PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

Food waste disposal has recently received much attention worldwide due to its major impact on environmental pollution and economic costs. Using high moisture content of food waste has the highest negative environmental impact due to increased greenhouse gas emissions, odor, and leachate. Drying technologies play an important role in reducing the moisture content of food waste, which is necessary for environmental sustainability and safety. The first part of this review highlights that sun-drying is the most cost-effective drying method. However, it has not been widely recommended for food waste management due to several limitations, including the inability to control sunray temperature and the inability to control end-product quality. Thermal drying eliminates moisture from food waste quickly, preventing hydrolysis and biodegradation. Thermal dryers, such as the GAIA GC-300 dryer, and cabinet dryer fitted with a standard tray, are the best alternative to sun drying. The second part of this review highlights that dehydrated food waste products are slightly acidic (4.7–5.1), have a high electrical conductivity (EC) value (4.83–7.64 mS cm-1), with high nutrient content, due to low pH levels, dehydrated food waste is not suitable for direct use as a fertilizer for the plants. So, the dried food waste should be composted before application to the plants because the composting process will dominate the limitation of phytotoxins, anoxia, salinity, and water repellence. Trench compost can be a good choice for decomposing dried organic waste because trench compost relies solely on soil decomposing microorganisms and insects.

• Abdullah, M., Rosmadi, H. A., Azman, N. Q. M. K., Sebera, Q. U., Puteh, M. H., Muhamad, A., & Zaiton, S. N. A. (2018). Effective drying method in the utilization of food waste into compost materials using effective microbe (EM). In AIP Conference Proceedings (Vol. 2030, No. 1, p. 020120). AIP Publishing LLC. https://doi.org/10.1063/1.5066761

• Al-Domi, H., Al-Rawajfeh, H., Aboyousif, F., Yaghi, S., Mashal, R., & Fakhoury, J. (2011). Determining and addressing food plate waste in a group of students at the University of Jordan. Pakistan Journal of Nutrition, 10(9), 871-878. https://doi.org/10.3923/pjn.2011.871.878

• Al-kharabsheh, S., & Goswami, D. Y. (2004). Solar Distillation and Drying. University of Florida. https://doi.org/10.1016/B0-12-176480-X/00319-3

• Anis, S., Kurniawan, Y. A., Sumbodo, W., Alhakim, R., & Lestari, S. E. (2018). Thermal characteristics of microwave reactor for pyrolysis of food waste. Journal of Physical Science, 29, 1-13. https://doi.org/10.21315/jps2018.29.s2.1

• Artola, A., Barrena, R., Font, X., Gabriel, D., Gea, T., Mudhoo, A., & Sánchez, A. (2009). Composting from a sustainable point of view: Respirometric indices as key parameter. Dynamic Soil, Dynamic Plant, 3(1),1-16.

• Arumugam, V., Abdullah, I., Yusoff, I. S., Abdullah, N. L., Tahir, R. M., Nasir, A. M., Omar, A. E., & Ismail, M. H. (2021). The impact of COVID-19 on solid waste generation in the perspectives of socioeconomic and people’s behavior: A case study in Serdang, Malaysia. Sustainability, 13(23), Article 13045. https://doi.org/10.3390/su132313045

• Assegehegn, G., Brito-del la Fuente, E. J.M., & Gallegos,C. (2020). Freeze-drying: A relevant unit operation in the manufacture of foods, nutritional products, and pharmaceuticals. Advances in Food and Nutrition Research, 93, 1-58. https://doi.org/10.1016/bs.afnr.2020.04.001

• Bahtiar, S. A., Muayyad, A., Ulfaningtias, L., Anggara, J., Priscilla, C., & Miswar, M. (2017). Compost use banana weevil (Musa Acuminata) to boost growth and content of sugar sweet corn (Zea mays L. Saccharata). Journal of Agricultural Science, 14(1), 18-22. https://doi.org/10.32528/agr.v14i1.405

• Bennamoun, L., & Li, J. (2018). Drying process of food: Fundamental aspects and mathematical modeling. In Natural and artificial flavoring agents and food dyes (pp. 29-82). Academic Press. https://doi.org/10.1016/B978-0-12-811518-3.00002-8

• Bhatta, S., Janezic, T. S., & Ratti, C. (2020). Freeze-drying of plant-based foods. Foods, 9(1), 1-22. https://doi.org/10.3390/foods9010087

• Blakeney, M. (2019). Food loss and food waste: Causes and solutions. Edward Elgar Publishing. https://doi.org/10.4337/9781788975391

• Branch, E., & Borghei, A. M. (2021). Evaluate the drying of food waste using cabinet dryer. ResearchSquare. https://doi.org/10.21203/rs.3.rs-874515/v1

• Brock, C., Oltmanns, M., Matthes, C., Schmehe, B., Schaaf, H., Burghardt, D., Horst, H., & Spieß, H. (2021). Compost as an option for sustainable crop production at low stocking rates in organic farming. Agronomy, 11, 1-17. https://doi.org/10.3390/agronomy11061078

• Cam, I. B., Gulmez, H. B., Eroglu, E., & Topuz, A. (2017). Strawberry drying: Development of a closed-cycle modified atmosphere drying system for food products and the performance evaluation of a case study. Drying Technology, 36(12), 1460-1473. https://doi.org/10.1080/07373937.2017.1409233

• Changrue, V., & Raghavan, V. G. S. (2006). Microwave drying of fruits and vegetables. Stewart Postharvest Review, 2(6), 1-7. https://doi.org/10.2212/spr.2006.6.4

• Chauhan, C., Dhir, A., Akram, M. U., & Salo, J. (2021). Food loss and waste in food supply chains. A systematic literature review and framework development approach. Journal of Cleaner Production, 295, Article 126438. https://doi.org/10.1016/j.jclepro.2021.126438

• Chua, G. K., Tan, F. H. Y., Chew, F. N., & Mohd-Hairul, A. R. (2019). Nutrients content of food wastes from different sources and its pre-treatment. In AIP Conference Proceedings (Vol. 2124, No. 1, p. 020031). AIP Publishing LLC. https://doi.org/10.1063/1.5117091

• Compost Education Centre. (2010). Trench composting (Factsheet Series). https://compost.bc.ca/wp-content/uploads/2021/03/5-Trenching.pdf

• Crohn, D. M. (2016). Assessing compost quality for agriculture. California Digital Library. https://doi.org/10.3733/ucanr.8514

• Dhamodharan, K., Sudharsan, V., Veluchamy, C., Pugazhendhi, A., & Rajendran, K. (2019). Science of the total environment emission of volatile organic compounds from composting : A review on assessment, treatment and perspectives. Science of the Total Environment, 695, Article 133725. https://doi.org/10.1016/j.scitotenv.2019.133725

• Dhar, A. (2016). Evaluation of food waste diversion potential and economics of using food waste dehydrators (Doctoral dissertation). The University of Texas, USA.

• Dhumne, L. R., Bipte, V. H., & Jibhkate, Y. M. (2016). Solar dryers for drying agricultural products. International Journal of Engineering Research, 3(2), 80-84.

• Durance, T., & Yaghmaee, P. (2011). Microwave dehydration of food and food ingredients. Comprehensive Biotechnology, 2(1), 617-628. https://doi.org/10.1016/B978-0-08-088504-9.00306-8

• Ebner, J. H., Labatut, R. A., Lodge, J. S., Williamson, A. A., & Trabold, T. A. (2016). Anaerobic co-digestion of commercial food waste and dairy manure: Characterizing biochemical parameters and synergistic effects. Waste Management, 52, 286-294. https://doi.org/10.1016/j.wasman.2016.03.046

• Ermolaev, E., Sundberg, C., Pell, M., Smårs, S., & Jönsson, H. (2019). Effects of moisture on emissions of methane, nitrous oxide and carbon dioxide from food and garden waste composting. Journal of Cleaner Production, 240, Article 118165. https://doi.org/10.1016/j.jclepro.2019.118165

• Feng, H., Yin, Y., & Tang, J. (2012). Microwave drying of food and agricultural materials: Basics and heat and mass microwave drying of food and agricultural materials. Food Engineering Reviews,4(2), 89-106. https://doi.org/10.1007/s12393-012-9048-x

• Firdaus, A. R. M., Samah, M. A. A., & Hamid, K. B. A. (2018). CHNS analysis towards food waste in composting. Journal CleanWAS, 1(1), 06-10. https://doi.org/10.26480/jcleanwas.01.2018.06.10

• Fisgativa, H., Tremier, A., & Dabert, P. (2016). Characterizing the variability of food waste quality : A need for efficient valorisation through anaerobic digestion. Waste Management, 50, 264-274. https://doi.org/10.1016/j.wasman.2016.01.041

• Galanakis, C. M. (2012). Recovery of high added-value components from food wastes: Conventional, emerging technologies and commercialized applications. Trends in Food Science and Technology, 26(2), 68-87. https://doi.org/10.1016/j.tifs.2012.03.003

• Georganas, A., Giamouri, E., Pappas, A. C., Papadomichelakis, G., Galliou, F., Manios, T., Tsiplakou, E., Fegeros, K., & Zervas, G. (2020). Bioactive compounds in food waste: A review on the transformation of food waste to animal feed. Foods, 9(3), 1-18. https://doi.org/10.3390/foods9030291

• Guerra-Rodríguez, E., Vázquez, M., & Diaz-Raviña, M. (2001). Dynamics of physicochemical and biological parameters during the co-composting of chestnut burr/leaf litter with solid poultry manure. Journal of the Science of Food and Agriculture, 81(7), 648-652. https://doi.org/10.1002/jsfa.866

• Hall, M. (2016). Techno-environmental analysis of generating animal feed from wasted food products. Rochester Institute of Technology.

• Haouas, A., El Modafar, C., Douira, A., Ibnsouda-Koraichi, S., Filali-Maltouf, A., Moukhli, A., & Amir, S. (2021). Evaluation of the nutrients cycle, humification process, and agronomic efficiency of organic wastes composting enriched with phosphate sludge. Journal of Cleaner Production, 302, Article 127051. https://doi.org/10.1016/j.jclepro.2021.127051

• Harrison, R. B. (2008). Composting and formation of humic substances. Encyclopedia of Ecology, 5, 713-719. https://doi.org/10.1016/B978-008045405-4.00262-7

• Hegde, V. N., Hosur, V. S., Rathod, S. K., Harsoor, P. A., & Narayana, K. B. (2015). Design, fabrication and performance evaluation of solar dryer for banana. Energy, Sustainability and Society, 5(1), 1-12. https://doi.org/10.1186/s13705-015-0052-x

• Ho, K. S., & Chu, L. M. (2019). Characterization of food waste from different sources in Hong Kong. Journal of the Air and Waste Management Association, 69(3), 277-288. https://doi.org/10.1080/10962247.2018.1526138

• Iacovidou, E., Ohandja, D. G., Gronow, J., & Voulvoulis, N. (2012). The household use of food waste disposal units as a waste management option: A review. Critical Reviews in Environmental Science and Technology, 42(14), 1485-1508. https://doi.org/10.1080/10643389.2011.556897

• Ishola, T. M., & Ishola, E. T. (2019). Composting and sustainable development. In W. L. Filho (Ed.) Encyclopedia of Sustainability in Higher Education (pp. 1-8). Springer. https://doi.org/10.1007/978-3-319-63951-2_122-1

• Ismail, M. H., Ghazi, T. I. M., Hamzah, M. H., Manaf, L. A., Tahir, R. M., Nasir, A. M., & Omar, A. E. (2020a). Impact of movement control order (Mco) due to coronavirus disease (covid-19) on food waste generation: A case study in klang valley, malaysia. Sustainability, 12(21), 1-17. https://doi.org/10.3390/su12218848

• Ismail, M. H., Khan, K. A., Ngadisih, N., Irie, M., Ong, S. P., Hii, C. L., & Law, C. L. (2020b). Two-step falling rate in the drying kinetics of rice noodle subjected to pre-treatment and temperature. Journal of Food Processing and Preservation, 44(11), 1-11. https://doi.org/10.1111/jfpp.14849

• Ismail, M. H., Lik, H. C., Routray, W., & Woo, M. W. (2021). Determining the effect of pre-treatment in rice noodle quality subjected to dehydration through hierarchical scoring. Processes, 9(8), 1-12. https://doi.org/10.3390/pr9081309

• Jahanbakhshi, A., & Kheiralipour, K. (2019). Influence of vermicompost and sheep manure on mechanical properties of tomato fruit. Food Science and Nutrition, 7(4), 1172-1178. https://doi.org/10.1002/fsn3.877

• Jiménez, E. I., & García, V. P. (1992). Relationships between organic carbon and total organic matter in municipal solid wastes and city refuse composts. Bioresource Technology, 41(3), 265-272. https://doi.org/10.1016/0960-8524(92)90012-M

• Kannah, R. Y., Merrylin, J., Devi, T. P., Kavitha, S., & Sivashanmugam, P. (2020). Bioresource technology reports food waste valorization: Biofuels and value added product recovery. Bioresource Technology Reports, 11, Article 100524. https://doi.org/10.1016/j.biteb.2020.100524

• Khan, A., & Ishaq, F. (2011). Chemical nutrient analysis of different composts (vermicompost and pitcompost) and their effect on the growth of a vegetative crop Pisum sativum. Asian Journal of Plant Science and Research, 1(1), 116-130.

• Khodifad, B. C., & Dhamsaniya, N. K. (2020). Drying of food materials by microwave energy - A review. International Journal of Current Microbiology and Applied Sciences, 9(5), 1950-1973. https://doi.org/10.20546/ijcmas.2020.905.223

• Kibler, K. M., Reinhart, D., Hawkins, C., Motlagh, A. M., & Wright, J. (2018). Food waste and the food-energy-water nexus: A review of food waste management alternatives. Waste Management, 74, 52-62. https://doi.org/10.1016/j.wasman.2018.01.014

• Liaquat, R., Jamal, A., Tauseef, I., Qureshi, Z., Farooq, U., Imran, M., & Ali, M. I. (2017). Characterizing bacterial consortia from an anaerobic digester treating organic waste for biogas production. Polish Journal of Environmental Studies, 26(2), 709-716. https://doi.org/10.15244/pjoes/59332

• Lim, W. J., Chin, N. L., Yusof, A. Y., Yahya, A., & Tee, T. P. (2016). Food waste handling in Malaysia and comparison with other Asian countries. International Food Research Journal, 23, S1-S6.

• Liu, H., Jiaqiang, E., Ma, X., & Xie, C. (2016). Influence of microwave drying on the combustion characteristics of food waste. Drying Technology, 34(12), 1397-1405. https://doi.org/10.1080/07373937.2015.1118121

• Loizidou, A. S. D. M. M. (2015). Dehydration of domestic food waste at source as an alternative approach for food waste management. Waste and Biomass Valorization, 6(2), 167-176.

• Mahmood, A., Iguchi, R., & Kataoka, R. (2019). Multifunctional food waste fertilizer having the capability of Fusarium - Growth inhibition and phosphate solubility: A new horizon of food waste recycle using microorganisms. Waste Management, 94, 77-84. https://doi.org/10.1016/j.wasman.2019.05.046

• Makan, A., Assobhei, O., & Mountadar, M. (2013). Effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco. Journal of Environmental Health Science and Engineering, 10(1), 1-9. https://doi.org/10.1186/1735-2746-10-3

• Maragkaki, A., Galliou, F., Markakis, N., Sabathianakis, G., Tsompanidis, C., Lolos, G., Mavrogiannis, G., Koukakis, G., Lasaridi, K., & Manios, T. (2016). Initial investigation of the solar drying method for the drying of olive oil by-products. Waste and Biomass Valorization, 7(4), 819-830. https://doi.org/10.1007/s12649-016-9505-5

• McAdams, B., von Massow, M., Gallant, M., & Hayhoe, M. A. (2019). A cross industry evaluation of food waste in restaurants. Journal of Foodservice Business Research, 22(5), 449-466. https://doi.org/10.1080/15378020.2019.1637220

• Melikoglu, M., Lin, C. S. K., & Webb, C. (2013). Analysing global food waste problem: Pinpointing the facts and estimating the energy content. Central European Journal of Engineering, 3(2), 157-164. https://doi.org/10.2478/s13531-012-0058-5

• Mirabella, N., Castellani, V., & Sala, S. (2014). Current options for the valorization of food manufacturing waste: A review. Journal of Cleaner Production, 65, 28-41. https://doi.org/10.1016/j.jclepro.2013.10.051

• Nowak, D., & Jakubczyk, E. (2020). The freeze-drying of foods - The characteristic of the process course and the effect of its parameters on the physical properties of food materials. Foods, 9(10), Article 1488. https://doi.org/10.3390/foods9101488

• O’Connor, J., Hoang, S. A., Bradney, L., Rinklebe, J., Kirkham, M. B., & Bolan, N. S. (2022). Value of dehydrated food waste fertiliser products in increasing soil health and crop productivity. Environmental Research, 204, Article 111927. https://doi.org/10.1016/j.envres.2021.111927

• O’Connor, J., Hoang, S. A., Bradney, L., Dutta, S., Xiong, X., Tsang, D. C. W., Ramadass, K . Vinu, A., Kirkham, M. B., & Bolan, N. S. (2021). A review on the valorisation of food waste as a nutrient source and soil amendment. Environmental Pollution, 272, Article 115985. https://doi.org/10.1016/j.envpol.2020.115985

• Obi, O. F., Ezeoha, S. L., & Egwu, C. O. (2016). Evaluation of air oven moisture content determination procedures for pearl millet (Pennisetum glaucum L.). International Journal of Food Properties, 19(2), 454-466. https://doi.org/10.1080/10942912.2015.1038566

• Palaniveloo, K., Amran, M. A., Norhashim, N. A., Mohamad-Fauzi, N., Peng-Hui, F., Hui-Wen, L., Kai-Lin, Y., Jiale, L., Chisn-Yee, M. G., Jing-Yi, L., Gunasekaran, B., Razak, S. A. (2020). Food waste composting and microbial community structure profiling. Processes, 8(6), 1-30. https://doi.org/10.3390/pr8060723

• Papanikola, K., Papadopoulou, K., Tsiliyannis, C., Fotinopoulou, I., Katsiampoulas, A., Chalarakis, E., Georgiopoulou, M., Rontogianni, V., Michalopoulos, I., Mathioudakis, D., Lytras, G. M., & Lyberatos, G. (2019). Food residue biomass product as an alternative fuel for the cement industry. Environmental Science and Pollution Research, 26(35), 35555-35564. https://doi.org/10.1007/s11356-019-05318-4

• Papargyropoulou, E., Lozano, R., K. Steinberger, J., Wright, N., & Ujang, Z. (2014). The food waste hierarchy as a framework for the management of food surplus and food waste. Journal of Cleaner Production, 76, 106-115. https://doi.org/10.1016/j.jclepro.2014.04.020

• Pergola, M., Persiani, A., Pastore, V., Palese, A. M., Adamo, C. D., De Falco, E., & Celano, G. (2020). Sustainability assessment of the green compost production chain from agricultural waste: A case study in Southern Italy. Agronomy,10(2), Article 230. https://doi.org/10.3390/agronomy10020230

• Rahman, M. S., & Perera, C. O. (2007). Drying and food preservation. In Handbook of food preservation (pp. 421-450). CRC Press. https://doi.org/10.1201/9781420017373-26

• Ravindran, R., & Jaiswal, A. K. (2016). Exploitation of food industry waste for high-value products. Trends in Biotechnology, 34(1), 58-69. https://doi.org/10.1016/j.tibtech.2015.10.008

• Sakaguchi, L., Pak, N., & Potts, M. D. (2018). Tackling the issue of food waste in restaurants: Options for measurement method, reduction and behavioral change. Journal of Cleaner Production, 180, 430-436. https://doi.org/10.1016/j.jclepro.2017.12.136

• Sotiropoulos, A., Malamis, D., & Loizidou, M. (2015). Dehydration of domestic food waste at source as an alternative approach for food waste management. Waste and Biomass Valorization, 6(2), 167-176. https://doi.org/10.1007/s12649-014-9343-2

• Salemdeeb, R., zu Ermgassen, E. K. H. J., Kim, M. H., Balmford, A., & Al-Tabbaa, A. (2017). Environmental and health impacts of using food waste as animal feed: a comparative analysis of food waste management options. Journal of Cleaner Production, 140, 871-880. https://doi.org/10.1016/j.jclepro.2016.05.049

• Schroeder, J. T., Labuzetta, A. L., & Trabold, T. A. (2020). Assessment of dehydration as a commercial-scale food waste valorization strategy. Sustainability, 12(15), 1-13. https://doi.org/10.3390/su12155959

• Silvennoinen, K., Heikkilä, L., Katajajuuri, J., & Reinikainen, A. (2015). Food waste volume and origin : Case studies in the Finnish food service sector. Waste Management, 46, 140-145. https://doi.org/10.1016/j.wasman.2015.09.010

• Salim, N. S., Singh, A., & Raghavan, V. (2017). Potential utilization of fruit and vegetable wastes for food through drying or extraction techniques. Novel Techniques in Nutrition and Food Science, 1(2), 1-13. https://doi.org/10.31031/NTNF.2017.01.000506

• Sotiropoulos, A., Malamis, D., Michailidis, P., Krokida, M., & Loizidou, M. (2016). Research on the drying kinetics of household food waste for developing and optimizing domestic waste drying technique. Environmental Technology, 37(8), 929-939. https://doi.org/10.1080/21622515.2015.1092588

• Sozzi, A., Zambon, M., Mazza, G., & Salvatori, D. (2021). Fluidized bed drying of blackberry wastes: Drying kinetics, particle characterization and nutritional value of the obtained granular solids. Powder Technology, 385, 37-49. https://doi.org/10.1016/j.powtec.2021.02.058

• Spiker, M. L., Hiza, H. A. B., Siddiqi, S. M., & Neff, R. A. (2017). Wasted food, wasted nutrients: nutrient loss from wasted food in the united states and comparison to gaps in dietary intake. Journal of the Academy of Nutrition and Dietetics, 117(7), 1031-1040. https://doi.org/10.1016/j.jand.2017.03.015

• Sulaiman, N. F. A. R., & Ahmad, A. (2018). Save the food for a better future: A discussion on food wastage in Malaysia. International Journal of Law, Government and Communication, 3(10), 12-21.

• Taylor, P., Ong, S. P., Law, C. L., Ong, S. P., & Law, C. L. (2011). Drying kinetics and antioxidant phytochemicals retention of salak fruit under different drying and pretreatment conditions. Drying Technology, 29(4), 429-441. https://doi.org/10.1080/07373937.2010.503332

• Teresita, M., Villota, O., David, C., Casallas, P., Camilo, D., & Ayala, B. (2021). Composting of solid waste from the coffee milling process using trench composting and a bioreactor with the help of efficient microorganisms in the Libre University, Socorro headquarters. Ingenieria Solidaria, 17(1), 1-28. https://doi.org/10.16925/2357-6014.2021.01.05

• Thani, N. M., Kamal, S. M. M., Sulaiman, A., Taip, F. S., Omar, R., & Izhar, S. (2020). Sugar recovery from food waste via sub-critical water treatment. Food Reviews International, 36(3), 241-257. https://doi.org/10.1080/87559129.2019.1636815

• Tiquia, S. M. (2005). Microbiological parameters as indicators of compost maturity. Journal of Applied Microbiology, 99(4), 816-828. https://doi.org/10.1111/j.1365-2672.2005.02673.x

• Tony, M. A., & Tayeb, A. M. (2011, November 14-16). The use of solar energy in a low-cost drying system for solid waste management: Concept, design and performance analysis. In Eurasia Waste Management Symposium (pp. 14-16). Istanbul, Turkey.

• Toundou, O., Pallier, V., Feuillade-Cathalifaud, G., & Tozo, K. (2021). Impact of agronomic and organic characteristics of waste composts from togo on Zea mays L. nutrients contents under water stress. Journal of Environmental Management, 285, Article 112158. https://doi.org/10.1016/j.jenvman.2021.112158

• Tun, M. M., & Juchelková, D. (2019). Drying methods for municipal solid waste quality improvement in the developed and developing countries: A review. Environmental Engineering Research, 24(4), 529-542. https://doi.org/10.4491/eer.2018.327

• Twain, M. (2020). Soil pH and soil acidity. In Roughing It (pp. 107-115). University of California Press. https://doi.org/10.1525/9780520948068-019.

• Vakalis, S., Moustakas, K., Semitekolos, D., Novakovic, J., Malamis, D., Zoumpoulakis, L., & Loizidou, M. (2018). Introduction to the concept of particleboard production from mixtures of sawdust and dried food waste. Waste and Biomass Valorization, 9(12), 2373-2379. https://doi.org/10.1007/s12649-018-0214-0

• Venkatachalam, S. K., Vellingri, A. T., & Selvaraj, V. (2020). Low-temperature drying characteristics of mint leaves in a continuous-dehumidified air drying system. Journal of Food Process Engineering, 43(4), 1-15. https://doi.org/10.1111/jfpe.13384

• Wang, H., Zhang, M., & Adhikari, B. (2014). Food and bioproducts processing drying of shiitake mushroom by combining freeze-drying and mid-infrared radiation. Food and Bioproducts Processing, 94, 507-517. https://doi.org/10.1016/j.fbp.2014.07.008

• Wang, J., Xiong, Y. S., & Yu, Y. (2004). Microwave drying characteristics of potato and the effect of different microwave powers on the dried quality of potato. European Food Research and Technology, 219(5), 500-506. https://doi.org/10.1007/s00217-004-0979-1

• Wang, L., Li, Y., Prasher, S. O., Yan, B., Ou, Y., Cui, H., & Cui, Y. (2019). Organic matter, a critical factor to immobilize phosphorus, copper, and zinc during composting under various initial C/N ratios. Bioresource Technology, 289, Article 121745. https://doi.org/10.1016/j.biortech.2019.121745

• Wheeler Jr, R. R., Hadley, N. M., Dahl, R. W., Williams, T. W., Zavala Jr, D. B., Akse, J. R., & Fisher, J. W. (2007). Microwave enhanced freeze drying of solid waste. Journal of Aerospace, 116(1), 510-537. https://doi.org/10.4271/2007-01-3266

• Zaha, C., Dumitrescu, L., & Manciulea, I. (2013). Correlations between composting conditions and characteristics of compost as biofertilizer. Bulletin of the Transilvania University of Brasov Engineering Sciences Series 1, 6(1), 51-58.

• Zaki, A. H. (2019, September 29). Waste not, want not - It’s time we get serious about food waste. New Straits Times. https://www.nst.com.my/lifestyle/sunday-vibes/2019/09/525506/waste-not-want-not-%E2%80%93-its-time-we-get-serious-about-food-waste