The work of the World Food Waste Network is best demonstrated by a selection of Case Studies including:
- Extraction of Pectin from Pumpkins
- Profitability of Fodder Legume Production
- Microwave Enabled Synthesis of Polyesters
- Short-term Scientific Missions
1. Extraction of Pectin from Pumpkins
by ZUZANA KOSTALOVA, Slovak Academy of Sciences, SK
visiting AURORE RICHEL, University of Liege, BE
Zuzana's mission was to gain knowledge and experience in the isolation and characterisation of polysaccharides from agricultural waste. Her research focused on extracting the multipurpose polysaccharide Pectin from the parts of the Styrian oil pumpkin that remain after the seeds have been removed.
Commercially Pectin is isolated by hot acid maceration of citrus fruit peel and apple pomace, however, it has been demonstrated that microwaves can be used to isolate Pectin quicker from several fruit and vegetables. Zuzana explored both methods of Pectin extraction in order to make direct comparisons. Pumpkin was dried, ground and mixed at different ratios with water. These samples were then either:
- heated at 85°C for one hour in a water bath; or
- microwaved at varying temperatures (80,100 and 120°C) for different lengths of time (2, 6 and 10 mins).
Samples from both methods then underwent a series of filtering, washing and centrifugation to obtain the Pectin.
The yield for each sample was calculated as a percentage by dividing final weight by the original weight. The composition of the samples including their molecular weight were determined using various forms of high-performance chromatography.
Results showed that the percentage yield for those samples microwaved was between 3.1 to 7.4% and 5.7 to 7.3% for those heated in acid. In both methods highest percentages were obtained for those samples with a ratio of 50mL of water to 1g of pumpkin. The yield was also increased with a longer exposure time. Those samples microwaved for 10 minutes produced a greater yield than those that were microwaved for two minutes. Conversely, a temperature increase reduced the average molecular weight of the Pectin and the time in the microwave had a nominal effect. The ratio of the sample was strongly correlated to the average molecular weight—a higher water content resulted in a higher average molecular weight.
The best conditions were: liquid/solid ratio of 50:1, a microwave heating time of 10 min and an extraction temperature of 102.2 °C. A medium Mw pectin (139 kDa) was isolated with the same yield as the pectin isolated by conventional hot acid extraction, but in much shorter time. Indeed, the extraction time was shortened by 83%, which is economically advantageous, moreover within the same single step, the native polysaccharides were modified.[BACK TO TOP]
2. Profitability of Fodder Legume Production
by FRANKA PAPANDIEK, ZALF, DE
visiting PIERGIUSEPPE MORONE, University of Rome, IT
Franka visited Rome to work with Piergiuseppe on a Cost Benefit Analysis (CBA) of reintroducing fodder legumes into crop cycles.
LEARNING ABOUT CBA FROM PIERGIUSEPPE WAS A HUGE ADVANTAGE TO ME AND MY RESEARCH
FRANKA PAPANDIEK, ZALF, DE
The decline of fodder legumes use comes as a result of cheap imported protein soy to feed cattle and low cost nitrogen fertilisers. However, fodder legumes have many advantages over their alternatives, these are:
- providing a sustainable source of nitrogen;
- production is at a relatively consistent cost;
- they provide diversity in the local environment- reducing the need for pesticides;
- they improve soil structure and composition; and
- the biomass produced can be used as a fermentation media to produce lactic acid, which is used in the foods, detergents and the pharmaceutical industry.
Despite these benefits, their inclusion in a seven year crop rotation plan might prove to be disadvantageous as the return in yield (and sales) of other crops is reduced and the initial costs and maintenance of a biorefinery might not return profit. They investigated this by setting up three different scenarios on two different size sites (small and medium) in Northern Germany. The scenarios were as follows:
- no fodder legume production in rotation –status quo;
- fodder legume production in rotation; and
- fodder legume production in rotation and biorefinery.
WE REALLY SUCCEEDED; GETTING INTERESTING RESULTS IN A SHORT AMOUNT OF TIME
PIERGIUSEPPE MORONE, UNIVERSITY OF ROME, IT
The results show that in the first scenario, the internal rate of return (i.e the rate interest would have to be for it to be more profitable to invest the money) was 26% for both farms. This rate increased to 41% for both farms when fodder legume was included into the crop rotation- as outlined in scenario two. This is likely to be linked to the reduced usage of maize silage, as now they have legume silage, and savings associated with barley which grows after the legume- as its yield increased by 13% and the amount of fertiliser used is reduced to zero. The third scenario, the internal rate of return varies between 15 to 41% for the small farm and 12 to 87% for the medium farm. This is due to variations in the sale price of the fermentation juice. However, this scenario shows that large benefits can be made but with a large risk.
Going forward, further analysis varying the fermentation media ratios and uses, the variation of locations and crops and the inclusion of environmental impact all require new investigation to support the return of fodder legumes.
3. Microwave Enabled Synthesis of Polyesters
by ALESSANDRO PELLIS, BOKU, AT
visiting THOMAS J FARMER, University of York, UK
Read the full peer-reviewed publication describing this work here.
Alessandro visited Tom to work on enabling the synthesis of polyesters using microwave energy.
TO COMBINE MY BIOCATALYSIS EXPERTISE WITH TOM'S KNOWHOW ON MW-ASSISTED REACTIONS
ALESSANDRO PELLIS, BOKU, AT
The use of microwaves has several advantages over the traditional heating of using an oil bath. These are:
- avoiding hot spots;
- energy stops and starts immediately;
- energy consumption is low, and
- they have been used successfully with the polymerisation enzyme Candida Antarctica Lipase B to produce small esters.
They have also been used in the, more green method of, solvent free synthesis of copolymers of polycaprolactone and polystyrene.
To investigate further Alessandro and Tom set up four scenarios, in which to synthesise polyesters:
- solvent-free microwave reactions
- solvent-free oil bath reactions
- organic media microwave reactions
- organic media oil bath reactions
The samples from each were then analysed using NMR and chromatography. The results for both the solvent-free and organic media reactions showed that microwave and oil bath heated experiments are comparable in terms of average molecular weight and percentage monomer conversion.
With the exception of maintaining the high temperatures in the microwave, the results of both methods are directly compatible. The higher temperatures in this instance are attributed to denaturing the enzyme.
This study shows that microwaves can be used with enzymes for the polycondensation of polyesters.
WE PRODUCED A PAPER IN A GREAT ENVIRONMENT- I MET LOTS OF NICE PEOPLE...I'M WRITING A PROPOSAL TO MOVE TO THE UK.
ALESSANDRO PELLIS, BOKU, AT[BACK TO TOP]
4. Short-term Scientific Missions
Networking is an essential part of our research. One key element of networking is Short-term Scientific Missions (STSM) for Early Stage Researchers (ESR). These researchers work between collaborating institutions to share knowledge, expertise and facilities to reach a common end goal.
Details of STSM from 2013 to 2016 are shown on the map below. Click on the Google Map Pins to find out information about institutions, click on the black lines between the institutions to find out about the STSM. To information was written at the completion of the STSM by the named researcher.
As of 21st November 2016, STSM applications funded by COST have been ended. However, international collaboration is still possible through the WFWN.