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Home > Raman and Fluorescence Spectroscopy Based Studies of Extra Virgin Olive Oil Evoo and Desi Ghee

Raman and Fluorescence Spectroscopy Based Studies of Extra Virgin Olive Oil Evoo and Desi Ghee

Thesis Info

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Author

Naveed Ahmad

Program

PhD

Institute

Mirpur University of Science and Technology

City

Mirpur

Province

KPK

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/12867/1/Naveed%20Ahmed_Phy_2018_MUST_PRR.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727064421

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Raman and Fluorescence spectroscopic techniques have been employed for studying the temperature effects on the molecular composition of extra virgin olive oil (EVOO). In addition, both techniques have also been employed for the characterization of Desi Ghee (liquefied butter) obtained from Buffalo milk along with the effects of temperature on its molecular composition. Raman spectra of EVOO samples has been obtained at excitation wavelength of 785 nm. Intensity ratio of Raman bands at 1267 cm-1 and 1302 cm-1 have been used to determine the loss of unsaturation in heated EVOO samples as compared to nonheated ones. Similarly, Fluorescence emission bands at 380, 440, 455 and 525 nm are labelled for vitamin E, band at 673 nm is assigned to chlorophyll, band at 525 nm is assigned to beta carotene. As a result of heating, emission bands at 525 nm got affected most revealing deterioration of beta carotene and vitamin E. The ratio between the sum of intensities of fluorescence bands at 380, 440, 470, 525 nm to 673 nm from heated and non-heated EVOO samples has been used to determine the deterioration of beta carotene and vitamin E contents. Results of both Raman and Fluorescence spectroscopic analysis have suggested a temperature range from 140 to 150 oC reasonably safe for cooking/frying of food with EVOO. In addition, EVOO can be heated for longer period of time up to 30 minutes but with the passage of time it deteriorates. However, in pressure cooker EVOO can be used for comparatively longer times up to 60 minutes. It has also been found that one time use of EVOO is better for cooking within defined temperature range and its reuse may be avoided. In conclusion, EVOO can be safely used for frying/cooking in the defined cooking range with proper management of heat source. Moreover, for the classification of heated and non-heated EVOO samples, principle component analysis (PCA) has been employed which differentiate the samples on the basis of their spectral differences. Similarly, Raman spectra at 785 nm depicted molecular composition of DG with prominent Raman bands around 1125 and 1440 cm-1 labelled for saturated fatty acids, 1258, 1270 and 1300 cm-1 assigned to unsaturation, 1525 cm-1 represents beta carotene and 1655 cm-1 is labelled for isomers of conjugated linoleic acid (CLA). The variations in the intensity ratio of Raman bands at 1258/1270 cm-1 indicates the loss of unsaturation and at 1440 cm-1 and 1650 cm-1 exhibit degradation of valuable lipids and CLA contents as a result of heating. In addition, Fluorescence spectra of ghee samples obtained at excitation wavelength of 280 and 410 nm showed that DG is enriched with CLA, vitamin-A and small quantities of vitamin D, E and K. Further, heating analysis has revealed that Ghee remains stable around a temperature range of 140-150 oC when heated for a time period of 30 minutes. Principal component analysis (PCA) has been used for the classification of overlapping spectral data which was difficult to differentiate visually. Results of both Raman and Fluorescence spectroscopy have suggested a temperature-range from 140 to 180 oC considered safe for household cooking/frying purposes using DG. Conclusively, it is found that both EVOO and DG show negligible deterioration of their natural molecular composition when heated at temperature range from 140-150 oC. Therefore, this temperature range sounds good for cooking/frying with EVOO and DG. Moreover, both EVOO and DG start getting oxidized more at temperatures from 180-200 oC with the evolution of secondary oxidation products and become rancid at 250 oC.
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ڈاکٹر مسیح الزماں

ڈاکٹر اعجاز حسین ؍ ڈاکٹر مسیح الزماں
گزشتہ مہینہ میں ڈاکٹر اعجاز حسین سابق صدر شعبہ اردو الہ آباد یونیورسٹی کا انتقال حرکت قلب بند ہوجانے سے مظفرپور میں ہوگیا، جہاں وہ ممتحن بن کر گئے ہوئے تھے، ان کی میت الہ آباد لائی گئی، اپنی ملازمت سے سبکدوش ہونے کے بعد بھی لکھنے پڑھنے کا شغل جاری رکھا تھا، اہم اور مفید کتابوں کے مصنف تھے، جن میں مختصر تاریخ ادب اردو اور نئے ادبی رجحانات وغیرہ زیادہ مقبول ہوئیں، اپنے شاگردوں میں بہت مقبول رہے، ان کی وفات سے اردو ادب ایک بہت ہی لائق مصنف اور خدمت گزار سے محروم ہوگیا، ان سے کچھ ہی روز پہلے ڈاکٹر مسیح الزماں ریڈیو شعبہ اردو الہ آباد یونیورسٹی کی بھی وفات اچانک ہوگئی، اردو کی مرثیہ نگاری ان کا خاص موضوع تھا، ان کی عمر وفا کرتی تو اس صنف میں ان کا ادبی کارنامہ بڑا قابل قدر ہوتا، وہ پروفیسر مسعود حسن رضوی سابق صدر شعبہ اردو لکھنؤ یونیورسٹی کے داماد تھے، جن کے لئے اس کبرسنی میں یہ سانحہ بڑا ہی جانکاہ ہوگا۔
دعا ہے کہ خدا اردو ادب کے ان دونوں خدمت گزاروں کو غریق رحمت کرے، آمین ثم آمین۔ (صباح الدین عبدالرحمن، مارچ ۱۹۷۵ء)

 

گلوبلائزیشن: تعارف, محركات اور مقاصد

The humanity witnesses a strange international phenomenon called the Globalization which endeavors to make an intellectual unification in the sphere of norms — education, social, economic and politics. 77m carries a strong challenge for the Muslim societies across the world. Through a focus on the educational, cultural, economical and politiiclal spheres and to employ the devices of communication — media and the internet. The world has shrunk into a small village which is diminishing the geographical, historical, political and educational boundaries. The world is undergoing the transition in materialistic and educational values and principles which are not accorded as per the Islamic values. Through media and interactive modes of communication. Hence, it becomes necessary to examine all aspects of this subject to be on a firm position of this transformation to preserve and safeguard our Muslim identity. In this context, the concept of globalization by Muslim and western scholars and its impact on globalization are discussed along with some proposals in order to cope with the negative effects of globalization in the Muslim societies.

Efficacy of Entomopathogenic Fungi and Their Combinations With Some Selective Insecticides Against Bemisia Tabaci Genn. and Tetranychus Urticae Koch on Cotton

The cotton whitefly, Bemisia tabaci Genn. and Two-Spotted Spider Mites (TSSM), Tetranychus urticae Koch are emerging as important sucking pests of cotton crop. The indiscriminate use of pesticides against insect pests have resulted in the development of resistance among these pests as well as environmental and health hazards. The use of microbial control agents is an important approach to combat this menace. The present study was therefore, carried out to determine the efficacy of some strains of entomopathogenic fungi viz., Metarhizium anisopliae, Isaria fumosorosea, Lecanicillium muscarium and Beaveria bassiana against all immature stages of whitefly and eggs and adult females of TSSM in the Department of Entomology at University of Agriculture, Faisalabad, Pakistan and Department of Pure and Applied Ecology, Swansea University, Swansea U.K. for the bioassays on whitefly. The potential of various entomopathogenic fungi was evaluated on 2 nd instar nymphs of whitefly and four of them were found promising. The detailed studies were carried out on other immature stages of whitefly with the promising strains. The dose- mortality response was observed by using serial dilutions, 1×10 5 to 1×10 8 conidia mL -1 against most susceptible stage using detached leaf immersion method for whitefly and spraying the detached leaf for bioassay with TSSM. All tested fungal isolates caused mortality in the tested stages of both insects under consideration except eggs of whitefly for which very low susceptibility was observed. The L. muscarium (V17) isolate was highly virulent among the tested ones for whitefly nymphs while Pf (n32) isolate was highly virulent against both the stages of TSSM. The mortality of each stage was recorded daily up to 8 days for both the insects under study. The % mortality significantly differed based on fungal isolates, stage of the insect and conidial concentrations. The % mortality increased with increasing the dose of conidial concentration of each fungal isolate in each insect. For whitefly, the most virulent isolate, (V17) has LC 50 value of 1.9×10 5 conidia mL -1 and it killed about 89.58 % of the treated second instar nymphs 8 days post treatment while its LT 50 value at higher concentration is 4.03 days. For TSSM, the most virulent isolate was Pf (n32) with lowest LC 50 value of 9.1 × 10 4 conidia mL -1 on 8 th day and LT 50 value of 4.58 days at 1×10 8 conidia mL -1 . It killed about 82.16 % of the inoculated females 8 days post treatment. The xresults indicated that L. muscarium and I. fumosorosea strains have potential as microbial control agent against cotton whitefly and mites, respectively, in Pakistan. The studies were also carried out to determine the LC 50 values and also efficacy of some commercial insecticides and acaricides against whitefly and TSSM in the laboratory. Four different insecticides were evaluated in the lab against 2 nd instar nymphs of whitefly on cotton. All the tested insecticides caused significant mortality of whitefly from 3-5 days post treatment. However, the most effective insecticides for whitefly, up to 5 days were Mospilon ® and Confidor ® with very low LC 50 values while others were also equally effective but with high LC 50 values. Similarly, the chlorfenapyr 36 SC, pyridaben 15 EC and fenpyroximate 5 SC proved to be the best miticides among the tested ones for the control of TSSM based on their LC 50 values. The nine commercial pesticides and their effects on germination of conidia and mycelial growth of highly efficacious fungal strains viz., I. fumosorosea and L. muscarium were investigated in vitro. There was a significant variation in conidial germination as well as mycelial growth by all tested pesticides depending upon the dose of pesticide and type of fungus. Among the pesticides tested azocyclotin was proved to be highly toxic to germination of spores as well as mycelial growth followed by pyridaben, acetamiprid and propergite while buprofezin was the least toxic. Isaria was proved to be more sensitive at field recommended doses than Lecanicillium strain to all pesticides. Generally, among all pesticides used the insecticides were more compatible to fungi than acaricides although these also inhibited germination of spores and fungal growth to some extent. The combined application of pesticides with selective fungi proved to be synergistic giving more control than used alone. The combined effects were tested under greenhouse conditions on potted plants. Buprofezin, acetamiprid, imidacloprid and diafenthuron were used against 2 nd instar nymphs of whitefly while chlorfenapyr, pyridaben and fenpyroximate were used against TSSM. Only buprofezin and imidacloprid insecticides showed synergistic effects and others additive while no one showed antagonistic results. Chlorfenapyr combined with fungus yielded highest mortality among acaricides tested. However, further investigations under field conditions may reveal more comprehensive results.