Alam Zeb

Triacylglycerols composition, oxidation and oxidation compounds in camellia oil using liquid chromatography-mass spectrometry.

Camellia seed oil is one of most important edible oil, rich in oleic acid and contains many natural antioxidants with various biological activities. During preparation of foods or storage camellia oil oxidizes by the auto-oxidation and produce oxidized compounds. Traditional analytical techniques like FFA, POV are used for the determination of oxidation and adulteration of oils and fats. These methods were rarely able to detect the oxidized compounds produced and extent of oxidation. This paper presents the uses of liquid chromatography coupled to electrospray ionization mass spectrometry (HPLC-ESI-MS) for the analysis of triacylglycerols (TAGs) composition and evaluation of auto-oxidation and oxidation products of camellia seed oil. The camellia oil was auto-oxidized for 12 months at room temperature. The TAGs were identified from their characteristics fragmentations such as protonated molecular ion, ammonium and sodium adducts, diacylglycerols, epoxy-diacylglycerols fragments and mono-acylglycerol fragments in ESI-MS mass spectra. HPLC-ESI-MS data revealed the separation and identification of 15 TAGs. The major TAGs separated and identified in camellia seed oil were POO, OOO, OLO, PLO/POL, OLL, SOO, ALO and OLLn. The auto-oxidation studies revealed a total loss of LnLLn, LnOLn, LLLn and OLLn amounting about 13.5% total oxidation. The auto-oxidation products were epoxy hydroperoxides, epoxy epidioxides, and mono-epoxides. It was observed that these were characteristic compounds produced in high oleic oils.

Sea buckthorn seed oil protects against the oxidative stress produced by thermally oxidized lipids.

Thermally oxidized vegetable ghee was fed to the rabbits for 14 days with specific doses of sea buckthorn seed oil (SO). The ghee and SO were characterized for quality parameters and fatty acid composition using GC-MS. Rabbits serum lipid profile, hematology and histology were investigated. Major fatty acids were palmitic acid (44%) and oleic acid (46%) in ghee, while SO contains oleic acid (56.4%) and linoleic acid (18.7%). Results showed that oxidized vegetable ghee increases the serum total cholesterol, LDL-cholesterols, triglycerides and decrease the serum glucose. Oxidized ghee produced toxic effects in the liver and hematological parameters. Sea buckthorn oil supplementation significantly lowered the serum LDL-cholesterols, triglycerides and increased serum glucose and body weight of the animals. Sea buckthorn oil was found to reduce the toxic effects and degenerative changes in the liver and thus provides protection against the thermally oxidized lipids induced oxidative stress.

A Simple Spectrophotometric Method for the Determination of Thiobarbituric Acid Reactive Substances in Fried Fast Foods

A simple and highly sensitive spectrophotometric method was developed for the determination of thiobarbituric acid reactive substances (TBARS) as a marker for lipid peroxidation in fried fast foods. The method uses the reaction of malondialdehyde (MDA) and TBA in the glacial acetic acid medium. The method was precise, sensitive, and highly reproducible for quantitative determination of TBARS. The precision of extractions and analytical procedure was very high as compared to the reported methods. The method was used to determine the TBARS contents in the fried fast foods such as Shami kebab, samosa, fried bread, and potato chips. Shami kebab, samosa, and potato chips have higher amount of TBARS in glacial acetic acid-water extraction system than their corresponding pure glacial acetic acid and vice versa in fried bread samples. The method can successfully be used for the determination of TBARS in other food matrices, especially in quality control of food industries.

A reversed phase HPLC-DAD method for the determination of phenolic compounds in plant leaves

A simple, fast and efficient HPLC-DAD method was developed for the determination of phenolic compounds in grape leaves. The best separation was achieved in 40 min using gradient elution of methanol, deionized water and acetic acid on a Zorbax plus C18 column (4.6 × 100 mm, 3.5 μm) at 25 °C. The phenolic compounds were identified with the help of a diode array detector at 280, 320 and 360 nm. The method was precise, accurate, specific and highly reproducible for quantitative and qualitative purposes. The method was used to determine the phenolic composition of grape leaves. A total of 13 phenolic compounds were tentatively identified, namely gallic acid, caffeoylmalic acid, pro-anthocyanin B1, coumaroylhexose-4-O-hexoside, gallic acid derivatives, caffeic acid, quercetin-3-malonylglucoside, quercetin-3-glucoside, kaempferol-3-O-sophorotrioside and kaempferol-3-glucoside. The result demonstrates that this method can be successfully used for the quality control in the identification of phenolic compounds in grapes and other matrices of plant origin.

Phenolic profile and antioxidant potential of wild watercress (Nasturtium officinale L.)

Phenolic profile, antioxidant potential and pigment contents of wild watercress (Nasturtium officinale L.) were studied to assess the potential for future studies and its applications in neutraceuticals and bioactive functional ingredients. Different extracts of watercress (roots, stem and leaves) were analysed for pigment composition, total phenolic contents, and radical scavenging activity. The phenolic profile of the leaves and roots was studied using reversed phase HPLC–DAD. Results showed that total phenolic compounds in all samples were higher in the methanolic extracts than its corresponding aqueous extracts. The RSA of methanolic extracts was higher than aqueous extracts. Fourteen phenolic compounds were identified in the leaves, where coumaric acid and its derivatives, caftaric acid and quercetin derivatives were present in higher amounts. In roots, a total of 20 compounds was tentatively identified, with coumaric acid and its derivatives, sinapic acid, caftaric acid and quercetin derivatives were the major phenolic compounds. In conclusion, watercress has significant antioxidant activity and contains important phenolic compounds, which could be of potential biological interest.

Oxidation and formation of oxidation products of β-carotene at boiling temperature.

β-Carotene is one of the most important lipid component extensively used in food industries as source of pro-vitamin A and colorant. During processing and storage β-carotene is oxidized and degraded to various oxidation compounds. Some of these compounds are also the key aroma compounds in certain flowers, vegetables and fruits. The methods for analysis and determination of these oxidized products formed during food boiling or preparation are key to the understanding the chemistry of these compounds. This paper presents a novel analytical method incorporating high performance liquid chromatography with diode array and mass spectrometric detection for the characterization of oxidation, isomerization and oxidation products of β-carotene in toluene at boiling temperature. HPLC and APCI-MS was optimized using oxidized sample and flow injection analysis of the standard β-carotene respectively. β-Carotene was oxidized in the Rancimat at 110°C for 30, 60 and 90 min. The oxidized samples were than analyzed by HPLC system at 450 nm and 350 nm as well as scanning and single ion monitoring mass spectrometry. A total of ten oxidation products and three Z-isomers were reported. Extensive isomerization was observed during treatment at the control accelerated conditions. The oxidation products include five apo-carotenals, three diepoxides, one mono-epoxide and one short chain species. Results show that the method was reproducible, accurate and reliable for the separation and identification of oxidation products of β-carotene.

Cancer incidence in the districts of Dir (North West Frontier Province), Pakistan: a preliminary study.

Background: Pakistan has a high incidence of cancer. The most severely affected province is the North West Frontier Province, which has districts of low socioeconomic status such as those in Dir. The purpose of this study was to analyze the cancer registry record of patients from the districts in Dir in order to obtain a net cancer incidence for use in proposing future health plans. Methods: The medical records of 1,105 patients registered at the Institute of Radiotherapy and Nuclear Medicine in Peshawar were traced. Information regarding age, gender and affected sites were obtained. Results: The incidence of cancer increased, with a mean incidence of 15.04 per 100,000 in 2000–2004. Of the 1,105 patients, 62% were male and 38% were female. The most affected female age groups were 41–50 and 51–60; while males in the age groups of 51–60 and 61–70 had the highest risk. The leading cancers were lymph/blood, and cancers of the digestive system, skin and breast. Conclusion: The increasing trend of cancer in Dir is alarming. Since this study was a preliminary investigation, it could provide a leading role in prevention, treatment and future planning regarding cancer in Pakistan.

Characterization of sesame (Sesamum indicum L.) seed oil from Pakistan for phenolic composition, quality characteristics and potential beneficial properties

Sesame (Sesamum indicum, L.) seed oil was characterized for quality characteristics, phenolic composition and was supplemented to rabbits in different doses to assess potential beneficial effects. The phenolic profile of the oil was studied using reversed phase HPLC-DAD method. Sesame oil was rich in total phenolic contents, flavonoids, pigments and possess strong antioxidant activity. The HPLC-DAD results showed 16 polyphenolic compounds in sesame seed oil. Rosmarinic acid hexoside (12.6xa0μg/g), 3-coumaroylquinic acidxa0(11.3xa0μg/g), hydroxybenzoic acidxa0(7.74xa0μg/g), quercetin-3,4-diglucoside-(6-feruloyl glucoside) xa0(5.25 μg/g) and ellagic acid pentoside (4.98xa0μg/g) were the major phenolic compounds. Sesame oil supplementation significantly improved the body weight of the rabbits without affecting the vital organs. Significant improvement was also observed in serum lipids in a dose dependent manner, while no significant effects were documented in hematological and liver histological parameters. These results indicate that supplementation of SO was beneficial owing to the presence of high levels of important polyphenolic compounds and can be used as a good functional food supplement.

A simple, sensitive HPLC-DAD method for simultaneous determination of carotenoids, chlorophylls and α-tocopherol in leafy vegetables

Leafy vegetables are the important components of our diet and are the source of several beneficial phytochemicals. A sensitive, simple analytical method is therefore required to precisely measure the phytochemical composition. A validated reversed phase high performance liquid chromatography with diode array detection (HPLC-DAD) method was developed to determine simultaneously carotenoids, chlorophylls and α-tocopherol composition of six leafy vegetables (B. compestris, B. rapa, B. juncea, M. neglecta, and two spinach varieties). Carotenoids were extracted and efficiently separated using a tertiary mobile gradient system of methanol–water, water and MTBE in 40xa0min on a reversed phase C18 column. The method was simple, precise, accurate and highly reproducible. Twelve carotenoids namely lutein and its three isomers, β-carotene-5,6-epoxide, neoxanthin, violaxanthin, two cis-isomers of zeaxanthin, 8-apo-carotenal, all-trans-β-carotene and its 13-cis-isomer; one fatty acid ester (β-cryptoxanthin ester); α-tocopherol and chlorophyll a & b were quantified in vegetable leaves. α-Tocopherol, neoxanthin, violaxanthin, lutein, 8-apo-carotenal, chlorophyll a and all-trans-β-carotene were present in higher amounts. Significant variations in the major compounds were observed in the selected vegetables. It was concluded that the developed method was highly sensitive, accurate and can be used to analyze carotenoids, chlorophylls and α-tocopherol simultaneously in leafy vegetables as well as in other plant leaves.

Effects of High Temperature Frying of Spinach Leaves in Sunflower Oil on Carotenoids, Chlorophylls, and Tocopherol Composition

Spinach is one of the highly consumed vegetable, with significant nutritional, and beneficial properties. This study revealed for the first time, the effects of high temperature frying on the carotenoids, chlorophylls, and tocopherol contents of spinach leaves. Spinach leaves were thermally processed in the sunflower oil for 15, 30, 45, and 60 min at 250°C. Reversed phase HPLC-DAD results revealed a total of eight carotenoids, four chlorophylls and α-tocopherol in the spinach leaves. Lutein, neoxanthin, violaxanthin, and β-carotene-5,6-epoxide were the major carotenoids, while chlorophyll a and b were present in higher amounts. Frying of spinach leaves increased significantly the amount of α-tocopherol, β-carotene-5,6-epoxide, luteoxanthin, lutein, and its Z-isomers and chlorophyll b isomer. There was significant decrease in the amounts of neoxanthin, violaxanthin, chlorophyll b, b and chlorophyll a with increase of frying time. The increase of frying time increased the total phenolic contents in spinach leaves and fried sunflower oil samples. Chemical characteristics such as peroxide values, free fatty acids, conjugated dienes, conjugated trienes, and radical scavenging activity were significantly affected by frying, while spinach leaves increased the stability of the frying oil. This study can be used to improve the quality of fried vegetable leaves or their products at high temperature frying in food industries for increasing consumer acceptability.