p_use
Western Sydney
University
Research Proposal: Nutritional profiles and
comparisons of 4 native Carpo
otus species unde
di↵erent growth conditions
Tobias Palme
May 2020
Abstract
The following research proposal aims to assess the suitability of 4 Australian
native, edible halophytes from the genus Carpo
otus as an alternative food crop
for human consumption under di↵ering soil and salinity conditions.
Species of Carpo
otus have traditionally been consumed as a vegetable by
African and Australian indigenous groups due to their nutritional value, natural
abundance and supposed medicinal value, the research proposal assesses the cu
ent
state of nutritional knowledge available, and propose a design to test the qualities of
the native species over a range of nutritional factors to build up a complete profile.
Signature:Tobias Palmer Date: 29/05/2020
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Contents
1 Background 1
2 Literature Review 1
3 Methodology 3
3.1 Materials. . . . . . . . . . . . . . . . . . . . . . . . . . XXXXXXXXXX3
3.2 Method. . . . . . . . . . . . . . . . . . . . . . . . . . . XXXXXXXXXX3
3.3 Statistical analysis. . . . . . . . . . . . . . . . . . . . . XXXXXXXXXX5
4 Gantt Chart 5
5 Proposed Budget 6
6 Results 6
7 Conclusion 7
1 Background
The predicted e↵ects of climate change are likely to decrease the amount of land useable
y traditional commercial agriculture. Specifically, increases in desertification, higher soil
salinity, lower water availability and overall poorer soil quality are likely e↵ects which
would largely limit what kinds of crops that can be grown in many areas cu
ently used
for food production. This presents a need to research alternate crops which can grow in
these environments while still providing edible and nutritious foodstu↵ (Wyk, 2011)
Halophytes from the family Carpo
otus are a traditional food source of indigenous
groups from South Africa and Australia, they are an edible succulent whose leaves and
fruits are thought to have medicinal and highly nutritious properties (Pirie et al., 2013).
2 Literature Review
At the time of writing there is no complete nutritional profile in place for any of the 4
native species of Carpo
otus in Australia (C. Rosii, C.Glaucescens, C. Modestus and
C. Virescens), however there has been some research done on Capro
otus Edulis, South
Africa’s native Capro
otus. Research by Rocha et al XXXXXXXXXXwas able to produce a
nutritional profile for C.Edulis shown below in figure 1.
In their discussion, they compare C.Edulis to many kinds of commonly grown vegetables,
with the main areas of similarity being moisture content, crude fat/crude protein and fi
e
content. They noted that the Polyunsaturated fat content of C.Edulis was significant at
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Figure 1: Nutritional profile of C.edulis from Rocha et al. (2017)
32.5% making it a source of dietary PUFA’s. The Authors also note that the ash content
is particularly high, and hypothesised this as being likely due to the halophytes being
collected from a coastal setting in Portugal, and therefore accumulating large quantities
of Na+ and Cl- , as well as other minerals during coastal exposure.
Further analysis of mineral content of C.Edulis resulted in figure 2.
Figure 2: Mineral analysis of C. edulis (Rocha et al., 2017)
The Authors noted high values for Ca, Fe and Mn, further illustrating C.Edulis’s nutrient
value as a source for biologically available minerals. Although the heavy metals reported
in the nutrition profile were either too low to be detected (Pb, Ni and Cd) or well below
safe levels for ingestion, the authors do note that halophytes do bioaccumulate heavy
metals if grown in contaminated soils. Typically this accumulation occurs in underground
organs but needs to be taken into account if grown in a commercial setting.
Based on our literature review there is evidence of halophytes from the Carpo
otus
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species being a valuable alternative crop based on nutritional profiles created for Capro-
otus Edulis (Rocha et al., XXXXXXXXXXVarone et al., 2017), as well as micronutrient research
done on Carpo
otus Rossii (Pirie et al., XXXXXXXXXXPirie et al., 2013).
The following research proposal will aim to create a nutritional profile of all 4 native
species of Carpo
otus as well as C. Edulis, in order to determine which one would be
most suitable for adoption as an alternate crop. The 5 di↵erent species will also be
compared across di↵erent growing conditions of salinity, and soil quality as these are
factors which are important when determining the viability of the species for human use
under non ideal conditions.
3 Methodology
3.1 Materials.
Plant specimens for the 5 species of Carpo
otus (C. Edulis, C. Rosii, C.Glaucescens, C.
Modestus and C. Virescens) are to be sourced through the University for Western Sydney
from trusted sources, so as to ensure that the plant samples are true representatives of
their species.
The proposed experiment requires 6 di↵erent conditions for plant growth with 6-10 plants
specimens used by each species to create an average. For a total of XXXXXXXXXXplant speci-
mens. All plant specimens are grown in commercial 15cm diameter plastic pots with free
drainage holes at bottom. At the start of the experiment, plant specimen circumference,
leaf number and average leaf size is recorded.
3.2 Method.
The plant samples are to be all grown under the same lighting/water schedules. Specif-
ically the plants are grown in greenhouse conditions of high light exposure ( recorded
using Bureau of meteorology info to give approximations) with adequate ventilation to
ensure the inhibition of pests and fungal development. Care is taken to ensure that all
plants receive the same amount of light as each other during the day.
The watering schedule for the plants is automated with a drip i
igation system. Each
plant specimen receives 30 ml of water every alternate day for the duration of the 4 month
growing period.
For each of the 5 species of Carpo
otus, there are 6 growth conditions, in order to
determine which condition results in the highest yield/nutritional value as well as which
species of Carpo
otus perform better under which conditions of growth.
The 6 conditions are:
1. Good soil/Ideal Salinity
2. Poor soil/Ideal salinity
3. Good soil/Low salinity
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4. Poor soil/Low salinity
5. Good Soil/high salinity
6. Poor soil/High Salinity
Plants in the Good soil conditions were planted in standard commercial grade potting
mix (Hortico All Purpose Potting Mix ). plants in the Poor condition were planted in a
mix of 50% commercial grade potting mix and beach sand.
Salinity conditions were determined using the results obtained in the experiments by Pirie
et al XXXXXXXXXXand Varone et al. (2017), Ideal salinity was 100mM, Low salinity 0mM and
High salinity 200mM (aprox, look up the numbers)
At the end of the 3 month growth period the plant specimens circumference, leaf numbe
and average leaf size is recorded and the change in values to original is determined.
For the nutritional profile, the plant specimens are dried at 40C for 3 days then powdered
and stored at -20C, following the same method in Rocha et al. (2017)
The following nutritional properties are to be determined via di↵ering methodologies.
Moisture content.
Moisture content is determined at the time of sample preparation, through calculating
the di↵erence in weight of the plant samples before the 3 day oven drying and at the
conclusion. Since the drying is at a low temperature but a long duration, organic volatility
is almost non existant, and the loss of matter can be determined to be almost exclusively
water loss.
Protein content.
The Dumas method is used to determine the protein content of the samples. Rocha et al.
(2017) used the Macro Kjeldahl method, but since there are 100’s of samples to analyse,
an automatable process like the Dumas method will be used instead.
Fat content.
Crude fat content will be determined through solvent extraction, specifically the Bligh
and Dyer method. It was decided than specific fat analysis, i.e. the lipid types in the
samples is beyond the scope of this experiment, so not necessary.
Ca
ohydrate content.
Total ca
ohydrate content for each sample is determined through the di↵erence equation.
Total ca
ohydrates = Sample weight (post dried) – total protein –total fat – total ash.
Ash/Mineral content.
Ash content is to be determined through dry ashing which is combustion at 500C in a
furnace, to remove organics form the sample, leaving only the inorganic minerals.
Mineral content is to be determined through atomic absorption spectroscopy, 300mg of
the dried sample is mixed with 6ml of HNO3 (65%), 1 ml of HClO4 and 1 ml of H2O2
prior to analysis, in accordance with the methodology set out in Rocha et al XXXXXXXXXXthe
8 essential biological minerals are being tested for.
Other organic compounds.
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High Performance Liquid Chromatography is to be used to test for the content of the
following organic compounds as they are of a nutritional interest being vitamins beneficial
to human diet: Retinal, retinol, beta carotene, Thaimin, Riboflavin, niacin, Pantothenic
acid, pyridoxine, biotin, folic acid, hydroxocobalamin, asco
ic acid, ergocalciferol, toco-
pherols, tocotrienols and phytomenadione.
In all cases, 10mg of sample is prepared with 10ml of ultrapure water and analysed
through the HPLC. The retention times for each compound are compared to obtained
cali
ation standard curves in order to determine a concentration.
3.3 Statistical analysis.
For each of the 6 growth conditions, a one way ANOVA will be ca
ied out using ‘R’
statistical software, comparing the means of the 5 Carpo
otus species for the follow-
ing variables. Change to plant specimen circumference, change to average leaf number,
change to average leaf size, Moisture content, Protein content, Fat content, Ca
ohydrate
content, Ash content, Specific mineral content, Specific Vitamin content.
Where an ANOVA indicates a statistically significant di↵erence in means, Follow up
student’s t tests are to be ca
ied out in ‘R’ software to determine where this significance
lies.
4 Gantt Chart
Figure 3 shows the proposed timetable for the research project, anticipated to start
January 2021.
Figure 3: 7 month research window for proposed research project