Trends in nutraceuticals: Impact on food safetyFood process engineering – Functional foods &...
Transcript of Trends in nutraceuticals: Impact on food safetyFood process engineering – Functional foods &...
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
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1999 2002 2007 2010 2015
US
D$
Billi
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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
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Re mRb1 Rb1 Tot al
Gi
ns
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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
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Re mRb1 Rb1 Tot alGi
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id
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xt
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ct
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(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
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Re mRb1 Rb1 Tot al
Gi
ns
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id
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xt
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ct
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(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).
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Ext r act i on Ti me ( mi n)
Amou
nt e
xtra
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(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%
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SD
G e
xtr
ac
tio
n y
ield
(%
)
0.05
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7
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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
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2.52
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Extraction Method
mg G
AE
/g d
ry p
eel
Conventional
RF
(a)
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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.
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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
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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