Oil extraction from seeds of ligustrum vulgare and evaluation of its qualitative properties during storage.

Abstract

Abstract Background: Fats and oils are one of the main ingredients in the food formulation. Oils stability is one of the main parameters in the evaluation of their quality. Today, attention to the use of vegetable oils has increased due to its potential health benefits and high oxidative stability. Privet has widely been used as an edible herb and stuffing as well as a traditional medicine as it contains biologically beneficial compounds, which have anti-inflammatory, antidiabetic, antioxidant and pro-apoptotic activities. Although privet includes numerous uses in cosmetics and conventional medicine, information on its fatty acids (FA), and antioxidant activities have not been investigated. In this study we tried to identify privet oil and analyze the effects of storage on their physicochemical characteristics and contents of fatty acids, phytosterols, phenolics and tocopherols extracted from cold-press seeds. Materials and Methods: After preparing the oil seeds pulp and seed were separated. Oil was extracted from the pulp and seeds of privet (Ligustrum vulgare L.) fruits using cold pressing and solvent extraction methods. Privet pulp oil extracted using a solvent analysis was only carried on the initial extraction sample and the privet seed oil extracted using cold-press method was stored at room temperature (25°C) for 3 months and its quality characteristics (acid value, peroxide value, fatty acid content, oxidative stability by rancimet test and Schaal test, total phenolic compounds, phytosterol and tocopherol content) were evaluated.

Results & Conclusion: The results obtained from this study showed that privet pulp had a low oil content (2.6 %); however, the seed had a higher oil content (10 %). The main fatty acids for the oil samples were oleic acid, linoleic acid and palmitic acid in order of prominence. Also, seed and pulp oil had suitable oxidative stability, 8.04 and 9.78h, respectively. The results of 90 days of oil storage showed that increasing the storage time increased the acid and peroxide values, phenolic compounds and γ- tocopherol and decreased chlorophyll and carotenoid contents and alpha tocopherol. Also, storage of ligustrum vulgare oil had no overall effect on fatty acids and phytosterol levels. Ligustrum vulgare oil containing high levels of bioactive components such as phenolic compounds, tocopherols and phytosterols. In conclusion, the seeds of privet, due to their higher oil content, good stability and high levels of bioactive components, can be recommended as a new vegetable oil source for use in human foods.

Keywords: ligustrum vulgare, Seed oil, Fatty acids, Cold-press, Tocopherols, Storage