Mohamed Fawzy Ramadan

Oil cactus pear (Opuntia ficus-indica L.)

Seeds and pulp of cactus pear (Opuntia ficus-indica L.) were compared in terms of fatty acids, lipid classes, sterols, fat-soluble vitamins and b-carotene. Total lipids (TL) in lyophilised seeds and pulp were 98.8 (dry weight) and 8.70 g/kg, respectively. High amounts of neutral lipids were found (87.0% of TL) in seed oil, while glycolipids and phospholipids occurred at high levels in pulp oil (52.9% of TL). In both oils, linoleic acid was the dominating fatty acid, followed by palmitic and oleic acids, respectively. Trienes, g-and a-linolenic acids, were estimated in higher amounts in pulp oil, while a-linolenic acid was only detected at low levels in seed oil. Neutral lipids were characterised by higher unsaturation ratios, while saturates were higher levels in polar lipids. The sterol marker, b-sitosterol, accounted for 72% and 49% of the total sterol content in seed and pulp oils, respectively. Vitamin E level was higher in the pulp oil than in the seed oil, whereas g-tocopherol was the predominant component in seed oil and d-tocopherol was the main constituent in pulp oil. b-Carotene was also higher in pulp oil than in seed oil. Oils under investigation resembled each other in the level of vitamin K1 (0.05% of TL). Information provided by the present work is of importance for further chemical investigation of cactus pear oil and industrial utilisation of the fruit as a raw material of oils and functional foods. # 2003 Elsevier Science Ltd. All rights reserved.

Recovered lipids from prickly pear [Opuntia ficus-indica (L.) Mill] peel: a good source of polyunsaturated fatty acids, natural antioxidant vitamins and sterols

Abstract Compositions and concentrations of fatty acids, lipid classes, sterols, fat-soluble vitamins and β-carotene were determined in extracted lipids from prickly pear [ Opuntia ficus-indica (L.) Mill] peel. Total lipids (TL) recovered were found to be 36.8 g kg −1 (on dry weight basis). The level of neutral lipids was the highest, followed by glycolipids and phospholipids, respectively. Among the TL, linoleic acid was the dominating fatty acid, while oleic and palmitic acids were estimated to be in relatively equal amounts. Compared with the neutral lipids, the polar fractions were generally characterised by higher percentages of saturated fatty acids and lower percentages of unsaturated fatty acids in all subclasses. Concerning trienes, γ-linolenic acid was present at 8.60% of TL, while α-linolenic acid was present at 0.69%. Recovered lipids were characterised by a high percentage of unsaponifiables (12.8% TL) and found to be a rich source of vitamin E and sterols. Free sterols accounted for ca. 29% of the total unsaponifiables, wherein β-sitosterol and campesterol were the major sterols. In terms of vitamin E, α-tocopherol constitutes about 80.0% of total vitamin E present, the rest being β-, γ- and δ-tocopherols in decreasing order. Moreover, lipids under investigation were characterised by a high levels of β-carotene and vitamin K 1 . The information obtained in the present investigation is useful for characterising lipid of prickly pear peel and further chemical and nutritional investigations of prickly pear peel. The results are also important for industrial utilisation of the major by-product of the fruit.

Analysis of glycolipids from black cumin (Nigella sativa L.), coriander (Coriandrum sativum L.) and niger (Guizotia abyssinica Cass.) oilseeds

Abstract Edible plant glycolipids (GL) are anticipated to play a role in human nutrition. Total glycolipids (TGL) were separated from black cumin (Nigella sativa L.), coriander (Coriandrum sativum L.) and niger (Guizotia abyssinica Cass.) seed oils by silica gel chromatography. Different GL subclasses were then identified and separated using high-performance liquid chromatography with ultraviolet adsorption (HPLC/UV). Separation was accomplished using Zorbax-Sil (5 μm) column with an isocratic elution by mixed solvents of isooctane/2-propanol (1:1, v/v) and detection at 206 nm. Methods are described for the analysis of GL constituents, sugar and sterols (ST), using gas–liquid chromatography equipped with flame ionization detector (GLC/FID). A relatively high level of TGL was found in all studied oilseeds. Six GL subclasses were detected in black cumin seed oil, wherein diglucosyldiacylglycerol (DGD) was the prevalent component, followed by glucocerebroside (CER). Among the TGL from coriander and niger oilseeds, acylated steryl glucoside (ASG), steryl glucoside (SG) and CER were detected. The fatty acid profiles of GL fractions from black cumin and niger seed oils was generally similar, wherein linoleic acid C18:2n-6 was the dominating fatty acid, followed by oleic acid C18:1n-9. Petroselinic acid C18:1n-12 was the fatty acid marker in GL subclasses obtained from coriander seed oil, followed by linoleic acid C18:2n-6. Four ST moieties were identified in black cumin and coriander SG and ASG fractions, while the fractions from niger oilseeds showed only three distinct ST peaks. As component sugar, glucose was the only sugar detected in all samples.

Characterization of phospholipid composition of black cumin (Nigella sativa L.) seed oil

Black cumin (Nigella sativa L.) seed oil was extracted with two different solvents, n-hexane (H) and a mixture of chloroform/methanol (CM) (2:1, by volume). Amount of total lipid (TL) was higher in the CM miscelle (39.2% of seed fresh weight) than in the H extract (37.9%). Chemical characteristics as well as fatty acid profile of the TL extracts were compared and the analysis revealed that the major fatty acid was linoleic acid C18:2n-6 (ca. 57% of total fatty acid methyl esters (FAME)) followed by oleic acid C18:1n-9. Palmitic acid C16:0 was the major saturated fatty acid and detected in appreciable level. Chromatography on a silica column with solvent of increasing polarity yielded 96.1-97.2% neutral lipids (NL) and ca. 3% of polar lipids. Gas liquid chromatography with flame ionization detector (GLC/FID) showed that the major fatty acid present in all lipid classes was C18:2n-6 followed by C18:1n-9 and C16:0 acids, respectively. Phospholipid (PL) classes were separated via normal-phase HPLC. Separation was achieved on a silica column by gradient elution from isooctane/2-propanol (6:8, by volume) to isooctane/2-propanol/water (6:8:0.6, by volume) lasting 35 min with UV detection at 205 nm. The major individual PL classes were found to be phosphatidylcholine (PC; ca. 46-48% of total PL) followed by phosphatidylethanolamine (PE), phosphatidylserine (PS) and phosphatidylinositol (PI), respectively. Phosphatidylglycerol (PG), lysophosphatidylethanolamine (LPE) and lysophosphatidylcholine (LPC) were isolated in smaller quantities. The level of saturated fatty acids, namely palmitic C16:0 and stearic C18:0 acids, was considerably higher in PL classes than in the corresponding triacylglycerols. Characterization of PL profile from Nigella sativa L. seed oil as well as the development of new source of PL was the primary aim of this study.

Physicochemical Properties of Different Types of Starch Phosphate Monoesters

Different types of starch were phosphorylated to different degrees of substitution using monosodium and disodium hydrogen orthophosphate at 160 °C under vacuum. Generally, phosphation enhanced the physicochemical properties of the modified starches compared to their native counterparts. Solubility and swelling power greatly increase when phosphorylation was carried out to a low degree of substitution, while the solubility and swelling power decreased gradually by increasing the degree of substitution. However, the values of the monoesters were still higher than those of the corresponding native polysaccharides. Viscosities of different starch types except corn amylose showed the highest values at the lowest degree of substitution, when the degree of phosphation increased the viscosity values decreased. Native potato starch formed a clear paste (96% transmittance) due to the presence of phosphate groups while the paste clarity of potato starch decreased gradually by increasing the degree of phosphation. Generally, phosphorylation increased the light transmittance of the other starches investigated at the lowest degree of substitution but the clarity decreased by increasing the degree of substitution.

Antiradical and antimicrobial properties of cold-pressed black cumin and cumin oils

Cold-pressed black cumin seed oil (BCSO) and cumin seed oil (CSO) were evaluated for their fatty acid profiles, phytosterol and tocopherol contents, antiradical properties and inhibition of microbial growth. The main fatty acids in BCSO were linoleic followed by oleic and palmitic acids. Petroselinic acid (C18:1n-12) was the main fatty acid in CSO, while linoleic acid was the second major unsaturated acid. Six sterol compounds were measured in BCSO and CSO, wherein the sterol marker was β-sitosterol. α-Tocopherol constituted 45% of tocopherols in BCSO, while β-tocopherol was the main component in CSO. BCSO and CSO oils had higher antiradical action against DPPH· and galvinoxyl radicals than virgin olive oil. Antimicrobial properties of BCSO and CSO were studied, and the results revealed that CSO inhibited the growth of all microorganisms tested, while BCSO inhibited the growth of all microorganisms tested except A. niger and A. flavus. BCSO and CSO had a drastic effect on the biosynthesis of protein and lipids in cells of B. subtilis.

Degradability of different phosphorylated starches and thermoplastic films prepared from corn starch phosphomonoesters

Different starch types (corn, rice, potato, corn amylose and corn amylopectin) were phosphorylated to varying degrees of substitution (DS) and tested both for acid hydrolysis during 3 h in a boiling bath and for enzymatic hydrolysis with a thermostable bacterial α-amylase (Bacillus licheniformis) for 30 min at 95 °C. Generally, phosphorylated starches showed a reduced degree of acid hydrolysis during the entire time of hydrolysis (3 h) as well as reduced susceptibility to α-amyIase hydrolysis. The enzyme action was inhibited by the presence of phosphate groups in the modified starch molecules and the extent of inhibition increased with increasing degree of phosphate substitution, regardless of the starch type. Thermoplastic films were fabricated by blending modified corn starches of different DS with polyacrylate, urea and water at a ratio of 4:5:1:50, heating for 30 min at 95 °C before casting and allowing to cool, stand and dry at room temperature. The plastic films prepared from phosphorylated corn starch showed both higher disintegration rate and a greater degradability by thermostable bacterial α-amylase than the ones prepared from non-phosphorylated starch. These new acquired properties can meet the increasing demand for biodegradable disposable plastic bags.

Effect of genotype, environment, and their interaction on phytochemical compositions and antioxidant properties of soft winter wheat flour

The effect of genotype (G), growing environment (E), and their interaction (G×E) on the antioxidant properties and chemical compositions were investigated using the flour samples of 10 wheat varieties grown in four different locations in Maryland. Lutein content of wheat flour ranged from 0.10 to 0.69 μg/g, and α-tocopherol ranged from 0.12 to 0.83 μg/g. Total carotenoids were primarily affected by E (45.7%), while G×E interaction had a larger effect on the level of total tocopherols (71.6%). E had the largest effect on antioxidant activity against oxygen, hydroxyl, and ABTS(·+) radicals. G had the least influence on the measured phytochemicals and antioxidant activity assays. Total carotenoids had a significant correlation with average low air temperature (r=0.359, p<0.01) as well as precipitation level (r=0.214, p<0.01). ABTS(·+) radical scavenging capacity had a positive correlation with average air temperature (r=0.705, p<0.01), while hydroxyl radical scavenging capacity had a negative correlation with temperature (r=-0.269. p<0.01). These results show that environment, genotype, and their interaction could influence the levels of lipophilic antioxidants and antioxidant activities of wheat flour.

Granular Properties of Different Starch Phosphate Monoesters

Different starch types (corn, rice, and potato starch, corn amylose and corn amylopectin) were phosphorylated by reaction with a mixture of mono and disodium phosphate at different molar ratios (mol phosphate/mol anhydrous glucose) under heat and vacuum. The starch granules of the modified and the native starches were microscopically examined for their sizes and morphology. The correlation between the variation in granular size of the modified starches with the extent of phosphorylation and some other physicochemical properties was studied. The granular size was generally increased while the iodine absorption capacity was decreased by phosphorylation. There were strong correlations between the variation in the starch granular size in dependence on phosphorylation and the corresponding changes in some physicochemical parameter of starch, e.g. solubility, swelling and paste clarity. This relationship was most evident in the case of phosphorylated corn amylopectin. Starch granular size can be taken as a quick indicator of the physicochemical properties of the native and modified starches.

Phospholipid composition of niger (Guizotia abyssinica cass.) seed oil

Niger (Guizotia abyssinica Cass.) seeds were extracted with chloroform/methnol (2:1, v/v) and total lipid content was 49.9% of seed weight. The major fatty acid was linoleic acid followed by oleic acid as a second unsaturated fatty acid. Palmitic acid was the major saturated fatty acid followed by stearic acid. Column chromatography with solvent of increasing polarity yielded 93.0% neutral lipids, 4.90% glycolipids and 0.60% phospholipids (PL). Polar lipids were characterized by higher palmitic acid and lower linoleic acid levels. PL subclasses were separated via high-performance liquid chromatography (HPLC). The major individual PL subclasses were found to be phosphatidylcholine followed by phosphatidylethanolamine, phosphatidylinositol and phosphatidylserine, respectively. Phosphatidylglycerol and lysophosphatidylcholine, on the other hand, were detected in smaller quantities. The predominant PL-bound fatty acids presented were linoleic, palmitic and oleic acids.