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Full Research Article

Physico-chemical and Functional Properties of Microwave and Sun-dried Chitosan: A Comparative Study

A
A. Jeyakumari1,*
K
K. Elavarasan1
V
V. Renuka1
J
J. Bindu1
1Division of Fish Processing, ICAR-Central Institute of Fisheries Technology, Kochi-682 029, Kerala, India.

ABSTRACT

Background: Generally, chitosan is dried by sun drying and it is a time-consuming process. Hence, improved drying process of chitosan is needed by the industry to speed up the drying process without affecting its properties.

Methods: In the present study, chitosan was prepared from industrial chitin (shrimp shell) by a cold process and subjected to microwave drying at different powers ranging from 400 to 1600w and its properties were evaluated. Chitosan dried under sun light was used as a control.

Result: The lowest drying time (23 min) was achieved for chitosan processed at 1600w than sundried one (120 min). The highest viscosity (2117cP) was observed for chitosan processed at 1600w compared to that of the sun dried one (828.50cP). The degree of deacetylation (DD) ranged from 77.3%-80.8%. The highest L* value (74.70) and lower a* (2.02) and b* (16.42) value was obtained for the sundried chitosan than microwave dried sample. However, the other physical and chemical properties of microwave-dried chitosan were comparable to those of sun-dried chitosan. The highest water binding capacity (WBC) was observed for the chitosan processed at 1400w. The highest fat binding capacity was obtained for chitosan processed under 400w. DSC and FTIR studies revealed that there was no significant change in the thermal and structural pattern of chitosan. Results suggested that microwave drying can serve as an effective alternative to sun drying of chitosan and offer wide range of its applications.

INTRODUCTION

Shrimp is considered to be one of the most important frozen export items in India. During the financial year 2023-24, frozen shrimp accounted for 40.19% of total exports with earnings of 4881.27 million dollars (MPEDA, 2024). Shrimps are processed into different forms including, whole, peeled, head less etc. During shrimp processing, shells are generated as waste accounting 40-45% of the raw shrimp weight. Shell waste contains 25-40% protein, 40-55% ash, 15% carotenoid pigment and 15-20% chitin (Younes et al., 2014). These shell wastes can be used for the production of high-value-added products, such as chitin, chitosan, glucosamine hydrochloride and carotenoprotein. Among these, chitosan has wide applications in the food, pharmaceutical, cosmetic and textile Industries (Shahidi et al., 1999; Younes et al., 2014; Matica et al., 2019; Jeyakumari et al., 2023). Moreover, chitosan is used for the preparation of biodegradable films, removal of heavy metals, clarification and de-acidification of fruit juices (Mohanasrinivasan et al., 2014; Samuel et al., 2025; Sheet et al., 2026). Chitosan is chemically referred to as β (1, 4) linked copolymer of D-glucosamine and N-acetyl-D-glucosamine. It is soluble in dilute organic acids such as acetic acid. Chitosan is prepared from chitin via deacetylation using concentrated alkali solutions. Chitin is a natural polysaccharide present in crustacean shells, insect exoskeletons and fungal cell walls. Chitin is a linear polymer of N-acetylglucosamine units linked by β-1,4 glycosidic bonds and insoluble in water and acidic solutions. Generally, chitosan is dried under sun drying after the acetylation process to preserve the products with adequate moisture for storage, maintain their characteristics and for further product development.  However, this is a time-consuming process. Hence, an improved drying process for chitosan is required by the industry to speed up the drying process without affecting its properties. Chitosan can be dried using different methods such as oven drying, freeze drying, supercritical CO2 drying, bed drying, microwave drying and irradiation.  Most studies have used different drying methods for chitosan solutions and characterized their physicochemical properties but not for chitosan flakes. A few studies have attempted to use gamma irradiation/ microwave heating to modify the functional properties of chitosan and the deacetylation of chitin (Cheng et al., 2020; Dong et al., 2023; Siddhartha et al., 2020). To the best of our knowledge, there have been no reports on the drying of chitosan in flake form using the microwave drying method and its quality. In microwave drying, the materials become trembled within the molecules by the electromagnetic field produced during microwave heating and provide an increased rate of reaction in a shorter time (Abeykoon et al., 2016; Mahardika et al., 2019; Anantharaman, 2025). Based on the above information, this study aimed i) to prepare chitosan from industrial chitin and dry it under sun/ microwave drying conditions and ii) to assess the impact of microwave drying on chitosan quality.

MATERIALS AND METHODS

Raw material
 
Chitin prepared from shrimp shells was procured from the Private Industry (Matysyafed) located at Cochin, Kerala, for the production of chitosan. All chemicals and reagents used in the study were of analytical grade and procured from M/s. Merck, India.
 
Preparation of chitosan
 
Chitin was subjected to deacetylation process using 50% NaOH under ambient conditions for two days. After 48 h, the alkali was drained and the residual chitosan was washed with potable water until the pH of the chitosan became neutral pH (pH=7). It was then centrifuged in a bucket centrifuge to remove the maximum amount of water from the shell. They were then divided into six lot. The first lot was dried in sunlight. Other lots were subjected to a microwave drying process with a varying power ranging from 400 to 1600w.  The selected power levels were chosen to evaluate the influence of low, medium and high microwave energy inputs on the drying behavior and physicochemical properties of chitosan. Chitosan samples (100 g wet chitosan flakes per batch) were uniformly spread in a microwave-safe tray as a thin layer with an approximate thickness of 5 mm during microwave drying to ensure uniform microwave energy distribution and efficient moisture removal. Maintaining a thin and homogeneous sample layer facilitated effective heat and mass transfer while minimizing localized overheating and non-uniform drying. Dried chitosan was packed in a high-density polyethylene (HDPE)  pouches and stored under ambient conditions for further analysis.
 
Methods
 
The moisture, chitosan nitrogen and ash contents of dried chitosan were estimated according to the AOAC (2023) method. The degree of deacetylation was estimated according to the method described by Muzzarelli and Rocchetti (1985). The viscosity was measured using a Brookfield viscometer (Model: DV-E; Brookfield Engineering Laboratories, Inc., USA). The water (WBC) and fat binding capacity (FBC) of chitosan were evaluated according to Knorr (1982). The color of the chitosan was analyzed using a Hunter- Lab Scan XE-Spectrocolorimeter (Hunter Associates Laboratory, Reston USA). DSC analysis was performed using a DSC analyzer (Ta Instruments, USA). The analysis was performed under nitrogen gas at a heating rate of 10°C/min. FTIR analysis was carried out using FTIR (Shimadzu IR-Prestige-21). The data obtained by various quality analyses were subjected to one-way ANOVA (analysis of variance). Duncan’s multiple range test was performed at 95% confidence level (P<0.05) using the SPSS package (version 16.0; SPSS Inc, Chicago,IL USA). All analysis were carried out in triplicate and values are represented as mean ±SD.

RESULTS AND DISCUSSION

Proximate composition
 
The moisture content of the chitosan varied from 3.35% to 7.58%. It has been reported that commercial chitosan has more than 10% moisture content (Abdel-Rahman  et al., 2015). The nitrogen content of chitin and chitosan generally fall between 5-8% which makes them suitable for application in various sectors (Nessa et al., 2011). In the present study, the chitosan nitrogen content ranged from 4.22 to 6.64%. The ash content ranged from 0.49% to 1.43%. It has been reported that high quality chitin and chitosan have ash contents of less than 1% (Rasweefali et al., 2021). Accordingly, these results indicate the good quality of chitin used in this study. The physical and chemical properties of microwave and sundried chitosan are given in Table 1. The drying time of chitosan under different process conditions varied from 23 to 120 min. The lowest drying time (23 min) was achieved for chitosan processed under microwave drying at 1600 watts than the sundried sample (120 min). Instrumental color analysis showed that L* (whiteness) values ranged from 71.22 to 74.70. The a* (redness) value ranged from 2.02 to 3.38. The b* (yellowness) value ranged from 16.42 to 18.57. The results indicated that sundried chitosan had a higher L* value (74.70) and lower b* (16.42) values than the others. The higher L* values observed in sun-dried chitosan indicate superior whiteness retention compared to microwave-dried samples. This may be primarily attributed to the photolytic effects of sunlight during the drying process. In addition, the gradual and mild moisture removal associated with sun drying minimizes thermal stress and suppresses browning reactions. In contrast, microwave drying involves rapid volumetric heating which may accelerate pigment degradation and browning reactions, leading to comparatively lower L* values. Therefore, while microwave drying offers improved drying efficiency and shorter processing time, sun drying appears to favor better visual quality through sunlight-induced photolytic bleaching effects (Youn et al., 2007) . Rasweefali et al., (2021) reported a lower L* value (68.99) for chitosan dried under sunlight. It has been reported that the color value of chitosan is influenced by the processing method, time, presence of carotenoid pigment in the shell etc. (Seo et al., 2007; Dornish et al., 2001).

Table 1: Physical and chemical properties of microwave and sundried chitosan.


 
Functional properties of microwave and sundried chitosan
 
Degree of deacetylation
 
The degree of deacetylation measures the free amino group content of the polymer chain (Matica et al., 2019). It is one of the most important quality parameters that determines the physico-chemical and functional properties of chitosan and its application (Shirvan et al., 2019; Knaul et al., 1998). Degree of deacetylation was used to differentiate between chitin and chitosan. Generally, the degree of deacetylation of commercial chitosan ranges from 70-95%. In this study, the degree of deacetylation ranged from 77.3%-80.8%. If the degree of deacetylation is above 70%, it is termed chitosan (Sagheer et al., 2009). The degree of deacetylation is influenced by several factors including the species, alkali concentration, process time and temperature (Knaul et al., 1998; El Knidri et al., 2018; Hargono et al., 2010; Aranaz et al., 2021). The functional properties of microwave and sundried chitosan are given in Table 2.

​

Table 2: Functional properties of microwave and sundried chitosan.


 
Viscosity
 
Viscosity is an important functional property of chitosan that determines its industrial application. The viscosity of chitosan depends on its degree of deacetylation, molecular weight, particle size and storage time (Chattopadhyay and Inamdar, 2010). In this study, the viscosity ranged from 828.50cP to 2117cP. Aranaz et al., (2021) reported that viscosity increased with an increase in the degree of deacetylation. In the present study, sundried chitosan showed a lower viscosity of 828.50 cP than the microwaved dried chitosan. However, it does not follow this trend with respect to microwave power treatment. Moreover, there is a drop in viscosity for chitosan dried at1600W power. The increased viscosity observed in microwave-dried chitosan flakes may be attributed to structural and molecular modifications induced during microwave-assisted drying. Rapid volumetric heating generated by microwave energy can enhance intermolecular interactions among chitosan chains, promoting greater chain entanglement and reduced molecular mobility, which subsequently increases resistance to flow. Moreover, the accelerated moisture removal associated with microwave drying may facilitate the formation of a more compact and densely aggregated polymer network, contributing to higher apparent viscosity. Mahmoud and Billa (2024) reported that microwave treatment can modify the physicochemical and molecular characteristics of chitosan, including its viscosity and structural organization. Siddhartha et al., (2020) observed a decrease in the viscosity with respect to the irradiation dose.  Furthermore, they reported that when the irradiation dose level is increased, depolymerization or degradation or polymer chain length is reduced, which influence the decrease in viscosity. 
 
Water binding and Fat binding capacity
 
Water binding and fat binding capacity also determines chitosan applications. It has been reported that the water binding capacity of shrimp chitosan varies from 581% to 1150% (Hossain and Iqbal, 2014). The water binding capacity of chitosan varies with the process and reaction time applied during chitosan preparation (Mohanasrinivasan et al., 2014; Jeon et al., 2002; No et al., 2000).  In the present study, the water binding capacity of chitosan varied from 169.86% to 399.65%. The highest water binding capacity was observed for the 1400W processed chitosan sample. No et al., (2000) reported a water binding capacity of 355 to 611% for chitosan prepared from crab shells. Rasweefali et al., (2021) observed the highest water binding capacity of 800% for deep sea mud shrimp. The difference in the water binding capacity of the samples is due to the difference in the protein content, crystallinity and amount of salt forming groups in the product (Knorr, 1982). Unlike WBC, the fat binding capacity of chitosan also depends on the process and reaction time applied during chitosan preparation (Hossain and Iqbal, 2014).  In the present study, FBC is varied from 541.41 to 933.51%. Rasweefali et al., (2021) observed an FBC of 700-820% for chitosan from deep sea mud shrimp. Chitosan with a high fat binding capacity can be used as a dietary ingredient and anti-cholesterolemic agent in functional food product development (Garcia et al., 2015).
 
Thermal behaviour of chitosan
 
A DSC thermograph of chitosan dried using different drying methods is shown in Fig 1. The DSC analysis showed an endothermic peak at aaproxmately109.41°C-150.65°C which indicated evaporation of moisture content from the sample. Garcia et al., (2015) observed a similar pattern for chitosan treated with different irradiation doses. The second thermal event exhibited an exothermic peak between 303.03°C-313.53°C. This may be due to the decomposition pattern of chitosan including the degradation of glucopyranose units and their subsequent oxidation Garcia et al.  (2015).  Andrade et al., (2012) observed a decomposition pattern for shrimp chitosan between 300-400°C. The results indicated that there was no significant change in the thermal behavior of chitosan dried under different conditions, indicating that the structural pattern of chitosan was not affected by the microwave drying process.

Fig 1: DSC thermograph of chitosan dried at different drying methods.



FTIR Structural pattern of chitosan
 
In the present study, all chitosan samples had similar characteristic bands (Fig 2) which indicated that there was no significant change in the structural pattern of chitosan under different drying methods. The FTIR spectrum showed a band at 3353 represent the amine group. The band at 2863 represent C-H stretching.  Moreover, in the range of 1900-1660 cm-1 range no band was observed confirming the absence of carbonyl and carboxyl groups (Nessa et al., 2011).  The presence of a band at 1646 cm-1 indicated the presence of primary amine groups, confirming the deacetylation of chitin (Nessa et al., 2011; Islam et al., 2014). The band at 1374 cm-1 indicated the presence of amide III bands, C-N stretch. The absorbance at 893 and 1149 cm-1 confirmed the presence of pyranose and the saccharide structure of chitosan (Islam et al., 2014).

Fig 2: FTIR structural pattern of Chitosan dried at different drying methods.

CONCLUSION

In this study, chitosan prepared from shrimp chitin was subjected to different drying methods and its physicochemical and functional properties were assessed.  The lowest drying time (23 min) was achieved for chitosan processed at 1600W than the sundried sample (120 min). Further, the structural pattern of chitosan was not affected by the microwave drying process as indicated by DSC and FTIR analysis. However, variations in functional properties and color parameters, particularly lightness (L* value), were observed with increasing microwave power levels. Although microwave drying reduced the whiteness of chitosan compared to sun drying, it substantially improved drying efficiency and processing time. Overall, the findings suggest that microwave drying can serve as a rapid and effective alternative to conventional sun drying for chitosan processing, with potential advantages for industrial-scale applications. Furthermore, the estimated investment required for establishing a small-scale industrial microwave drying setup is approximately ₹5-8 lakhs, with an anticipated break-even period of 8-15 months depending on production capacity and operational efficiency.

ACKNOWLEDGEMENT

The present study was supported by Indian council of Agricultural Research, Department of Agricultural Research and Education, Government of India. This is ICAR-CIFT contribution No.RPP/070/2024.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
 
Informed consent
 
This research did not involve any animal / human participation or any material that requires ethical approval. Therefore, informed consent was not required.

CONFLICT OF INTEREST

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.

REFERENCES


  1. Abdel-Rahman, R.M., Hrdina, R., Abdel-Mohsen, A.M., Fouda, M.M. G., Soliman A.Y., Mohamed, F.K., Mohsin, K. and Pinto, T.D. (2015). Chitin and chitosan from Brazilian atlantic coast: Isolation, characterization and antibacterial activity. International Journal of Biological Macromolecules. 80: 107-120. doi:10.1016/j.ijbiomac.2015.06.027.

  2. Abeykoon, C., Kelly, A.L., Brown, E.C. and Coates, P.D. (2016). The effect of materials, process settings and screw geometry on energy consumption and melt temperature in single screw extrusion. Applied Energy. 180: 880-894. doi: 10.1016/j.apenergy.2016.07.014.

  3. Anantharaman, R. (2025). Isolation and the use off-derived chitosan as a substrate-free edible coating to extend the postharvest shelf life of guava. Asian Journal of Dairy and Food Research. 44(6): 920-930. doi: 10.18805/ajdfr.DR-2392.

  4. Andrade, S.M.B., Rasiah., Ladchumananandasivam, R., Rocha, B.G., Belarmino, D.D. and Galvao, A.O. (2012). The use of exoskeletons of shrimp (Litopenaeus vanammei) and Crab (Ucides cordatus) for the extraction of chitosan and production of nanomembrane. Materials Sciences and Applications. 3: 495-508. doi: 10.4236/msa.2012. 37070.

  5. AOAC.  (2023) .Official Methods of Analysis  of the Association of Analytical Chemists. (22nd edn.). Washington, DC.

  6. Aranaz, I., Alcántara, A.R., Civera, M.C., Arias, C., Elorza, B., Heras Caballero, A. and Acosta, N. (2021). Chitosan: An overview of its properties and applications. Polymers. 13(19): 3256. doi: 10.3390/polym13193256.

  7. Chattopadhyay, D. and Inamdar, M.S. (2010). Aqueous behaviour of chitosan. International Journal of Polymer Science. 7: 939536. doi: 10.1155/2010/939536.

  8. Cheng, J., Zhu, H., Huang, J., Zhao, J., Yan, B., Ma, S., Zhang, H. and Fan, D. (2020). The physicochemical properties of chitosan prepared by microwave heating. Food science and Nutrition. doi: 10.1002/fsn3.1486.

  9. Dong, Q., Qiu, W., Feng, Y., Jin, Y., Deng, S., Tao, N. and Jin Y. (2023). Proteases and microwave treatment on the quality of chitin and chitosan produced from white shrimp (Penaeus vannamei). eFood.  doi: 10.1002/efd2.73.

  10. Dornish, M., Kaplan, D. and Skaugrud, O. (2001). Standards and Guidelines for Biopolymers in Tissue-engineered Medical Products: ASTM Alginate and Chitosan Standard Guides, In: Bioartificial organs III Tissue Sourc. Immunoisolation Clin. Trials,  [D. Hunkeler, A. Cherrington, A. Prokop, R. Rajotte (Eds.)], vol. 944, New York Academy of Sciences,  New York. 388-397.

  11. El Knidri, H., Belaabed, R., Addaou, A., Laajeb, A. and Lahsini, A. (2018). Extraction, chemical modification and characterization of chitin and chitosan. International Journal of Biological Macromolecules. 120: 1181-1189. doi: 10.1016/j.ijbio mac. 2018.08.139.

  12. Garcia, M.A., Nilia de la P., Castro, C., Jose, L., Rodriguez, J.L., Rapado, M., Zuluaga, R., Piedad Ganan, P. and Casariego, A. (2015).  Effect of molecular weight reduction by gamma irradiation on the antioxidant capacity of chitosan from lobster shells. Journal of Radiation Research and Applied Science. 8: 190-200. doi: 10.1016/j.jrras.2015.01.001.

  13. Hargono, H. and Djaeni, M. (2010). Utilization of chitosan prepared from shrimp shell as fat diluents. Journal of Coastal Development. 7(1): 31-37.

  14. Hossain, M.S. and Iqbal, A. (2014). Production and characterization of chitosan from shrimp waste. Journal of Bangaladesh Agricultural University. 12(1): 153-160. doi.org/10.3329/ jbau.v12i1.21405.

  15. Islam, A., Yasin, T. and Rehman, I.U. (2014). Synthesis of hybrid polymer networks of irradiated chitosan/poly(vinyl alcohol) for biomedical applications. Radiation Physics and Chemistry. 96: 115-119.doi: 10.1016/j.radphyschem.2013.11.016.

  16. Jeon, Y.J., Kamil, J.Y.V.A. and Shahidi, F. (2002). Chitosan as an edible invisible film for quality preservation of herring and Atlantic cod. Journal of Agricultural and Food Chemistry. 50(18): 5167-5178.doi: 10.1021/jf011693l.

  17. Jeyakumari, A., Narasimha Murthy, L., Visnuvinayagam, S. and Laly, S.J. (2023). Quality and shelf life evaluation of chitosan-coated dried bombay duck (Harpodon nehereus). Asian Journal of Dairy and Food Research. 42(4): 511- 516. doi: 10.18805/ajdfr.DR-2097.

  18. Knaul, J.Z., Kasaii, M.R., Bui, V.T. and Creber, K.A.M. (1998). Characterization of deacetylated chitosan and chitosan molecular weight review. Canadian Journal of Chemistry. 76: 1699-1706. doi: 10.1139/v98-154.

  19. Knorr, D. (1982). Functional properties of chitin and chitosan. Journal of Food Science. 47: 593-595.doi: 10.1111/j.1365 -2621.1982.tb10131.x.

  20. Mahardika, R., Jumnahdi, M. and Widyaningrum, Y. (2019). Chitin Deacetylation shells of Portunus pelagicus L. using microwave irradiation. Paper Presented at the IOP Conference Series: Earth and Environment Science. 353(1): 012037.

  21. Mahmoud, D.E. and Billa, N. (2024). Physicochemical modifications in microwave-irradiated chitosan: biopharmaceutical and medical applications. Journal of Biomaterials Science. 35(6): 898-915. doi: 10.1080/09205063.2023.2295645.

  22. Matica, A., Aachmann, T., Sletta, H. and Ostafe. (2019). Chitosan as a wound dressing starting material: Antimicrobial properties and mode of action. International Journal of Molecular Sciences. 20(23): 5889. doi: 10.3390/ijms 20235889.

  23. Mohanasrinivasan, V., Mishra, M., Paliwal, J.S., Singh, S.K., Selvarajan, E., Suganthi,V. and Subathra Devi, C. (2014). Studies on heavy metal removal efficiency and antibacterial activity of chitosan prepared from shrimp shell waste. 3 Biotech. 4(2): 167-175. doi:10.1007/s13205-013-0140-6.

  24. MPEDA. (2024). https://pib.gov.in/PressReleasePage. aspx?PRID= 2026456.

  25. Muzzarelli, R.A.A. and Rocchetti, R. (1985). Determination of the degree of acetylation of chitosans by first derivative ultraviolet spectrophotometry. Carbohydrate Polymers. 5(6): 461-472. doi: 10.1016/0144-8617(85)90005-0.

  26. Nessa, F., Masum, S.M., Asaduzzaman, M., Roy, S.M. and Jahan, M. (2011). A process for the preparation of chitin and chitosan from prawn shell waste. Bangladesh Journal Scientific Industrial Research. 45(4): 323-330. doi: 10. 3329/bjsir.v45i4.7330.

  27. No, H.K., Lee, K.S. and Meyers, S.P. (2000). Correlation between physicochemical characteristics and binding capacities of chitosan products. Journal of Food science. 65(7): 1134-1137. doi:10.1111/j.1365-2621. 2000.tb10273.x.

  28. Rasweefali, M.K., Sabu, S., Sunooj, K.V., Sasidharan, A. and Martin Xavier, K.A. (2021). Consequences of chemical deacetylation on physicochemical, structural and functional characteristics of chitosan extracted from deep-sea mud shrimp. Carbohydrate Polymer Technologies and Applications. 2: 100032. doi:10.1016/j.carpta.2020.100032.

  29. Sagheer, F.A.A., Al-Sughayer, M.A., Muslim, S. and Elsabee, M.Z. (2009). Extraction and characterization of chitin and chitosan from marine sources in Arabian Gulf. Carbohydrate Polymers. 77(2): 410-419. doi:10.1016/j.carbpol. 2009.01.032.

  30. Samuel, A.O.A., Tolulope,J.A. and Ayenampudi, S.B. (2025). Food drying: A review. Agricultural Reviews. 46(1): 86-93. doi: 10.18805/ag.R-2537.

  31. Seo, S., King, J.M., Prinyawiwatkul, W. (2007). Simultaneous depolymerization and decolorization of chitosan by ozone treatment. Journal of Food Science. 72(9): 522-526. doi:10.1111/j.1750-3841.2007.00552.x.

  32. Shahidi, F., Arachchi, J.K.V. and Jeon, Y.J. (1999). Food applications of chitin and chitosans. Trends in Food science and Technology. 10(2): 37-51. doi: 10.1016/S0924-2244(99) 00017-5.

  33. Sheet, S., Taher, Z. and Alkhashab, A. (2026). Application of active biodegradable packaging technologies using curcumin- enriched chitosan films to prolong the shelf life of soft chesse. Asian Journal of Dairy and Food Research. doi: 10.18805/ajdfr.DRF-630.

  34. Shirvan, A.R., Shakeri, M. and Bashari, A. (2019). Recent advances in application of chitosan and its derivatives in functional finishing of textiles. In: The Impact and Prospects of Green Chemistry for Textile Technology. Shahid-ul-islam and B.s. Butola (eds.). 107-133. doi: 10.1016/B978-0- 08-102491-1.00005-8.   

  35. Siddhartha, P., Anil, Bisnu, P.D.,  Bryan, R.N.,Tanmay, S., Salwa, S., Hisham, A.E., Teh Sabariah, B.A.M., Paramananda, J., Yugal, K.M. and Diptikanta, A. (2020). Structural characterization and antioxidant potential of chitosan by gamma irradiation from the carapace of horseshoe crab. Polymers. 12: 2361. doi:10.3390/polym12102361.

  36. Youn, D.K., No, H.K. and Prinyawiwatkul, W. (2007). Physical characteristics of decolorized chitosan as affected by sun drying during chitosan preparation. Carbohydrate Polymers. 69(4): 707-712. doi: 10.1016/j.carbpol. 2007.01.023.

  37. Younes, I., Hajji, S., Frachet, V., Rinaudo, M., Jellouli, K., Nasri, M. (2014). Chitin extraction from shrimp shell using an enzymatic treatment. Antitumor, antioxidant and antimicrobial activities of chitosan. International Journal of Biological Macromolecules. 69: 489-498. doi: 10.1016/j.ijbiomac.2014.06.013.
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    Full Research Article

    Physico-chemical and Functional Properties of Microwave and Sun-dried Chitosan: A Comparative Study

    A
    A. Jeyakumari1,*
    K
    K. Elavarasan1
    V
    V. Renuka1
    J
    J. Bindu1
    1Division of Fish Processing, ICAR-Central Institute of Fisheries Technology, Kochi-682 029, Kerala, India.

    ABSTRACT

    Background: Generally, chitosan is dried by sun drying and it is a time-consuming process. Hence, improved drying process of chitosan is needed by the industry to speed up the drying process without affecting its properties.

    Methods: In the present study, chitosan was prepared from industrial chitin (shrimp shell) by a cold process and subjected to microwave drying at different powers ranging from 400 to 1600w and its properties were evaluated. Chitosan dried under sun light was used as a control.

    Result: The lowest drying time (23 min) was achieved for chitosan processed at 1600w than sundried one (120 min). The highest viscosity (2117cP) was observed for chitosan processed at 1600w compared to that of the sun dried one (828.50cP). The degree of deacetylation (DD) ranged from 77.3%-80.8%. The highest L* value (74.70) and lower a* (2.02) and b* (16.42) value was obtained for the sundried chitosan than microwave dried sample. However, the other physical and chemical properties of microwave-dried chitosan were comparable to those of sun-dried chitosan. The highest water binding capacity (WBC) was observed for the chitosan processed at 1400w. The highest fat binding capacity was obtained for chitosan processed under 400w. DSC and FTIR studies revealed that there was no significant change in the thermal and structural pattern of chitosan. Results suggested that microwave drying can serve as an effective alternative to sun drying of chitosan and offer wide range of its applications.

    INTRODUCTION

    Shrimp is considered to be one of the most important frozen export items in India. During the financial year 2023-24, frozen shrimp accounted for 40.19% of total exports with earnings of 4881.27 million dollars (MPEDA, 2024). Shrimps are processed into different forms including, whole, peeled, head less etc. During shrimp processing, shells are generated as waste accounting 40-45% of the raw shrimp weight. Shell waste contains 25-40% protein, 40-55% ash, 15% carotenoid pigment and 15-20% chitin (Younes et al., 2014). These shell wastes can be used for the production of high-value-added products, such as chitin, chitosan, glucosamine hydrochloride and carotenoprotein. Among these, chitosan has wide applications in the food, pharmaceutical, cosmetic and textile Industries (Shahidi et al., 1999; Younes et al., 2014; Matica et al., 2019; Jeyakumari et al., 2023). Moreover, chitosan is used for the preparation of biodegradable films, removal of heavy metals, clarification and de-acidification of fruit juices (Mohanasrinivasan et al., 2014; Samuel et al., 2025; Sheet et al., 2026). Chitosan is chemically referred to as β (1, 4) linked copolymer of D-glucosamine and N-acetyl-D-glucosamine. It is soluble in dilute organic acids such as acetic acid. Chitosan is prepared from chitin via deacetylation using concentrated alkali solutions. Chitin is a natural polysaccharide present in crustacean shells, insect exoskeletons and fungal cell walls. Chitin is a linear polymer of N-acetylglucosamine units linked by β-1,4 glycosidic bonds and insoluble in water and acidic solutions. Generally, chitosan is dried under sun drying after the acetylation process to preserve the products with adequate moisture for storage, maintain their characteristics and for further product development.  However, this is a time-consuming process. Hence, an improved drying process for chitosan is required by the industry to speed up the drying process without affecting its properties. Chitosan can be dried using different methods such as oven drying, freeze drying, supercritical CO2 drying, bed drying, microwave drying and irradiation.  Most studies have used different drying methods for chitosan solutions and characterized their physicochemical properties but not for chitosan flakes. A few studies have attempted to use gamma irradiation/ microwave heating to modify the functional properties of chitosan and the deacetylation of chitin (Cheng et al., 2020; Dong et al., 2023; Siddhartha et al., 2020). To the best of our knowledge, there have been no reports on the drying of chitosan in flake form using the microwave drying method and its quality. In microwave drying, the materials become trembled within the molecules by the electromagnetic field produced during microwave heating and provide an increased rate of reaction in a shorter time (Abeykoon et al., 2016; Mahardika et al., 2019; Anantharaman, 2025). Based on the above information, this study aimed i) to prepare chitosan from industrial chitin and dry it under sun/ microwave drying conditions and ii) to assess the impact of microwave drying on chitosan quality.

    MATERIALS AND METHODS

    Raw material
     
    Chitin prepared from shrimp shells was procured from the Private Industry (Matysyafed) located at Cochin, Kerala, for the production of chitosan. All chemicals and reagents used in the study were of analytical grade and procured from M/s. Merck, India.
     
    Preparation of chitosan
     
    Chitin was subjected to deacetylation process using 50% NaOH under ambient conditions for two days. After 48 h, the alkali was drained and the residual chitosan was washed with potable water until the pH of the chitosan became neutral pH (pH=7). It was then centrifuged in a bucket centrifuge to remove the maximum amount of water from the shell. They were then divided into six lot. The first lot was dried in sunlight. Other lots were subjected to a microwave drying process with a varying power ranging from 400 to 1600w.  The selected power levels were chosen to evaluate the influence of low, medium and high microwave energy inputs on the drying behavior and physicochemical properties of chitosan. Chitosan samples (100 g wet chitosan flakes per batch) were uniformly spread in a microwave-safe tray as a thin layer with an approximate thickness of 5 mm during microwave drying to ensure uniform microwave energy distribution and efficient moisture removal. Maintaining a thin and homogeneous sample layer facilitated effective heat and mass transfer while minimizing localized overheating and non-uniform drying. Dried chitosan was packed in a high-density polyethylene (HDPE)  pouches and stored under ambient conditions for further analysis.
     
    Methods
     
    The moisture, chitosan nitrogen and ash contents of dried chitosan were estimated according to the AOAC (2023) method. The degree of deacetylation was estimated according to the method described by Muzzarelli and Rocchetti (1985). The viscosity was measured using a Brookfield viscometer (Model: DV-E; Brookfield Engineering Laboratories, Inc., USA). The water (WBC) and fat binding capacity (FBC) of chitosan were evaluated according to Knorr (1982). The color of the chitosan was analyzed using a Hunter- Lab Scan XE-Spectrocolorimeter (Hunter Associates Laboratory, Reston USA). DSC analysis was performed using a DSC analyzer (Ta Instruments, USA). The analysis was performed under nitrogen gas at a heating rate of 10°C/min. FTIR analysis was carried out using FTIR (Shimadzu IR-Prestige-21). The data obtained by various quality analyses were subjected to one-way ANOVA (analysis of variance). Duncan’s multiple range test was performed at 95% confidence level (P<0.05) using the SPSS package (version 16.0; SPSS Inc, Chicago,IL USA). All analysis were carried out in triplicate and values are represented as mean ±SD.

    RESULTS AND DISCUSSION

    Proximate composition
     
    The moisture content of the chitosan varied from 3.35% to 7.58%. It has been reported that commercial chitosan has more than 10% moisture content (Abdel-Rahman  et al., 2015). The nitrogen content of chitin and chitosan generally fall between 5-8% which makes them suitable for application in various sectors (Nessa et al., 2011). In the present study, the chitosan nitrogen content ranged from 4.22 to 6.64%. The ash content ranged from 0.49% to 1.43%. It has been reported that high quality chitin and chitosan have ash contents of less than 1% (Rasweefali et al., 2021). Accordingly, these results indicate the good quality of chitin used in this study. The physical and chemical properties of microwave and sundried chitosan are given in Table 1. The drying time of chitosan under different process conditions varied from 23 to 120 min. The lowest drying time (23 min) was achieved for chitosan processed under microwave drying at 1600 watts than the sundried sample (120 min). Instrumental color analysis showed that L* (whiteness) values ranged from 71.22 to 74.70. The a* (redness) value ranged from 2.02 to 3.38. The b* (yellowness) value ranged from 16.42 to 18.57. The results indicated that sundried chitosan had a higher L* value (74.70) and lower b* (16.42) values than the others. The higher L* values observed in sun-dried chitosan indicate superior whiteness retention compared to microwave-dried samples. This may be primarily attributed to the photolytic effects of sunlight during the drying process. In addition, the gradual and mild moisture removal associated with sun drying minimizes thermal stress and suppresses browning reactions. In contrast, microwave drying involves rapid volumetric heating which may accelerate pigment degradation and browning reactions, leading to comparatively lower L* values. Therefore, while microwave drying offers improved drying efficiency and shorter processing time, sun drying appears to favor better visual quality through sunlight-induced photolytic bleaching effects (Youn et al., 2007) . Rasweefali et al., (2021) reported a lower L* value (68.99) for chitosan dried under sunlight. It has been reported that the color value of chitosan is influenced by the processing method, time, presence of carotenoid pigment in the shell etc. (Seo et al., 2007; Dornish et al., 2001).

    Table 1: Physical and chemical properties of microwave and sundried chitosan.


     
    Functional properties of microwave and sundried chitosan
     
    Degree of deacetylation
     
    The degree of deacetylation measures the free amino group content of the polymer chain (Matica et al., 2019). It is one of the most important quality parameters that determines the physico-chemical and functional properties of chitosan and its application (Shirvan et al., 2019; Knaul et al., 1998). Degree of deacetylation was used to differentiate between chitin and chitosan. Generally, the degree of deacetylation of commercial chitosan ranges from 70-95%. In this study, the degree of deacetylation ranged from 77.3%-80.8%. If the degree of deacetylation is above 70%, it is termed chitosan (Sagheer et al., 2009). The degree of deacetylation is influenced by several factors including the species, alkali concentration, process time and temperature (Knaul et al., 1998; El Knidri et al., 2018; Hargono et al., 2010; Aranaz et al., 2021). The functional properties of microwave and sundried chitosan are given in Table 2.

    ​

    Table 2: Functional properties of microwave and sundried chitosan.


     
    Viscosity
     
    Viscosity is an important functional property of chitosan that determines its industrial application. The viscosity of chitosan depends on its degree of deacetylation, molecular weight, particle size and storage time (Chattopadhyay and Inamdar, 2010). In this study, the viscosity ranged from 828.50cP to 2117cP. Aranaz et al., (2021) reported that viscosity increased with an increase in the degree of deacetylation. In the present study, sundried chitosan showed a lower viscosity of 828.50 cP than the microwaved dried chitosan. However, it does not follow this trend with respect to microwave power treatment. Moreover, there is a drop in viscosity for chitosan dried at1600W power. The increased viscosity observed in microwave-dried chitosan flakes may be attributed to structural and molecular modifications induced during microwave-assisted drying. Rapid volumetric heating generated by microwave energy can enhance intermolecular interactions among chitosan chains, promoting greater chain entanglement and reduced molecular mobility, which subsequently increases resistance to flow. Moreover, the accelerated moisture removal associated with microwave drying may facilitate the formation of a more compact and densely aggregated polymer network, contributing to higher apparent viscosity. Mahmoud and Billa (2024) reported that microwave treatment can modify the physicochemical and molecular characteristics of chitosan, including its viscosity and structural organization. Siddhartha et al., (2020) observed a decrease in the viscosity with respect to the irradiation dose.  Furthermore, they reported that when the irradiation dose level is increased, depolymerization or degradation or polymer chain length is reduced, which influence the decrease in viscosity. 
     
    Water binding and Fat binding capacity
     
    Water binding and fat binding capacity also determines chitosan applications. It has been reported that the water binding capacity of shrimp chitosan varies from 581% to 1150% (Hossain and Iqbal, 2014). The water binding capacity of chitosan varies with the process and reaction time applied during chitosan preparation (Mohanasrinivasan et al., 2014; Jeon et al., 2002; No et al., 2000).  In the present study, the water binding capacity of chitosan varied from 169.86% to 399.65%. The highest water binding capacity was observed for the 1400W processed chitosan sample. No et al., (2000) reported a water binding capacity of 355 to 611% for chitosan prepared from crab shells. Rasweefali et al., (2021) observed the highest water binding capacity of 800% for deep sea mud shrimp. The difference in the water binding capacity of the samples is due to the difference in the protein content, crystallinity and amount of salt forming groups in the product (Knorr, 1982). Unlike WBC, the fat binding capacity of chitosan also depends on the process and reaction time applied during chitosan preparation (Hossain and Iqbal, 2014).  In the present study, FBC is varied from 541.41 to 933.51%. Rasweefali et al., (2021) observed an FBC of 700-820% for chitosan from deep sea mud shrimp. Chitosan with a high fat binding capacity can be used as a dietary ingredient and anti-cholesterolemic agent in functional food product development (Garcia et al., 2015).
     
    Thermal behaviour of chitosan
     
    A DSC thermograph of chitosan dried using different drying methods is shown in Fig 1. The DSC analysis showed an endothermic peak at aaproxmately109.41°C-150.65°C which indicated evaporation of moisture content from the sample. Garcia et al., (2015) observed a similar pattern for chitosan treated with different irradiation doses. The second thermal event exhibited an exothermic peak between 303.03°C-313.53°C. This may be due to the decomposition pattern of chitosan including the degradation of glucopyranose units and their subsequent oxidation Garcia et al.  (2015).  Andrade et al., (2012) observed a decomposition pattern for shrimp chitosan between 300-400°C. The results indicated that there was no significant change in the thermal behavior of chitosan dried under different conditions, indicating that the structural pattern of chitosan was not affected by the microwave drying process.

    Fig 1: DSC thermograph of chitosan dried at different drying methods.



    FTIR Structural pattern of chitosan
     
    In the present study, all chitosan samples had similar characteristic bands (Fig 2) which indicated that there was no significant change in the structural pattern of chitosan under different drying methods. The FTIR spectrum showed a band at 3353 represent the amine group. The band at 2863 represent C-H stretching.  Moreover, in the range of 1900-1660 cm-1 range no band was observed confirming the absence of carbonyl and carboxyl groups (Nessa et al., 2011).  The presence of a band at 1646 cm-1 indicated the presence of primary amine groups, confirming the deacetylation of chitin (Nessa et al., 2011; Islam et al., 2014). The band at 1374 cm-1 indicated the presence of amide III bands, C-N stretch. The absorbance at 893 and 1149 cm-1 confirmed the presence of pyranose and the saccharide structure of chitosan (Islam et al., 2014).

    Fig 2: FTIR structural pattern of Chitosan dried at different drying methods.

    CONCLUSION

    In this study, chitosan prepared from shrimp chitin was subjected to different drying methods and its physicochemical and functional properties were assessed.  The lowest drying time (23 min) was achieved for chitosan processed at 1600W than the sundried sample (120 min). Further, the structural pattern of chitosan was not affected by the microwave drying process as indicated by DSC and FTIR analysis. However, variations in functional properties and color parameters, particularly lightness (L* value), were observed with increasing microwave power levels. Although microwave drying reduced the whiteness of chitosan compared to sun drying, it substantially improved drying efficiency and processing time. Overall, the findings suggest that microwave drying can serve as a rapid and effective alternative to conventional sun drying for chitosan processing, with potential advantages for industrial-scale applications. Furthermore, the estimated investment required for establishing a small-scale industrial microwave drying setup is approximately ₹5-8 lakhs, with an anticipated break-even period of 8-15 months depending on production capacity and operational efficiency.

    ACKNOWLEDGEMENT

    The present study was supported by Indian council of Agricultural Research, Department of Agricultural Research and Education, Government of India. This is ICAR-CIFT contribution No.RPP/070/2024.
     
    Disclaimers
     
    The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
     
    Informed consent
     
    This research did not involve any animal / human participation or any material that requires ethical approval. Therefore, informed consent was not required.

    CONFLICT OF INTEREST

    The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.

    REFERENCES


    1. Abdel-Rahman, R.M., Hrdina, R., Abdel-Mohsen, A.M., Fouda, M.M. G., Soliman A.Y., Mohamed, F.K., Mohsin, K. and Pinto, T.D. (2015). Chitin and chitosan from Brazilian atlantic coast: Isolation, characterization and antibacterial activity. International Journal of Biological Macromolecules. 80: 107-120. doi:10.1016/j.ijbiomac.2015.06.027.

    2. Abeykoon, C., Kelly, A.L., Brown, E.C. and Coates, P.D. (2016). The effect of materials, process settings and screw geometry on energy consumption and melt temperature in single screw extrusion. Applied Energy. 180: 880-894. doi: 10.1016/j.apenergy.2016.07.014.

    3. Anantharaman, R. (2025). Isolation and the use off-derived chitosan as a substrate-free edible coating to extend the postharvest shelf life of guava. Asian Journal of Dairy and Food Research. 44(6): 920-930. doi: 10.18805/ajdfr.DR-2392.

    4. Andrade, S.M.B., Rasiah., Ladchumananandasivam, R., Rocha, B.G., Belarmino, D.D. and Galvao, A.O. (2012). The use of exoskeletons of shrimp (Litopenaeus vanammei) and Crab (Ucides cordatus) for the extraction of chitosan and production of nanomembrane. Materials Sciences and Applications. 3: 495-508. doi: 10.4236/msa.2012. 37070.

    5. AOAC.  (2023) .Official Methods of Analysis  of the Association of Analytical Chemists. (22nd edn.). Washington, DC.

    6. Aranaz, I., Alcántara, A.R., Civera, M.C., Arias, C., Elorza, B., Heras Caballero, A. and Acosta, N. (2021). Chitosan: An overview of its properties and applications. Polymers. 13(19): 3256. doi: 10.3390/polym13193256.

    7. Chattopadhyay, D. and Inamdar, M.S. (2010). Aqueous behaviour of chitosan. International Journal of Polymer Science. 7: 939536. doi: 10.1155/2010/939536.

    8. Cheng, J., Zhu, H., Huang, J., Zhao, J., Yan, B., Ma, S., Zhang, H. and Fan, D. (2020). The physicochemical properties of chitosan prepared by microwave heating. Food science and Nutrition. doi: 10.1002/fsn3.1486.

    9. Dong, Q., Qiu, W., Feng, Y., Jin, Y., Deng, S., Tao, N. and Jin Y. (2023). Proteases and microwave treatment on the quality of chitin and chitosan produced from white shrimp (Penaeus vannamei). eFood.  doi: 10.1002/efd2.73.

    10. Dornish, M., Kaplan, D. and Skaugrud, O. (2001). Standards and Guidelines for Biopolymers in Tissue-engineered Medical Products: ASTM Alginate and Chitosan Standard Guides, In: Bioartificial organs III Tissue Sourc. Immunoisolation Clin. Trials,  [D. Hunkeler, A. Cherrington, A. Prokop, R. Rajotte (Eds.)], vol. 944, New York Academy of Sciences,  New York. 388-397.

    11. El Knidri, H., Belaabed, R., Addaou, A., Laajeb, A. and Lahsini, A. (2018). Extraction, chemical modification and characterization of chitin and chitosan. International Journal of Biological Macromolecules. 120: 1181-1189. doi: 10.1016/j.ijbio mac. 2018.08.139.

    12. Garcia, M.A., Nilia de la P., Castro, C., Jose, L., Rodriguez, J.L., Rapado, M., Zuluaga, R., Piedad Ganan, P. and Casariego, A. (2015).  Effect of molecular weight reduction by gamma irradiation on the antioxidant capacity of chitosan from lobster shells. Journal of Radiation Research and Applied Science. 8: 190-200. doi: 10.1016/j.jrras.2015.01.001.

    13. Hargono, H. and Djaeni, M. (2010). Utilization of chitosan prepared from shrimp shell as fat diluents. Journal of Coastal Development. 7(1): 31-37.

    14. Hossain, M.S. and Iqbal, A. (2014). Production and characterization of chitosan from shrimp waste. Journal of Bangaladesh Agricultural University. 12(1): 153-160. doi.org/10.3329/ jbau.v12i1.21405.

    15. Islam, A., Yasin, T. and Rehman, I.U. (2014). Synthesis of hybrid polymer networks of irradiated chitosan/poly(vinyl alcohol) for biomedical applications. Radiation Physics and Chemistry. 96: 115-119.doi: 10.1016/j.radphyschem.2013.11.016.

    16. Jeon, Y.J., Kamil, J.Y.V.A. and Shahidi, F. (2002). Chitosan as an edible invisible film for quality preservation of herring and Atlantic cod. Journal of Agricultural and Food Chemistry. 50(18): 5167-5178.doi: 10.1021/jf011693l.

    17. Jeyakumari, A., Narasimha Murthy, L., Visnuvinayagam, S. and Laly, S.J. (2023). Quality and shelf life evaluation of chitosan-coated dried bombay duck (Harpodon nehereus). Asian Journal of Dairy and Food Research. 42(4): 511- 516. doi: 10.18805/ajdfr.DR-2097.

    18. Knaul, J.Z., Kasaii, M.R., Bui, V.T. and Creber, K.A.M. (1998). Characterization of deacetylated chitosan and chitosan molecular weight review. Canadian Journal of Chemistry. 76: 1699-1706. doi: 10.1139/v98-154.

    19. Knorr, D. (1982). Functional properties of chitin and chitosan. Journal of Food Science. 47: 593-595.doi: 10.1111/j.1365 -2621.1982.tb10131.x.

    20. Mahardika, R., Jumnahdi, M. and Widyaningrum, Y. (2019). Chitin Deacetylation shells of Portunus pelagicus L. using microwave irradiation. Paper Presented at the IOP Conference Series: Earth and Environment Science. 353(1): 012037.

    21. Mahmoud, D.E. and Billa, N. (2024). Physicochemical modifications in microwave-irradiated chitosan: biopharmaceutical and medical applications. Journal of Biomaterials Science. 35(6): 898-915. doi: 10.1080/09205063.2023.2295645.

    22. Matica, A., Aachmann, T., Sletta, H. and Ostafe. (2019). Chitosan as a wound dressing starting material: Antimicrobial properties and mode of action. International Journal of Molecular Sciences. 20(23): 5889. doi: 10.3390/ijms 20235889.

    23. Mohanasrinivasan, V., Mishra, M., Paliwal, J.S., Singh, S.K., Selvarajan, E., Suganthi,V. and Subathra Devi, C. (2014). Studies on heavy metal removal efficiency and antibacterial activity of chitosan prepared from shrimp shell waste. 3 Biotech. 4(2): 167-175. doi:10.1007/s13205-013-0140-6.

    24. MPEDA. (2024). https://pib.gov.in/PressReleasePage. aspx?PRID= 2026456.

    25. Muzzarelli, R.A.A. and Rocchetti, R. (1985). Determination of the degree of acetylation of chitosans by first derivative ultraviolet spectrophotometry. Carbohydrate Polymers. 5(6): 461-472. doi: 10.1016/0144-8617(85)90005-0.

    26. Nessa, F., Masum, S.M., Asaduzzaman, M., Roy, S.M. and Jahan, M. (2011). A process for the preparation of chitin and chitosan from prawn shell waste. Bangladesh Journal Scientific Industrial Research. 45(4): 323-330. doi: 10. 3329/bjsir.v45i4.7330.

    27. No, H.K., Lee, K.S. and Meyers, S.P. (2000). Correlation between physicochemical characteristics and binding capacities of chitosan products. Journal of Food science. 65(7): 1134-1137. doi:10.1111/j.1365-2621. 2000.tb10273.x.

    28. Rasweefali, M.K., Sabu, S., Sunooj, K.V., Sasidharan, A. and Martin Xavier, K.A. (2021). Consequences of chemical deacetylation on physicochemical, structural and functional characteristics of chitosan extracted from deep-sea mud shrimp. Carbohydrate Polymer Technologies and Applications. 2: 100032. doi:10.1016/j.carpta.2020.100032.

    29. Sagheer, F.A.A., Al-Sughayer, M.A., Muslim, S. and Elsabee, M.Z. (2009). Extraction and characterization of chitin and chitosan from marine sources in Arabian Gulf. Carbohydrate Polymers. 77(2): 410-419. doi:10.1016/j.carbpol. 2009.01.032.

    30. Samuel, A.O.A., Tolulope,J.A. and Ayenampudi, S.B. (2025). Food drying: A review. Agricultural Reviews. 46(1): 86-93. doi: 10.18805/ag.R-2537.

    31. Seo, S., King, J.M., Prinyawiwatkul, W. (2007). Simultaneous depolymerization and decolorization of chitosan by ozone treatment. Journal of Food Science. 72(9): 522-526. doi:10.1111/j.1750-3841.2007.00552.x.

    32. Shahidi, F., Arachchi, J.K.V. and Jeon, Y.J. (1999). Food applications of chitin and chitosans. Trends in Food science and Technology. 10(2): 37-51. doi: 10.1016/S0924-2244(99) 00017-5.

    33. Sheet, S., Taher, Z. and Alkhashab, A. (2026). Application of active biodegradable packaging technologies using curcumin- enriched chitosan films to prolong the shelf life of soft chesse. Asian Journal of Dairy and Food Research. doi: 10.18805/ajdfr.DRF-630.

    34. Shirvan, A.R., Shakeri, M. and Bashari, A. (2019). Recent advances in application of chitosan and its derivatives in functional finishing of textiles. In: The Impact and Prospects of Green Chemistry for Textile Technology. Shahid-ul-islam and B.s. Butola (eds.). 107-133. doi: 10.1016/B978-0- 08-102491-1.00005-8.   

    35. Siddhartha, P., Anil, Bisnu, P.D.,  Bryan, R.N.,Tanmay, S., Salwa, S., Hisham, A.E., Teh Sabariah, B.A.M., Paramananda, J., Yugal, K.M. and Diptikanta, A. (2020). Structural characterization and antioxidant potential of chitosan by gamma irradiation from the carapace of horseshoe crab. Polymers. 12: 2361. doi:10.3390/polym12102361.

    36. Youn, D.K., No, H.K. and Prinyawiwatkul, W. (2007). Physical characteristics of decolorized chitosan as affected by sun drying during chitosan preparation. Carbohydrate Polymers. 69(4): 707-712. doi: 10.1016/j.carbpol. 2007.01.023.

    37. Younes, I., Hajji, S., Frachet, V., Rinaudo, M., Jellouli, K., Nasri, M. (2014). Chitin extraction from shrimp shell using an enzymatic treatment. Antitumor, antioxidant and antimicrobial activities of chitosan. International Journal of Biological Macromolecules. 69: 489-498. doi: 10.1016/j.ijbiomac.2014.06.013.
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