Using multivariate models to link seasonality and biodiesel efficiency in red sea brown algae

This study evaluated five Phaeophyta species from the northern Red Sea during different seasons, focusing on their physiological parameters as potential candidates for biodiesel production. Multivariate statistical analysis was used to assess the effect of seawater's physicochemical parameters on the bioactive compounds of Phaeophyta. The findings demonstrated that carbohydrate concentrations peaked during cooler seasons, with Hormophysa cuneiformis exhibiting a maximum value of 206.76 mg/g in the fall. The protein concentration demonstrated species-specific stability, with Sargassum aquifolium maintaining relatively constant levels of approximately 67 mg/g. Padina gymnospora significantly diminished from 46.47 mg/g in winter to 20.37 mg/g in spring. The lipid content exhibited considerable seasonal fluctuations, with P. gymnospora attaining a peak of 9.78 mg/g during summer. The predominant fatty acids were palmitic and stearic, crucial for the stability of biodiesel. Turbinaria decurrens exhibited higher cetane numbers of 76.33 in summer and remarkable cold flow properties of 3.31 °C in fall, underscoring its suitability for high-quality biodiesel production. This indicates that multivariate analysis and comprehension of seasonal variation can improve the optimization of cultivation, harvesting, and biodiesel production from the brown macroalgae in the Red Sea.