Converting grape tannins from winery

marc into active packaging

Rotoura

August, 2018

Paul A. Kilmartin

(University of Auckland)

2

RESEARCH TEAM

Subcontract

ors

Investment

Partners

Dr Louis Tremblay

Ecotoxicology

Dr Patrick Cahill

Antifouling

Dr Tripti Singh

Wood Preservation

A/Prof Steve Moratti

Polymer

Supramolecular Chemistry

Prof Paul Kilmartin

Co-Director

Conducting Polymers

A/Prof Simon Swift

Co-Director

Applied Microbiology

A/Prof Simon Swift

Applied Microbiology

Designer Biocides

Dist Prof Margaret Brimble

Organic Chemistry

Dr Jianyong Jin

Polymer Science

Dr David RennisionOrganic Chemistry

Prof Paul Kilmartin

Conducting Polymers

Natural Products

Synthetic/Natural Hybrids

Prof Ralph Cooney

Surface and Materials

Dr Sudip Ray

Polymer Engineering

Prof JadrankaTravas-Sejdic

Nano-technology

Dr Jenny Malmström

Imaging

Dr Duncan McGillivray

Biosurfaces

Surface Presentation

A/Prof Silas Villas-Bôas

Natural ProductMicrobiology

Prof Gillian Lewis

Biofilms

Dr Siouxsie Wiles

Medical Microbiology

Microbiology

Agro-wastes represent an abundant and

economical source of antioxidant compounds

Grape tannins can be extracted from

grape marc, produced in large

quantities in regions such as

Marlborough and the Hawkes Bay

Extraction and Purification

Grape tannins were prepared from Sauvignon blanc grape

marc using an equal quantity of water with 24 hours extraction.

Purification was performed with Amberlite FPX-66 resin, with

release into ethanol, then removed to produce the powder.

Staphylococcus aureus - Gram Pos Escherichia coli - Gram Neg

2.5 mg/mL Minimum Bactericidal Concentration 40 mg/mL

Tannin characterization: Anti-microbial testingTesting minimum bactericidal concentrations of a tannin extract against

(a) S. aureus and (b) E. coli, using agar plates, with exposure to the extract at

concentrations of 2, 1, 0.5, 0.25, 0.125, 0.06, 0.03, and 0% of grape tannin

Structural changes to grape tannins with heating

Polymeric tannins → oligomeric and monomeric structures

Blue-shift of –OH….H overlapping peaks from 3237 to 3257 cm-1

implies weakening of H-bond networks

Degradation at 250 °C seen with 1108 and 1160 cm-1 bands

250 °C

200 °C

150 °C

100 °C

HDPE = high density polyethylene (at 180 oC)

LLDPE = linear low density polyethylene (at 150 oC)

PP = polypropylene (at 180 oC)

aa'

a''

a

a'

a"

b

b'

b''

b

b'

b''

b

b'

b''

0

10

20

30

40

50

60

70

80

HDPE LLDPE PP

Pe

r c

en

t D

PP

H r

ad

ica

l s

ca

ve

ng

ed

0% GT

0.5% GT

1% GT

2% GT

3% GT

Antioxidant activity of polymers melt blended with

grape tannin (GT) as % DPPH radicals scavenged

HDPE = high density PE (at 180 oC)

LLDPE = linear low density PE (at 150 oC)

PP = polypropylene (at 180 oC)

3-5 min in a

Brabender

DSE25 twin-

screw extruder

K.J. Olejar, S. Ray, and P.A. Kilmartin, “Enhanced

antioxidant activity of polyolefin films integrated with

grape tannins”, Journal of the Science of Food and

Agriculture 96 (2016) 2825-2831.

Ethyl cellulose films

Good antimicrobial activity of ethyl cellulose and GT

Some increase in activity with incorporation of GT

Control

0.5 % GT

0

1 % GT

0 % GT

Biodegradable

Only need ethanol and a plasticizer for film formation

Sample

Neat Control 0% GME 0.5% GME 1% GME

CF

U (

log

10

sca

le)

1e+2

1e+3

1e+4

1e+5

1e+6

1e+7

1e+8Staphylococcus aureus - Gram Pos

0% GT 0.5% GT 1% GT

aa

a b

b

c

d

0

10

20

30

40

50

60

70

80

EC EC + 0.25% GT EC + 0.5% GT EC + 1.0% GT EC + 2.0% GT EC + 3.0% GT

Perc

en

t A

BT

S r

ad

ical

Scaven

ged

Antioxidant activity of the blended polymers

expressed as percent ABTS radical scavengingEC is ethyl cellulose and GT is grape tannin

Grape tannins display high antioxidant activity in

the ethyl cellulose blend – a promising start!

EC EC +

0.25% GT

EC +

0.5% GT

EC +

1% GT

EC +

2% GT

EC +

3% GT

K.J. Olejar, S. Ray, A. Ricci and P.A. Kilmartin, “Superior

antioxidant polymer films created through the incorporation of

grape tannins in ethyl cellulose”, Cellulose 21 (2014) 4545-4556

Solid waste from extraction process used to bulk up compost

Corn plants at Day 2 post-emergence

A) 100% depleted marc

B) 50:50 depleted marc: compost

C) 100% compost growth medium

EPA seedling emergence testing

guidelines

Corn

% Marc Concentration

Mixture pH % Emergence % Viable Root (cm) Stalk (cm)

0 7.02 ± 0.06a 93 ± 12 100 30 ± 6a 21 ± 6a

25 6.85 ± 0.03b 100 ± 0 100 17 ± 3b 16 ± 3b

50 6.76 ± 0.01c 87 ± 12 100 16 ± 4b 17 ± 3ab

75 6.42 ± 0.01d 85 ± 13 100 15 ± 3bc 17 ± 3ab

100 5.58 ± 0.01e 100 ± 0 100 11 ± 3c 14 ± 5b

Depleted grape marc blended with compost can be a

via alternative for growth of vegetable seedlings

Acknowledgements

Dr Ken Olejar Chalotte Vandermeer

Dr Sudip Ray Dr Zoran Zujovic

A/P Simon Swift Prof Ralph Cooney

Dr Tripti Singh & Dr Meeta Patel (Scion)

Prof Keith Gordon (University of Otago)

Arianna Ricci & A/Prof Andrea Versari (University of Bologna)

Funding:

Use of bioactive in edible films /packaging

SCION and NZCFPN Packaging Conference/ Workshop, Rotorua, NZ.22-23 August 2018

A/ Professor Siew Young QuekDirector, Food Science ProgrammeSchool of Chemical SciencesThe University of Auckland

Shelf-life extension

Consumer demand for natural ingredients

Antimicrobial property

Antioxidant property

Bioactive films/ packaging

Maintain food quality and safety

Edible, biodegradable,

sustainable

Antimicrobial agents

o Bacteriocins

o Spices

o Essential oils

o Enzymes

o Natural extracts

o Chitosan

o Peptide – Nisin

o Organic acids and salts

Functions:

o Ability to inhibit microbial growth

o Maintain antimicrobial activity

o Physical and barrier properties

Functions: The system works by maintaining the content of antioxidant for preventing oxidation process during food processing and storage.

Antioxidant compounds

o α-tocopherol & L-ascorbic acid

o Phenolic compounds

• Phenolic acids

• Phenolic diterpenes

• Flavonoids

• Volatile oils

o Plant pigments (Anthocyanin)

o Extracts of grape seeds and skins

• Instead of mixing antimicrobial/antioxidant compounds directly with food, incorporating them in films allows the functional effect at the food surface where the microbial growth is mostly found and oxidation occur.

• Bioactive packaging include systems such as:

o adding a sachet into the package

o dispersing bioactive agents in the packaging

o coating bioactive agents on the surface of the packaging material

o utilizing bioactive compounds with film forming properties or edible matrices

Antimicrobial agent

Bioactive films/ packaging

15

Overview of Research

Selection of materials

MIC, MBC

16

Electrospinning• Antioxidant, phenolics and zein

• Potential for food packaging

J. Food Eng. (2012), 109, 645-651

Bioactive components and the polymers applied in electrospinning

Date

Bioactive component Polymer Finding References

Epigallocatechin gallate(EGCG)

Zein Release of EGCG from fibre is dependent on relative humidity

Li et al., 2009

-carotene Zein Higher oxidative stability against UV irradiation

Fernandez et al., 2009

-carotene WPC 10%, glycerol 20%

Higher oxidative stability against UV irradiation

Lopez-Rubio and Lagaron, 2012

Gallic acid Zein Thermal stability and retention of antioxidant activity

Neo et al., 2013

Anthocyanin-rich raspberry extract

WPI Enhanced antimicrobial activity and anthocyanin content

Wang et al., 2013.

Chitosan Zein Enhanced antimicrobial properties for active packaging and biomedical applications

Torres - Giner et al., 2009

Curcumin Zein Improved sustained release, free radical scavenging ability

Drosou et al., 2017

Quercetin and ferulic acid Amaranth protein isolate and pullulan

Enhanced thermal stability, release characteristics and antioxidant protection ability

Drosou et al., 2017

R-(+) limonene Pullulan/-CD Increased storage stability, controlled release

Drosou et al., 2017

Food

Chemistry

Analytical

Lab

Mass Spec suite - Electrospray MS, ICP-MS, LCMS,

GC-MS, GC-O-MS

Others: NMR, microscopy (SEM, TEM Atomic

Force), spectroscopy (Raman, IR), rheometer

Food Grade Lab and Sensory

Evaluation Facility

STARCH FILMS FOR FOOD PACKAGING---RECENT ADVANCES

Fan Zhu

University of Auckland, New Zealand

wikipedia

Starch sources

Starch

Pérez & Bertoft, 2010

(a) taro; (b) chestnut; (c) ginger; (d) manioc; (e) corn; (b) (f) green banana; (g) wheat and (h) potato.

Amylose and amylopectin

Gelatinization and retrogradation

• Gelatinization:

• breaking down the intermolecular bonds of starch molecules in the presence of water and heat, allowing the hydrogen bonding sites to engage more water.

• Retrogradation:

• reaction that takes place when the amylose and amylopectin chains in cooked, gelatinized starch realign themselves as the cooked starch cools.

wikipedia

Starch films: (i) casting, (ii) blown extrusion and (iii) the thermo-compression moulding

Versino et al., 2016

Starch diversity: different starch sources and different composition of the same starch

Size-exclusion chromatograms of five debranched corn starches: (A) AMIOCA corn starch, (B) regular corn starch, (C) HYLON V starch, (D) HYLON VII starch, and (E) LAPS

Richardson et al., 2000

Effect of starch type on film properties

ESEM micrographs of cross-section and surface exposed to air during drying of wheat, corn and potato starch films (Magnification ×1000).

Starch modifications:

•Modified starch, also called starch derivatives, are prepared by physically, enzymatically, or chemically treating native starch to change its properties

•To enhance their performance in different applications. Starches may be modified to increase their stability against excessive heat, acid, shear, time, cooling, or freezing; to change their texture; to decrease or increase their viscosity; to lengthen or shorten gelatinization time; or to increase their visco-stability.

Effect of starch hydroxypropylation on film properties

Appearance of cast-films made from native (a) and hydroxypropylated (b) corn starches. In (b), high amylose corn starch was hydroxypropylated with propyleneoxide (PO) at 3–12% (starch weight basis, [s.w.b.]). All films were plasticized with 20% glycerol (s.w.b.)

•Low degree of hydroxypropylation could effectively reduce the brittleness in high-amylose corn starch films with minimal plasticizer required.

•Hydroxypropylation increased the flexibility of the films by decreasing the intermolecular interactions.

Using plant extracts rich in polyphenols for antioxidant and antimicrobial properties in starch films

Concluding remarks

•The film properties are much determined by the starch type and starch modifications.

•Addition of functional ingredients can make starch films for various applications such as antimicrobial and antioxidant food products.

•Starch films as biodegradable material have promising applications in places such as China and New Zealand where the environmental conditions are major concerns.