Minimizing Organic Waste Generated by Pineapple Crown: A Simple Process to Obtain Cellulose for the Preparation of Recyclable Containers

Chitosan-based foam composites for hexavalent chromium remediation: Effect of microcellulose and crosslinking agent content

Potentially toxic metal ions, such as hexavalent chromium (Cr6+), present in water concern the population's health due to their persistence, bioaccumulation potential, and high toxicity. Highly porous materials based on polysaccharides are promising technologies for metal removal due to their high surface area, biodegradability, and low toxicity. This study evaluated the effect of concentrations of microcellulose (0.5, 1, and 1.5 %) and glutaraldehyde (1, 2, and 3 %) in the adsorption capacity and mechanical properties of chitosan foams. The developed foams exhibited a three-dimensional structure with interconnected pores. Compared to foams without microcellulose, adding 1.5 % microcellulose increased up to 180 % in maximum stress supported by the foams and up to 135 % in Young's modulus. However, Cr6+ sorption capacity decreased with increasing microcellulose and crosslinking agent content due to the occupation of amino groups. Still, the foams exhibited a highly favorable sorption behavior, and the Sips isotherm model provided the best fit to the experimental data. The maximum sorption capacity reached approximately 1.4 mmol·g-1 at pH 4.0 and 25 °C. The foam structural integrity, enhanced mechanical properties, and efficient sorption capacity make them viable alternatives for environmentally friendly and cost-effective treatment of water contaminated with Cr6+ ions.

Valorisation of Pineapple Cannery Waste as a Cost Effective Carbon Source for Poly 3-hydroxyabutyrate (P3HB) Production

Pineapple is one of the most important agro-industrial sugar-based fruits in Thailand. In this study, the waste stream from pineapple cannery processing was utilised and evaluated for potential use in the production of a main biopolymer group widely known as polyhydroxyalkanoates (PHAs) through aerobic batch fermentation. Firstly, pineapple cannery waste (PCW) collected from three processing sources, pineapple juice (PAJ), peel and core juice (PCJ), and pulp-washing water (PWW), was used as a carbon source. Secondly, it was characterised and pretreated. Then, batch fermentation was performed by using the optimal condition (200 rpm agitation rate, 37 °C, and fermentation time of 72 h) under two different nutrient conditions in each type of carbon source. The results revealed that PHAs were produced during 24-72 h of fermentation without any interference. The PHAs product obtained was characterised by their properties. Interestingly, GC-MS showed homopolymer of poly 3-hydroxybutyrate (P3HB) group characteristics, such as OH, CH, and C=O; meanwhile, H1 NMR analysis showed signals corresponding to CH3, CH2, and CH, respectively. Remarkably, utilising the PCW showed a high-potential cheap carbon source for the production of PHAs as well as for the treatment of wastewater from the fruit industry.

Isolation and Characterization of Nanocrystalline Cellulose Isolated from Pineapple Crown Leaf Fiber Agricultural Wastes Using Acid Hydrolysis

Pineapple crown leaf fiber (PCLF) is one of the major biomass wastes from pineapple processing plants. It consists mostly of carbohydrate polymers, such as cellulose, hemicellulose, and lignin. It can be further processed to form a more valuable and widely used nanocrystalline cellulose (NCC). This study investigates the effect of hydrolysis time on the properties of the produced NCC. The acid hydrolysis was conducted using 1 M of sulfuric acid at hydrolysis times of 1–3 h. The resulting NCCs were then characterized by their morphology, functional groups, crystallinity, thermal stability, elemental composition, and production yield. The results show that the NCC products had a rod-like particle structure and possessed a strong cellulose crystalline structure typically found in agricultural fiber-based cellulose. The highest NCC yield was obtained at 79.37% for one hour of hydrolysis. This NCC also displayed a higher decomposition temperature of 176.98 °C. The overall findings suggest that PCLF-derived NCC has attractive properties for a variety of applications.