Physicochemical and phytochemical properties of Tunisian carob molasses

  • Leila TounsiEmail author
  • Imen Ghazala
  • Nabil Kechaou
Original Paper


Carob molasses is widely consumed in many Mediterranean countries, including Tunisia where it is known as ‘Rub El Kharroub’. The main objective of the present study was to evaluate the physicochemical properties and biological activities of both commercial and homemade Tunisian carob molasses. The physicochemical characterization revealed that the main parameters (color and HMF concentration) were related to non-enzymatic browning reactions occurring during juice concentration. The phytochemical analysis proved that the presence of bioactive compounds (volatile compounds, phenolic substances and products of non-enzymatic browning reactions) in carob molasses samples justify their biological effects (antioxidant and antibacterial activities). Accordingly, such characteristics may qualify Tunisian carob molasses (both homemade and commercial) as nutritious and healthy food that could be directly consumed or used a functional ingredient in food and pharmaceutical industry.


Carob molasses Chemical composition Aromatic compounds Biological activities 



The authors would like to thank the industry “Confiserie Triki-le Moulin” (Sfax, Tunisia) for the financial support and analytical assistance. The authors are also grateful to all the Tunisian families (Bekalta, Monastir) for providing kindly carob molasses samples and explaining their manufacturing process.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


  1. 1.
    K. Dhaouadi, M. Belkhir, I. Akinocho, F. Raboudi, D. Pamies, E. Barrajón, C. Estevan, S. Fattouch, Sucrose supplementation during traditional carob syrup processing affected its chemical characteristics and biological activities. Food Sci. Technol. 57, 1–8 (2014)Google Scholar
  2. 2.
    L. Tounsi, S. Karra, H. Kechaou, N. Kechaou, Processing, physico-chemical and functional properties of carob molasses and powders. J. Food Meas. Charact. 11, 1440–1448 (2017)CrossRefGoogle Scholar
  3. 3.
    O.B. Karaca, I.B. Saydam, M. Güven, Physicochemical, mineral and sensory properties of set-type yoghurts produced by addition of grape, mulberry and carob molasses (Pekmez) at different ratios. Int. J. Dairy Technol. 65, 111–117 (2012)CrossRefGoogle Scholar
  4. 4.
    F. Abbès, W. Kchaou, C. Blecker, M. Ongena, G. Lognay, H. Attia, S. Besbes, Effect of processing conditions on phenolic compounds and antioxidant properties of date syrup. Ind. Crops Prod. 44, 634–642 (2013)CrossRefGoogle Scholar
  5. 5.
    K. Dhaouadi, F. Raboudi, C. Estevan, E. Barrajon, E. Vilanova, M. Hamdaoui, S. Fattouch, Cell viability effects and antioxidant and antimicrobial activities of Tunisian date syrup (Rub El Tamer) polyphenolic extracts. J. Agric. Food Chem. 59, 402–406 (2011)CrossRefGoogle Scholar
  6. 6.
    K. Dhaouadi, F. Raboudi, L. Funez-Gomez, D. Pamies, C. Estevan, M. Hamdaoui, S. Fattouch, Polyphenolic extract of barbary-fig (Opuntia ficus-indica) syrup: RP-HPLC-ESI-MS analysis and determination of antioxidant, antimicrobial and cancer-cells cytotoxic potentials. Food Anal. Methods 6, 45–53 (2013)CrossRefGoogle Scholar
  7. 7.
    B.S. Wang, L.W. Chang, Z.C. Kang, H.L. Chu, H.M. Tai, M.H. Huang, Inhibitory effects of molasses on mutation and nitric oxide production. Food Chem. 126, 1102–1107 (2011)CrossRefGoogle Scholar
  8. 8.
    M. Sengül, M.F. Ertugay, M. Sengül, Y. Yüksel, Rheological characteristics of carob Pekmez. Int. J. Food Prop. 10, 39–46 (2007)CrossRefGoogle Scholar
  9. 9.
    H. Vaikousi, K. Koutsoumanis, C.G. Biliaderis, Kinetic modelling of non-enzymatic browning of apple juice concentrates differing in water activity under isothermal and dynamic heating conditions. Food Chem. 107, 785–796 (2008)CrossRefGoogle Scholar
  10. 10.
    S. Benjakul, W. Visessanguan, V. Phongkanpai, M. Tanaka, Antioxidative activity of caramelisation products and their preventive effect on lipid oxidation in fish mince. Food Chem. 90, 231–239 (2005)CrossRefGoogle Scholar
  11. 11.
    J.A. Rufián-Henares, F.J. Morales, Functional properties of melanoidins: In vitro antioxidant, antimicrobial and antihypertensive activities. Food Res. Int. 40, 995–1002 (2007)CrossRefGoogle Scholar
  12. 12.
    L. Tounsi, N. Kechaou, Le caroubier (Ceratonia siliqua L.) et ses fruits: descriptions, intérêts et applications (Éditions Universitaires Européennes, Sarrebruck, 2017)Google Scholar
  13. 13.
    M.M. Özcan, D. Arslan, H. Gökçalik, Some compositional properties and mineral contents of carob (Ceratonia siliqua) fruit, flour and syrup. Int. J. Food Sci. Nutr. 58, 652–658 (2007)CrossRefGoogle Scholar
  14. 14.
    A. Şimşek, N. Artik, Studies of composition of concentrates from different fruit. GIDA 27, 459–467 (2002)Google Scholar
  15. 15.
    N. Tetik, İ. Turhan, M. Karhan, H.R. Öziyci, Characterization of, and 5-hydroxymethylfurfural concentration in carob Pekmez. GIDA 35, 417–422 (2010)Google Scholar
  16. 16.
    N. Tetik, I. Turhan, H.R. Oziyci, M. Karhan, Determination of d-pinitol in carob syrup. Int. J. Food Sci. Nutr. 62, 572–576 (2011)CrossRefGoogle Scholar
  17. 17.
    O.S. Toker, M. Dogan, N.B. Ersöz, M.T. Yilmaz, Optimization of the content of 5-hydroxymethylfurfural (HMF) formed in some molasses types: HPLC-DAD analysis to determine effect of different storage time and temperature levels. Ind. Crop. Prod. 50, 137–144 (2013)CrossRefGoogle Scholar
  18. 18.
    CIE, Colorimetry, Supplement No. 2, Publication No. 15. (Commision International de l’Eclairage, Paris, France, 1986)Google Scholar
  19. 19.
    AFNOR, Jus de fruits et de légumes - Détermination de l’acidité titrable. NF EN 12147. (Association Française de Normalisation, Paris, France, 1997)Google Scholar
  20. 20.
    N. Turkmen, F. Sari, E.S. Poyrazoglu, Y.S. Velioglu, Effects of prolonged heating on antioxidant activity and colour of honey. Food Chem. 95, 653–657 (2006)CrossRefGoogle Scholar
  21. 21.
    A.E. Cohen, Y. Birk, C. Mannheim, I. Saguy, A rapid method to monitor quality of apple juice during thermal processing. Food Sci. Technol. 31, 612–616 (1998)Google Scholar
  22. 22.
    A. Orphanides, V. Goulas, M. Chrysostomou, V. Gekas, Recovery of essential oils from carobs through various extraction methods, in Recent Advances in Environment, Energy Systems and Naval Science (2011), pp. 219–224Google Scholar
  23. 23.
    M. Dubois, K.A. Gilles, J.K. Hamilton, P.A. Rebers, F. Smith, Colorimetric method for determination of sugars and related substances. Anal. Chem. 28, 350–356 (1956)CrossRefGoogle Scholar
  24. 24.
    G.L. Miller, Use of dinitrosalicylic acid reagent for determination of reducing sugar. Anal. Chem. 31, 426–428 (1959)CrossRefGoogle Scholar
  25. 25.
    AOAC, Official Methods of Analysis, 17th edn. (Association of Official Analytical Chemists, Washington, DC, 2000)Google Scholar
  26. 26.
    L.Y. Chew, K.N. Prasad, I. Amin, A. Azrina, C.Y. Lau, Nutritional composition and antioxidant properties of Canarium odontophyllum Miq. (dabai) fruits. J. Food Compos. Anal. 24, 670–677 (2011)CrossRefGoogle Scholar
  27. 27.
    AFNOR, Jus de fruits et de légumes - Dosage des minéraux par spectrométrie d’absorption atomique. NF V76-117. (Association Française de Normalisation, Paris, France, 1994)Google Scholar
  28. 28.
    R.E. Kitson, M.G. Mellon, Colorimetric determination of phosphorus as molybdivanadophosphoric acid. Ind. Eng. Chem. Anal. Ed. 16, 379–383 (1944)CrossRefGoogle Scholar
  29. 29.
    V.L. Singleton, J.A. Rossi, Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents. Am. J. Enol. Vitic. 16, 144–158 (1965)Google Scholar
  30. 30.
    R. Avallone, M. Plessi, M. Baraldi, A. Monzani, Determination of chemical composition of carob (Ceratonia siliqua): protein, fat, carbohydrates, and tannins. J. Food Compos. Anal. 10, 166–172 (1997)CrossRefGoogle Scholar
  31. 31.
    P. Prieto, M. Pineda, M. Aguilar, Spectrophotometric quantitation of antioxidant capacity through the formation of a phosphomolybdenum complex: specific application to the determination of vitamin E. Anal. Biochem. 269, 337–341 (1999)CrossRefGoogle Scholar
  32. 32.
    P. Bersuder, M. Hole, G. Smith, Antioxidants from a heated histidine-glucose model system. I: Investigation of the antioxidant role of histidine and isolation of antioxidants by high-performance liquid chromatography. J. Am. Oil Chem. Soc. 75, 181–187 (1998)CrossRefGoogle Scholar
  33. 33.
    A. Yildirim, A. Mavi, A.A. Kara, Determination of Antioxidant and Antimicrobial activities of Rumex crispus L. Extracts. J. Agric. Food Chem. 49, 4083–4089 (2001)CrossRefGoogle Scholar
  34. 34.
    D. A. Van den Berghe, A. J. Vlietinck, Screening methods for antibacterial and antiviral agents from higher plants. in Methods in Plant Biochemistry. (Academic Press, London, 1991), pp. 47–69Google Scholar
  35. 35.
    A.S. Karaman, A. Kayacier, Effect of temperature on rheological characteristics of molasses: modeling of apparent viscosity using adaptive neuro-fuzzy inference system (ANFIS). Food Sci. Technol. 44, 1717–1725 (2011)Google Scholar
  36. 36.
    A. Guilherme, T.L. Honorato, A.S. Dornelles, G.A.S. Pinto, E.S. Brito, S. Rodrigues, Quality evaluation of mesquite (Prosopis juliflora) pods and cashew (Anacardium occidentale) apple syrups. J. Food Process Eng. 32, 606–622 (2009)CrossRefGoogle Scholar
  37. 37.
    IEC, Multimedia systems and equipment: colour measurement and management, International Standard 61966-2-1. (International Electrotechnical Commission, Geneva, Switzerland, 1999)Google Scholar
  38. 38.
    M. Akbulut, H. Coklar, G. Ozen, Rheological characteristics of Juniperus drupacea fruit juice (Pekmez) concentrated by boiling. Food Sci. Technol. Int. 14, 321–328 (2008)CrossRefGoogle Scholar
  39. 39.
    Codex Alimentarius, List of codex specifications for food additives, CAC/MISC 6-2013 (2013)Google Scholar
  40. 40.
    A. Dehpour, B. Babakhani, S. Khazaei, M. Asadi, Chemical composition of essential oil and antibacterial activity of extracts from flower of Allium atroviolaceum. J. Med. Plants Res. 5, 3667–3672 (2011)Google Scholar
  41. 41.
    A. Djilani, A. Dicko, The therapeutic benefits of essential oils, in Nutrition, Well-Being and Health. (InTech, New York, 2012), pp. 155–178Google Scholar
  42. 42.
    M.M. Raj, H.V. Patel, L.M. Raj, N.K. Patel, Synthesis, characterization and in-vitro antimicrobial evaluation of some novel isoxazoline derivatives. Int. J. Res. Pharm. Chem. 3, 612–618 (2013)Google Scholar
  43. 43.
    A. Ben Hsouna, M. Trigui, R. Ben Mansour, R.M. Jarraya, M. Damak, S. Jaoua, Chemical composition, cytotoxicity effect and antimicrobial activity of Ceratonia siliqua essential oil with preservative effects against Listeria inoculated in minced beef meat. Int. J. Food Microbiol. 148, 66–72 (2011)CrossRefGoogle Scholar
  44. 44.
    M.J. Cantalejo, Effects of roasting temperature on the aroma components of carob (Ceratonia siliqua L.). J. Agric. Food Chem. 45, 1345–1350 (1997)CrossRefGoogle Scholar
  45. 45.
    M.A. Farag, D.M. El-Kersh, Volatiles profiling in Ceratonia siliqua (Carob bean) from Egypt and in response to roasting as analyzed via solid-phase microextraction coupled to chemometrics. J. Adv. Res. 8, 379–385 (2017)CrossRefGoogle Scholar
  46. 46.
    G. Macleod, M. Forcen, Analysis of volatile components derived from the carob. Phytochemistry 31, 3113–3119 (1992)CrossRefGoogle Scholar
  47. 47.
    M.E. Wakefield, G.P. Bryning, L.E. Collins, J. Chambers, Identification of attractive components of carob volatiles for the foreign grain beetle, Ahasverus advena (Waltl) (Coleoptera: Cucujidae). J. Stored Prod. Res. 41, 239–253 (2005)Google Scholar
  48. 48.
    ‬M. Papagiannopoulos, H. R. Wollseifen, A. Mellenthin, B. Haber, R. Galensa, Identification and quantification of polyphenols in carob fruits (Ceratonia siliqua) and derived products by HPLC-UV-ESI/MS. J. Agric. Food Chem. 52, 3784–3791 (2004)Google Scholar
  49. 49.
    F. Abbès, M.A. Bouaziz, C. Blecker, M. Masmoudi, H. Attia, S. Besbes, Date syrup: effect of hydrolytic enzymes (pectinase/cellulase) on physico-chemical characteristics, sensory and functional properties. Food Sci. Technol. 44, 1827–1834 (2011)Google Scholar
  50. 50.
    E.I. Oikeh, E.S. Omoregie, F.E. Oviasogie, K. Oriakhi, Phytochemical, antimicrobial, and antioxidant activities of different citrus juice concentrates. Food Sci. Nutr. 4, 103–109 (2016)CrossRefGoogle Scholar
  51. 51.
    S.L. Chen, D.J. Yang, H.Y. Chen, S.C. Liu, Effect of hot acidic fructose solution on caramelisation intermediates including colour, hydroxymethylfurfural and antioxidative activity changes. Food Chem. 114, 582–588 (2009)CrossRefGoogle Scholar
  52. 52.
    G. Hwang, H.Y. Kim, K.S. Woo, J. Lee, H.S. Jeong, Biological activities of Maillard reaction products (MRPs) in a sugar-amino acid model system. Food Chem. 126, 221–227 (2011)CrossRefGoogle Scholar
  53. 53.
    M.I. Halpin-Dohnalek, E.H. Marth, Staphylococcus aureus: production of extracellular compounds and behavior in foods—a review. J. Food Prot. 52, 267–282 (1989)CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Université de Sfax, École Nationale d’Ingénieurs de Sfax, Laboratoire de Recherche en Mécanique des Fluides Appliquée – Génie des Procédés-Environnement, Groupe de Recherche en Génie des Procédés AgroalimentairesSfaxTunisia
  2. 2.Université de Sfax, École Nationale d’Ingénieurs de Sfax, Laboratoire d’Amélioration des Plantes et Valorisation des AgroressourcesSfaxTunisia

Personalised recommendations