Trends in nutraceuticals:

Impact on food safety

Bioresource Engineering Department

Macdonald Campus of McGill University

Valérie Orsat, Eng., Ph.D.

Food process engineering – Functional

foods & nutraceuticals

Today’s food industry is experiencing its

greatest growth figures in:

Functional and fortified foods

Natural and organic foods

Fruits and vegetables

38.2 46.7

74.7

187.0

243.0

0

50

100

150

200

250

300

1999 2002 2007 2010 2015

US

D$

Billi

on

Year

Global Nutraceutical Market Trend

Many foods contain substances that have been determined to possess a

certain Health Functionality. The concentrations of those substances

are small and no immediate health function can be expected from

consuming the food.

The long term consumption of these healthy substances may help to

prevent the onset of certain illnesses (cancer, chronic heart problems,

etc.).

What are functional /

nutraceutical foods?

Some functional

food products

available

Yogourts Cardivia, Activia,

Danacol and Essensis from

Danone

The Danacol (plant sterols)

and Activia (pro-biotic) have

been very successful.

Essensis, green tea and borage

extracts, vitamin E and probiotic

for “cosmetic benefits” was

launched in Europe.

Eggs (Large)

1 dz Omega 3 Naturoeuf 3.33 $

Eggs (Large)

1 dz Regular 2.49 $

Great Market

Potential

Consumers are paying the price for

the enhanced products having a

potential health benefit

The approach of the past decade has been to:

Separate and purify the functional constituents for the

production of ingredients (to enrich foods) and/or

supplements

We must also concentrate efforts on

Improving the bioavailability of those nutrients

(through adequate handling/processing)

And

Improve nutrient retention during processing and

ensure food safety of fortified foods

Storage and handling

Drying and thermal processing

Challenges in product processing

and handling

Proper handling is essential for the challenging

development of new markets in functional properties of

foods.

The quality of the processed material must have a certain

reliability.

The development of improved processing and preservation

practices is critical to the commercial and social

development of “healthy for you” foods.

To achieve a thorough understanding, collaborative studies are

required, combining expertise in food chemistry, biochemistry,

plant physiology, nutrition, medicine, engineering, etc.

Phytochemicals are very reactive and their content varies

depending on plant cultivar, ripeness at harvest, storage conditions

and level of processing.

Production of target ingredients must ensure the preservation of

their inherent quality attributes. In general the concentration of

bioactive compounds will steadily decrease during processing.

The development of handling/processing methods to minimize the

loss of bioactive components is imperative.

R&D remains product dependent and empirical.

Innovation can bring great quality improvements

-Hybrid processes (improved designs, etc.)

-New technologies and energy combinations (High pressure, High

electric fields, etc.)

Wide variety in

flaxseed cultivars

Flaxseeds are advertised for their fatty

acid profile as the best contributor of α-

linolenic acid (omega-3) of the oilseeds.

However there are great variations in their

content between different cultivars

(varying from 25 to 55 % of the total fatty

acids).

“Natural Products” Sourcing “natural” ingredients to substitute “chemical” ingredients

Antioxidants

Antimicrobials

Texturing agents

etc.

To develop improved Techno and Health

functionalities of foods that appeal to the consumer!

The Current Trend

“Natural” does not necessarily

mean safe!

The issue of food safety is important

given the little information available on

the toxicity and shelf-stability of some

of the many and new “naturally

sourced” ingredients.

5-10 servings of fruits

and vegetables

How do we eat them?

Does it affect the

availability of the target

nutrient?

Nutrition and health

If we fortify our food, any food

or all foods, do we have the

toxicological studies to ensure

long term safety?

Acute and sub-chronic toxicity studies may be

required

To establish the dosage that would

yield no observed adverse effect

(NOAEL)

o mutagenicity

o hematological

o histopathological, etc.

Certain plant extracts do present a risk.

In many cases fortification is

considered required and

widely recognized as safe!

In 1998, the government of Canada

amended its Food and Drug Act to ensure

the functional property of flour and bread

sold in Canada. They must each contain

a certain minimum of thiamine, riboflavin,

niacin, folic acid and iron.

The Case of Folic Acid

A public health issue

Some research

results from the

lab

Microwave Assisted Extraction (MAE)

Problems

Long processing time –

several hrs up to several days

Difficulty to obtain tightly

bound components

High temperature over long

time has to be used in many

cases

Conventional solvent

extraction

Extracting some components

from seeds, food, and feed sample

(Ganzler, et al. 1986)

Soxhlet Extraction: 3 hrs

MAE: 3.5 minutes

MAE

Create high temperature working region

within cold environment (with hexane)

Or a rapid overall heating of the solvent

and material (with water or ethanol)

Compared to conventional extraction

methods, microwave-assisted extraction

has the following benefits:

Reduced processing time

Higher yield of extracts

Better quality products

Especially beneficial to heat sensitive

products

Extraction setups

RFXRFX

RTE RTE

MAE

To extract ginsenosides Re and Rb1, methanol is a good solvent

Ginsenoside mRb1 is more water soluble

Influence of solvents on the

extraction of ginsenosides

0

10

20

30

40

Re mRb1 Rb1 Tot al

Gi

ns

en

os

id

es

ex

tr

ac

te

d

(m

g)

MeOH MeOH/ H2O=7/ 3 MeOH/ H2O=1/ 1 MeOH/ H2O=3/ 7

Study of MAE of ginseng

Microwave extraction of ginsenosides from American ginseng

Influence of sample/solvent ratio on the extraction of ginsenosides

0

10

20

30

40

50

Re mRb1 Rb1 Tot alGi

ns

en

os

id

es

e

xt

ra

ct

ed

(m

g)

2g/ 10mL 2g/ 20mL 2g/ 40mL 2g/ 60mL

Microwave extraction of ginsenosides from American ginseng

Influence of particle size on the extraction of ginsenosides

0

10

20

30

40

50

Re mRb1 Rb1 Tot al

Gi

ns

en

os

id

es

e

xt

ra

ct

ed

(m

g)

Bl ended 1x1x1 mm 3x3x3 mm 5x5x5 mm

Microwave extraction of ginsenosides from American ginseng

Extraction of total ginsenosides (Re,

mRb1 and Rb1).

0

10

20

30

40

50

60

0 20 40 60

Ext r act i on Ti me ( mi n)

Amou

nt e

xtra

cted

(mg

)

MAE RTE RFX

Microwave-Assisted

Extracts from

flaxseeds

• Flaxseed is rich in the lignan

secoisolariciresinol diglucoside (SDG).

• SDG is a phytoestrogen and a

powerful antioxidant.

• SDG reduces the risk of developing

cardiovascular diseases and breast

cancer.

Alcoholic extraction is inefficient ◦ 48 h of extraction at room temperature yields

only 86% SDG

Pressurized low water polarity is inefficient ◦ 140-160°C, 5.2 MPa

◦ Yields 80-86% SDG

The Challenge of Lignan Extraction

MAE –

Evaluation Efficient,

maximum SDG

extraction yield

Fast, only 3 min

Accurate, 97.5%

recovery of SDG

Precise,

coefficients of

variation ≤ 4%

100

94

79

73

60

70

80

90

100

110

SD

G e

xtr

ac

tio

n y

ield

(%

)

0.05

1

2

7

0

1

2

3

4

5

6

7

8

MAE

Direct alkaline

hydrolysis

Alkaline + acidic

methanolyses

Alcoholic extraction +

alkaline hydrolysis

Ex

trac

tio

n t

ime

(h

)

MAE vs. Reference Methods

Nemes & Orsat 2012. Food Analytical Methods 5, 551-563

Coming up in MAE:

Extraction of the anthocyanins

from blueberry leaves

Extraction of squalene and

plant sterols from grain

amaranth

Extraction is enhanced by increased temperatures.

Microwave assisted extraction further enhances

the yield and quality of extracts.

Our challenge now is to engineer the scale up

of the process. Using microwaves at 2450

MHz is not easily conducive to large scale

processing. Hence we are pursuing research

at lower frequencies such as 915 MHz or 27

MHz in the radio-frequency range.

In Summary for MAE:

Radio Frequency Assisted Extraction System

Data acquisition system

Data logger RF applicator

Matching box cooling system

Fiber optic sensor

Fiber optic

holder

Flow meter

Matching

box

RF generator

Fiber optic thermometer

Radio Frequency Assisted Extraction System (applicator, generator & data acquisition)

Radio-frequency extraction

Lower frequency than MW, thus longer wavelength

Fiber optic holder

Glass

vessel

Fiber optic

Metal

cover

Vertical

electrode

s

Cooling

fan

Silver plated copper connectors

Glass vessel Vertical

electrodes

Metal cabinet

Top view of the RF applicator

Stirring application in RFAE Placing the vessel in the RF

applicator

Fiber optic thermometer Glass vessel sandwiched between

the electrodes

Apple peel extracts

Preliminary Experiment :Comparison Study

Between RF and Conventional (Hot plate) Method

1.78

2.52

10

15

20

25

30

Extraction Method

mg G

AE

/g d

ry p

eel

Conventional

RF

(a)

72

77

70

72

74

76

78

80

Extraction Method

DP

PH

Inhib

itio

n (

%)

Conventional

RF

(b)

Total phenolic compounds (a) and percentage DPPH inhibition (b)

of apple peel extract via two extraction methods, conventional and

RF extraction. Both extraction were performed for 10 minutes at

50 C. Conventional extraction was performed via hot plate heating.

• Screening experiment of apple peel flavonoids using RFAE

• Optimization of flaxseed SDG and apple peel flavonoids using RFAE

• Comparison study between RFAE, MAE, UAE and conventional method for flavonoids

Coming up!

Study of cranberry seed oil

extraction by different extraction

methods

Investigated the effect of three extraction

methods on the α – tocopherol content in

cranberry seed oil.

58

60

62

64

66

68

70

72

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Temp(⁰C)

Conc.of.α -

tocopherol(µg)

Reflux Reflux MAE UAE Reflux

A B C D E

Note: Reflux- Heat reflux method; MAE- Microwave assisted extraction; UAE-

Ultrasound assisted extraction. A- Reflux: 3hrs ; Sample ratio1:10 at 62 ⁰C .B-

Reflux:7.5 hrs; Sample ratio1:10 at 66⁰C. C-MAE:15 min;125W and Sample ratio 1:6

at 66⁰C. D-UAE:15 min;100W and Sample ratio 1:10 at 66⁰C.E-Reflux:3 hrs; Sample

ratio1:10 at 70⁰C.

Enhancement of the antioxidant content in

elderberry (Sambucus nigra) by pulsed ultraviolet light

Abiotic Stress

An abiotic stress is the stress caused by environmental

conditions to plants (i.e. extreme weather conditions,

ultraviolet radiation, light, etc).

Plants produce or stimulate synthesis of various

secondary metabolites when they are subjected to

various abiotic stresses. Various stresses can induce

polyphenols’ synthesis in plants, especially in fruits and

vegetables.

These metabolites are produced to defend the plant

against abiotic stresses. The secondary metabolites

mainly include various antioxidants.

10 seconds treatment with 1.1 J/cm2 /pulse gave the highest increase around 50 %

Spray drying of elderberry juice from UV treated berries was investigated with inlet temperature ranging from 70°C to 120°C and two feed flow rate 180 ml/hr, 300ml/hr were considered for the experiment.

Five different wall materials were used in the spray drying, namely gum acacia, maltodextrin, soya protein powder, soya milk powder and isolated soya protein to increase the mass recovery percentage.

Operating parameters and wall materials ratio were optimized in terms of total phenolic content retention, color and recovery percentage of spray dried powder.

The spray drying inlet temperature of 80°C with feed flow rate of 180 ml/hr gave better phenolic content retention.

The gum acacia and maltodextrin gave higher mass recovery percentage with more than 70% and highest actual phenolic content in the produced powder.

Microencapsulation of

Lactobacillus acidophilus and

Lactobacillus rhamnosus in

Raspberry juice by Spray

Drying

Sub lethal thermal shock minimized the cell death

during and after spray drying

Viability is mainly dependent on outlet

temperatures and process conditions

Sugars and pectins in raspberry and maltodextrin

aided the survival of probiotics during spray drying

and during storage thus improving product shelf life

Use of pulses to increase functional

and nutraceutical properties in food

systems

Pulses contain high amount of protein,

fibre, vitamins (e.g., folate) and minerals

and are low in fat.

Consumption of lentil should be

promoted as a high fiber food source to

increase dietary fiber intake which is

important for North Americans who

currently consume less than half of the

recommended amount.

Furthermore, lentils could serve as a

good source of prebiotic for yogurt and

probiotic starter cultures.

Acid production in probiotic fermented milk

supplemented

with 1-3% lentil flour, skim milk and control sample

4

4.5

5

5.5

6

6.5

7

-1 1 3 5 7 9 11 13 15 17 19 21 23 25

pH

Time (h)

1 SM

2 SM

3 SM

1 LF

2 LF

3 LF

Control

Acid production and microbial growth in 2-3% lentil

flour and 1-3% pea flour supplemented yogurt was

higher than skim milk supplemented yogurt.

Stability of the yogurt cultures and the viable count

of L. bulgaricus was higher in pea flour in comparison

with lentil flour supplemented yogurt.

Syneresis decreased due to lentil or pea flour

comparing with skim milk supplemented yogourt and

probiotics and 2% and 3% lentil flour lowered

syneresis better than pea flour.

Fermentation process was faster in lentil or

pea flour comparing with skim milk

supplemented probiotic .

Pea flour stimulates L. rhamnosus earlier

than lentil flour, but lentil flour could shorten the

fermentation process better than pea flour.

The viable counts of L. rhamnosus in lentil

flour or pea flour supplemented were higher

than skim milk supplemented probiotic and the

CFUs in 1-3% pea flour was higher than 1-3%

lentil flour supplemented sample.

Continued

research

endeavours

Develop the potential of radio-frequencies for the

enhancement of phytochemical extractions. With lower

frequency dielectric heating we will achieve easier scale-up

engineering solutions.

Pursue the research on extracting a variety of valuable

components from various matrices, especially from by-

products biomass such as fruit pomace, leaves, grain hulls,

etc.

Concluding

Functional/nutraceutical foods target adding

“health-oriented” ingredients to foods.

The challenge is to innovate in the processes to

have milder / more gentle processing of

ingredients in order to retain the target nutrients

and promote their bioavailability.

More research will require to be integrated to

ensure the safety of these foods in terms of long

term toxicology and shelf stability.

Thank You!

To my team of great students and for your kind attention