food ScienceIowa State UniversityAmes, Iowa

Philip J Lloyd

Energy InstituteCape Peninsula University of Technology

Cape Town, South Africa

Igor O Lomovsky

Department of Solid State ChemistrySiberian Branch of the Russian Academy of Science Novosibirsk, Russia

Oleg I Lomovsky

Department of Solid State ChemistrySiberian Branch of the Russian Academy of ScienceNovosibirsk, Russia

María Dolores Luque de Castro

Department of Analytical ChemistryUniversity of Córdoba

Córdoba, Spain

M C Madhusudhan

Department of Food Engineering

Central Food Technological Research

Institute

Mysore, India

Krishna Murthy Nagendra Prasad

Department of Nutrition and Dietetics

Universiti Putra Malaysia

Department of Food Engineering

Central Food Technological Research

Food Research Center

Agriculture and Agri-Food Canada

Guelph, Ontario, Canada

Lund, Sweden

Jessy van Wyk

Department of Food TechnologyCape Peninsula University of Technology

Bellville, South Africa

Peggy Vauchel

ProBioGEM LaboratoryLille 1 UniversityVilleneuve d’Ascq, France

Eugene Vorobiev

Département de Génie des Procédés Industriels

Université de Technologie de Compiègne

Main Abbreviations

ARMES affinity-based reverse micellar extraction and separation

CAEP cellulase/pectinase-assisted aqueous extraction processing

CAN-BD carbon dioxide assisted nebulization with a bubble dryer

CE-MS capillary electrophoresis coupled to mass spectrometry

DDGS dried distiller’s grains with solubles

DIC instant controlled pressure drop technology (from the French, détente

instantanée contrôlée)

EAEP enzyme-assisted aqueous extraction processing

FMASE focused microwave assisted Soxhlet extraction

NP nonylphenol polyethoxylate

PAEP protease-assisted aqueous extraction processing

SFME solvent-free microwave extraction or hydrodistillation

UAEE ultrasonic-assisted enzymatic extraction

WEPO water extraction with particle formation on-line

1.1  WHAT THIS CHAPTER IS ABOUT

tion technology in general, so that the reader can place in context the detailed topics

This chapter is strictly introductory It aims to provide an overview of solvent extrac-in subsequent chapters It contains essentially no new information, so the reader will look in vain for detailed references to most of the issues discussed Much can be found in standard chemical engineering texts Texts such as Rydberg et al (2004) or the earlier Lo et al (1983) handbook provide much depth about the technology, but nothing about its application in food processing Schügerl’s (1994) monograph has some very relevant material, although its focus is definitely on biotechnology rather than food technology A recent encyclopedic review of food technology (Campbell-Platt 2009) devotes a scant two pages to the topic of solvent extraction

1.2  WHAT IS MEANT BY EXTRACTION

One of the oldest recorded methods of separation is solvent extraction, which dates back to the Palaeolithic age (Herrero et al 2010) In food processing, extraction is defined as the transfer of one or more components of a biological feed from its source material into a fluid phase, followed by separation of the fluid phase and recovery of the component(s) from the fluid The feed is usually of plant origin, but the principles

of extraction remain the same if the material is animal or piscine in origin

Extraction is a process that is growing in importance It is generally more energy efficient than competitive processes such as expression—the pressing of biological feed materials to liberate fluids For example, sugar is extracted from sugar beets with hot water, which yields a sucrose stream free of contaminants and of higher concentration (typically 15% sugar) than can be achieved by expression Solvent extraction can be made selective for specific components of the feed For instance, supercritical carbon dioxide (SC-CO2) will selectively dissolve caffeine from coffee beans to yield decaffeinated coffee The extracted caffeine can then be recovered for sale as a pharmaceutical Extraction can recover thermally labile components that would be degraded by heating, such as gelatin from collagen Table 1.1 gives some examples of typical extraction processes employed industrially

ing extraction, to provide a basis for understanding the rationale behind some of the technical advances described in later chapters

The intent of this chapter is to give an overview of the broad principles underly-1.6.1.7 Aqueous Two-Phase Extraction 211.6.1.8 Enzyme-Assisted Aqueous Extraction 211.6.2 Impact of Refining 211.6.3 Combined Methods and Sample Extraction 221.7 Conclusion 22Acknowledgments 22References 22

Some Examples of Industrial Extraction Processes

Malted barley Brewing worts Sugars, grain solutes

Citrus press residues Citrus molasses –

Rosemary leaves Rosemary essential oil Rosemary essential oil Citrus peel Citrus essential oils Citrus essential oils

Alkaline water Defatted soy flour Soya protein –

Methylene chloride Green coffee beans Decaffeinated coffee Caffeine

Supercritical CO2 Green coffee beans Decaffeinated coffee Caffeine

Hops Hops extract (resin) Hops essential oils

(myrcene, humulene, caryophyllene, and farnesene), alpha and beta acids

Ginger rhizomes Ginger extract Gingerols Pomegranate seeds Pomegranate seed oil Pomegranate seed oil Vanilla beans Vanilla essence

Spices (turmeric, nutmeg, mace, cardamom, etc.)

Spice extracts Egg yolk Decholesterolized egg

yolks

Cholesterol Wheat germ Wheat germ oils rich

in tocopherols

–

Methyl ethyl ketone Spices Spice oleoresins –

Tributyl phosphate Phosphoric acid Food-grade

phosphoric acid

–

Source: Schwarztberg, H.G., in Handbook of Separation Process Technology (Chapter 10), R.W

Rousseau (Ed.), New York: Wiley-Interscience ISBN: 0471 89558X, 1987.

1.3  PHYSICAL PRINCIPLES OF EXTRACTION

1.3.1  NomeNclature of extractioN

A component that it is desired to be removed from the feed through extraction is called the “solute.” The phase that is mixed with the feed to remove the solute is the “solvent.” After the solvent has been mixed with the feed and the solute has transferred from the feed phase into the solvent phase, the solvent phase is called the

“extract” and the feed phase is now called the “raffinate.” It must be stressed that, in food processing, the feed is usually solid, semisolid, or gel-like, whereas much of the science of extraction is based on liquid feeds However, there are very close parallels provided allowance is made for the impact of the nature of the feed on mass transfer properties, as further discussed in Section 1.3.3 Indeed, much of the rest of this text

is concerned with means of improving the rate of mass transfer so that the science derived from liquid feeds may be better applied to the processing of food products

1.3.2  Solubility

When a feed containing a solute is contacted with a solvent in which the solute is reasonably soluble, then the solute will distribute itself between the feed and the solvent until there is equilibrium between the feed and the solvent phases When this occurs, the chemical potential of the solute in each phase is the same The chemical potential is made up of two terms—the concentration of the solute and its activity in the phase concerned However, in processing foods, it is rarely possible to measure the activity of the solute in the feed; thus, the primary concern is with the solubility

of the solute in the solvent Figure 1.1, for instance, shows the solubility of caffeine

in SC-CO2 and in SC-CO2–ethanol mixtures The solubility increases with pressure and with the addition of ethanol to the solvent, but decreases with temperature

2.0 1.5 1.0 0.5

CO2 + 5% EtOH 343.2 K

CO2 + 5% EtOH 323.2 K

CO2 + 5% EtOH 313.2 K

FIGURE 1.1  Solubility of caffeine in SC-CO2 and CO2–ethanol (From Kopcak, U and

Mohamed, R.S., J Supercrit Fluids 34, 209, 2005 With permission.)