No abstract / Applied Science, Faculty of / Chemical and Biological Engineering, Department of / Graduate

In this work, a rapid Fourier transform near infrared (FT-NIR) spectroscopic peroxide value (PV) method was developed and a prototype Continuous Oil Analysis and Treatment (COAT) system was assessed for monitoring and analytical purposes. High erucic acid rapeseed oil, a principle representative of triglyceride based oils suitable for biodegradable lubricating applications and mineral oil were used to test the methodology developed. / The FT-NIR PV method is based on a well defined stoichiometric reaction of triphenylphospine (TPP) with hydroperoxides to form triphenylphospine oxide (TPPO). A partial least squares calibration model for the prediction of PV was developed using the NIR spectral region where TPP and TPPO co-absorb. The resulting calibration was highly linear over the analytical range of 100PV. Validation of the method carried out by comparing the PV of PLS prediction to the results of AOCS iodometric procedures indicated an excellent concurrence between the two methods. By programming the FT-NIR spectrometer, the analytical procedure simply consists of the addition of TPP stock solution to oil sample, mixing, taking its spectrum and predicting PV value. Through selected testing procedures, the prototype COAT system utilizing FTIR spectroscopy, advanced sample handling system designs, and computer programming was proved to be effective in monitoring the oil quality and behavior of antioxidants in real time. / Both approaches offer combined advantages of speed, accuracy, low labor cost, automation, and environmental friendliness mainly derived from FTIR spectroscopy, and can serve as convenient means for routine quality control applications in oils and fats industry. Potential application based on the joint usage of the two methods in the obtaining of true value of oil stability was also presented in this text. (Abstract shortened by UMI.)

No description available.

Thesis (Master of Applied Sciences in Chemistry)--Cape Peninsula University of Technology, 2018. / The high demand of omega-3 fish oil nutraceuticals (dietary supplements) is due to the numerous health benefits contributed by the polyunsaturated fatty acids (PUFA’s). The nutraceutical industry is required to follow good manufacturing practice (GMP) standards in order to ensure label claims and prevent adulteration. It is vital that the quality control (QC) procedures will be able to detect adulterated products. It is thus necessary to ensure the analytical techniques are adequate by using validated methods. The qualification or identification of natural fish oils is a difficult task due to overlapping concentration ranges of PUFA’s and other similar properties. Gas chromatography (GC) is the prescribed technique in the nutraceutical industry for analysis of omega-3 fatty acids, but it is time-consuming and costly. Near infrared (NIR) spectroscopy is a rapid and cost-effective technique that can replace the prescribed method if proven equivalent, through validation according to pharmaceutical criteria. In this study, NIR spectroscopy in combination with chemometrics was considered as an alternative method to GC, to identify various commercial fish oils and to quantify the PUFA’s. Identification methods were developed for nine commercial omega-3 fish oils using spectral libraries. Quantitative NIR methods were developed for arachidonic acid (AA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in fish oils expressed as mg.g-1 as well as percentage (%) area using partial least squares (PLS) regression and independent validation by superimposing datasets with mutual properties. Based on the statistics in terms of SEC, R2, SEP and r of the PUFA models, the NIR method was equivalent to the prescribed GC methods and precision results obtained were within the prescribed criteria. NIR spectroscopy and chemometrics can be used for conclusive identification and quantification of omega-3 fish oils, thereby minimizing the risk of adulteration. The method also complied with the prescribed pharmaceutical method validation criteria; therefore, was demonstrated as an alternative method to GC for the nutraceutical industry.

Typescript. Thesis (Ph. D.)--University of Hawaii, 1938. Bibliography: leaves 150-158.

Typescript. Thesis (Ph. D.)--University of Hawaii, 1951. Bibliography: leaves [98]-103.

Thesis (PhD (Chemistry and Polymer Science))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: Due to the commercial, nutritional and health value of vegetable oils, seeds and beans, the analysis of their components is of much interest. In this dissertation oil-containing food products, specifically vegetable oils, seeds and beans, were investigated. Selected minor components of three locally produced vegetable oils, namely apricot kernel, avocado pear and macadamia nut oils were investigated using 31P NMR spectroscopy. These minor components, including 1,2 diacylglycerols, 1,3 diacylglycerols and free fatty acids, were identified in the 31P NMR spectra of each of the three vegetable oils for the first time. Two approaches were used for the quantification of the minor components present in the spectra. A calibration curve approach used known concentrations of standard minor components to establish calibration curves while a direct correlation approach calculated the unknown concentration of minor components in the vegetable oils using a known amount of standard compound within the analysis solution. These approaches aided in determining the concentration of minor components during storage studies in which vegetable oils were stored in five different ways: exposed to light, in a cupboard, in a cupboard wrapped in tin foil, at -8 °C and at 5 °C. It was found that determining the best storage condition for each oil was difficult since individual minor components were affected differently by the various storage conditions. However, in general the best storage conditions appeared to be 5 °C and -8 °C. The oil, protein and carbohydrate contents of sesame, sunflower, poppy, and pumpkin seeds, and soy, mung, black and kidney beans were analysed by thermogravimetric analysis and 13C NMR solid state NMR spectroscopy. It was shown that the first derivative of TGA data for seeds and beans can give valuable information about the carbohydrate, moisture, protein and fat content. This has not been previously demonstrated. For the seeds, the integration of a region between 270–480 ºC was equal to the sum of the oil and protein content and compared well to quantitative results obtained by other conventional methods. For beans the integration of a region between 180-590 ºC, gave a value which represented the sum of the oil, protein and carbohydrate content. 13C solid state NMR spectroscopy, including SPE-MAS, CP-MAS and variable contact time experiments, was carried out on these seeds and beans and gave valuable information on the solid-like and liquid-like components. To our knowledge these seeds and beans have never been previously analysed using this technique. 13C SPE-MAS NMR spectroscopy indicated that the seeds contained more liquid-like components than the beans. In turn the 13C CP-MAS NMR spectra indicated that beans had higher levels of solid-like components than the seeds. These conclusions correlated well with the quantities of liquid-like components and solid-like components that were determined by conventional methods and TGA. Preliminary studies using T1pH experiments on the components present in the seeds and beans led to a few observations. Most interesting is that a model using a two- phase fit in order to determine T1pH values appears to be more accurate than a one-phase model. / AFRIKAANSE OPSOMMING: Groente olies, sade en bone is ‘n onderwerp van groot belang omrede hul kommersiële, voeding en gesondheidswaardes. In hierdie tesis is olie-bevattende voedselprodukte, spesifiek groente-olies, sade en bone geanaliseer. Geselekteerde komponente teenwoordig in klein hoeveelhede in drie lokaal geproduseerde groente-olies, naamlik appelkoos-pit, avokadopeer en makadamia-neut olies is geanaliseer met behulp van 31P KMR spektroskopie. Hierdie komponente, insluitend 1,2 diasielglyserole, 1,3 diasielglyserole en ongebonde vetsure, is vir die eerste keer geïdentifiseer in die 31P KMR spektra van die drie groente olies. Twee benaderings is gebruik vir die hoeveelheids-bepaling van die komponente in die spektra. ‘n Yking-kurwe metode het gebruik gemaak van bekende hoeveelhede konsentrasies standaard komponente vir die opstel van yking-kurwes, terwyl ‘n direkte korrelasie metode gebruik is om die onbekende konsentrasie van komponente in groente olies te bepaal met behulp van ‘n bekende hoeveelheid standaard verbinding teenwoordig in die oplossing. Hierdie metodes het gelei tot die bepaling van die konsentrasies van die komponente gedurende vyf verskillende berging toestande wat ingesluit het: Blootgestel aan lig, in ‘n donker kas, in ‘n donker kas toegevou in tin foelie, bevries by -8 °C en in ’n koelkas by 5 °C. Dit was bevind dat bepaling van die beste bergingstoestand vir elke olie moeilik is aangesien die individuele komponente verskillend geaffekteer word deur die verskeie berging toestande. Die beste bergings toestand oor die algemeen blyk egter om by 5 °C en -8 °C te wees. Sesamsaad, sonneblomsaad, papawersaad en pampoensaad sowel as sojaboontjie, mungboontjie, swartboontjie en pronkboontjie se olie, protein en koolhidraat komponente was geanaliseer met behulp van termogravimetriese analise (TGA) en 13C soliede toestand KMR spektroskopie. Dit was bevind dat die eerste afgeleide van die TGA data waardevolle inligting lewer oor die komponent inhoud van elk van die sade en bone. Hierdie is nog nie vantevore bevind nie. Vir die sade, was die integrasie van ‘n area tussen 270–480 ºC gelyk aan die som van die olie en proteïen inhoud en het goed vergelyk met die waardes verky deur algemene analitiese metodes. Vir die boontjies, was die integrasie van ‘n area tussen 180-590 ºC gelyk aan die som van die olie, protein en koolhidraat inhoud. 13C vaste staat KMR spektroskopie, insluitende SPE-MAS, CP-MAS en variëerbare kontak-tyd eksperimente, was gedoen en het waardevolle inligting gelewer omtrent die solied-agtige en mobiel-agtige komponente. Hierdie sade en bone is tot ons kennis nog nie van te vore met die tegnieke ondersoek nie. 13C SPE-MAS NMR spektroskopie het aangedui dat daar ‘n groter hoeveelheid mobiel-agtige komponente in sade as in bone teenwoordig is. 13C CP-MAS NMR spektroskopie het weer aangedui dat daar ‘n groter hoeveelheid solied-agtige komponente in bone as in sade teenwoordig is. Hierdie gevolgtrekkings het goed vergelyk met die waarnemings verkry deur konvensionele analitiese metodes en TGA. Voorlopige studies op die komponente van sade en bone deur T1pH eksperimente het tot ‘n paar gevolgtrekkings gelei waarvan die mees interessantste was dat ‘n twee-fase model vir die bepaling van T1pH waardes beter resultate lewer as ‘n een-fase model.

O desafio das indústrias de alimentos na substituição da gordura trans em diversos produtos reside no desenvolvimento de formulações e processos que apresentem funcionalidade equivalente e viabilidade econômica. A interesterificação química representa uma opção tecnológica importante para a produção de gorduras visando diversas aplicações comerciais, sem a formação de ácidos graxos trans. O óleo de palma contém quantidades aproximadamente iguais de ácidos graxos saturados e insaturados e pelo seu fracionamento obtêm-se duas frações: a estearina (fração sólida) e a oleína (fração líquida). A estearina e oleína de palma são opções interessantes para a produção de grande variedade de produtos como margarinas e shortenings. Assim, o objetivo deste trabalho foi modificar as propriedades físico-químicas de misturas de estearina e oleína de palma pelo uso da interesterificação química. As amostras foram analisadas quanto à composição em ácidos graxos e triacilgliceróis, distribuição regioespecífica dos ácidos graxos nos triacilgliceróis, índice de iodo, pontos de amolecimento e de fusão, conteúdo de gordura sólida, consistência e estrutura cristalina. Os ácidos graxos saturados são predominantes na estearina (71,9%), sendo que 65,5% correspondem ao ácido palmítico. A oleína tem como principal constituinte o ácido oléico, que representa 45,4%. À medida que aumenta a proporção de oleína de palma nas misturas, aumentam a quantidade de ácidos graxos insaturados e o índice de iodo e diminui a quantidade de ácidos graxos saturados. Após a interesterificação química, os pontos de fusão e amolecimento, a consistência e o conteúdo de gordura sólida aumentaram nas misturas que apresentavam maior proporção de oleína em função do aumento no teor de triacilgliceróis trissaturados. Por outro lado, estas propriedades não se modificaram nas misturas com maior proporção de estearina. Este comportamento se deve à distribuição aleatória dos ácidos graxos nos triacilgliceróis após a interesterificação, que forma triacilgliceróis em proporções diferentes das existentes originalmente. Os principais triacilgliceróis nas misturas foram PPP, PPO e POO. Antes da interesterificação os ácidos graxos saturados foram encontrados principalmente nas posições sn-1,3. Mudanças significativas na composição dos ácidos graxos na posição sn-2 após a interesterificação química foram encontradas em misturas com mais de 60% de oleína de palma. A mistura e a interesterificação permitiram obter gorduras com diferentes graus de plasticidade, aumentando as possibilidades de uso das frações estearina e oleína de palma. / The challenge of the food industries for the replacement of trans fat in various products lies in the development of formulations and processes which have equivalent functionality and economic viability. The chemical interesterification of palm stearin and palm olein is an important technological option for the production of fats targeting commercial applications, without formation of trans fatty acids Palm oil contains similar amounts of saturated and unsaturated fatty acids. After fractionation two fractions are obtained: stearin (solid fraction) and olein (liquid fraction). Palm stearin and palm olein are alternatives for the production of many products, such as margarines and shortenings. The objective of this work was to modify the physical and chemical properties of mixtures of palm stearin and palm olein by using chemical interesterification. The following properties were analyzed: fatty acid and triacylglycerol compositions, regiospecific distribution of fatty acids in triacylglycerols, iodine value, softening and melting points, solid fat content, consistency and crystal microstructure. Saturated fatty acids are predominant in palm stearin (71.9%), which corresponds to 65.5% of palmitic acid. Palm olein has as its main constituent the oleic acid, which represents 45.4% of the unsaturated fatty acids. The increase of the proportion of palm olein in the mixture causes increase on the amount of unsaturated fatty acids and iodine value and decrease on the content of saturated fatty acids. After chemical interesterification, melting and softening points, consistency and solid fat content increased in the blends that had higher proportion of palm olein, as a consequence of the increase in the trisaturated triacylglycerols. On the other hand, these properties did not alter in the blends with higher proportion of palm stearin. This behavior is due to the random distribution of fatty acids in triacylglycerols after interesterification, which forms triacylglycerols in proportions that are different from those originally present. The major triacylglycerols in the blends were PPP, PPO and POO. Before interesterification the saturated fatty acids were found mainly in the sn-1,3 positions. Significant changes in the fatty acid composition in the sn-2 position after chemical interesterification were found in blends with more than 60 % of palm olein. Blending and interesterification of fats resulted in structured lipids with different degrees of plasticity, increasing the possibilities of use of stearin and olein fractions.

O desafio das indústrias de alimentos na substituição da gordura trans em diversos produtos reside no desenvolvimento de formulações e processos que apresentem funcionalidade equivalente e viabilidade econômica. A interesterificação química representa uma opção tecnológica importante para a produção de gorduras visando diversas aplicações comerciais, sem a formação de ácidos graxos trans. O óleo de palma contém quantidades aproximadamente iguais de ácidos graxos saturados e insaturados e pelo seu fracionamento obtêm-se duas frações: a estearina (fração sólida) e a oleína (fração líquida). A estearina e oleína de palma são opções interessantes para a produção de grande variedade de produtos como margarinas e shortenings. Assim, o objetivo deste trabalho foi modificar as propriedades físico-químicas de misturas de estearina e oleína de palma pelo uso da interesterificação química. As amostras foram analisadas quanto à composição em ácidos graxos e triacilgliceróis, distribuição regioespecífica dos ácidos graxos nos triacilgliceróis, índice de iodo, pontos de amolecimento e de fusão, conteúdo de gordura sólida, consistência e estrutura cristalina. Os ácidos graxos saturados são predominantes na estearina (71,9%), sendo que 65,5% correspondem ao ácido palmítico. A oleína tem como principal constituinte o ácido oléico, que representa 45,4%. À medida que aumenta a proporção de oleína de palma nas misturas, aumentam a quantidade de ácidos graxos insaturados e o índice de iodo e diminui a quantidade de ácidos graxos saturados. Após a interesterificação química, os pontos de fusão e amolecimento, a consistência e o conteúdo de gordura sólida aumentaram nas misturas que apresentavam maior proporção de oleína em função do aumento no teor de triacilgliceróis trissaturados. Por outro lado, estas propriedades não se modificaram nas misturas com maior proporção de estearina. Este comportamento se deve à distribuição aleatória dos ácidos graxos nos triacilgliceróis após a interesterificação, que forma triacilgliceróis em proporções diferentes das existentes originalmente. Os principais triacilgliceróis nas misturas foram PPP, PPO e POO. Antes da interesterificação os ácidos graxos saturados foram encontrados principalmente nas posições sn-1,3. Mudanças significativas na composição dos ácidos graxos na posição sn-2 após a interesterificação química foram encontradas em misturas com mais de 60% de oleína de palma. A mistura e a interesterificação permitiram obter gorduras com diferentes graus de plasticidade, aumentando as possibilidades de uso das frações estearina e oleína de palma. / The challenge of the food industries for the replacement of trans fat in various products lies in the development of formulations and processes which have equivalent functionality and economic viability. The chemical interesterification of palm stearin and palm olein is an important technological option for the production of fats targeting commercial applications, without formation of trans fatty acids Palm oil contains similar amounts of saturated and unsaturated fatty acids. After fractionation two fractions are obtained: stearin (solid fraction) and olein (liquid fraction). Palm stearin and palm olein are alternatives for the production of many products, such as margarines and shortenings. The objective of this work was to modify the physical and chemical properties of mixtures of palm stearin and palm olein by using chemical interesterification. The following properties were analyzed: fatty acid and triacylglycerol compositions, regiospecific distribution of fatty acids in triacylglycerols, iodine value, softening and melting points, solid fat content, consistency and crystal microstructure. Saturated fatty acids are predominant in palm stearin (71.9%), which corresponds to 65.5% of palmitic acid. Palm olein has as its main constituent the oleic acid, which represents 45.4% of the unsaturated fatty acids. The increase of the proportion of palm olein in the mixture causes increase on the amount of unsaturated fatty acids and iodine value and decrease on the content of saturated fatty acids. After chemical interesterification, melting and softening points, consistency and solid fat content increased in the blends that had higher proportion of palm olein, as a consequence of the increase in the trisaturated triacylglycerols. On the other hand, these properties did not alter in the blends with higher proportion of palm stearin. This behavior is due to the random distribution of fatty acids in triacylglycerols after interesterification, which forms triacylglycerols in proportions that are different from those originally present. The major triacylglycerols in the blends were PPP, PPO and POO. Before interesterification the saturated fatty acids were found mainly in the sn-1,3 positions. Significant changes in the fatty acid composition in the sn-2 position after chemical interesterification were found in blends with more than 60 % of palm olein. Blending and interesterification of fats resulted in structured lipids with different degrees of plasticity, increasing the possibilities of use of stearin and olein fractions.