Physicochemical characterization and nano-emulsification of three species of pumpkin seed oils with focus on their physical stability

• Published in: Food chemistry 2021-05, Vol.343, p.128512, Article 128512
• Main Authors: Ordoñez Lozada, Maria Isabel, Rodrigues Maldonade, Iriani, Bobrowski Rodrigues, Daniele, Silva Santos, Débora, Ortega Sanchez, Beatriz Alejandra, Narcizo de Souza, Paulo Eduardo, Longo, João Paulo, Bernardo Amaro, Geovani, de Lacerda de Oliveira, Lívia
• Format: Article
• Language: English
• Subjects: Antioxidants - chemistry; Brazil; Carotenoids - analysis; Cucurbita - chemistry; Emulsions - chemistry; Fatty Acids, Unsaturated - analysis; Food Storage; Hydrogen-Ion Concentration; Long-term storage; Low energy emulsification; Nanostructures - chemistry; Oil-in-water nanoemulsions; Oxidation-Reduction; Plant Oils - chemistry; Polyunsaturated fatty acids; Pumpkin seed oil; Seeds - chemistry; Temperature; Tocopherol; Tocopherols - analysis
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.128512

•The physicochemical properties of seed oils from three pumpkin species were assessed.•PSO was different in tocopherol, carotenoids and unsaturated fatty acids contents.•Phase inversion temperature (PIT) method was suitable to fabricate PSO nanoemulsions.•Droplet size of nanomax and nanopepo increased earlier during storage at 25 °C.•As the pH of the medium increased, the values of ζ-potential also increased increasing the stability. We present the chemical composition, quality parameters and antioxidant capacity of pumpkin seed oils (PSO) from Cucurbita pepo, Cucurbita maxima, and Cucurbita moschata cultivated in Brazil. In addition, PSO nanoemulsions (nanopepo, nanomax and nanomosc) were developed and their physical stabilities were assessed under long-term storage at two temperatures. Among the PSO, C. pepo presented the highest contents of polyunsaturated fatty acids, total carotenoids, and chlorophylls, but the lowest oxidative stability. Conversely, C. maxima PSO showed highest oxidative stability and total tocopherol content but the lowest chlorophyll content. Nanomax and nanopepo were more stable to droplet growth at 4 °C, while nanomosc was more stable at 25 °C. Nanopepo was the most stable formulation after the heating–cooling cycles, whereas nanomax was the most stable under centrifugation regardless the temperature. Overall, all nanoemulsions presented droplet diameter lower than 200 nm and ζ-potential approaching −30 mV until the end of storage.