Ethylene for processing
RICHARD COLGAN, NATURAL RESOURCES
INSTITUTE, UNIVERSITY OF GREEENWICH
International Storage Conference
Sponsored by Certis, 13 February 2014
Sustainable Arable Link: Reducing energy usage
and wastage by improving ethylene control of
potato sprouting.
• A collaboration between the Natural Resources Institute, Scottish Crop Research
Institute, AHDB-Potato Council, Greenvale AP Ltd, Cygnet Potato breeders Ltd,
Pepsico International Ltd, Landseer Ltd and Greenwich University Enterprise Ltd
supported by the Sustainable Arable Link Programme (DEFRA and RERAD)
Ethylene as an alternative form of sprout control
for processing potatoes
• Concerns exist over the long-term use of CIPC
• Ethylene is used currently as an alternative to CIPC for fresh
marketed potatoes
• Ethylene effectiveness on processing potatoes stored at higher
temperature is variety dependant
• Ethylene induced sugar accumulation can lead to poorer processing
quality
• There is a need to improve potatoes sensitivity to ethylene and limit
sugar accumulation during long-term storage
Improving the use of ethylene for sprout control will
be achieved with short and long-term objectives
Long-term solution: Marker Assisted Breeding
Commercial partner breeding programs for selection of new varieties with
improved sensitivity to ethylene induced spout control
• Identifying QTL’s for ethylene control of sprout suppression in selected
potato breeding material – trait placed on a genetic map of potato (NRI/JHI)
• Identifying changes in the gene expression profiles of buds/sprouts during
exposure to ethylene – identification of candidate gene markers (NRI/JHI)
Short-term solution: Develop sprout control strategies using a
combination of ethylene and other treatments.
• Best practice protocol for ethylene application to processing potatoes
• Combination of ethylene and other plant growth regulators/inhibitors
e.g. 1-Methylcyclopropane (SmartFreshTM) (NRI/SBCSR)
Identifying best practice for ethylene suppression
of sprouting in processing varieties
• Evaluate the sprouting response and sugar accumulation in
processing
varieties in response to ethylene treatment
• Identify additional treatments used in conjunction with ethylene to extend
sprout control during storage
•
Identify treatments that may reduce sugar accumulation in ethylenetreated tubers (1-MCP)
• 1-MCP (SmartFresh) an inhibitor of
ethylene action
•
Applied as a gas to stores at low
doses (625ppb)
•
May reduce ethylene induced sugar
accumulation in tubers
•
Doesn’t appear to interfere with
sprout suppression
Evaluation of varietal response to ethylene
• In Year 1: Sylvana, Russet Burbank, Maris Piper, Hermes, Saturna,
Cabaret and Verdi
• Stored at 6°C and 9°C and treated with continuous ethylene or
ethylene + 1-MCP for 6 months
• Tubers inspected every 2 months for sprout length and sugar content
Sprout suppression by ethylene is variety
dependant
Sylvana
Russet Burbank
Russet Burbank: Occasion 4
25
25
20
20
Sprout length (mm)
Sprout length (mm)
Sylvanna: Occasion 4
15
10
5
15
10
5
0
0
Untreated
Ethylene
6.0 c
6.0 c
Ethylene +
MCP
Untreated
Ethylene
Ethylene +
MCP
9.0 c
9.0 c
9.0 c
6.0 c
Untreated
6.0 c
Saturna
Ethylene
6.0 c
Untreated
9.0 c
Ethylene
9.0 c
Ethylene +
MCP
9.0 c
Hermes
Saturna and Hermes
were less responsive
to sprout suppression
Hermes: Occasion 4
Saturna: Occasion 4
25
25
20
20
Sprout length (mm)
Sprout length (mm)
Ethylene +
MCP
6.0 c
15
10
5
15
10
5
0
Untreated
Ethylene
6.0 c
6.0 c
Ethylene +
MCP
6.0 c
Sylvana and Russet
Burbank were
responsive to
ethylene-induced
sprout suppression
after 4 months storage
at 9°C
Untreated
Ethylene
Ethylene +
MCP
9.0 c
9.0 c
9.0 c
0
Untreated
6.0 c
Ethylene
6.0 c
Ethylene +
MCP
6.0 c
Untreated
9.0 c
Ethylene
9.0 c
Ethylene +
MCP
9.0 c
Accumulation of sugars in response to
ethylene treatment is variety dependant
Sylvana
Russet Burbank
Sylvanna: Occasion 4
Russet Burbank: Occasion 2
0.500
0.500
0.400
Sucrose
Glucose
0.300
Fructose
0.200
% Sugars (FW)
% Sugars (FW)
0.400
Sucrose
Glucose
0.300
Fructose
0.200
0.100
0.100
0.000
Untreated
Ethylene
Ethylene +
MCP
Untreated
Ethylene
Ethylene +
MCP
6.0 c
6.0 c
6.0 c
9.0 c
9.0 c
9.0 c
0.000
Untreated
Ethylene
Ethylene + 1MCP
Untreated
Ethylene
Ethylene + 1MCP
6.0 c
6.0 c
6.0 c
9.0 c
9.0 c
9.0 c
Hermes
Saturna
Hermies: Occasion 4
Saturna: Occasion 4
0.500
0.50
0.400
Sucrose
Glucose
0.300
Fructose
0.200
0.100
0.40
% Sugars (FW)
% Sugars FW
Saturna and Hermes
were less responsive
to ethylene-induced
sugar accumulation
than Sylvana and
Russet Burbank.
Sucrose
0.30
Glucose
Fructose
0.20
0.10
0.000
Untreated
Ethylene
Ethylene +
MCP
Untreated
Ethylene
Ethylene +
MCP
6.0 c
6.0 c
6.0 c
9.0 c
9.0 c
9.0 c
0.00
Untreated
Ethylene
Ethylene +
MCP
Untreated
Ethylene
Ethylene +
MCP
6.0 c
6.0 c
6.0 c
9.0 c
9.0 c
9.0 c
Induction of sugars by
ethylene was lower in
tubers stored after 4
months storage at 9°C
Improving the sprout growth control by combining
ethylene with other sprout suppressants
Ethylene + Methyl jasmonate
Ethylene + 1,4 Dimethyl napthalene (1,4 DMN)
Tested on Maris Piper stored at 9°C
Methyl Jasmonate - Maris piper
Ethylene + 1,4 DMN
Ethylene + Methyl jasmonate
1,4 DMN - Maris Piper
60
60
50
Apical sprout length (mm)
50
40
30
20
10
40
30
20
10
11
20
Fe
04
n
Ja
07
b
20
10
20
ec
D
1,4 DMN
1,4 DMN + ethylene
Control
Ethylene
15
04
Fe
b
20
11
20
11
07
Ja
n
20
10
ec
D
11
0
0
15
•
•
•
Additional sprout suppression achieved by combining ethylene with other
known sprout suppressants.
Apical sprout length (mm)
•
Methyl jasmonate
Methyl jasmonate + ethylene
Control
Ethylene
Optimising 1-MCP (SmartFreshTM) application to
lower sugar accumulation in stored potato
•
•
•
•
•
•
•
•
•
Optimisation of 1-MCP application to six commercial varieties
Six month storage trial conducted at SBCSR
Cabaret, Hermes, Maris Piper, Russet Burbank, Saturna, Sylvana
1-MCP (625 ppb) applied on arrival at crop intake temp.
Following overnight exhaust, tuber pull down to 9°C at 0.5°C/day.
Manual ethylene ramp from 0 to 10 ppm at 9°C
Further applications to subsamples at 2 months and 4 months
Tubers treated with 1,2 or 3 doses of 1-MCP over during storage
Sugar content, sprout length and fry colour; Cabaret, Maris Piper,
Sylvana and Russet Burbank processed as chips and Hermes and
Saturna as crisps
Ethylene effects on sprout growth and fry colour
Maris Piper
Sprout Length (mm)
Sprout Length
80
70
60
50
40
30
20
10
0
SO1
SO2
SO1
Untreated
SO2
MCPx1
SO2
SO1
MCPx2
SO2
SO3
SO1
Ethylene
SO2
SO3
Eth + MCPx1
SO2
SO3
Eth + MCPx2
SO3
commercial sprout
length acceptability
less than 2mm
Eth +
MCPx3
+/- s.d
Fry Colour (chips)
Fry Colour Score
7
6
5
Values below 4
(USDA 1) are
commercially
acceptable
4
3
2
1
SO1
SO2
Untreated
SO1
SO2
MCPx1
SO2
MCPx2
SO1
SO2
Ethylene
SO3
SO1
SO2
SO3
Eth + MCPx1
SO2
SO3
Eth + MCPx2
SO3
Eth +
MCPx3
Ethylene effects on sprout growth and fry colour
Russet Burbank
Sprout Length (mm)
Sprout Length
80
70
60
50
40
30
20
10
0
SO1
SO2
Untreated
SO1
SO2
MCPx1
SO2
SO1
MCPx2
SO2
SO3
SO1
Ethylene
SO2
SO3
Eth + MCPx1
SO2
SO3
Eth + MCPx2
SO3
Eth +
MCPx3
commercial sprout
length
acceptability
less than 2mm
+/- s.d
Fry Colour (chips)
Fry Colour Score
7
6
5
Values below 4
(USDA 1) are
commercially
acceptable
4
3
2
1
SO1
SO2
Untreated
SO1
SO2
MCPx1
SO2
MCPx2
SO1
SO2
Ethylene
SO3
SO1
SO2
SO3
Eth + MCPx1
SO2
SO3
Eth + MCPx2
SO3
Eth +
MCPx3
Sugar profiles of Maris Piper treated with
1-MCP and ethylene
•Sugar concentration stable in the presence of ethylene
•1-MCP as a single, double or triple application reduced sugar content in
ethylene-treated Maris Piper
Sugar profiles of Russet Burbank treated with
1-MCP and ethylene
•Ethylene induced glucose and fructose peak declines by 4-6 months
•1-MCP less effective in lowering sugars in the presence of ethylene
Summary- Ethylene
•
•
•
•
•
•
Ethylene reduced sprouting in all varieties tested
•
•
•
A tendency for ethylene to stimulate sugar accumulation in tubers stored at 9°C
At 6°C sugar accumulation was greater
The increase in sugar accumulation caused a slight decrease in processing quality,
especially for crisps in tubers stored at 9°C.
Varieties response to ethylene suppression of sprout growth varied:
- Very responsive: Markies, Russet Burbank and Sylvana
- Intermediate: Cabaret and Maris Piper
- Poor response: Hermes and Saturna
- Improved sprout control by ethylene may be achieved by combination with other
sprout suppressants (1,4 DMN, methyl jasmonate)
Summary- 1-MCP (SmartFreshTM)
•
1-MCP has no effect on sprout vigour
•
1-MCP can in the short-term lower sugar accumulation in some
ethylene-treated potato varieties
•
For example ethylene induction of crisp fry colour in Hermes can be
lowered by 1-MCP application at intake.
•
Multiple applications of 1-MCP during the storage season has a limited
effect on sugar accumulation.
•
New Potato Council-funded project investigating dose rate and timing of
1-MCP application to minimise reducing sugar content in tubers
Acknowledgements
We would like to thank