Designing Microstructures for Food Functionality

José Miguel AguileraDepartment Chemical and Bioprocess Engineering, P. Universidad Católica de Chile

Presented at CIBUS 2008, Federalimentare, Parma, Italy, May 7th 2008.

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Evolution of the food industry from theviewpoint of food engineering

1850 19501900 2000

Product Engineering

• Materials science• Colloidal chemistry• Food physics• Polymer science• Probing tools

Food safety & qualityHealth & well beingGastronomy

Functionalfoods

Low-caloriefoods

Freezing

TVP

Freezedrying

Steamretorting

Plateheat-exchanger

UHT

Ice cream

Val

uead

ded Emerging

technol.

Process Engineering• Unit operations• Transport phenomena• Equipment design• Automation• Packaging

High throughputLow costPreservation

MAKE SERVICE CARE

Spraydrying

Bruin and Jongen, 2004

PLEASURE

3

Gut

• Texture• Eating quality• Flavor release

(+) Delivering health and wellness through foods

Gut

Brain

• Nutrient bioavailablity• Satiety• Gut health• Allergies

• Wellbeing• Sensorial• Pleasure

Emphasis on productsand processing by the body

Mouth

Delivering abundant andsafe foods at low cost

Mouth

• Raw material production• Preservation• Quality

Farm Fork

A change of paradigm in food processing

Emphasis on processing of food

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Some things have changed in the last 20 years

• Increased evidence linking some components in the dietto major chronical non-transmissible diseases.

• Prevalescence of obesity – “globesity”• We have found that the microstructure of food products

plays a major role in important attributes: texture, flavorrelease, bioavailability of nutrients.

• New drivers: Health, wellbeing and pleasure. This meansinterfacing with several other sciences… and chefs.

• With the emerging science of food materials there are ample opportunities for innovation in traditionalprocesses (e.g., novel ingredients, new unit operations –membranes, microfluidics, etc).

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Why designing foods?

Food industry has annual sales turnover of US$ 3.5 trillion.

Technol. push

Health benefits“Globesity”Wellbeing - vitalityPleasure – gastronomyShorter life cyclesDemographics

Market pullIncreased knowledgeNew ingredientsNovel devices

Sept 27, 2007. National Starch’s Texture Center of Excellence to strengthen and expand its consumer understanding, sensory analysis, materials science, formulation, and ingredient development capabilities relating to texture.

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3 trends shaping consumer attitudes and behaviours

Consumer benefits meeting trends

*PleasureHealth

Convenience

« for me »IndulgencePremiumizationLuxury

Easy to handleOn the goDelivery of solutions

Fresh & naturalPreventionPersonalized

PerfectNutrition?

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Functional foods and functional ingredients

Functionalcomponent

Functionalingredient

Health

Health: Lower caloric density, induce satietyIndulgence: New structuresConvenience: e.g., replace w/advantage

In foods: ↑consumption (diet)

Added: Extract, protect anddeliver

“Functional foods” are foods or dietary components that may provide a health benefit beyond basic nutrition. In general, claims are: enhanced function and reduced risk of disease. Examples can include fruits and vegetables, whole grains, fortified or enhanced foods and beverages, and some dietary supplements.Inulin – Gi tract health; Flavanol – Circulatory health; Omega 3 FA – Reducedrisk of heart disease; Isoflavones – Bone health; CMP (whey) –Immunomodulation; Lycopene – Prostate cancer

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The market of functional foods

In 2004 the functional foods market was estimated to be US$7 - 63bn, depending on sources and definitions. In 2005, the global functional food market reached US$73.5 bn(estimates). By 2010 is expected to be US$167 bn.(www.marketresearch.com)

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Food design by processingStructure formation in dairy products

MECHANICAL

HEAT

WHEY PROTEINS

0.001

0.01

0.1CASEIN

MICELLES

ACID

ENZYMESubmicelle

SIZE

IN M

ICR

ON

S

FAT GLOBULE

HEAT

Membrane

10

1

PROCESSING

Whipped cream(ice cream)

Fluid milk

Cheese

Yogurt

“ACTIVE”STATE

FINAL STRUCTURE(not at same scale)

Butter

air

BUILDING BLOCKS

plasma

- -

---

gel network

emulsion

plastic solid

foam

Aguilera and Stanley, 1999

INTERACTIONS

Complex liquid

MECHANICAL

HEAT

WHEY PROTEINS

0.001

0.01

0.1CASEIN

MICELLES

ACID

ENZYMESubmicelle

SIZE

IN M

ICR

ON

S

FAT GLOBULE

HEAT

Membrane

10

1

PROCESSING

Whipped cream(ice cream)

Fluid milk

Cheese

Yogurt

“ACTIVE”STATE

FINAL STRUCTURE(not at same scale)

Butter

air

BUILDING BLOCKS

plasma

-- --

------

gel network

emulsion

plastic solid

foam

Aguilera and Stanley, 1999

INTERACTIONS

Complex liquid

SOLN

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The scales of food microstructures andrelated sciences (approx.)

1 nm 10 nm 100 nm 1 μm 1 mm10 μm 100 μm 1 cm 1 m

Food product physics

“Nano” sciences

Colloidal sciencePolymer science

Microbialcells

Glutennetwork

Chemistry

Particlegels

Water0.3 nm

Casein

Cookedstarch

Powderparticles

Plant cellwalls

Crystals

Bubbles

FOO

D P

RO

DU

CT

S

Networkgels

GrainsFat droplets

Resolutionof the eye

CHOpolymers

Emulsifiers

Micelles

Starch

Flavors

Proteins

Fiber

Detectionin themouth

MicrobubblesMicrodroplets

Funct. deliverymicroencapsulation

Digesta

Nanocarriers

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Food structure formation: A change in paradigm

BeforeBefore In the futureIn the future

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Structuring water: Ultra fat-free spreads

ULTRA FAT-FREE MARGARINE (5 Cal vs 90 Cal/spoonful)

Heertje, Roijers & Hendrickx, 1998

Lamellar phase

α-gel

coagel

Fat crystal network

MonoglyceridesMicrostructure of butterFat globules entrappedin a matrix

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The routes to design and deliver functionalingredients

• Pharma-modelled deliverysystems

• Fascinating nanosystemsdesigned in hierachicalfashion

• Single molecule release independent from digestion of matrix

• Encapsulated system « rides»with product as a carrier

• Fortification model approach– health benefit = add-on

A. Shefer & S. Shefer, Food Technology (2003) 57,40-42

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Food composition vs nutrient bioavailabilty

• Food composition tables: The nutrient content(determined by chemical analyses) of different foods.

• Nutrient bioavailability: Concerned with the fraction ofan ingested nutrient available for utilization or storage in normal physiological function after absorption from thegut.

• Bioavailability is influenced by: the chemical form of thenutrient, the state of the food matrix, the presence ofsuppressors or cofactors, synergistic effects amongnutrients and other components in digesta, formation ofstable structures that are slowly metabolized, and so on.

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“Food matrix” and bioavailability of carotenoids

Processing

Conclusion: Modifying the food microstructure by processing affects bioavailability

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Structure and bioavailability of nutrientsRelease of nutrients from foods & absorption in the gut

Parada, J. & Aguilera, J.M. 2007. Food microstructure affects the bioavailability of several nutrients. J. Food Sci. 72:R21-R32.

FOOD GUT

Food structure breakdown and reassemblyin the gut

The hidden processing of food…

• Increased scientific evidence that diet is related to somemajor chronic diseases.• Delayed satiety contributes to control overeating –obesity. Satiety may be controlled by food structure(e.g.,immobilizing air/water in food portions, gels that swellin the stomach, etc). • The release and bioavailability of conventional nutrientsand bioactive molecules depend on physiologicalconditions, interactions and structural reassembly(colloidal) in the digestive system.• Interesting developments: Imaging digestion process in real time (MRI); monitoring food intake and imaging ofbrain activation (fMRI, PET).

Re-thinking food structuringMicro-engineering of food foams by microfluidic devices

(A) Monodispersed

bubbles %10=Ω

(B) Polydispersed

bubbles %20=Ω

(C) Wet foam

%60=Ω

(D) Critical

wet foam %85=Ω

(E) Dry foam

%95=Ω

(F) Slug

%98=Ω

Bubbly regime Foam regime

Airbubble

(A) Monodispersed

bubbles %10=Ω

(B) Polydispersed

bubbles %20=Ω

(C) Wet foam

%60=Ω

(D) Critical

wet foam %85=Ω

(E) Dry foam

%95=Ω

(F) Slug

%98=Ω

Bubbly regime Foam regime

Airbubble

Skurtys, O. & Aguilera, J.M. 2007. Structuring bubbles and foams in gelatine solutions within a circular microchannel device. J. Coll. Interface Sci. (in press)

Foam architectures in capillaries

liquid

airQQ

=Ω

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Food materials science

Monoglycerides can be made to self-assemble into manydifferent microstructures.Modifying oil phases with internally self-assembled aqueousstructures. Results are special emulsions for delivery (e.g., phytosterols,antioxidants, etc.)

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Food as the unit of nutrition

• To understand the nutrition-health interface

• Obtaining richer information on the bases of food synergies

• Including the action of the foodmatrix to understand nutrientbehaviours

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Designing for gastronomyThe pleasure of eating….

The international restaurant industry generates between US$1.5 and $2 trillion/year in sales.

http://www.forbes.com/travel/2005/10/12/restaurants-mostexpensive-world-cx_sb_1013feat_ls.html

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What is gastronomic engineering?

Gastronomic engineering is applyingconcepts of food materials science and foodengineering to guide the physical and chemicaltransformations needed in culinary practice forthe design of micro- and macrostructures thatprovide amazing textures, astounding tastesand the controlled release of flavor.

Unique characteristics of working with chefs:• Known market – restaurant• Almost no cost restrictions• No scale-up engineering required• Great to bring science closer to people!

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Food design for health, wellbeing and pleasureMoving food engineering into new interfaces…

• Apetite and satiety• Physiology of digestion• Molecular nutrition

• New ingredients, new tools• Functional assemblies• Protection & delivery ofbioactive components• Micro(nano)fabrication

• Perception of diets/health• Gastronomy• Psychology of eating• Neurobiology

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Conclusions

• The emphasis on processed foods for the health, pleasure and convenience markets will continue to grow.

• New evidence will arise on specific in vivo effects andthe actual activity of biomolecules - alone and in mixtures - targeted to different segments of thepopulation (personalized nutrition).

• Technologies are already becoming available toseparate, concentrate, protect and deliver thesebioactive compounds as such (pharma approach) and in foods.

• People will continue to eat foods for the pleasure ofeating. Chefs are credible promoters of new ingredients, textures and flavors, and a vital source of innovation forthe food industry.

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Thank you!