Enzymatic synthesis of xylitol fatty acid ester was performed in hexane using Novozym 435 (immobilized Candida antarctica lipase on macroporous resin). Taguchi method based on three levels, six variables L27 orthogonal array robust design was implemented to optimize experimental conditions. The effects of reaction parameters including reaction time (7-24 h), enzyme amount (0.05-0.3 g), temperature (30-60 °C), amount of molecular sieve (1-4 g), substrate molar ratio (0.3-1) and xylitol concentration (0.005-0.015 g/ml) on the percentage yield of sugar ester were investigated. The optimum conditions derived via Taguchi method were: reaction time 7 h, temperature 60 °C, amount of enzyme 0.12 g, amount of molecular sieve 2.5 g, substrate molar ratio 1 and xylitol concentration 0.015 g/ml. The actual experimental yield was 96.10% under optimum condition, which compared well to the maximum predicted value of 96.27%.

The particle size of Virgin coconut oil nanoemulsions was optimized using D-optimal mixture design and the optimum formulation was physicochemically characterized.

aCoconut coir, an agricultural waste, was chemically modified using esterification by fatty acid chloride (oleoyl chloride and octanoate chloride) for oil spill removal purposes. The modified coir (coir-oleate and coir-octanoate) were characterized by spectroscopy, thermal studies, contact angle, and morphological studies. The modified coir exhibited an enhancement towards the hydrophobic property but a decreased thermal stability. The oil adsorption performance was tested using a batch adsorption system. The effect of sorbent dosage, oil concentration, and effect of adsorption time on the adsorption capacity of the modified coir were also studied. From the analysis, the long chain oleoyl chloride (C18) was shown to be a better modifier compared to octanoate chloride (C8). The isotherm study indicated that the oil adsorption fitted well to a Langmuir model rather than Freundlich model. From the kinetic study, the result revealed a good fit in pseudo-second order model for all samples studied. The study therefore suggests that esterified coconut coir can serve as a potential biomaterial for the adsorption of spilled oil during operational failures.

A predictive model of a virgin coconut oil (VCO) nanoemulsion system for the topical delivery of copper peptide (an anti-aging compound) was developed using an artificial neural network (ANN) to investigate the factors that influence particle size. Four independent variables including the amount of VCO, Tween 80: Pluronic F68 (T80:PF68), xanthan gum and water were the inputs whereas particle size was taken as the response for the trained network. Genetic algorithms (GA) were used to model the data which were divided into training sets, testing sets and validation sets. The model obtained indicated the high quality performance of the neural network and its capability to identify the critical composition factors for the VCO nanoemulsion. The main factor controlling the particle size was found out to be xanthan gum (28.56%) followed by T80:PF68 (26.9%), VCO (22.8%) and water (21.74%). The formulation containing copper peptide was then successfully prepared using optimum conditions and particle sizes of 120.7 nm were obtained. The final formulation exhibited a zeta potential lower than -25 mV and showed good physical stability towards centrifugation test, freeze-thaw cycle test and storage at temperature 25°C and 45°C.