Optimized ultrasonic‐assisted extraction of papaya seed oil from Hainan/Eksotika variety

Abstract

Hainan/Eksotika papaya is a popular cultivated plant in Hainan Island, China. Papaya seed oil (PSO) contains functional compounds with good antioxidant activity, especially monounsaturated fatty acids. In this work, the ultrasound‐assisted extraction (UAE) of PSO was optimized using response surface methodology. It was found that the optimal extraction performance was realized when the elevated time was set to 20 min, the ultrasound power was set to 250 W, and the n‐hexane‐to‐sample ratio was set to 16:1 (v/w). The highest yield of PSO (32.27%) was obtained under the optimal conditions, and PSO showed good oxidative stability. Differential scanning calorimetry analysis showed that the melting point of Hainan/Eksotika PSO was low, while its crystallization temperature was high. FTIR and NMR were used to analyze the chemical structure of PSO, which also proved that PSO possessed good stability without oxidative degradation. In addition, scanning electron micrograph was employed to investigate the change in seed microscopic structure. The results showed UAE caused serious structural damage of sample cell membranes and walls, which help oil access to the solvent with a high extraction ratio. The results indicated that UAE is an efficient environmental‐friendly, and promising technique could be applied to produce PSO or other edible oil with a better health‐beneficial value in food industry.

An overview of papaya seed oil extraction methods

“…Besides, Zhang et al () also measured the efficiency of UASE of papaya seed oil using an ultrasonic water bath. To achieve the best extraction conditions, UASE parameters were optimised using a Box–Behnken experimental design.…”

“…Extraction of papaya seed oil using different polarity of solvents (acetone, ethanol, ethyl acetate and hexane) was performed by Lee et al (2011). In this study, the polarity Zhang et al (2018Zhang et al ( , 2019 of the solvents followed the order of ethanol>ace-tone> ethyl acetate>hexane. They soaked the seed powder with the solvent for 1 week, followed by oil recovery using evaporation.…”

“…Carotenoids are a group of natural plant pigments familiar to all through the orange, red and yellow colours of fruits and vegetables. Previously, the colour of papaya seed oil has been reported to be golden yellow or reddish yellow (Zhang et al, 2019), indicating the presence of carotenoid compounds. By using HPLC, two carotenoid compounds, namely, b-cryptoxanthin (4.29 mg kg À1 ) and b-carotene (2.76 mg kg À1 ) were identified (Malacrida et al, 2011).…”

“…The shape of papaya fruit varies from oval to elongated and usually weighing 500-1000 g (Adesuyi & Ipinmoroti, 2011). The seeds in papaya fruit, accounting for approximately 20% of the total fresh weight, contain high-lipid and high-protein contents (Zhang et al, 2019). Most of the papaya seeds are discarded as an agricultural waste during the fruit processing despite being edible.…”

Potencial Do Nabo Forrageiro Para Biodiesel: Extração Do Óleo E Produção De Ésteres

“…O rendimento em óleo máximo obtido por EAU foi de ~53% em apenas 26 min de extração, o qual foi 10% maior comparado a extração Soxhlet realizada em 11 h de processo. A mesma comparação foi realizada por Zhang et al (2019) para o óleo das sementes de mamão, o que resultou em rendimentos em óleo de ~32% e 25% para a EUA e Soxhlet, respectivamente. Além disso, o óleo das sementes de mamão obtido pela EAU apresentou boa estabilidade oxidativa…”