Microwave-assisted aqueous enzymatic extraction of oil from pumpkin seeds and evaluation of its physicochemical properties, fatty acid compositions and antioxidant activities

• Published in: Food chemistry 2014-03, Vol.147, p.17-24
• Main Authors: Jiao, Jiao, Li, Zhu-Gang, Gai, Qing-Yan, Li, Xiao-Juan, Wei, Fu-Yao, Fu, Yu-Jie, Ma, Wei
• Format: Article
• Language: English
• Subjects: Antioxidant activities; Antioxidants - chemistry; Antioxidants - isolation & purification; Biological and medical sciences; Cellulase - chemistry; Cucurbita - chemistry; Fatty acid compositions; Fatty Acids - chemistry; Fatty Acids - isolation & purification; Food toxicology; Liquid-Liquid Extraction - instrumentation; Liquid-Liquid Extraction - methods; Medical sciences; Microwave-assisted aqueous enzymatic extraction; Microwaves; Physicochemical properties; Plant Oils - chemistry; Plant Oils - isolation & purification; Polygalacturonase - chemistry; Pumpkin (Cucurbita maxima) seed oil; Seeds - chemistry; Toxicology
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2013.09.079

•A green MAAEE method is performed for the extraction of oil from pumpkin seeds.•MAAEE process with enzyme cocktail is optimised by response surface methodology.•MAAEE-oil reveals similar physicochemical properties with Soxhlet extraction-oil.•MAAEE-oil has higher contents of valuable PUFA, tocopherols and phenolics.•MAAEE-oil shows stronger antioxidant activities than Soxhlet extraction-oil. Microwave-assisted aqueous enzymatic extraction (MAAEE) of pumpkin seed oil was performed in this study. An enzyme cocktail comprised of cellulase, pectinase and proteinase (w/w/w) was found to be the most effective in releasing oils. The highest oil recovery of 64.17% was achieved under optimal conditions of enzyme concentration (1.4%, w/w), temperature (44°C), time (66min) and irradiation power (419W). Moreover, there were no significant variations in physicochemical properties of MAAEE-extracted oil (MAAEEO) and Soxhlet-extracted oil (SEO), but MAAEEO exhibited better oxidation stability. Additionally, MAAEEO had a higher content of linoleic acid (57.33%) than SEO (53.72%), and it showed stronger antioxidant activities with the IC50 values 123.93 and 152.84, mg/mL, according to DPPH radical scavenging assay and β-carotene/linoleic acid bleaching test. SEM results illustrated the destruction of cell walls and membranes by MAAEE. MAAEE is, therefore, a promising and environmental-friendly technique for oil extraction in the food industry.