The Pretreatment of the Seeds Affects the Quality and Physicochemical Characteristics of Watermelon Oil and Its By-Products


OK S. , YILMAZ E.

JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY, cilt.96, ss.453-466, 2019 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 96 Konu: 4
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1002/aocs.12191
  • Dergi Adı: JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
  • Sayfa Sayıları: ss.453-466

Özet

The aims of this study were to produce cold-pressed oils from watermelon seeds, which were previously treated with seed boiling and roasting, and to characterize the oils and press cakes. The watermelon seeds were found as rich sources of protein, oil, and minerals. Seed boiling pretreatment resulted in a higher oil recovery (51.31%) than seed preroasting (44.21%). Seed pretreatments did not cause any difference in the fatty acid (FA), sterol, and tocopherol compositions. Linoleic acid (LNA) was the major FA (54.57 and 54.62%) with higher contents of total unsaturated (74.41 and 75.52%) FA. beta-Sitosterol (202.79 mg/100 g oil and 202.90 mg/100 g oil) and gamma-tocopherol (361.45 mg kg(-1) oil and 365.98 mg kg(-1) oil) were the major components. The oils started to crystallize at around 1.80 and 1.75 degrees C, and completely crystallized oils melted at around -35.66 and -35.78 degrees C, respectively. Seed boiling pretreatment reduced the quantity of the most phenolic compounds in the oil (51.54 and 22.74 mg kg(-1) total phenolics). The oxidative induction times of the oils were 11.91 and 11.49 min. In these cold-pressed oils, volatile compounds associated with roasted/nutty and vegetable/herbal aroma descriptions were predominantly detected. Sensory descriptive analysis indicated that the oils are poor in terms of different sensory terms. Consumer tests showed that these oils are acceptable for direct consumption. Hence, this raw material could be used to produce edible oils.