Variability of the chemical compositions of fatty acids, tocopherols and lipids antioxidant activities, obtained from the leaves of Pistacia lentiscus L. growing in Algeria

Abstract

BACKGROUND: One of the objectives of food industry is to seek new resources of oil that preferably presents nutritional values. For human health, fats and particularly vegetable oils are considered as an important source of energy when glucose is not available. In addition, the search for effective, natural compounds with antioxidant activity has been intensified in recent years to replace the synthetic products. OBJECTIVE: The aim of the present work was to determine the fatty acids profile (and variability) of the lipid fractions extracted from five different populations of the leaves of Pistacia lentiscus L. growing in Algeria. In addition, the antioxidant activities of the lipidic fractions were also determined. METHODS: The chemical compositions of tocopherols were also analyzed by HPLC for the first time for this plant part. The chemical percentage variability (presence of two main distinguished clusters) of the fatty acids was discussed using statistical analysis methods (Agglomerative Hierarchical Clustering “AHC” and principal component analysis “PCA”). The antioxidant activity of the dewaxed lipid fractions were investigated in vitro using two different assays: DPPH (1,1-diphenyl, 2-picrylhydrazyl) free radicals scavenging activity and β-carotene bleaching test. RESULTS: For the overall samples, the main saturated fatty acids components were capric acid (C10:0 = 2.49–13.88%), myristic acid (C14:0 = 4.71–9.12%) and palmitic acid (C16:0 = 5.31–9.03%). Alternatively, the main unsaturated fatty acids were oleic acid (C18:1w9 = 3.42–4.85%), linoleic acid (C18:2w6 = 10.94–16.99%) and most importantly α-linolenic acid (C18:3w3 = 20.92–48.92%), which is known for its multiple dietary, pharmaceutical and clinical benefits. CONCLUSION: The results of fatty acids methyl esters identification using GC and GC-MS showed a clear variability in the composition of fatty acids. The main result of this study illustrate the nutritional potential (richness in MUFA such as C18:1w9, presence of essential fatty acids such as C18:2w6 at all the stages of maturation, richness in omega-3 fatty acids such as C18:3w3. of the oil of P. lentiscus leaves, which can provide opportunities for rational exploitation for medicinal purposes and in the food industries. Regarding tocopherols HPLC analysis, the samples were rich in α-tocopherol (58.51–89.17% of the total tocopherols identified). Finally, and for antioxidant activity measured by β-carotene assay, the obtained values suggested good antioxidant activities when compared with antioxidants of reference.