Process kinetics optimization for extraction of essential oil from the peel of Citrus sinensis for the development of food packaging film
Authors: Amanullah Muthahar Fazila , Rasamani Padmapriya , Sukumar M. 
Published: April 2024

The goals of the present work were to achieve maximum extraction efficiency from Citrus sinensis peel and effective utilization of its bioactive compounds. This work focused on studying the physicochemical characteristics and yield percentage of citrus essential oil (CEO) extracted from citrus peels at different extraction times, extraction temperatures, solid–liquid ratios, and solvent combinations, and the data of yield percentage was subjected to find the best kinetic model for better yield. C. sinensis peel powder was subjected to Soxhlet extraction of essential oil at varied solid:liquid ratios (1/2, 1/4, 1/6, 1/8, and 1/10), time intervals in minutes (120, 150, 180, 210, 240, 270, and 280), temperatures (50, 60, 70, 80, 90, and 100°C), and solvents (n‐hexane, petroleum ether, chloroform, methanol, and water) to characterize their impact on yield percentage. The essential oil extraction kinetics were assessed using the experimental data and two different kinetic models (zero‐order and first‐order kinetic model). The bioactive compounds were assessed using GC–MS, as well. Amongst the other solvents, maximum extraction yield was observed at 90°C for 270 min using n‐hexane. GC–MS results showed that d‐limonene was the predominant compound constituting 41.41%. A good agreement between applied kinetic models and experimental data was demonstrated by the first‐order model (R2 = .9830) and the zero‐order kinetic model (R2 = .9719). Thus, the effective conditions for maximum extraction yield of CEO peels were optimized and the extracted CEO can be used in food packaging applications for shelf‐life extension.

Practical applications

Effective food waste management is vital for promoting sustainable resource usage, reducing environmental impact, saving money and energy, addressing global hunger, and upholding ethical and social responsibilities. It is important to minimize food waste throughout the entire food supply chain. Citrus peels are the by‐products of the citrus fruit processing industry and households which contribute to organic waste and its management is an important consideration for environmental sustainability. Thus, this study aims to manage these wastes by extracting essential oil from them and optimizing their process. The role of Citrus sinensis essential oil in the food industry includes natural flavoring with a consistent flavor profile, versatility in culinary applications, provides a natural and clean label, and are cost‐effective. Also, the universally recognized and enjoyed flavor of C. sinensis makes its essential oil a popular choice for products with broad consumer appeal. However, it is essential to follow regulatory guidelines for food‐grade essential oils and adhere to recommended usage levels. The results of this study have practical implications for improving yield, quality, efficiency, and sustainability of the extracted essential oil in the food industry. The optimized data can positively impact various aspects of food production, by enhancing flavor profiles, reducing the processing time and costs, and thus facilitating scale‐up potential. In addition, proper storage conditions should be maintained to ensure the stability and quality of the extracted essential oil over time.