The physico-chemical characteristics of the seeds and seed oils of four citrus species, Mitha (Citrus limetta), Grapefruit (Citrus paradisi), Mussami (Citrus sinensis), and Kinnow (Citrus reticulata) were investigated. The hexane-extracted oil content of citrus seeds ranged from 27.0 to 36.5%. The protein, fiber and ash contents were found to be 3.9-9.6%, 5.0-8.5%, and 4.6-5.6%, respectively. The extracted oils exhibited an iodine value of 99.9-110.0; refractive index (40°C), 1.4639-1.4670; density (24°C), 0.920-0.941 mg/mL; saponification value, 180.9-198.9; unsaponifiable matter, 0.3-0.5%; acid value (mg KOH/g of oil), 0.5-2.2 and color (1-in. cell) 1.4-3.0R + 15.0-30.0Y. The oils revealed a good oxidative stability as indicated by the determinations of specific extinctions at 232 and 270 nm (2.3-4.4 and 0.6-0.9, respectively), p-anisidine value (2.2-3.2) and peroxide value (1.6-2.4 mequiv/kg of oil). The citrus seed oils mainly consisted of linoleic acid (36.1-39.8%). Other prominent fatty acids were palmitic acid (25.8-32.2%), oleic acid (21.9-24.1%), linolenic acid (3.4-4.4%), and stearic acid (2.8-4.4%). The contents of tocopherols (a, c, and d) in the oil were 26.4-557.8, 27.7-84.1, and 9.1-20.0 mg/kg, respectively. The results of the present study demonstrated that the seeds of citrus species investigated are a potential source of valuable oil which might be utilized for edible and other industrial applications.

The present investigation was carried out to appraise the levels of total phenols and vitamin C as well as antioxidant potential at three different ripening stages (un-ripe, semi-ripe and fully-ripe) of guava (Psidium guajava L.) fruit collected from three different geographical regions of Pakistan (Islamabad, Faisalabad and Bhakkar). The antioxidant potential of guava fruit extracts was assessed by means of different in-vitro antioxidant assays, namely inhibition of peroxidation in linoleic acid system, reducing power and radical scavenging capability. Overall, fruit at the un-ripe stage (G1) exhibited the highest levels of TPC, TFC, reducing power and DPPH radical scavenging activity, followed by the semi-ripe (G2) and fully-ripe (G3) stages. On the other hand, vitamin C content increased as the fruit maturity progressed, with highest value seen at the fully-ripe stage (G3) followed by the semi-ripe (G2) and un-ripe stage (G1). The concentration of vitamin C

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This study focuses on the evaluation of antioxidant activity, phenolic and flavonoids contents of selected flaxseed cultivars, native to Pakistan. Antioxidant activities were determined using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, ferric ion reducing ability and inhibition of linoleic acid peroxidation (LAP). Total phenolic content (TPC) was determined using Folin-Ciocalteu reagent, whereas colorimetric method was used to assess total flavonoids (TF). The TPC, TF, DPPH˚ scavenging activity and LAP were 2560 to 3286 mg gallic acid equivalent (GAE)/100 g, 232.53 to 346.67 mg catechin equivalent (CE)/100g and 63.08 to 86.58%, 65.59 to 84.25%, respectively. Results of the present study revealed that flaxseed cultivars possess varying degree of antioxidant capacity and therefore may be considered as a potent source of natural antioxidants.