Document Type : Research Article


Department of Food Science and Technology, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran


Cucumber is an economically important crop, containing vitamins, minerals, antioxidants, and flavonoids. However, due to loss of weight and firmness, microbial contamination, mechanical damage, and yellowing, the storage duration of cucumber is limited to 3–5 days at room temperature. Therefore, pretreatments are crucial for prolonging its shelf life. Chitosan is a cationic polysaccharide and can interact electrostatically with anionic, partially demethylated pectin. Besides, chitosan has inhibitory effects on fungal rot and prevents weight loss in fruits. Pectin can form excellent films. Because of increasing demand to reduce synthetic chemicals as antimicrobial agents, substances derived from plants, such as essential oils, can play a significant role in the future.  Several essential oils and essential oil components have shown antimicrobial activity against spoilage and pathogenic microorganisms during fruit and vegetable storage. Essential oils of thyme and cinnamon contained phenolic groups have been found to be most consistently effective against microorganisms, however, essential oils are volatile and irritant. Therefore, forming an inclusion complex using b-cyclodextrin can improve solubility, control volatile, and induce off-flavors and unpleasant odor of the essential oils. The objectives of this study were to develop the microencapsulated thymol (thyme) and trans-cinnamaldehyde (cinnamon) essential oils to produce antimicrobial agents and subsequently evaluate the effectiveness of edible coating made of chitosan and pectin containing microencapsulated trans-cinnamaldehyde or thymol essential oils to improve qualitative and quantitative characteristics and shelf life of cucumber.
Materials and Methods
The inclusion complexes of trans-cinnamaldehyde and thymol in beta-cyclodextrin (CD) were prepared separately by freeze-drying. Each essential oil was dispersed in 1000 ml of beta-cyclodextrin aqueous solution (16 mmol/L, 18.15 g) in molecular ratio 1:1 (2.4 gr thymol, 2.11 gr trans-cinnamaldehyde) and mixed in a laboratory stirrer for 24 hour at room temperature , then frozen (-70 ºc) and freeze-dried (<20Pa, 48 h). Lyophilized samples were stored inside a freezer (-20 ºc) until further use. Cucumbers cv. Nagene with uniform size, appearance, ripeness and without mechanical damage or fungal contamination were selected. Then They were then sanitized by immersion in chlorine solution (150 mg/kg) for 1 min and air dried. Edible coatings were prepared as three immersion solutions of chitosan, pectin, and calcium chloride (CaCl2). The fruits were coated with pectin (1%) and chitosan (0-0.5%-1%) containing beta-cyclodextrin microencapsulated trans-Cinnamaldehyde or thymol each (0-0.25%-0.5%). After coating by chitosan, the fruits were immersed in 1% Calcium chloride solution to induce crosslinking reaction. After dipping step, fruits dried for 8 minutes at room temperature to remove the excess solution attached to the surface .Uncoated fruits served as control. Then fruits were preserved in cold storage (temperature: 10ºc; relative humidity: 90-95%) for 15 days. chemical (total soluble solids, titratable acidity) and physical (total color difference, Hardness, and weight loss) Characterization of fruits were measured immediately after harvest and after 5, 10 and15 days. Microbial tests (total count, mold, and yeast) were done at the end of preservation time. Analytical data were subjected to analysis of variance and factorial adopted completely randomized design and a Duncan comparison test was used.
Results and Discussion
The results showed that weight loss, total soluble solids, and the total color difference increased and hardness and titratable acidity decreased gradually in all samples during cold storage (<0.05). Chitosan and essential oils slowed down this rising or decreasing trends. Interactive effects of chitosan, essential oil type, essential oil concentration, and storage time had positive effects on these quality attributes. The fruits coated with the highest concentration of chitosan (1%) and thymol (0.5%) essential oils showed the least weight loss, loss of hardness, and color change throughout 15 days of storage. Besides thymol in comparison with trans-Cinnamaldehyde was more efficient to prevent yeasts and molds on the surface of cucumber. By increasing chitosan and essential oil amounts, the ability of inhibiting microbial growth by coating is enhanced.
The results of chemical, physical and microbial tests, showed that multi-layer coating solution containing chitosan 1% with thymol 0.5% was effective in extending the shelf life of cucumber. The combined usage of microencapsulated thymol essential oil and chitosan-based coating on cucumber could be considered a healthy and effective treatment that reduces microbial spoilage and preserves quality and color characteristics in cucumber and represents an innovative method for commercial application. Therefore, this coating can be used as an alternative to chemical fungicides to prevent fungal rot of cucumber and other fruits, however, it is suggested that more studies should be done in this field.


Main Subjects

©2023 The author(s). This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source.

  1. Abdelghany, A.M., Menazea, A.A., & Ismail, A.M. (2019). Synthesis, characterization and antimicrobial activity of Chitosan/Polyvinyl Alcohol blend doped with Hibiscus sabdariffa extract. Journal of Molecular Structure, 1197, 603-609.
  2. Adetunji, C.O., Fadiji, A.E., & Aboyeji, O.O.(2014). Effect of chitosan coating combined Aloe vera gel on cucumber (Cucumis sativa) post-harvest quality during ambient storage. Journal of Emerging Trends in Engineering and Applied Sciences, 5(6), 391-397.
  3. Ali, A., Zahid, N., Manickam, S., Siddiqui, Y., & Alderson, P.G. (2014). Double layer coatings: a new technique for maintaining physico-chemical characteristics and antioxidant properties of dragon fruit during storage. Food and Bioprocess Technology, 7, 2366-2374.
  4. Aragüez, L., Colombo, A., Borneo, R., & Aguirre, A. (2020). Active packaging from triticale flour films for prolonging storage life of cherry tomato. Food Packaging and Shelf Life, 25, 100520.
  5. Attokaran, M. (2017). Natural food flavors and colorants. Chap 98, 354-398. 14796
  6. Aziziyan Dehkordi, B., Zamindar, N., Ghorbani, Z., & Mosaffa, L. (2020). Changes in the physicochemical and microbial properties of fresh-cut cucumber during storage as affected by modified atmosphere packaging and films of polypropylene containing clay nanoparticles. Journal of Nutrition Science and Food Technology, 15(12), 83-62. (In Persian)  
  7. Boonsiriwit, A., Xiao, Y., Joung, J., Kim, M., Singh, S., & Lee, Y.S. (2020). Alkaline halloysite nanotubes/low density polyethylene nanocomposite films with increased ethylene absorption capacity: Applications in cherry tomato packaging. Food Packaging and Shelf Life, 25, 100533.
  8. Chen, A., Yang, Z., Zhang, N., Zhao, S., & Chen, M. (2015). Effects of cold shock intensity on physiological activity of harvested cucumbers during storage. Scientia Horticulturae, 197, 420–427.
  9. Cid-López, M.L., Soriano-Melgar, L.D.A.A., García-González, A., Cortéz-Mazatán, G., Mendoza, E., Rivera-Cabrera, F., & Peralta-Rodríguez, R.D.(2021). The benefits of adding calcium oxide nanoparticles to biocompatible polymeric coatings during cucumber fruits postharvest storage. Scientia Horticulturae, 287, 110285.
  10. Chien, P.J., Sheu, F., & Yang, F.H. (2007). Effects of edible chitosan coating on quality and shelf life of sliced mango fruit. Journal of Food Engineering, 78, 225-229.
  11. Eboibi, O., & Uguru, H. (2017). Storage conditions effect on physical, mechanical and textural properties of intact cucumber (cv Nandini) fruit. International Journal of Engineering and Technical Research (IJETR), 7(11), 48-56.
  12. Gelly, M., Recasens, I., Girona, J., Mata, M., Arbones, A., Rufat, J., & Marsal, J.(2004). Effects of stage II and postharvest deficit irrigation on peach quality during maturation and after cold storage. Journal of the Science of Food and Agriculture, 84(6), 561–568.
  13. Goy, R.C., Britto, D.D., & Assis, O.B. (2009). A review of the antimicrobial activity of chitosan. Polímeros: Ciência e Tecnologia, 19(3), 241-247.
  14. Hamzah, H.M., Osman, A., Tan, C.P., & Ghazali, F.M. (2013). Carrageenan as an alternative coating for papaya (Carica papaya cv. Eksotika). Postharvest Biology and Technology, 75, 142–146.
  15. Hernández-Muñoz, P., Almenar, E., Del Valle, V., Velez, D., & Gavara, R. (2008). Effect of chitosan coating combined with postharvest calcium treatment on strawberry (Fragaria× ananassa) quality during refrigerated storage. Food Chemistry, 110(2), 428-435.
  16. Hernández-Muñoz, P., Almenar, E., Ocio, M.J., & Gavara, R. (2006). Effect of calcium dips and chitosan coatings on postharvest life of strawberries (Fragaria x ananassa). Postharvest Biology and Technology, 39(3), 247-253.
  17. ISO 4833-1. (2013). Microbiology of the food chain -Horizontal method for the enumeration of microorganisms -Part 1: Colony count at 30 °C by the pour plate technique. 1st. Edition. 9 pages. (In Persian)
  18. ISO 21527-1. (2008). Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration of yeasts and molds -Part 1: Colony count technique in products with water activity greater than 0.95. 1st. Edition. 8 pages. (In Persian)
  19. Istúriz-Zapata, M.A., Hernández-López, M., Correa-Pacheco, Z.N., & Barrera- Necha, L.L. (2020). Quality of cold-stored cucumber as affected by nanostructured coatings of chitosan with cinnamon essential oil and cinnamaldehyde. LWT - Food Science and Technology,
  20. Karathanos, V.T., Mourtzinos, I., Yannakopoulou, K., & Andrikopoulos, N.K. (2007). Study of the solubility, antioxidant activity and structure of inclusion complex of vanillin with β-cyclodextrin. Food Chemistry, 101(2), 652-658.
  21. Koseki, S., Kyoichiro, Y., Seiichiro, I., & Kazuhiko, I. (2004). Efficacy of acidic electrolyzed water for microbial decontamination of cucumbers and strawberries. Journal of Food Protection, 67, 1247-1251.
  22. Krzemiski, A., Marudova, M., Moffat, J., Noel, T.R., Parker, R., & Welliner, N. (2006). Deposition of pectin/ poly-l- lysine multilayers with pectin of varying degrees of esterification. Biomacromolecules, 7(2), 498-506.
  23. Li, M., Yu, H., Xie, Y., Guo, Y., Cheng, Y., Qian, H., & Yao, W. (2021). Effects of double layer membrane loading eugenol on postharvest quality of cucumber. LWT, 145, 111310.
  24. Lin, D., & Zhao, Y. (2007). Innovations in the development and application of edible coatings for fresh and minimally processed fruits and vegetables. Comprehensive Reviews in Food Science and Food Safety, 6(3), 60-75.
  25. Maleki, G., Sedaghat, N., Woltering, E.J., Farhoodi, M., & Mohebbi, M. (2018). Chitosan-limonene coating in combination with modified atmosphere packaging preserve postharvest quality of cucumber during storage. Journal of Food Measurement and Characterization, 12, 1610-1621.
  26. Mantilla, M., Castel-Perez, M.E., Gomes, C., & Moreira, R.G. (2013). Multilayered antimicrobial edible coating and its effect on quality and shelf -life of fresh cut pineapple (Ananas comosus). LWT-Food Science and Technology, 51, 37-43.
  27. Martinon, M.E., Moreira, R.G., Castel-Perez., & Gomes, C. (2014). Development of a multilayered antimicrobial edible coating for shelf-life extension of fresh-cut cantaloupe (Cucumis melo) stored at 4º. LWT - Food Science and Technology, 56, 341-350.
  28. Marudova, M., Lang, S., Brownsey, G.J., & Ring, S.G. (2005). Pectin–Chitosan multilayer formation. Carbohydrate Research, 340, 2144–2149.
  29. McGuire, R. (1992). Reporting of objective color measurements. Hortscience, 27(12), 1254-1255.
  30. Mohammadian, M., Waly, M.I., Moghadam, M., Emam-Djomeh, Z., Salami, M., & Moosavi-Movahedi, A.A. (2020). Nanostructured food proteins as efficient systems for the encapsulation of bioactive compounds. Food Science and Human Wellness, 9(3), 199-213.
  31. Mohammadi, A., Hashemi, M., & Hosseini, S.M. (2016). Postharvest treatment of nanochitosan-based coating loaded with Zataria multiflora essential oil improves antioxidant activity and extends shelf-life of cucumber. Innovative Food Science &Emerging Technologie, 33, 580-588.
  32. Moalemiyan, M., & Ramaswamy, H.S. (2012). Quality retention and shelf-life extension in Mediterranean cucumbers coated with a pectin-based film. Journal of Food Research, 1(3), 159-168. JFR.V1N3
  33. Mourtzinos, I., Kalogeropoulos, N., Papadakis, S.E., Konstantinou, K., & Karathanos, V.T. (2008). Encapsulation of nutraceutical monoterpenes in β-Cyclodextrin and modified starch. Journal of Food Science, 73(1), 89-94.
  34. Omoba, O.S., & Onyekwere, U. (2016). Postharvest physicochemical properties of cucumber fruits (Cucumber sativus) treated with chitosan-lemon grass extracts under different storage durations. African Journal of Biotechnology, 15(50), 2758-2766.
  35. Pérez-Santaescolástica, C., Munekata, P.E., Feng, X., Liu, Y., Bastianello Campagnol, P.C., & Lorenzo, J.M. (2020). Active edible coatings and films with Mediterranean herbs to improve food shelf-life. Critical Reviews in Food Science and Nutrition.
  36. Rabea, E.I., Badawy, M.E.T., Stevens, C.V., Smagghe, G., & Steurbaut, W. (2003). Chitosan as antimicrobial agent: applications and mode of action. Biomacromolecules4(6), 1457-1465.
  37. Rajabi, H., Ghorbani, M., Jafari, S.M., Mahoonak, A.S., & Rajabzadeh, G. (2015). Retention of saffron bioactive components by spray drying encapsulation using maltodextrin, gum Arabic and gelatin as wall materials. Food Hydrocolloids, 51, 327-337.
  38. Sarker, A., Deltsidis, A., & Grift, T.E. (2021). Effect of Aloe vera gel-carboxymethyl cellulose composite coating on the degradation kinetics of cucumber. Journal of Biosystems Engineering, 46, 112-118.
  39. Serna‐Escolano, V., Serrano, M., Valero, D., Rodríguez‐López, M.I., Gabaldón, J.A., Castillo, S., & Martínez‐Romero, D. (2019). Effect of thymol and carvacrol encapsulated in Hp‐β‐Cyclodextrin by two inclusion methods against Geotrichum citriaurantii. Journal of Food Science, 84(6), 1513-1521.
  40. Simionato, I., Domingues, F.C., Nerín, C., & Silva, F. (2019). Encapsulation of cinnamon oil in cyclodextrin nanosponges and their potential use for antimicrobial food packaging. Food and Chemical Toxicology, 132, 110647.
  41. Smith, R.L., Cohen, S.M., Doull, J., Feron, V.J., Goodman, J.I., Marnett, L.J., & Adams, T.B. (2005). A procedure for the safety evaluation of natural flavor complexes used as ingredients in food: essential oils. Food and Chemical Toxicology, 43(3), 345-363.
  42. Shahdadi Sardo, A., Sedaghat, N., Taghizadeh, M., & Milani, E. (2017). Effect of packaging type and chitosan edible coating on the physico-chemical and sensory characteristics of Royal greenhouse cucumber during storage conditions. Iranian Food Science and Technology Research Journal, 13, 2(42), 363-378. (In Persian).
  43. Turek, C., & Stintzing, F.C. (2013). Stability of essential oils: a review. Comprehensive Reviews in Food Science and Food Safety, 12(1), 40-53.