PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

Drying desiccated coconut is always challenging due to its sensitivity to heat, which can reduce its color quality. The main goal of this study is to optimize infrared drying (IR) efficiency without affecting the final color quality of desiccated coconut. Single-mode infrared drying was optimized using Response Surface Methodology (RSM) with a central composite rotatable design (CCRD). Using a radiation output of 600 Watts and a fixed distance of 15 cm from the emitter, a single layer of fresh shredded coconut with a wet basis of approximately 51.35±4.0% was dried to less than 3% (w.b). Drying temperature and air velocity were taken into consideration as independent parameters. The selected optimal drying conditions, with the desirability value (D = 0.812), were 61°C drying temperature and 2.2 m/s air velocity. The response of optimal values for drying time, specific energy consumption (SEC), color changes, and whiteness index were 36.826 minutes, 19.821 kWh/kg, 3.431, and 71.762, respectively. Models for predicting these response values had R2 values of more than 0.90. All responses were shown to be significantly impacted by drying temperature and air velocity (p<0.05), with drying temperature having a larger effect than air velocity. The optimal drying parameters were validated with a less than 2% deviation.

• Abidin, M. H. Z., Sabudin, S., Zakaria, J. H., & Batcha, M. F. M. (2014). Thin layer modeling of grated coconut drying. Applied Mechanics and Materials, 660, 367–372. https://doi.org/10.4028/www.scientific.net/AMM.660.367
  
  Aboud, S. A., Altemimi, A. B., Al-hiiphy, A. R. S., Yi-chen, L., & Cacciola, F. (2019). A comprehensive review on infrared heating. Molecules, 24(22), Article 4125. https://doi.org/10.3390/molecules24224125
  
  Adak, N., Heybeli, N., & Ertekin, C. (2017). Infrared drying of strawberry. Food Chemistry, 219, 109–116. https://doi.org/10.1016/j.foodchem.2016.09.103
  
  Adoyo, G. O., Sila, D. N., & Onyango, A. N. (2021). Physico-chemical properties of kernel from coconut (Cocos nucifera L.) varieties grown at the Kenyan Coast. African Journal of Food Science, 15(8), 313–321. https://doi.org/10.5897/ajfs2021.2116
  
  Aggary, S., & Arowanti, O. (2012). Modelling the drying characteristics of osmosised coconut strips at constant air temperature. Journal of Food Processing & Technology, 3(4), Article 1000151. https://doi.org/10.4172/2157-7110.1000151
  
  Alouw, J. C. (2023). Towards the 2023 sustainable development goals summit. International Coconut Commuity. https://www.unescap.org/sites/default/d8files/event-documents/ICC_Statement - International Coconut Community_AI3.pdf
  
  AOAC. (2005). In official methods of analysis (18th ed.). Association of Officiating Analytical Chemists.
  
  Bhat, M. I., Shahi, N. C., Singh, A., & Malik, S. (2020). Response surface optimization of quality parameters of turmeric slices in an innovative infrared assisted hybrid solar dryer. International Journal of Chemical Studies, 8(3), 1958–1967. https://doi.org/10.22271/chemi.2020.v8.i3aa.9492
  
  Delfiya, D. S. A., Prashob, K., Murali, S., Alfiya, P. V., Samuel, M. P., & Pandiselvam, R. (2021). Drying kinetics of food materials in infrared radiation drying: A review. Journal of Food Process Engineering, 45(6), Article e13810. https://doi.org/10.1111/jfpe.13810
  
  Doymaz, I., Kipcak, A. S., & Piskin, S. (2015). Characteristics of thin-layer infrared drying of green bean. Czech Journal of Food Sciences, 33(1), 83–90. https://doi.org/10.17221/423/2014-CJFS
  
  Erbay, Z., & Icier, F. (2009). Optimization of hot air drying of olive leaves using response surface methodology. Journal of Food Engineering, 91(4), 533–541. https://doi.org/10.1016/j.jfoodeng.2008.10.004
  
  Fernando, A. J., Gunathunga, C., Brumm, T., & Amaratunga, S. (2021). Drying turmeric (Curcuma longa L.) using far-Infrared radiation: Drying characteristics and process optimization. Journal of Food Process Engineering, 44(9), Article e13780. https://doi.org/10.1111/jfpe.13780
  
  Golpour, I., Kaveh, M., Amiri Chayjan, R., & Guiné, R. P. F. (2020). Optimization of infrared-convective drying of white mulberry fruit using response surface methodology and development of a predictive model through artificial neural network. International Journal of Fruit Science, 20(2), S1015-S1035. https://doi.org/10.1080/15538362.2020.1774474
  
  Huang, X., Li, W., Wang, Y., & Wan, F. (2021). Drying characteristics and quality of Stevia rebaudiana leaves by far-infrared radiation. LWT-Food Science and Technology, 140, Article 110638. https://doi.org/10.1016/j.lwt.2020.110638
  
  International Coconut Community. (2009). APCC quality standard. International Coconut Community. https://coconutcommunity.org/viewpdf/apcc_quality_standards_for_coconut_products/4
  
  Isik, A., Ozdemir, M., & Doymaz, I. (2019). Infrared drying of bee pollen: Effects and impacts on food components. Czech Journal of Food Sciences, 37(1), 69–74. https://doi.org/10.17221/410/2017-CJFS
  
  Jafari, F., Movagharnejad, K., & Sadeghi, E. (2020, April 15-17). Investigation of drying kinetics of eggplant slices using infrared. [Paper presentation]. The 11th International Chemical Engineering Congress & Exhibition (IChEC 2020), Guilan, Iran.
  
  Jongyingcharoen, J. S., Wuttigarn, P., & Assawarachan, R. (2019). Hot air drying of coconut residue: Shelf life, drying characteristics, and product quality. IOP Conference Series: Earth and Environmental Science, 301(1), Article 012033. https://doi.org/10.1088/1755-1315/301/1/012033
  
  Kaveh, M., Abbaspour-Gilandeh, Y., Fatemi, H., & Chen, G. (2021). Impact of different drying methods on the drying time, energy, and quality of green peas. Journal of Food Processing and Preservation, 45(6), Article e15503. https://doi.org/10.1111/jfpp.15503
  
  Kıan-pour, N. (2020). Fundamental drying techniques applied in food science and technology. International Journal of Food Engineering Research, 6(1), 35-63.
  
  Kipcak, A. S., & Doymaz, İ. (2020). Microwave and infrared drying kinetics and energy consumption of cherry tomatoes. Chemical Industry and Chemical Engineering Quarterly, 26(2), 203–212. https://doi.org/10.2298/CICEQ190916039K
  
  Kipcak, A. S., Doymaz, İ., & Moroydor-Derun, E. (2019). Infrared drying kinetics of blue mussels and physical properties. Chemical Industry and Chemical Engineering Quarterly, 25(1), 1-10. https://doi.org/10.2298/CICEQ170808014K
  
  Koca, I., Yilmaz, V. A., Odabas, I. H., & Tekguler, B. (2018). Optimization of drying parameters for chestnut fruits using central composite design. Acta Horticulturae, 1220, 221–226. https://doi.org/10.17660/ActaHortic.2018.1220.31
  
  Lamdande, A. G., Prakash, M., & Raghavarao, K. S. M. S. (2018). Storage study and quality evaluation of fresh coconut grating. Journal of Food Processing and Preservation, 42(1), Article e13350. https://doi.org/10.1111/jfpp.13350
  
  Madamba, P. S. (2003). Thin layer drying models for osmotically pre-dried young coconut. Drying Technology, 21(9), 1759–1780. https://doi.org/10.1081/DRT-120025507
  
  Madhiyanon, T., Phila, A., & Soponronnarit, S. (2009). Models of fluidized bed drying for thin-layer chopped coconut. Applied Thermal Engineering, 29(14–15), 2849–2854. https://doi.org/10.1016/j.applthermaleng.2009.02.003
  
  Majdi, H., Esfahani, J. A., & Mohebbi, M. (2019). Optimization of convective drying by response surface methodology. Computers and Electronics in Agriculture, 156, 574–584. https://doi.org/10.1016/j.compag.2018.12.021
  
  Manohar, M., Joseph, J., Selvaraj, T., & Sivakumar, D. (2013). Application of desirability-function and RSM to optimise the multi-objectives while turning Inconel 718 using coated carbide tools. International Journal of Manufacturing Technology and Management, 27(4–6), 218–237. https://doi.org/10.1504/IJMTM.2013.058899
  
  Moses, J. A. A., Paramasivan, K., Sinija, V. R. R., Alagusundaram, K., Brijesh kumar, T., Alugusundaram, K., & Kumar, B. (2013). Effect of microwave treatment on drying characteristics and quality parameters of thin layer drying of coconut Jeyan. Asian Journal of Food and Agro-Industry, 6(2), 72–85.
  
  Muga, F. C., Marenya, M. O., & Workneh, T. S. (2021). Modelling the Thin-layer drying kinetics of marinated beef during infrared-assisted hot air processing of biltong. International Journal of Food Science, 2021(1), Article 8819780. https://doi.org/10.1155/2021/8819780
  
  Ngampeerapong, C., & Chavasit, V. (2019). Nutritional and bioactive compounds in coconut meat of different sources: Thailand, Indonesia and Vietnam. Chiang Mai University Journal of Natural Sciences, 18(4), 562–573. https://doi.org/10.12982/CMUJNS.2019.0037
  
  Niamnuy, C., & Devahastin, S. (2005). Drying kinetics and quality of coconut dried in a fluidized bed dryer. Journal of Food Engineering, 66(2), 267–271. https://doi.org/10.1016/j.jfoodeng.2004.03.017
  
  Nor, N. A. A. M., Arif, E. E. E., Omar, N. R. N., Abidin, A. Z. Z., Muhammad, R. M., Rahim, H., Nazmi, M. S., & Sulaiman, N. H. (2020). Total productivity and technical efficiency of coconuts in Malaysia. Economic and Technology Management Review, 15, 11–22.
  
  Nordin, R., Rozalli, N. H. M., & Yang, T. A. (2019). Application of response surface methodology to optimize the drying conditions of black tea using a superheated steam dryer. International Journal of Food Studies, 8(2), 81–92. https://doi.org/10.7455/ijfs/8.2.2019.a8
  
  Nurkhoeriyati, T., Kulig, B., Sturm, B., & Hensel, O. (2021). The effect of pre‐drying treatment and drying conditions on quality and energy consumption of hot air‐dried celeriac slices: Optimisation. Foods, 10(8), Article 1758. https://doi.org/10.3390/foods10081758
  
  Omolola, A. O., Jideani, A. I. O., Kapila, P. F., & Jideani, V. A. (2015). Optimization of microwave drying conditions of two banana varieties using response surface methodology. Food Science and Technology (Brazil), 35(3), 438–444. https://doi.org/10.1590/1678-457X.6700
  
  Pan, Z. (2021). Innovative infrared heating technologies for food and agricultural processing. Technology & Innovation, 21(4), 1–16. https://doi.org/10.21300/21.4.2020.8
  
  Park, B. S., Kang, T. H., Lee, J. H., Choi, J. M., & Han, C. S. (2015). Drying Characteristics of radishes using far infrared ray dryer. Journal of Biosystems Engineering, 40(1), 61–66. https://doi.org/10.5307/jbe.2015.40.1.061
  
  Patil, U., Benjakul, S., Prodpran, T., Senphan, T., & Cheetangdee, N. (2017). A comparative study of the physicochemical properties and emulsion stability of coconut milk at different maturity stages. Italian Journal of Food Science, 29(1), 145–157. https://doi.org/10.14674/1120-1770/ijfs.v536
  
  Pestaño, L. D. B. (2015, April 12). Mathematical modeling of the drying process of coconut meat. [Paper presentation]. Third International Conference on Advances in Applied Science and Environmental Engineering, London, United Kingdom. https://doi.org/10.15224/978-1-63248-055-2-80
  
  Riadh, M. H., Ahmad, S. A. B., Marhaban, M. H., & Soh, A. C. (2015). Infrared heating in food drying: An overview. Drying Technology, 33(3), 322–335. https://doi.org/10.1080/07373937.2014.951124
  
  Sadeghi, E., Asl, A. H., & Movagharnejad, K. (2019). Mathematical modelling of infrared-dried kiwifruit slices under natural and forced convection. Food Science & Nutrition, 7(11), 3589-3606. https://doi.org/10.1002/fsn3.1212
  
  Sadeghi, E., Movagharnejad, K., & Asl, A. H. (2020). Parameters optimization and quality evaluation of mechanical properties of infrared radiation thin layer drying of pumpkin samples. Journal of Food Process Engineering, 43(2), Article e13309. https://doi.org/10.1111/jfpe.13309
  
  Sahari, Y., Anuar, M. S., Nor, M. Z. M., & Ghani, N. H. A. (2023). Characterization of single and hybrid mode drying of desiccated coconut. Journal of Food Engineering, 357, Article 111628. https://doi.org/10.1016/j.jfoodeng.2023.111628
  
  Sakare, P., Prasad, N., Thombare, N., Singh, R., & Sharma, S. C. (2020). Infrared drying of food materials: Recent advances. Food Engineering Reviews, 12(3), 381–398. https://doi.org/10.1007/s12393-020-09237-w
  
  Salehi, F., & Satorabi, M. (2021). Influence of infrared drying on drying kinetics of apple slices coated with basil seed and xanthan gums. International Journal of Fruit Science, 21(1), 519-527. https://doi.org/10.1080/15538362.2021.1908202
  
  Sarkar, A., Ahmed, T., Alam, M., Rahman, S., & Pramanik, S. K. (2020). Influences of osmotic dehydration on drying behavior and product quality of coconut (Cocos nucifera). Asian Food Science Journal, 15(3), 21–30. https://doi.org/10.9734/afsj/2020/v15i330153
  
  Sharma, S., Vaidya, D., Kaushal, M., & Gupta, A. (2020). Optimization of process parameters for hybrid drying of apple. International Journal of Fruit Science, 9(1), 1756–1760. https://doi.org/10.1080/15538362.2020.1812017
  
  Shingare, S. P., & Thorat, B. N. (2012). Dehydration of coconut using an infrared dryer. International Journal of Biotechnology, Chemical & Environmental Engineering, 1(3), 56–63.
  
  Sossa, J. W. Z., Orozco, G. L., Murillo, L. M. G., Osorio, M. P., & Suarez, N. S. (2021). Infrared drying trends applied to fruit. Frontiers in Sustainable Food Systems, 5, Article 650690. https://doi.org/10.3389/fsufs.2021.650690
  
  Srinivas, M. S., Champawat, P. S., & Jain, S. K. (2018). Effect of infrared radiation on the drying kinetics of osmosed papaya cubes. International Journal of Chemical Studies, 6(3), 1696–1698.
  
  Šumić, Z., Vakula, A., Tepić, A., Čakarević, J., Vitas, J., & Pavlić, B. (2016). Modeling and optimization of red currants vacuum drying process by response surface methodology (RSM). Food Chemistry, 203, 465–475. https://doi.org/10.1016/j.foodchem.2016.02.109
  
  Tajudin, N. H. A., Ang, W. L., Tasirin, S. M., & Rosli, M. I. (2021). Process variables optimization for heat pump drying of Roselle Calyx by using response surface methodology. Jurnal Kejuruteraan, 33(4), 903–914. https://doi.org/10.17576/jkukm-2021-33(4)-13
  
  Tajudin, N. H. A., Tasirin, S. M., Ang, W. L., Rosli, M. I., & Lim, L. C. (2019). Comparison of drying kinetics and product quality from convective heat pump and solar drying of Roselle calyx. Food and Bioproducts Processing, 118, 40–49. https://doi.org/10.1016/j.fbp.2019.08.012
  
  Torki-Harchegani, M., Ghanbarian, D., Maghsoodi, V., & Moheb, A. (2017). Infrared thin layer drying of saffron (Crocus sativus L.) stigmas: Mass transfer parameters and quality assessment. Chinese Journal of Chemical Engineering, 25(4), 426-432. https://doi.org/10.1016/j.cjche.2016.09.005
  
  Wang, H., Liu, D., Yu, H., Wang, D., & Li, J. (2019). Optimization of microwave coupled hot air drying for chinese yam using response surface methodology. Processes, 7(10), Article 745. https://doi.org/10.3390/pr7100745
  
  Wu, X. F., Zhang, M., & Li, Z. (2019). Influence of infrared drying on the drying kinetics, bioactive compounds and flavor of Cordyceps militaris. LWT-Food Science and Technology, 111, 790-798. https://doi.org/10.1016/j.lwt.2019.05.108
  
  Wynn, T. (2017). Nutrition studies on mature and immature coconut meat and coconut water. Yadanabon University Research Journal, 8(1), 1-8.
  
  Yadav, G., Gupta, N., Sood, M., & Anjum, N. (2020). Infrared heating and its application in food processing. The Pharma Innovation Journal, 9(2), 142–151.
  
  Yahya, S., Shahrir, A. M., Syariffudden, M. A. A. A., Shafie, A., Shukri, J. S., Zaimi, Z. A. A. M., & Redzuan, S. R. (2020). A study of drying parameters on drying time and colour quality of grated coconut using tumbling mechanism in convective dryer. Food Research, 4(6), 64–69. https://doi.org/10.26656/fr.2017.4(S6).023
  
  Younis, M., Abdelkarim, D., & Zein El-Abdein, A. (2018). Kinetics and mathematical modeling of infrared thin-layer drying of garlic slices. Saudi Journal of Biological Sciences, 25(2), 332–338. https://doi.org/10.1016/j.sjbs.2017.06.011
  
  Zainol, F. A., Arumugam, N., Daud, W. N. W., Suhaimi, N. A. M., Ishola, B. D., Ishak, A. Z., & Afthanorhan, A. (2023). Coconut value chain analysis: A systematic review. Agriculture, 13(7), Article 1379. https://doi.org/10.3390/agriculture13071379
  
  Zeng, Y., Liu, Y., Zhang, J., Xi, H., & Duan, X. (2019). Effects of far-infrared radiation temperature on drying characteristics, water status, microstructure and quality of kiwifruit slices. Journal of Food Measurement and Characterization, 13(4), 3086–3096. https://doi.org/10.1007/s11694-019-00231-3
  
  Zhou, L., Guo, X., Bi, J., Yi, J., Chen, Q., Wu, X., & Zhou, M. (2017). Drying of garlic slices (Allium sativum L.) and its effect on thiosulfinates, total phenolic compounds and antioxidant activity during infrared drying. Journal of Food Processing and Preservation, 41(1), Article e12734. https://doi.org/10.1111/jfpp.12734