Bactericidal and Antioxidant Activity of Essential Oils from <Emphasis Type="Italic">Myristica fragrans</Emphasis> Houtt and <Emphasis Type="Italic">Salvia microphylla</Emphasis> H.B.K

This study chemically characterizes and evaluates the bactericidal and antioxidant activities of essential oils from Myristica fragrans and Salvia microphylla. The essential oils were obtained by steam distillation and were subsequently subjected to analysis by GC–MS and GC. The agar diffusion test was employed to evaluate the bactericidal activity, while the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and β-carotene/linoleic acid tests were used to determine the antioxidant activity. Terpin-4-ol (14.95%), sabinene (13.07%) and γ-terpinene (11.22%) were found to be the major constituents in the essential oil of M. fragrans by gas chromatography, whereas (E)-caryophyllene (15.35%), α-eudesmol (14.06%), β-eudesmol (8.74%) and γ-eudesmol (7.64%) were encountered in the essential oil of S. microphylla. Both essential oils showed bactericidal activity, with the essential oil of S. microphylla being more efficient. The antioxidant activity of the essential oils from M. fragrans and S. microphylla were demonstrated by the β-carotene/linoleic acid test, with IC₅₀ 976 and IC₅₀ 770 μg/mL, respectively.     

Comparison of Two Analytical Methods for Assessing Antioxidant Capacity of Rapeseed and Olive Oils

The oxygen radical absorbance capacity (ORAC) and the ferric reducing antioxidant power (FRAP) methods were used for the determination of antioxidant capacities (AC) of rapeseed oils at different steps of technological process and olive oils. The mean ORAC and FRAP results obtained for rapeseed oils (1,106–160 and 552–95.6 μmol TE/100 g) were higher than for olive oils (949–123 and 167–32.1 μmol TE/100 g). Although, FRAP values were lower than ORAC values for all studied oils, there is a linear and significant correlation between these two analytical methods (r = 0.9665 and 0.9298, P < 0.0005) for rapeseed and olive oils, respectively). Also, total phenolic compounds in rapeseed oils and olives correlated with antioxidant capacities (correlation coefficient ranged between 0.9470 and 0.8049). The refining process of rapeseed oils decreased the total phenolics content and antioxidant capacities by about 80%.     

Effects of Geographical Origin on the Conjugated Linolenic Acid of <Emphasis Type="Italic">Trichosanthes kirilowii</Emphasis> Maxim Seed Oil

Trichosanthes kirilowii Maxim (T. kirilowii) seeds from four geographical locations (Changxing, Quzhou, Yuexi, Dongzhi) contained 26.15–49.41% oil and 28.68–37.90% protein. The seed oil was distinguished by the conjugated linolenic acids, punicic acid (PA) and α-eleostearic acid (α-ESA). The main fatty acids in T. kirilowii seed oils were ranked in the following order: punicic acid (33.09–39.15%), linolenic acid (33.77–38.66%), oleic acid (15.15–24.88%), palmitic acid (2.36–4.86%). PA was the main isomer of CLNA (33.09–39.15%). No significant differences were found either in PA content or in α-ESA content of T. kirilowii seed from these geographical locations. Little difference was observed in the quantitative composition of the lipid contents of seeds from different geographical locations. The α-tocopherol content of T. kirilowii seed ranged from 6.34 to 31.74 mg/100 g, with the highest levels in Changxing seeds. The present results showed that T. kirilowii seeds were especially rich in PA, and their contents were not influenced by the geographical locations. Variation in some proximate compositions by geographical locations may be caused by ecological conditions, temperature, climate condition, technical and cultural conditions.     

A comparative study of fatty acid profiles of <Emphasis Type="Italic">Passiflora</Emphasis> seed oils from Uganda

A comparative study is presented of the FA composition (FAC) of the seed oils from the yellow passion fruit Passiflora edulis Sims var. flavicarpa (I), the purple fruit Passiflora edulis Sims var. edulis (II), the purple Kawanda hybrid, which is a cross between I and II (III), and the light-yellow apple passion fruit Passiflora maliformis L. (IV) grown in Uganda. Oil yields from the four varieties were between 18.5 and 28.3%. A GC analysis of the oils showed the most dominant FA to be linoleic (67.8–74.3%), oleic (13.6–16.9%), palmitic (8.8–11.0%), stearic (2.2–3.1%), and α-linolenic (0.3–0.4%) acids. The unsaturated FA content in the oils was high (85.4–88.6%). Iodine values of the seed oils of I, II, III, and IV calculated from the FAC were 133, 141, 133, and 138, respectively. The FAC and the iodine value of the seed oil in III are distinctly closer to the rootstock (I) than the scion (II). This indicates that the rootstock influence on the FAC of passion fruit seeds is graft-transmissible. The study further confirms that passion fruit seed oils represent a good source of essential unsaturated FA.     

Effect of Essential Oils from <Emphasis Type="Italic">Lippia geminata</Emphasis> and <Emphasis Type="Italic">Cymbopogon jwarancusa</Emphasis> on In vitro Growth and Sporulation of Two Rice Pathogens

Sheath blight and brown spot disease of rice caused by Rhizoctonia solani and Bipolaris oryzae causes significant yield loss in rice production worldwide. The present study was undertaken to examine the effect of two essential oils (EOs) from Lippia geminata and Cymbopogon jwarancusa on in vitro growth and sporulation of these two pathogens. The fungal radial growth was inhibited at very low concentration (25 ppm) of the EOs. Similarly, fungal spore production was also inhibited up to ≥80% at 500 ppm of EOs. However, fungal sporulation was completely retarded at 1,000 ppm of L. geminata EO. Very low oil concentrations (10 ppm) accelerated the radial growth (0–5 mm) and spore germination (3.5–8.5%) of the pathogens. At higher oil concentrations, the mycelial growth and spore productions were completely inhibited. The IC₅₀ value of the EO of C. jwarancusa was 365.45 and 336.74 ppm and for L. geminata, it was 420.16 and 481.47 ppm against B. oryzae and R. solani, respectively. GC–MS analysis of the oils showed 54.36% piperitone and 30.86% α-phellandrene as major compounds in C. jwarancusa whereas 25.9% geranial and 14.6% neral in L. geminata oil. Essential oils from Lippia geminata and Cymbopogon jwarancusa appear to be good candidates for the in vitro control of these two rice pathogens and can be successfully utilized in management strategies of pathogens in appropriate formulation.     

Effect of natural antioxidants in virgin olive oil on oxidative stability of refined,bleached, and deodorized olive oil

The factors influencing the oxidative stability of different commercial olive oils were evaluated. Comparisons were made of (i) the oxidative stability of commercial olive oils with that of a refined, bleached, and deodorized (RBD) olive oil, and (ii) the antioxidant activity of a mixture of phenolic compounds extracted from virgin olive oil with that of pure compounds andα-tocopherol added to RBD olive oil. The progress of oxidation at 60°C was followed by measuring both the formation (peroxide value, PV) and the decomposition (hexanal and volatiles) of hydroperoxides. The trends in antioxidant activity were different according to whether PV or hexanal were measured. Although the virgin olive oils contained higher levels of phenolic compounds than did the refined and RBD oils, their oxidative stability was significantly decreased by their high initial PV. Phenolic compounds extracted from virgin olive oils increased the oxidative stability of RBD olive oil. On the basis of PV, the phenol extract had the best antioxidant activity at 50 ppm, as gallic acid equivalents, but on the basis of hexanal formation, better antioxidant activity was observed at 100 and 200 ppm.α-Tocopherol behaved as a prooxidant at high concentrations (>250 ppm) on the basis of PV, but was more effective than the other antioxidants in inhibiting hexanal formation in RBD olive oil.o-Diphenols (caffeic acid) and, to a lesser extent, substitutedo-diphenols (ferulic and vanillic acids), showed better antioxidant activity than monophenols (p- ando-coumaric), based on both PV and hexanal formation. This study emphasizes the need to measure at least two oxidation parameters to better evaluate antioxidants and the oxidative stability of olive oils. The antioxidant effectiveness of phenolic compounds in virgin olive oils can be significantly diminished in oils if their initial PV are too high.     

Interprovenance variation in the composition of <Emphasis Type="Italic">Moringa oleifera</Emphasis> oilseeds from Pakistan

Interprovenance variation was examined in the composition of Moringa oleifera oilseeds from Pakistan. The hexane-extracted oil content of M. oleifera seeds harvested in the vicinity of the University of Agriculture, Faisalabad (Punjab, Pakistan), Bahauddin Zakariya University (Multan, Pakistan), and the University of Sindh, Jamshoro (Sindh, Pakistan), ranged from 33.23 to 40.90%. Protein, fiber, moisture, and ash contents were found to be 28.52–34.00, 6.52–7.50, 5.90–7.00, and 6.52–7.50%, respectively. The physical and chemical parameters of the extracted M. oleifera oils were as follows: iodine value, 67.20–71.00; refractive index (40°C), 1.4570–1.4637; density (24°C), 0.9012–0.9052 mg/mL; saponification value, 177.29–184.10; unsaponifiable matter, 0.60–0.83%; color (1-in. cell), 1.00–1.50 R+20.00–30.00Y; smoke point, 198–202°C; and acidity (% as oleic acid), 0.50–0.74. Tocopherols (α, γ, and δ) accounted for 114.50–140.42, 58.05–86.70, and 54.20–75.16 mg/kg, respectively, of the oils. The induction periods (Rancimat, 20 L/h, 120°C) of the crude oils were 9.64–10.66 h and were reduced to 8.29–9.10 h after degumming. Specific extinctions at 232 and 270 nm were 1.80–2.50 and 0.54–1.00, respectively. The major sterol fractions of the oils were campesterol (14.13–17.00%), stigmasterol (15.88–19.00%), β-sitosterol (45.30–53.20%), and ͤ⁵-avenasterol (8.84, 11.05%). The Moringa oils were found to contain high levels of oleic acid (up to 76.00%), followed by palmitic, stearic, behenic, and arachidic acids up to levels of 6.54, 6.00, 7.00, and 4.00%, respectively. Most of the parameters of M. oleifera oils indigenous to different agroclimatic regions of Pakistan were comparable to those of typical Moringa seed oils reported in the literature. The results of the present analytical study, compared with those for different vegetable oils, showed M. oleifera to be a potentially valuable oilseed crop.     

Antioxidant effects of d-tocopherols at different concentrations in oils during microwave heating

The effects of d-tocopherols at different concentrations (50 to 1000 ppm) on the oxidative stability of ethyl linoleate and tocopherol-stripped oils were investigated under microwave heating conditions. Purified substrate oils were prepared by aluminum oxide column chromatography. After the addition of tocopherols (α-, β-, γ- or δ-) to the oils, peroxide, carbonyl andp-anisidine values were measured in the samples after heating in a microwave oven. Further, the residual amount of tocopherol homologues in the oils after heating was determined by high-performance liquid chromatography for evaluation of their effects at different concentrations on oxidative deterioration. Microwave heating resulted in some acceleration in the oxidation of the purified substrate oils. Optimum concentrations of tocopherols required to increase oxidative stability were 100 ppm for α-, 150–200 ppm for β- or γ- and 500 ppm for δ-tocopherol, respectively. The antioxidant effect of tocopherols decreased in the order α>β ≒ γ>δ at each level, in all substrates. Therefore, α-tocopherol was consumed first, followed by β- or γ-tocopherol, and δ-tocopherol was consumed more slowly. The tocopherols had no further significant antioxidant activity (P>0.05) at concentrations higher than 500 ppm.     

Characteristics of Oil from Seeds of 4 Mungbean [<Emphasis Type="Italic">Vigna radiata</Emphasis> (L.) Wilczek] Cultivars Grown in Pakistan

Mungbean is a widely consumed legume globally. This study was carried out for detailed characterization of oils from mungbean seeds from four indigenously cultivated varieties, as very little information is available on the oil composition of mungbean seeds and inter-varietal variation in oil composition. The oil content was relatively low (2.1–2.7%). The investigated physiochemical parameters included refractive indices (RI) at 40 °C (1.4673–1.4698), relative density (0.9580–0.9618), iodine value (IV) (111.4 –117.1), saponification value (SV) (173.1–181.7 mg KOH/g) and unsaponifiable matter (UM) (13.8–15.01%). Phospholipids and triglycerides were the dominant lipid fractions followed by monoglycerides. Linoleic acid and oleic acid were the dominant fatty acids (FA). Characterization was also made by TLC. Tocopherol analysis demonstrated highest content of γ-tocopherol among its isomers, while α-tocotrienol was present in highest amount in all studied cultivars, among its isomers. Results from most of the parameters revealed significant (P ≤ 0.05) differences among the cultivars. The findings of the study reveal mungbean [Vigna radiata (L.) wilczek], to be a potentially valuable legume crop with comparable nutritional quality oil among all the cultivars.     

Physico-Chemical Characteristics of Citrus Seeds and Seed Oils from Pakistan

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 (α, γ, and δ) 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.     

Ultrasonic attenuation of edible oils

The frequency dependence (1–60 MHz) of the ultrasonic attenuation coefficient of canola oil, corn oil, olive oil, peanut oil, safflower oil, soybean oil, and sunflower oil was measured at 25°C. The attenuation coefficient of all the oils could be described by the relation: α ∼ Af ⁿ(with A between 6 and 40 × 10⁻¹², and n between 1.74 and 1.86).     

The up-regulation of hepatic acyl-coA oxidase and cytochrome P<Subscript>450</Subscript> 4A1 mRNA expression by dietary oxidized frying oil is comparable between male and female rats

We previously demonstrated that oxidized frying oil (OFO) activates peroxisome proliferator-activated receptor α (PPARα) and up-regulates hepatic acyl-CoA oxidase (ACO) and cytochrome P₄₅₀ 4A1 (CYP4A1) genes in male rats. As female rats were shown to be less responsive to some peroxisome proliferators (PP), this study compared the expression of a few PPARα target genes in male and female rats fed diets containing OFO. Male and female rats were fed a diet containing 20 g/100 g OFO (O diet) or fresh soybean oil (F diet) for 6 wk. Both male and female rats fed the O diet showed significantly higher liver weight, hepatic ACO and catalase activities, CYP4A protein, and expression of ACO and CYP4A1 mRNA (P<0.05) compared with their control groups. The mRNA expression of two other PPARα target genes, FA-binding protein and HMG-CoA synthase, were marginally increased by dietary OFO (P=0.0669 and 0,0521, respectively). Female rats fed the O diet had significantly lower CYP4A protein than male rats fed the same diet. The remaining OFO-induced effects were not significantly different between male and female rats fed the O diet. These results indicate that dietary OFO, unlike clofibrate or other PP, had minimal sexual dimorphic effect on the induction of hepatic PPARα target gene expression.     

Chemical Composition and Oxidative Stability of Kernel Oils from Two Current Subspecies of Pistacia atlantica in Iran

Pistacia atlantica subsp. mutica (PAM) and kurdica (PAK) kernel oils showed significantly lower unsaturated to saturated fatty acid ratios (6.39, 6.33, respectively) and calculated oxidizability (Cox) values (3.99, 4.13, respectively) than those of the P. vera L. cv. Ohadi (PVO) kernel oil (8.91, 4.41) samples. The highest peroxide value was observed for the PAK oil (4.07 mequiv kg⁻¹) (PAM, 1.94; PVO, 0.37) samples. Iodine values for the PAM, PAK, and PVO oils were 104.26, 104.77, and 110.66, respectively. The saponification number of the PVO oil was significantly greater than the PAM and PAK oils, which were statistically not different. The unsaponifiable contents, which were composed mainly of sterols, ranged from 5.63 to 6.14%. Statistically the total tocopherols contents of the PAM (818.58 mg α-tocopherol kg⁻¹) and PVO (815.90 mg α-tocopherol kg⁻¹) oils were significantly higher than that of the PAK oil (499.91 mg α-tocopherol kg⁻¹). Total phenolics contents differed significantly, the greatest concentration was for the PAM oil (81.12 mg gallic acid kg⁻¹), followed by the PVO (62.84 mg gallic acid kg⁻¹) and PAK (56.51 mg gallic acid kg⁻¹) oil samples. The wax contents of the oil samples were statistically in the same range, namely 5.67–6.48%. Oxidative stability data indicated that the PAM oil is the most resistant to the formation of lipid oxidation products, followed by the PAK and PVO oil samples.     

Evaluation of Lipophilic Antioxidant Efficacy in Vivo by the Biomarkers Hydroxyoctadecadienoic Acid and Isoprostane

The evaluation of antioxidant activity in vivo is difficult. In this study, the effects of dietary natural and synthetic antioxidants on the lipid peroxidation in mice were assessed using a biomarker, total hydroxyoctadecadienoic acid (tHODE). Biological samples such as plasma, erythrocytes, and tissues were first reduced and then saponified to convert various oxidation products of linoleates to tHODE. Subsequently, the absolute concentration of tHODE and its stereoisomer ratio, [9- and 13-(Z,E)-HODE)/[9- and 13-(E,E)-HODE], which is a measure of the hydrogen donor capacity of antioxidants, were determined by gas chromatography–mass spectrometry (GC–MS) analyses. These were then compared with total 8-iso-prostaglandin F_2α (t8-iso-PGF_2α) which was also assessed after reduction and saponification. Remarkable increases in tHODE and t8-iso-PGF_2α levels were observed in the plasma, erythrocytes, liver, and brain of mice that were fed an α-tocopherol (αT)-stripped (E-free) diet for 1 month when compared with those of mice that were fed a standard diet (αT = 0.002 wt%). When mice were fed for 1 month on an E-free diet supplemented with a lipophilic antioxidant (0.04 wt%), namely, αT, α-tocotrienol (αT3), γ-tocopherol (γT), or 2,3-dihydro-5-hydroxy-4,6-di-tert-butyl-2,2-dipentylbenzofuran (BO-653), a potent synthetic antioxidant, the increases of tHODE and t8-iso-PGF_2α in the plasma, erythrocytes, liver, and brain were suppressed to the levels lower than those of mice fed a standard diet. The (Z,E/E,E) HODE ratio was decreased in the plasma and erythrocytes of mice fed the E-free diet when compared with that in mice fed the standard diet. This stereo-isomeric ratio was significantly recovered by the addition of αT and BO-653. These results show that the tHODE level and the (Z,E/E,E) HODE ratio are useful biomarkers for the assessment of antioxidant capacity in vivo and that the antioxidant capacity decreased in the order: BO-653 > αT3 ≧ αT, γT, as assessed by tHODE levels from blood, liver, and brain.     

Characterization of Turkish Virgin Olive Oils Produced from Early Harvest Olives

Olives were collected from various districts of Turkey (North and South Aegean sub-region, Bursa-Akhisar, South East Anatolia region) harvested over seven (2001–2007) seasons. The aim of this study was to characterize the chemical profiles of the oils derived from single variety Turkish olives including Ayvalik, Memecik, Gemlik, Erkence, Nizip Yaglik and Uslu. The olive oils were extracted by super press and three phase centrifugation from early harvest olives. Chosen quality indices included free fatty acid content (FFA), peroxide value (PV) and spectrophotometric characteristics in the ultraviolet (UV) region. According to the FFA results, 46% (11 out of 24 samples) were classified as extra virgin olive oils; whereas using the results of PV and UV, over 83% (over 19 of the 24 samples) had the extra virgin olive oil classification. Other measured parameters included oil stability (oxidative stability, chlorophyll pigment, pheophytin-α), cis–trans fatty acid composition and color index. Oxidative stability among oils differed whereas the cis–trans fatty acid values were within the national and international averages. Through the application of two multivariate statistical methods, Principal component and hierarchical analyses, early harvest virgin olive oil samples were classified according to the geographical locations categorized in terms of fatty acid profiles. Such statistical clustering gave rise to defined groups. These data provide evidence of the variation in virgin olive oil quality, especially early harvest and cis–trans isomers of fatty acid profiles from the diverse agronomic conditions in the olive growing regions of Turkey.     

A Comparative Study of the Properties of Six Sudanese Cucurbit Seeds and Seed Oils

The proximate analysis of seeds and physicochemical properties of oils extracted from six Sudanese cucurbit seeds Cucumis mello var. agrestis, Cucumis melo var. flexuosus, Cucumis sativus, Citrullus lanatus var. colocynthoides, Cucumis prophetarum, and Luffa echinata were examined by established methods. For each variety, the proximate analysis showed ranges for moisture, protein, and carbohydrates as 3.70–6.87, 14.50–17.50, and 15.62–28.89% on a dry matter basis, respectively. The oils were extracted by Soxhlet using petroleum ether, with yields that ranged from 10.9 to 27.10% (wt/wt). The obtained extracted oils were subjected to phyiscochemical, fatty acid, and tocopherol analysis. The physicochemical characterization of the oil revealed that the refractive indices and relative densities of the oils fell within the narrow ranges of 1.334–1.442 and 0.874–0.920 g/cm³, respectively. Unsaponifiable matters ranged between 0.8 and 1.2 mg KOH/g, whilst peroxide values (PV) ranged from 2.3 to 4.1 meq/kg. The ranges of the values for free fatty acid (FFA %) were 1.2–4.0%. The predominant fatty acids were 16:0, 18:0, 18:1, and 18:2 with ranges of 8.9–14.2, 6.0–9.4, 14.6–32.1, and 43.6–65.5%, respectively. γ-Tocopherol was the predominant tocopherol in all samples ranging from 0.8 to 43.2% of the total tocopherols, followed by δ-tocopherol and α-tocopherol.     

Fatty acids of the seeds of <Emphasis Type="Italic">Origanum onites</Emphasis> L. and <Emphasis Type="Italic">O. vulgare</Emphasis> L.

Seed oils of Origanum onites L. from the Antalya and Mugla regions and O. vulgare L. from the Kirklareli region of Turkey were extracted with hexane in a Soxhlet apparatus. The oil yields were 14.1–20.0 and 18.5%, respectively. FA compositions of the seed oils were determined by GC and GC/MS. Twenty FA were identified in both O. onites and O. vulgare seeds. The major FA of both species were linolenic (56.3–57.0%; 61.8%), linoleic (21.5–21.7%; 18.8%), oleic (8.7–8.9%; 5.9%), palmitic (5.9–6.5%; 5.5%), stearic (2.1–2.4%; 2.1%), and (Z)-11-octadecenoic (0.6–0.8%; 0.5%), respectively.     

Analytical characterization of hemp (Cannabis sativa) seed oil from different agro-ecological zones of Pakistan

Cold-pressed oil content of Cannabis sativa (hemp) seeds from three different agro-ecological zones of Pakistan ranged from 26.90 to 31.50%. Protein, fiber, ash, and moisture content were found to be 23.00–26.50, 17.00–20.52, 5.00–7.60, and 5.60–8.50%, respectively. Results of some other physical and chemical parameters of the oil were as follows: iodine value, 154.00–165.00; refractive index (40°C), 1.4698–1.4750; density (24°C), 0.9180–0.9270 mg ml⁻¹; saponification value, 184.00–190.00; unsaponifiable matter, 0.70–1.25%; and color (1-in cell), 0.50–0.80 R+27.00–32.00 Y. The induction period (Rancimat, 20 L h⁻¹, 120°C) of the nondegummed and degummed oils ranged from 1.35 to 1.72 h and from 1.20 to 1.49 h, respectively. Specific extinctions at 232 and 270 nm were 3.50–4.18 and 0.95–1.43, respectively. The hemp oils investigated were found to contain high levels of linoleic acid, 56.50–60.50%, followed by α-linolenic, oleic, palmitic, stearic, and γ-linolenic acids: 16.85–20.00, 10.17–14.03, 5.75–8.27, 2.19–2.79, and 0.63–1.65%, respectively. Tocopherols (α, γ, and δ) in the nondegummed oils were found to be 54.02–60.40, 600.00–745.00, 35.00–45.60, respectively, and were reduced to 29.90–50.00, 590.00–640.00, and 30.40–39.50 mg kg⁻¹, respectively, after degumming. The results of the present analytical study, compared with those found in the typical literature on hempseed oils, showed C. sativa indigenous to Pakistan to be a potentially valuable nonconventional oilseed crop of comparable quality.     

Effects of tocopherols, ascorbyl palmitate, and lecithin on autoxidation of fish oil

The effects of α-, γ/δ, and δ-tocopherol concentrates (0.2–2.0%) alone and in combination with ascorbyl palmitate (0.1%) and lecithin (0.5%) on oxidative stability and flavor of fish oil were studied. Stability was assessed on oil stored in air at 20°C by peroxide value (PV) and off-flavor formation. Polymer content, para-anisidine value, and conjugation were used to characterize selected samples. When used alone, the protective effect of the tocopherols, as measured by PV, was δ≫γ/δ≫α, especially at the 2% concentration. Binary systems of ascorbyl palmitate-lecithin and lecithin-γ/δ or-δ-tocopherol were strongly synergistic in delaying peroxidation. The ternary blends provided the greatest protection against autoxidation. Refined fish oil with 2% δ-tocopherol, 0.1% ascorbyl palmitate, and 0.5% lecithin showed no significant peroxidation at 20°C over a period of 6 mon. The original antioxidant effect noted for the ternary systems in delaying peroxidation was not reflected in improved flavor stability. Off-flavors developed within 3 wk, making the oils unsuitable for use at high concentrations in ambient products that are unprotected from air.     

Characterization and compositional studies of the oils from some legume cultivars, <Emphasis Type="Italic">Phaseolus vulgaris</Emphasis>, grown in Southern Africa

Seed oils from six legume cultivars of Phaseolus vulgaris, grown in the Kingdom of Lesotho, were extracted and their physicochemical properties and FA compositions were determined in order to compare their dietary lipids with those in P. vulgaris cultivars grown in other parts of the world. The oil content of the beans was very low, ranging from 1.5 to 2.0% (w/w). The acid values ranged from 11.0 to 19.2 mg KOH/g, whereas a combination of the PV and the p-anisidine values in Holm's equation gave oxidation values that ranged from 11.0 to 15.0. Thus, considerable enzymatic hydrolysis and oxidation had taken place in the beans during storage. Iodine values ranged from 80.5 to 92.3 (Wijs method), indicating moderate unsaturation in the oils. However, capillary GC analysis, supported by proton NMR analysis of the FAME, gave a total unsaturation range from 79.67 to 84.24%. The dominant FA were α-linolenic acid (36.47–48.81%) and linoleic acid (20.96–36.10%), with appreciable amounts of palmitic acid (14.33–18.23%). This FA composition pattern is quite similar to the FA distribution reported for low oil-bearing legume seeds. Thus, notwithstanding the different climatic and soil conditions, the general properties of lipids in the southern African legume cultivars were quite similar to those of lipids in P. vulgaris cultivars grown in other parts of the world. The high content of α-linolenic acid in the cultivars of P. vulgaris could very likely play a beneficial role in reducing the risk of coronary heart disease among the large populations consuming them in the southern African region.