Effect of post-harvest treatments on the occurrence of Polycyclic Aromatic Hydrocarbon (PAHs) in raw cocoa beans sourced from Côte d'Ivoire

Effect of Post-harvest Treatments On The Occurrence

of Polycyclic Aromatic Hydrocarbon (PAHs)

In Cocoa Beans Sourced From Côte d’Ivoire

a _{Department of Food Science and Technology, University of Nangui Abrogoua, 02 Bp 801 Abidjan 02, Côte d'Ivoire} b _{UMR Qualisud, CIRAD - TA-B 95/16, 73 rue JF Breton, 34398 Montpellier Cedex 5, France}

Didier-Axel Sess-Tchotcha, Tagro Simplice Guehia, Maï Koumba Konéa, Angélique Fontana-Tachonb, Noël Durandb, Joël Grabulosb, Renaud Boulangerb, Didier Montetb

PAH occurrence in raw cocoa and derivative products is more and more worrying for the health of

chocolate consumers. Consequently, European Union has fixed PAH maximal content in cocoa

products by EU Standards 835/2011 and 2015/1933. Present research dealt with the impact of

post-harvest treatments on PAHs formation in raw cocoa.

Material and Methods

Raw cocoa sampling

Ivorian first genera.on of hybrids (Amelonado × West African Trinitario) variety cocoa pods harvested at Akoupé (Côte d’Ivoire) from tradi.onal planta.on in 2014 and 2015 (Figure 1) were used to cons.tute 370 cocoa samples in controlled condi.ons: health state of pods, fermenta.on methods, drying supports, storage condi.ons and .me

(Figure 2).

PAHs contents measurement

PAHs contents of cocoa were determined using an op.mized and validated method based on s.rred saponifica.on of 1 g of cocoa buSer for 1 hour in 6 mL of KOH, 1 M at 80°C. Benzo (a) anthracene (BaA); Chrysene (Chr), Benzo (a) Pyrene (BaP), Benzo (b) Fluoranthene (BbF) were then iden.fied and quan.fied by HPLC-Fluorescence and content of sum of the four PAHs (PHA4).

Results

• PAH4 content of raw cocoa resulted from good post-harvest treatments and drying prac.ces is about 5 - 6 μg.kg-1 _of cocoa buSer (Figure 3). • PAH4 content of raw cocoa stored for 28 days (Figure 3): • Tradi.onal warehouse is ranged 5.6 - 8 μg.kg-1 of cocoa buSer. • Tradi.onal kitchen (with wood smoke) reachs 35-39 μg.kg-1 of cocoa buSer slightly up EU standard 835/2011. • Ar.ficial dried cocoa in the presence of wood smoke recorded the highest PAH4 content reaching 142.05 μg.kg-1 _of cocoa buSer while natural dried cocoa presented the lowest content (Figure 4). • Sun or natural drying cocoa method is appropriated to limit PAH occurrence, however ar.ficial drying method specifically in the presence of wood smoke promotes contamina.on 3 to 4 .mes higher than the European standard (30µg.Kg-1 _{of cocoa buSer) (Figure 4).}

Conclusion and recommendations

Figure 3. Changes in PAH4 contents during various storage conditions of raw cocoa samples EEFSA, (2008). Scientific opinion of the pane l on contaminants in the food chain on a request fr

om the Europe

an commission

on polycyclic ar omatic hydrocarbons in fo od, The EFSA Journ al, 2008, 724p. EUROPEAN UNIO N (EU), (2015). Commission Regulation (EU) 2015/1933 of 27 October 2015 ame nding Regulation (EC) No 1881/2006 as regards maximum levels for polycyclic aromatic hydroca rbons in cocoa fibr e, banana chips, food supplements, dried herbs and dried spice s, Official Journal of the European Union, L 282/11, 3p. Grabulos J., (2011)

. Procédure pour

la détermination d

e 4 HAPs dans les produits carnés fum és (Benzo(a)Anthracène , Chrysène, Benzo(b)Fluor anthène, Benzo(a)pyrène), Pr ojet AFTER (FP7 n°245025), Deliverable D.1.2.3. 12, SOP : Anti-Nutri-Meatfish -001-fr. Guéhi, T.S., Zahouli I ., Ban-Koffi L., Fae A.M., Nemlin J. G ., (2010). Perform ance

of different drying methods

and their effects on the chemical quality attributes of raw cocoa materia l, International Jou rnal of Food Scien ce and Technology , 45, 1564–1571.

Referenc

es

C onception: Cir ad, Mar tine Dupor tal, June 2017 – © photos Didier -Ax el Sess-Tchotch

Figure 2. Diagram of cocoa beans sampling

Figure 4. PAHs contents in raw cocoa according to the drying methods

Controlled cocoa post-harvest treatments and sun drying method induce low PAHs content in raw

cocoa. Ar.ficial drying method and storage of cocoa in the presence of wood smoke provoke alarming

levels of PAHs very higher than interna.onal standards. They must be avoided. Occurrence of PAHs

in raw cocoa could be greatly reduced by using smokeless drying and storage methods.

Corresponding author: [email protected]