The work is intended to explore the suitability of underutilized coconut water (a byproduct of food industry) for the production of exopolysaccharides (EPS) by Agrobacterium sp. CFR 24. Besides checking the suitability of coconut water for the production of water-soluble (WS) and water-insoluble (WIS) EPS, certain fermentation parameters, such as initial pH, incubation period and kinetics of EPS production were investigated. The coconut water medium was found to support the production of both types of EPS. The optimal initial pH and temperature was found to be 6·0 and 30°C, respectively. In shake flask (150 rev min[superscript [-]1]) studies, high-cell density inoculum resulted in the production of 11·50 g l[superscript [-]1] of WIS-EPS and 4·01 g l[superscript [-]1] WS-EPS after 72 and 96 h of fermentation, respectively. Coconut water was found suitable for the production of microbial EPS by Agrobacterium sp. CFR 24 strain. Under optimum conditions, it produced a good amount of WIS-EPS, which is comparable with that of the sucrose medium (11 g l[superscript [-]1]). This is the first report on the use of coconut water as a fermentation medium for the production of any microbial EPS. Besides producing value-added products, use of this food industry byproduct, which is often being drained out, can significantly reduce the problem of environmental pollution.

This work proposes, for the first time, a method based on homogenous liquid-liquid microextraction with switchable hydrophilicity solvent as extraction phase (SHS-HLLME) for the determination of food-packaging contaminants including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di-n-octyl phthalate (DNOP), 4-octylphenol (4-OP), 4-nonylphenol (4-NP), and benzophenone (BZP) in coconut water samples by gas chromatography-mass spectrometry (GC-MS). Experimental parameters that can influence extraction efficiency, such as type and volume of SHS, sample volume, NaOH volume, temperature, and extraction time, were investigated. Using the optimal conditions, the calibration curves were linear from 0.5 to 30 μg L⁻¹ for DMP and DEP; 1 to 30 μg L⁻¹ for DBP, BBF, and DNOF; and 5 to 30 μg L⁻¹ for BZP, 4-OP, and 4-NP. The coefficients of determination ranged from 0.9830 to 0.9972. The relative recoveries varied from 82 to 130%, and the intra- and inter-day precision values were lower than 18% for all analytes for the concentrations of 5, 15, and 30 μg L⁻¹. Limit of detection and quantification ranged from 0.15 to 1.51 μg L⁻¹ and from 0.50 to 5.0 μg L⁻¹, respectively. In addition, the robustness of the methodology was examined and exhibited satisfactory results. Finally, the method developed was successfully applied for the analysis of six coconut water samples from food packaging. In this particular case, at least one analyte was found in five samples analyzed in the range of <LOQ to 3.37 μg L⁻¹.