Post on 14-Sep-2018
Valorisation of Pea
Harvest Residues for use
as Functional Food
Ingredients:
Post-Harvest Treatment of
Pea Haulm for the
Preservation of Nutrients
Rhianna Briars
Background
153 kt/year haulm (25000 acre peas)
vines, pods, leaves
Pea-Harvest: Annual 7 weeks Jul-Aug
Valorising Green Leafy Materials:
Chloroplasts
Membrane composed of galactolipids,
high in α-Linolenic Acid
Photosynthesis: Protein complexes of the
thylakoid membranes
Synthesise vitamins, pigments
Current Project Re-SAUCE
Aim: Assess methods of stabilising nutrients
• Explore Blanching and Juice Treatment Techniques:
Simply determine effectiveness of treatment techniques:
Aesthetically and using an Enzyme Assay
o Blanching
Steam: time, temperature
Water: time, temperature
Microwave: time, power
o Juice Treatment
Pasteurisation: time, temperature
Anti-oxidants: inhibitor, concentration
Material Treatment
Blanch
Freeze (store 2 month)
Juice
Pasteurise
Antioxidant addition
CRF extraction
Freeze Dry
Store Dried (1 month)
Store Dried (2 month)
Trials
Enzyme Assay
Peroxidase (POD): popular indicator enzyme for vegetable heat treatments
heat stability
Active in plant stress: counteract release of ROS
Colorimetric assay:
Colour change due to oxidation of Guaiacol
In presence of H2O2
> enzyme activity = faster colour change
Biomass Treatments
Treatment Conditions Enzyme Knock-out
No Treatment n/a
Hot Water Blanch 80°C (2 mins) 93%
Microwave Blanch 1.5 mins 84%
Steam Blanch 1 min 55%
Steam Blanch 2 min 59%
Steam Blanch 4 min 70%
Large Scale Steam Blanch 100°C at 1 bar1 min sterilisation
49%
Large Scale Steam Blanch 100°C at 1 bar4 min sterilisation
81%
Untreated
4 min Retort
Juice Treatments
Treatment Enzyme Knock-out
No Treatment n/a
2.5 mg/ml Chlorogenic Acid 18%
70°C Pasteurisation (3 mins) Increased POD activity
70°C Pasteurisation (3 mins)With chlorogenic acid
8%
70°C Pasteurisation (6 mins) 42%
70°C Pasteurisation (6 mins)With chlorogenic acid
90%
90°C Pasteurisation (3 mins) 60%
90°C Pasteurisation (3 mins)With chlorogenic acid
86%
90°C Pasteurisation (6 mins) 87%
90°C Pasteurisation (6 mins)With chlorogenic acid
98%
Treatment Trial
Pea Harvest: 17th July 2017
FRESH Frozen (2) BLANCHEDBlanched
Frozen (2)PASTEURISED
Blanch
Freeze (store 2 month)
Juice *POD *POD *POD *POD
Pasteurise *POD
CRF extraction
Freeze Dry *Nutr. *Nutr. *Nutr. *Nutr. *Nutr.
Store Dried (1 month) *Nutr. *Nutr. *Nutr. *Nutr. *Nutr.
Store Dried (2 month) *Nutr. *Nutr. *Nutr. *Nutr. *Nutr.
Material Treatment
Trials
Macronutrient Content
Fresh
Blanched (4 minute Retort)
Pasteurised (3 minute at 90°C)
↓55%
↓75%
↓34%
POD enzyme knockout
Steam Blanch: 66%; Pasteurised Juice: 100%
Micronutrient Storage Trial
↓23%
↓91-94%
0
1
2
3
4
5
6
7
8
Fresh Blanched Pasteurised
Lute
in C
on
cen
trat
ion
(m
g/g
CR
F D
W) Week 0 Week 4 Week 8
0
0.2
0.4
0.6
0.8
1
1.2
Fresh Blanched Pasteurisedβ
-Car
ote
ne
Co
nce
ntr
atio
n(m
g/g
CR
F D
W)
Week 0 Week 4 Week 8
0
0.1
0.2
0.3
0.4
0.5
0.6
Fresh Blanched Pasteurised
α-T
oco
ph
ero
l Co
nce
ntr
atio
n(m
g/g
CR
F D
W)
Week 0 Week 4 Week 8
Summary
• Steam Blanching pea haulm or Pasteurising extracted juice
knocks out POD enzymes:
o Starch appears to be gelatinised due to the heat treatment and the
prolonged heating during pasteurisation may denature proteins
o The micronutrient content is not overtly reduced
• During storage α-tocopherol and β-carotene appear to be stable irrespective of
treatment, whereas lutein suffers degradation
• The POD knock-out is retained during frozen storage (2 months):
o Freeze storing untreated pea haulm causes a break down in micronutrients
- particularly α-tocopherol
o POD knock-out seems to protect from this nutrient break down
Conference
Systems Change Thinking –
Creating Value from Unavoidable Food Supply Chain Wastes
Tuesday 16th January 2018
University of Nottingham,
Sutton Bonington Campus
https://foodwaste-systemschange.eventbrite.com