Evaluation of chitosan-coated liposome drying methods using freeze-drying, vacuum microwave drying, and spray drying: Physicochemical properties, energy efficiency, and CO2 emissions

Developing innovative foods that offer health benefits is a top priority for the food industry. Consumers are showing increasing interest in foods that promote health and contribute to the prevention of chronic non-communicable diseases such as obesity, diabetes, and cancer (Banu & Lunghar, 2023; Misra et al., 2021). Polyphenols are plant metabolites with recognized antioxidant, anti-inflammatory, cardioprotective, antimicrobial, neuroprotective, and immune-modulating activities (Bolat et al., 2024). However, their direct application in food matrices is limited due to their instability in the presence of factors such as light, oxygen, temperature, and pH (Kasapoğlu, Gültekin-Özgüven, et al., 2024). Encapsulation has emerged as an effective strategy to improve the stability, bioaccessibility, and protection of polyphenols (Esposto et al., 2021). Among encapsulation systems, liposomes stand out for their biocompatibility, their ability to incorporate hydrophilic and lipophilic compounds, and their potential to improve cellular absorption associated with cellular biocompatibility (Mohammadi et al., 2021; Nsairat et al., 2022). These phospholipid vesicles offer advantages such as high cargo capacity and control over the release of the active ingredient (Jara-Quijada et al., 2022; Joy et al., 2023), which has driven their incorporation into various food matrices, including chocolate (Gültekin-Özgüven et al., 2016), yogurt (Akgün et al., 2020; Ghorbanzade et al., 2017), mayonnaise (Savaghebi et al., 2021), and fruit juices (Ang et al., 2024, Ang et al., 2024; Jara-Quijada et al., 2025). However, their stability in aqueous suspension is limited, which hinders their storage and industrial use. Therefore, transforming liposomes into powders through drying processes has become a key step to extending their shelf life and facilitating their incorporation into food without compromising their functionality (Kasapoğlu, Sus, et al., 2024). Among the most used techniques are freeze-drying (FD) and spray-drying (SD). FD allows for the preservation of the structural integrity and biological activity of heat-sensitive compounds (Kandasamy & Naveen, 2022; Ma et al., 2022; Zhang et al., 2022), while SD offers industrial advantages due to its low operating cost, reproducibility, and production of stable powders with low moisture content (Ang et al., 2024a, 2024b; Banožić et al., 2023; Chen et al., 2020; Kasapoğlu, Sus, et al., 2024). Vacuum microwave drying (VMD) has emerged as a fast and efficient alternative that combines volumetric heating and low pressures, reducing oxidation and preserving sensory qualities (González-Cavieres et al., 2021). However, their application in liposomes is still nonexistent. The evaluation of these technologies must consider sustainability criteria, aligning with the Sustainable Development Goals through the efficient use of energy and the reduction of carbon emissions (Alara & Abdurahman, 2019). Quantifying energy consumption and carbon footprint has become a key tool for comparing technological alternatives in the food industry (Jara-Quijada, Pérez-Won, Tabilo-Munizaga, González-Cavieres, et al., 2024; Vega et al., 2021). However, no studies simultaneously compare powder quality, energy efficiency, and emissions associated with FD, SD, and VMD applied to liposomes. Therefore, this study aims to evaluate the quality of liposomal powders obtained through different drying methods, analyzing their physicochemical properties, energy efficiency, and carbon emissions, to identify viable and sustainable technological alternatives for the production of liposome-based functional ingredients.