Del Monaco, G.

La Cara, F.

Laratta, B.

Marques, Isabel Paula

Morana, A.

Santos, Carla A.

Vella, F. M.

Marques, Isabel Paula Ramos

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Valorization of chestnut manufacture process residues [Poster]

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On the other hand, extraction process utilizing environmental friendly solvents (water andalcohols) allows to obtain high added value biomolecules from the solid manufacture wastes.Table 1 reports the chestnut wastewater chemical/physical parameters and Table 2 theenergy potential of chestnut wastewaters.The extraction methods for shells residues were compared considering the biomoleculescontents (data not showed). The best result was obtained utilizing hot water at 100 °C in assolid/liquid ratio of 1:40 (data not showed). The ortho-diphenol fraction, provided with thehighest antioxidant power among the phenolic molecules, corresponded to 80% of the totalphenols. Some interesting phenolic compounds (as Rutin, Gallic, Ellagic, p-Coumaric and Ferulicacid) with antiradical activity were identified in the extracts. The chestnut shells extractsshowing highest phenolic amount were also tested for antioxidant properties and their activitywas evaluated through DPPH assay (Table 3).Poster number105Valorization of chestnut manufacture process residues1I.P. Marques, 2A. Morana, 2B. Laratta, 2F.M. Vella, 1C.A. Santos, 3G. del Monaco, 2*F. La Carae-mail: francesco.lacara@ibaf.cnr.it1National Laboratory on Energy and Geology (LNEG), Estrada Paço do Lumiar, 1649-038 Lisbon, Portugal2Institute of Agro-environmental and Forest Biology (IBAF) - 3Institute of Biosciences and BioResources (IBBR), National Research Council - Via Pietro Castellino 111, 80131 Naples, ItalyIntroductionEuropean chestnut (Castanea sativa, angiosperm family Fagaceae) has a eastern Mediterranean origin and actually is a significant tree inagricultural and forestry economy. For many centuries, chestnut fruits represented one of the most important food resources of rural areas.Chestnut world production is estimated in 1.1 million tons (FAO data). Italy, Portugal, Greece, and France represent the main Europeanproducers, with a global production of about 12%. A great part of production is used by agro‐industries for fresh consumption, industrialprocessing (shelling, freezing and peeling), and for various food products such as chestnut purée and marron‐glacé.Chestnut manufacture generate a large quantity of wastewaters (ChW) that needs to beproperly treated due to organic load content. Several processes are available for wastewatertreatment, but until now no efficient and eco‐friendly systems have been assessed. The peelingprocess produces a huge amount of solid residues (ChS), representing about the 10‐15% inweight of the chestnut production, that are very rich in biomolecules withantioxidant/antiradical activity. Nowadays, the need to replace synthetic antioxidants used inthe pharmaceutical, cosmetic and food industries has promoted the research of new sources ofnatural antioxidant molecules. The undervalued products obtained from the agriculture andforestry could be used as an inexpensive supply of such compounds.Research AimDevelopment of low‐cost efficient technologies for ChW and ChS treatment that lead to the recovery of valuable by‐products and energy generation, throughanaerobic digestion process, thus reducing the negative impacts of wastes in environment and increasing the competitiveness of chestnut companies.2nd FaBE 2015 . 28-31 May 2015 . Mykonos2nd International Conference on Food and Biosystems EngineeringMaterials and MethodsThe wastewater and the solid residues were collected from a chestnutprocessing industry. Several analytical and chromatograph methods,described elsewhere [1] were used to characterize chestnut effluents(ChW). The energy potential value of the wastewaters were estimatedusing the anaerobic digestion as a process providing the effluenttreatment and energy recovery, considering cogeneration (CHP) use.The extraction of bioactive compounds was carried out on chestnutshells (ChS) using different solvents (water, methanol or ethanol withHCl) and temperatures (20 ÷ 100 °C) in a solid/liquid ratio ranging from1:10 to 1:40 (w/v).Total phenols content was determined by the Folin-Ciocalteu methodand the results were expressed as mg of gallic acid equivalents pergram of dry matter [2]. Ortho-diphenols and flavonoids amounts werealso determined and the values were showed as mg of caffeic acid andcatechin equivalents per gram of dry matter respectively.Antiradical activity was evaluated by a modification of the methoddescribed by von Gadow et al. [3] and it is defined as the amount ofantioxidant (expressed as µg of total polyphenols) necessary todecrease the initial DPPH concentration by 50 % (EC50 = EfficientConcentration).ResultsEffluents coming from chestnut processing industries are toxic tobiological degradation mainly due to acid pH and phenols content(Table 1). Anaerobic digestion have been recognized as an effectivetreatment option to deal with high polluted and/or unbalanced andtoxic substrates [1]. From the energetic point of view (Table 2), 1 m3of chestnut wastewater, digested anaerobically, can potentially providea energy amount of about 10 kWh. By applying cogeneration system,approximately 3 kWh electricity and 5 kWh of thermal energy will beavailable.References[1] - Sampaio MA, Gonçalves MR, Marques IP. 2011. Anaerobic digestion challenge of raw olive mill wastewater. Bioresour. Technol. 102 (23), 10810-18 [doi:10.1016/j.biortech.2011.09.001].[2] Fernandez-Agullo A., Freire M.S., Antorrena G., Pereira J.A., Gonzalez-Alvarez J. 2014. Effect of the extraction technique and operational conditions on the recovery of bioactivecompounds from chestnut (Castanea sativa) bur and shell. Separation Science and Technology, 49, 267-277.[3] Von Gadow A, Joubert E, Hansmann CF. 1997. Comparison of antioxidant activity of aspalathin with that of other plant phenols of Rooibos tea (Aspalathon linearis), α-tocopherol, BHT andBHA. J Agr Food Chem, 45,632-638.Conclusions The best extraction method for chestnut shells was the water at boiling point and ortho-diphenolic content reproduced the same trend of those obtained for total phenols Chemical and biological parameters were performed by identification and quantification of phenolics and activity bioassays Only environmental friendly solvents (water and alcohols) were utilized in this research and so they could be safely used for applications in the food and cosmetic industries. Anaerobic digestion of ChW allows to treat the effluent and recover its energy potential though biogas/methane production. Values about 10 kWh 1 m-3 of ChW can be obtain.Future PlansFurther studies are needed to assess the best extraction method useful in recovering the highest amount of bioactive compounds from wastes ofCastanea sativa and toobtain the highest yield in biogas/methane production.Table 1ParametersChestnut wastewater(Chw)pH 4.54Total COD (kg m-3) 5.60 ± 0.00TS (kg m-3) 3.36 ± 0.14VS (kg m-3) 3.00 ± 0.14Ashes (g L-1) 0.11 ± 0.04TSS (kg m-3) 2.69 ± 0.37VSS (kg m-3) 2.58 ± 0.42Total Nitrogen (g m-3) 174.72 ± 3.96Ammonium ion (N g m-3) 7.00 ± 0.00Total phenols (g GAE/m-3) 60 ± 0.002Conductivity (mS cm-1) 1.08 ± 0.06Color (Abs 390nm) 1.58 ± 0.12Table 3BiomoleculesChestnut WastewaterChestnutShellsTotal phenols 0.060 ± 0.002(mg GAE/mL)17.68 ± 1.09(mg GAE/g DM)Ortho-diphenols0.048 ± 0.003(mg CAE/mL)8.29 ± 0.30(mg CAE/g DM)Fiavonoids 0.012 ± 0.001(mg CE/mL)7.36 ± 0.32(mg CE/g DM)AntiradicalActivity (EC50)8.50 ± 0.14 68.00  ± 3.50GAE, CAE and CE = Gallic acid, Caffeic acid and CatechinEquivalents; EC50 = Efficient ConcentrationTable 21m3 - Chestnut wastewatersEnergy availableCHPMethane volume (m3) 1,0energy (kWh) 9,92Electricity (kWh) 3,37thermal energy (kWh) 4,96

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Valorization of chestnut manufacture process residues [Poster]

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