Background: Cocoa butter is the main by-product manufactured from dry fermented cocoa beans. This cocoa by-product contains triacylglycerols, di- and mono-glycerides, phospholipids, glycolipids, and unsaponifiable matter. During primary post-harvest processing, cocoa beans can get contaminated with mold species that produce lipase, which can lead to the accumulation of free fatty acids (FFA). High FFA content in dry fermented cocoa beans can alter the physical properties of both the fat fraction and chocolate.
Aims: This study aimed to improve the quality of raw cocoa material sourced from Côte d’Ivoire regarding its FFA concentration.
Methods: In October 2018, fifty dry fermented cocoa bean samples were randomly collected on-farm level from Aniassué, Akoupé, and Yakassé-Attobrou, which are three big cocoa producing regions located in Southeast of Côte d’Ivoire. Contaminating filamentous fungi strains were isolated using Sabouraud chloramphenicol agar incubated at 25°C for 7 days. Morphological identification of fungi isolates was performed from younger culture. Biochemical study for the determination of lipolytic properties of fungi was carried out using Cazpeck-Dox Agar medium enriched with olive oil as carbon source and rhodamine B as an indicator of extracellular lipase production. Extraction, PCR amplification using a specific transcribed spacer primer (ITS4/ITS5), and sequencing of DNA from fungal species were performed for molecular identification.
Results: The study found approximately 154 fungal isolates belonging to 8 genera in tested cocoa beans sourced from Côte d’Ivoire. Only Rhizopus oryzae, Absidia corymbifera, Mucor heimalis, Aspergillus niger, Aspergillus tubingensis, Aspergillus aculeatus, Aspergillus flavus, Aspergillus tamari, Aspergillus fumigatus, Nigrospora sphaerica, Curvularia geniculate, and Penicillium chrysogenum species exhibited greater extracellular lipase producing ability. Absidia corymbifera, Aspergillus niger, Aspergillus fumigatus, and Rhizopus orysae were the most frequent and predominant species contaminated Ivorian cocoa beans. Dry fermented cocoa beans inoculated with Rhizopus oryzae, Absidia corymbifera, or Aspergillus niger recorded higher FFA content above 1.75%.
Conclusion: Reducing the growth of fungi species during cocoa primary post-harvest processing could sustainably produce raw cocoa material with less FFA content. This study clearly indicated that controlling lipolytic fungi contamination in dry fermented cocoa beans could reduce FFA content and sustainably improve the quality of cocoa beans sourced from Côte d’Ivoire, cocoa butter and chocolate produced thereof.
Author(s) Details:
Tape Joëlle Stéphanie,
Laboratoire de Biotechnologie et Microbiologie des Aliments, UFR Sciences et Technologies des Aliments, Université Nangui ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Houphouët Kouakou Richard,
Laboratoire de Biotechnologie et Microbiologie des Aliments, UFR Sciences et Technologies des Aliments, Université Nangui ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire.
Kone Koumba Maï,
Institut National Polytechnique Félix Houphouët-Boigny, Bp 1093, Yamoussoukro, Côte d’Ivoire.
Mounjouenpou Pauline,
Laboratoire de Technologie Alimentaire, IRAD. BP 2067 Yaoundé, Cameron.
Guibert Benjamin,
CIRAD, UMR Qualisud, TA B 96/16, 75 Av JF Breton, 34398 Montpellier Cedex 5, France and Qualisud, Univ. Montpellier, Avignon, CIRAD, Institut Agro, Université de La Réunion, Montpellier, France.
Metayer-Piro Isabelle,
CIRAD, UMR Qualisud, TA B 96/16, 75 Av JF Breton, 34398 Montpellier Cedex 5, France and Qualisud, Univ. Montpellier, Avignon, CIRAD, Institut Agro, Université de La Réunion, Montpellier, France.
Montet Didier,
CIRAD, UMR Qualisud, TA B 96/16, 75 Av JF Breton, 34398 Montpellier Cedex 5, France and Qualisud, Univ. Montpellier, Avignon, CIRAD, Institut Agro, Université de La Réunion, Montpellier, France.
Guehi Tagro Simplice,
Laboratoire de Biotechnologie et Microbiologie des Aliments, UFR Sciences et Technologies des Aliments, Université Nangui ABROGOUA, 02 BP 801 Abidjan 02, Côte d’Ivoire.