Physico-chemical Attributes of Fruit Seed Oils from Different Varieties of Peach and Plum

Abstract

The fruit seed kernel oils from different varieties of locally harvested peach and plum were evaluated for their physicochemical properties, and composition of fatty acids, tocopherols and phytosterols. The contents of protein, fiber, and ash for peach and plum whole seed basis were noted to be 21.0-23.3, 11.2-13.7; 6.9-9.9, 5.6-6.4 and 3.3-4.9, 2.3-3.0%, respectively. The oil content in the seed kernels ranged from 30.5-41.0% for peach and 25.5-29.8% for plum. The extracted peach and plum kernel oils (KO) had an average iodine value (g of I/100 g of oil) of 82.5-96.4, 99.5-102.1; density (at 24 °C) 0.87-0.92, 0.80-0.83 mg/mL; refractive index (40 °C) 1.4440-1.4490, 1.4400-1.4430; saponification value 181.1-187.4, 149.1-160.9 mg of KOH/g oil; unsaponifiable matter 0.78-0.89, 0.90-0.94%; free fatty acid (% oleic acid) 0.4-0.9, 0.8-1.0%, respectively. The values for specific extinctions at 232 and 268 nm of the peach and plum KO were found to be 1.3-1.4, 0.7-0.9 and 1.7-2.1, 0.8-0.9 whereas the peroxide value 0.7-1.3 and 1.1-1.2 meq O2/kg, respectively. The major fatty acid detected in both of the peach and plum KO was noted to be oleic acid with contribution of 59.8-64.5% and 63.5-66.7% followed by linoleic 28.0-32.8% and 24.4-26.4%, respectively. The contents of total tocopherols in plum and peach KO ranged from 409-458 and 360-386 mg/kg, respectively, with α tocopherol predominating in peach and δ tocopherol in plum. β-Sitosterol (78.8-84.9%) and ∆5-avenasterol (5.0-12.2%) were the main phytosterols in peach and plum KO. The results of this study revealed that these seeds could be explored as a potential source of high-oleic oils for the local oil and fat industry