Assessment and improvement of quality management during postharvest processing and storage of coffee in Papua New Guinea

The project inception was delayed by six months due to late signing of the agreement.
The key activities outlined in the project proposal have been carried out as follows:
Assess postharvest system constraints to smallholder management of coffee quality and product consistency.
The first year of the project implementation has been devoted to the acquisition of baseline data from a number of available sources.
First of all, the project teams needed to get acquainted with the current production techniques used in the highlands of Papua New Guinea, especially in the Eastern Highlands Province, where the Coffee Industry Corporation (CIC) and its research arm, Research and Growers Services Division, are located. In order to acquire the relevant information the project teams conducted field surveys using questionnaires designed jointly by the UNSW and CIC teams. The questionnaires covered a range of topics such as harvesting process, pulping, fermenting, washing coffee beans, drying, handling coffee waste, labour involvement, production figures by household, coffee transportation, form in which the coffee crop is sold (cherry, parchment, green beans), timing of sale, coffee buyers, attitude towards adoption of new technologies (drying, wet processing), coffee quality assessment from the perspective of roasters and exporters as well as a range of questions related to the socio-economic situation and educational level of the respondent. The surveys have been conducted mostly by the CIC team where their extension officers have a good local knowledge of coffee farming community.
Moreover, the project team liaised with the other two other ACIAR funded projects, ASEM/2004/047 (Coffee Green Scale), ASEM/2004/042 (Collaborative Marketing). The research teams of these projects have also conducted surveys about specific aspects of the coffee production and their findings provide a useful contribution in the assessment of the existing smallholder management of coffee quality. Some inputs have also been obtained from the AT projects at Goroka that have recently started collaborating with CIC team.
The surveys are on-going as well as the data analysis.
Develop and test solutions to system deficiencies, with particular attention to improvement of drying and storage
The project teams are currently working on the evaluation of the criteria for coffee quality assessment in PNG. This work has been mostly done at the UNSW where adequate laboratory facilities are available. Samples of green coffee have been imported from PNG and also from northern NSW. While drying and storage experiments were conducted with samples from northern NSW, the work on quality, especially on the aroma components was done on samples from both origins. The evaluation of the quality of coffee was based on the results of instrumental as well as sensory analysis. More work on the quality of PNG coffee will be done once the laboratory of Research and Growers Services Division in Aiyura near Ukarumpa has been constructed and equipped. The construction work is progressing. The UNSW project team will provide advise on the use of laboratory equipment once the latter has been procured. An ecologic coffee demucilager for wet process, model UCBE 500 M, has been ordered from the Australian supplier and is expected to be operational in March 2007. Moreover, the project teams are conducting thorough literature searches on various aspects of drying and storage that are proposed under similar climatic and socio-economic conditions in other coffee producing areas. The most attractive solutions will be considered and, if adequate for the conditions prevailing in PNG, incorporated in the experiments.
Devise and implement strategies for the adoption of system improvements
At this stage it would be premature to propose concrete solutions. However, some of the findings from experiments conducted at the UNSW with samples obtained from PNG as well as those from northern NSW may be included in strategies to be trialed in the field by the PNG team.

The key activities outlined in the project proposal have been carried out as follows:
Assess postharvest system constraints to smallholder management of coffee quality and product consistency.
Surveys on coffee postharvest practices were carried out in 2006-2007 in three highland provinces. Those were Eastern Highlands Province, Simbu and Western Highlands which are the major coffee producers in the country. The survey team interviewed 500 farmers living at an altitude between 1400 and 2000 m above sea level The results were corroborated by a second smaller survey carried out in the East Highland Province, in collaboration with ASEM/2004/047 (Sustainable Management of Coffee Green Scales in PNG)
Following items were included in the survey questionnaire:
General post harvest practice
Time and labor input into post harvest operations
The perspectives of exporters and roasters on quality improvement of coffee crop, and needs of farmers
The survey data were analysed and resulted in the following overview of the prevailing postharvest practices among smallholders.
The post harvesting techniques used by the smallholder farmers vary greatly from one location to another. A number of factors affect the techniques and methods used. Women carry out most post harvest work (65%) besides doing their household chores.
The smallholder farmers pick most of the cherry once they started the harvesting seasons irrespective of their maturity due to need of fast cash and fear of theft.
For those who do not own a coffee pulper, there are different ways and methods used to pulp cherries. The latter are often substandard. Delay in pulping that affects the quality is a common problem in smallholders as well.
Fermenting process is sometimes rushed or prolonged out of ignorance of the resulting poor quality.
Drying techniques vary. Some farmers use tables while other spread beans on 'canvas' (plastic sheets) on the ground. Storing of beans during drying process is either in a family house or in a separated storehouse.
A number of smallholders relay on hired labor for harvesting and to a lesser extend for postharvest processing.
The quality of smallholder coffee is affected by the poor understanding of the relationship between postharvest techniques used and quality. Most of the farmers show their concern about low price obtained for their coffee due to its poor quality.
Most farmers are eager to adopt new technology if and when one is develop, however their obvious constraint will be finance.
As a result of the survey, the project teams (CIC and UNSW) are developing and testing solutions to system deficiencies, with particular attention to improvement of drying and storage.
The project teams continue work started in 2006 on the evaluation of the criteria for coffee quality assessment in PNG. In 2007 an increasing number of experiments have been carried out at the CIC laboratory in Aiyura near Ukarumpa. The thermophysical laboratory has been constructed, most of the analytical equipment supplied and training provided. An eco-processor for coffee, model UCBE 500 M, was supplied and installed in April 2007 and CIC technical staff trained. A sensory evaluation of coffee processed with the eco-processor vs. traditional wet processing method using cupping tests showed no significant difference in taste between coffee processed by either of the methods. In view of these results, three more eco-processors have been imported to PNG by private processors. The CIC staff provided training to these processors. The introduction of eco-processors is likely to contribute towards improvement in coffee quality (reduction in processing time) and towards environmental protection as this method requires only 1 litre of water per kg of green coffee vs up to 50 litres using traditional wet processing method.
Sun drying trials of wet processed coffee (de-pulped and de-mucilaged with the eco-processor) have been conducted in 2007. The conclusions are as follows:
A range of drying surfaces was tested. The difference in rate of drying between the surfaces was of the order of 20% or less.
Elevation was tested. This factor was not significant.
Mesh surfaces generally performed better (approx 20%) than solid surfaces.
The notable exception was the existing method (blue plastic canvas on ground) which performed equally well with all methods.
This suggests that the method of sun drying has little effect on drying rate. If true, this further indicates that the drying rate determining step for coffee beans is not surface evaporation, but internal diffusion. Mesh and elevation may improve the first few hours of drying, but experimentally have little overall effect. Then the only way to improve drying rates (sun, solar or mechanical) is to raise the internal bean temperature.
With regard to the sensory evaluation, the CIC laboratory in Aiyura is in the process of setting up its own cupping tests in line with those at CIC in Lae.
Devise and implement strategies for the adoption of system improvements
The testing of eco-processor is progressing. A second unit (with a petrol engine) is currently being imported in order to carry out demonstration trials at village level.

The key activities outlined in the project proposal have been carried out as follows:
Assess postharvest system constraints to smallholder management of coffee quality and product consistency.
The following socio-economic surveys have been completed:
Case Study March to August (exclude July) 08
To be completed in 2009: Major CGS survey with ASEM/2004/017, survey 09, (which will provide details for both projects)
On-going work in 2009:
Implementation of the final socio-economic survey instrument will also provide an avenue for the dissemination of information on post-harvest best practice. Immediate feedback will be sought on the viability of uptake of the identified best practices during this final survey/extension. The plan to produce an information DVD on best practice to be distributed to local church halls (in conjunction with ASEM/2004/047, Sustainable management of coffee green scales in PNG), employing the services of Goroka-based Steve Layton - as earmarked in early project planning stages - is yet to be determined.
As a result of the survey, the project teams (CIC and UNSW) are developing and testing solutions to system deficiencies, with particular attention to improvement of drying and storage.
The outputs will be presented in the final report within 60 days after the completion of the project, i.e. by the end of August 2009.
Devise and implement strategies for the adoption of system improvements
Ecoprocessor
This is a method for reducing water usage in coffee processing, which combines three unit operations into one. Results of controlled trials at CRI have been positive. The testing of eco-processor is still progressing. A second unit (with a petrol engine) has been imported and is currently being used in demonstration trials at village level. Training is their use is required to ensure selection of the correct unit for the coffee type, and adjustment of the equipment can then give a similar product to conventional processing.
The results will be presented in the final report, by the end of August 2009.
Sundrying
The experiments were carried out using the traditional sun drying system on various surfaces mounted on drying tables. Studies on major factors affecting sundrying have given surprising results. The major factors considered were drying surface, elevation, shading and stirring. The current method (using blue plastic tarps) gives a result comparable with the optimum method. The drying trials are still being conducted. The results will be presented by the end of August 2009.
Solar dryers
Computer simulation studies of solar drying were performed, indicating that this was not a suitable design for the culture and climatic conditions. Firstly, the growing climate is cold and wet, secondly a high collection area is required, and thirdly a high degree of maintenance would be required to keep them operational. For these reasons it was decided not to continue with studies on solar dryers.
Greenhouse dryer
Drying studies have continued throughout the project, and the third possibility for improving drying is a relatively new development, the greenhouse dryer. Such dryers have been adopted by smallholders in coffee growing areas of Colombia. Early results have indicated that this option can work with a fraction of the space required fore a solar dryer. The dryer differs from solar dryers in its use of heat recycling. A new design of this type of dryer is currently being tested and will be compared to the traditional sun drying system.
Quality and aroma profiling
Work has been conducted on measuring chemical quality, including studies on best drying temperature, chemical changes during storage and chemical ratios during roasting. This work is continuing. The findings will be presented in the final report in August 2009.
Thermophysical lab at CRI in Aiyura
A major aspect of the project has been the construction and provision for a new laboratory at CRI, designed for measuring both physical (such as density) and heat (such as thermal conductivity) properties of coffee beans. This lab was used for the first time in the analysis of the sun-drying trials, later used for measuring coffee properties.
Green coffee storage
Coffee storage trials using dried green coffee beans (C. arabica, cv. K7, origin: northern NSW) and two storage temperatures (15 C and 30 C) with a reference sample kept in the freezer at - 20 C were conducted in environmental chambers for 24 months at the University of NSW in Sydney. The results show a positive effect of higher storage temperature on the aroma precursors.

Thus the project is covering all aspects of postharvest handling of coffee, with outcomes deliverable through proposed Open Day displays, reports, presentations to CIC and extension services.