Figure 3: Semi-mechanical presses to extract coconut milk
Rapid Diagnosis of Coconut Fruit Quality
and Sustainable Small-Scale Processing
PRADES Alexia1, DAVRIEUX Fabrice1, MIALET-SERRA Isabelle1, ASSA Rebecca Rachel2,3and ROUZIERE André1
In many tropical countries, the coconut fruit is served as a refreshing drink and is processed into fresh milk for daily meals, virgin coconut oil for wellness, etc. Whatever the product, the consumers demand is always “quality” which definition could be a combination of taste, texture, and appearance as well as safety and environmental protection. Quality starts with fruit growing and shall be maintained during processing. Therefore Cirad and its partners have (i) measured the coconut fruit quality during ripening process and (ii) worked on sustainability of traditional small-scale processing.
Experimental
Experimental
Results
Results
385 coconut kernel samples of two coconut hybrids (PB121 and VRD x VTT) were collected in Côte d’Ivoire and Vanuatu over 3 years. Six palm trees per cultivar were harvested. Coconut kernels were harvested at increasing ripeness stages (from rank 17 to rank 24 i.e.6 to 13 months old nuts) and were freeze-dried. Samples were analysed by conventional techniques as HPLC for total soluble sugars (TSS) concentration and non conventional techniques using Near Infrared Spectroscopy : NIRS and Accelerated Solvent Extraction : ASE® for lipid concentration (Fig.1).
Centre de coopération internationale en recherche agronomique pour le développement www.cirad.fr
1CIRAD, TA 80/16, 73 rue JF Breton 34398 Montpellier Cedex 5, France. 2Université de Cocody, Abidjan, République de Côte d’Ivoire. 3CNRA, Station Marc DELORME, Port-Bouet, République de Côte d’Ivoire
Contact: alexia.prades@cirad.fr
The spectral data (Fig.2) of 128 selected samples were correlated to the chemical analysis results. The developed PLS models fitted the data well, with coefficients of determination of 0.97 for TSS concentration and 0.88 for lipid concentration. The remaining 257 samples were predicted with the developed predictive model.
Acknowledgements
VARTC, Vanuatu and Marc DELORME Station, CNRA, Côte d’Ivoire for their precious collaboration MOFA & CSDP, Ghana for technical support, AFD for funding
Figure 2: Spectral data of the freeze-dried coconut kernel of VRDxVTT hybrid at increasing ripeness stages
This study demonstrated the potential of NIR spectroscopy for use as a diagnosis tool for quality control of coconut fruit during ripening and harvesting. Laboratory analysis of 385 coconut kernel samples for TSS and lipid concentrations would have taken 40 weeks in a so-called conventional study using standardised methods. With the combined use of Near Infrared Spectroscopy and Automatic Solvent Extraction (Tab.1), we reduced:
The duration of the study by 4 The volume of solvents by 12 The cost by 3.3
Table 1: Comparison between conventional and non conventional methodologies Figure 1 : NIRSystem 6500 (FOSS NIRSystems
Inc., USA ) and Accelerated Solvent Analyser ASE® (DIONEX Inc., USA)
Type of methodology
With conventional
methods
With non conventional methods
(NIRS + ASE®) savings% of
Solvents (litres) 109 9 92% Time (weeks) 40 10 75% Cost (euros) 54858 16613 70% © FOSS
Conclusion
Conclusion
Rapid methods for coconut fruit quality diagnosis
Rapid methods for coconut fruit quality diagnosis
(i)
(i)
Sustainable small
Sustainable small
-
-
scale processing
scale processing
(ii)
(ii)
9Improving working conditions(hygiene and safety) by
providing safe gratersand semi-mechanical presses(Fig.3) building sheds and concrete working areas
Figure 4: Three-stonesmodel replaced by new stove
The Coconut Sector Development Project of the Ghanaian Ministry of Food and Agriculture funded by Agence Française de Développement took place in the West and Central Regions of Ghana between 2001 and 2003. Cirad experts made several proposals to move from a pollutant aqueous oil extraction process to a more sustainable activity.
Figure 5: Suggested small pilot waste treatment unit (44m3/week) to be validated on field
9Protecting environmentby
dividing by 2 the volume of wateradded to the grated kernel (Tab. 2) decreasing the quantity of fuel material with new stove(Fig. 4) treating the liquid waste and getting back energy : biogas(Fig.5)
Traditional
process Improved process Number of coconuts
Volume of water (litres) Oil Extraction Efficiency (OEE) Ratio water/grated kernel Rate of water evaporation (kg/h)
350 200
371 108
67.7% 74.7%
3.7 2.2
25 40
Table 2: Comparison between traditional and improved process 0 0,2 0,4 0,6 0,8 1 1,2 1,4 1,6 1,8 800 1000 1200 1400 1600 1800 2000 2200 2400 Wavelength (nm) Lo g 1 /R
Rank 17 Rank 20 Rank 22 Rank 24
Liquid waste storage and
settling tank Feeding tank Anaerobic digester Raw effluent Biogas Grease Treated effluent
