Optimising Deodorisation of Kappaphycus striatus for Enhanced Applications in Food and Bioplastics Nur Afifah Mohd Fauziee1, Wan Aida Wan Mustapha1,2, Noor Soffalina Sofian Seng1,2, Noorul Syuhada Mohd Razali1,2, Hafeedza Abdul Rahman1,2, Adibi Rahiman Md Nor3, Dhanendra Sivarajah4, Seng Joe Lim1,2*
1Affiliation Department of Food Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
2Innovation Centre of Confectionery Technology (MANIS), Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia
3International Institute of Public Policy and Management, University of Malaya, 50603 Kuala Lumpur, Malaysia
4DWYCO Enterprise, 145, Persiaran Zaaba, Taman Tun Dr Ismail, 60000 Kuala Lumpur, WP Kuala Lumpur
*Corresponding author email: joe[at]ukm.edu.my
Abstract
Malaysia is among the leading producers of red seaweeds, particularly Kappaphycus sp., which are the largest tropical red seaweeds and display remarkable growth rates, doubling in biomass within 15 to 30 days. Kappaphycus sp. contains high levels of carbohydrates, approximately 65.20%, and is a rich source of biologically active compounds and hydrocolloids such as carrageenan. Despite these advantages, its strong and distinctive odour has hindered its wider use in food and bioplastic applications. This study investigated the volatile compounds in Kappaphycus striatus prepared using two drying methods: sun drying and oven drying. Using solid phase microextraction and gas chromatography-mass spectrometry, odour-active compounds such as 2-pentylfuran and hexanal were identified, contributing to fishy, green bean-like and grassy aromas. Deodorisation trials were carried out using activated charcoal, zeolite, ion exchange resin, and a combination of these under consistent conditions. Sensory evaluation by twelve trained panellists indicated that oven-dried samples treated with activated charcoal produced the lowest odour scores and were therefore selected for further optimisation. Deodorisation parameters were varied by adsorbent ratio, treatment time and temperature. Sensory analysis identified three conditions that most effectively reduced odour: 0.1:10 ratio for 30 minutes at 70C, 0.5:10 ratio for 60 minutes at 50C, and 1:10 ratio for 15 minutes at 27C. These treatments significantly lowered odour-active compounds and reduced water activity to between 0.29 and 0.56, without causing significant changes in colour. The findings confirm that deodorisation can be successfully achieved, enabling broader utilisation of K. striatus in both food and bioplastic industries.
Keywords: Deodourisation- Odour- Red Seaweed- Sensory- Volatile compounds
