The object of this research was to determine if an acceptable angel food cake alternative could be produced that had reduced calories and sucrose content. This was accomplished through replacing sucrose in meringue, angel food cake batter, and baked angel food cakes with polydextrose and either sucralose, acesulfame-K, or Rebaudioside A at different replacement levels (25, 50, 75, 100%). Meringue and cake batter properties were measured using rheological techniques. Baked angel food cakes were analyzed based on height, weight loss, moisture content, color, and TPA analysis. With meringue batter, 100% sucrose replacement was unacceptable since undissolved polydextrose made analyzing and end products impractical. While 75% sucralose and acesulfame-K sucrose replacement exhibited comparable air incorporation to the sucrose control in cake batter, baked angel food cakes showed a decrease in functional properties. Polydextrose was likely the cause. 25% sucralose and acesulfame-K sucrose replacement were no different from sucrose cakes in regards to height, overall textural appearance, crumb pore size, and hardness. These cakes resulted in an overall calorie reduction of 18.7%. In every experiment, Rebaudioside A replacement treatments exhibited trends opposite of sucralose and acesulfame-K treatments. Rebaudioside A treatments performed the worst for rheological properties and TPA analysis.

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Os produtos obtidos a partir da cana-de-açúcar possuem, além de altas concentrações de sacarose, flavonóides que podem atuar como quimiopreventivos e antioxidantes. Neste estudo foram elucidadas as estruturas dos flavonóides e dos ácidos cinâmicos mais abundantes no caldo de cana, sendo apresentadas duas novas substâncias, uma flavona, tricina-7-Ο-β-(6\"-p-metoxicinamato)-glucosideo e uma lignana, 3-hidroxi-1-[4,5-dihidroxi-3-metoxifenil]-2-[4-(3-hidroxi-1-(E)-propenil)-2,6-dimetoxifenoxi]-propil-β-D-glucopiranosídeo. Entre as flavonas analisadas, o derivado de tricina apresentou maior abundância. Foi também confirmada neste estudo a perda de compostos fenólicos durante o processamento industrial do açúcar. Nos colmos de cana-de-açúcar evidenciamos altas concentrações de ácidos clorogênico e cumárico, e baixos teores de flavonóides. No decorrer do processamento verificaram-se perdas significativas de ácidos cinâmicos e aumento nos teores de flavonóides. Os maiores teores foram verificados no xarope e os menores no açúcar VHP. Entretanto, a proporção dos compostos fenólicos teve pouca alteração durante o processamento. As flavonas encontradas na cana in natura se mantiveram durante todo o processamento, enquanto que não se detectou ácido ferúlico nas variedades e ácido caféico nos produtos. A atividade antioxidante dos produtos obtidos durante as etapas do processamento do açúcar foram avaliadas. As maiores atividades foram encontradas no xarope e melaço, enquanto que as menores, no caldo misto e açúcar VHP. Uma avaliação sobre o perfil dos compostos fenólicos de amostras de rapadura e caldo de cana obtidos no comércio local mostrou que a rapadura apresenta altos teores de luteolina, enquanto no caldo, prevalece tricina. Nas amostras de rapadura destacam-se altos teores de ácido clorogênico, composto que se mostrou ausente nas amostras obtidas durante as etapas do processamento industrial do açúcar. As atividades antioxidantes dos extratos de rapadura mostraram que mesmo em baixas concentrações a atividade é moderada. O caldo apresentou atividade semelhante, mas em concentrações mais elevadas. Quanto à atividade antiproliferativa, o extrato de rapadura apresentou atividades citostáticas para todas as linhagens e citocida para as linhagens de células cólon (HT-29), de mama (MCF-7), de mama resistente (NCI-ADR), de pulmão (NCI-460), de ovário (OVCAR), de rim (786-0) e de melanoma (UACC-62). O derivado de tricina, isolado a partir do caldo de cana, apresentou atividade antioxidante moderada. Suas atividades antiproliferativas foram mais pronunciadas para as linhagens de células de mama resistente (NCI-ADR) e de cólon (HT-29), com atividade citostática e citocida para as linhagens de pulmão (NCI-460), de mama (MCF-7), de ovário (OVCAR), de rim (786-0) e de melanoma (UACC-62). / Sugar cane products have high sucrose concentration and flavonoids that can function with chemopreventive and antioxidant. In this study have been elucidated flavonoids and cinnamic acids structures most abundant in sugar cane juice and were presented two new substances, one flavone, tricin-7-Ο-β-(6-methoxycinnamic)-glucoside and one lignan, 3-hydroxy-1-[4,5-dihydroxy-3-methoxyphenyl]-2-[4-(3-hydroxy-1-(E)-propenyl)-2,6-dimethoxyphenoxy]-propyl-β-D-glucopyranoside. Among the flavones analyzed, tricin presents high concentration. In this study was corroborated the loss of phenolic compounds during the processing industrial of sugar. In culm of sugar have been evidenced high concentrations of the chlorogenic and coumaric acids, and low flavonoid contents. During the processing has been proved significant loss of cinnamic acids and increase of flavonoids. The highest contents have been proved in the syrup and the smallest in the sugar VHP. However, the profile of the phenolic compounds had little alteration during the processing. The flavones finded in sugar cane in natura were remaining during all the processing and, are not find ferulic acid in the varieties and caffeic acid in the products. The antioxidant activities in products obtained during processing stage of sugar cane were evaluated. The highest activities were finded in the syrup and molasses and the smallest in sugar cane juice and sugar VHP. Assessment about the profile of the phenolic compounds in rapadura and sugar cane juice acquired in local commerce showed that the rapadura presents high contents of the luteolina, while in sugar cane juice, predominate tricin. In the sample of rapadura stand out high chlorogenic acid contents, compound that showed absent in sample from during the processing industrial stages of sugar. The antioxidants activities of rapadura extracts showed the in spite of in low concentration the activity is moderate. The sugar cane juice presented similar activity but, in high concentration. As for the antiproliferative activity, the rapadura extract presented cytostatic effect for ali lines and cytocidal for the colon cell lines (HT-29), of breast (MCF-7), of multi-drug resistant breast cells (NCI-ADR), of lung (NCI-460), of ovary (OVCAR), of kidney (786-0), and of melanoma (UACC-62). Tricin, isolated from sugar cane juice, presented moderate antioxidant activity. The antiproliferative effects of tricin were more pronunciated for multi-drug resistant breast cells (NCIADR) and of colon (HT-29), with cytostatic effect and cytocidal for lung lines (NCI460), of breast (MCF-7), ovary (OVCAR), of kidney (786-0), and of melanoma (UACC-62).

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / O melhoramento genÃtico convencional de feijÃo-caupi [Vigna unguiculata (L.) Walp] tem como proposta aperfeiÃoar suas propriedades agronÃmicas. Entretanto, a partir de uma preocupaÃÃo mundial, considerando alÃm das necessidades dos agricultores, empresÃrios e exportadores, tambÃm se busca desenvolver cultivares com maior qualidade nutricional para os consumidores. O objetivo geral deste trabalho foi analisar o efeito do melhoramento genÃtico convencional do feijÃo-caupi sobre os atributos nutricionais e propriedades funcionais de importÃncia industrial. Os atributos nutricionais foram avaliados inicialmente por meio da determinaÃÃo da composiÃÃo proximal e de minerais. As mÃdias (% base seca) dos valores de proteÃnas totais, lipÃdios, cinzas, fibra alimentar total e carboidratos digerÃveis foram 22,95; 1,60; 3,84; 17,80 e 53,87, respectivamente. Jà os teores de ferro e zinco foram em mÃdia 4,62 e 3,21 mg/100g de semente, respectivamente. Os genÃtipos com teor proteico acima de 25% apresentaram uma boa digestibilidade in vitro (cerca de 70%) e perfil de aminoÃcidos, inclusive os sulfurados, estando todos presentes em nÃveis acima do recomendado para crianÃas de 3 a 10 anos. Em comparaÃÃo com a soja, foram encontrados nÃveis baixos ou moderados de fatores tÃxicos e/ou antinutricionais nos genÃtipos com destaque em teor de proteÃna, ferro e zinco. Houve uma variaÃÃo no teor dos Ãcidos fenÃlicos (11,18 a 94,60 mg/g de semente), taninos (1,33 a 3,05 mg/g de semente), inibidores de tripsina (30,15 a 40,47 UI/mg de proteÃna), inibidores de quimotripsina (14,21 a 26,43 UI/mg de proteÃna) e lectinas (20.000 a 80.000 UH/Kg de semente). Ao se construir Ãndices de qualidade nutricional dos genÃtipos de feijÃo-caupi, verificou-se que os teores dos antinutrientes estudados podem modificar a classificaÃÃo dos mesmos. No entanto, quando os genÃtipos de feijÃo-caupi sÃo comparados com a soja, uma leguminosa amplamente consumida, percebe-se que esses fatores nÃo sÃo de grande relevÃncia, pois hà mÃtodos de inativaÃÃo e/ou remoÃÃo dos componentes indesejados. Propriedades funcionais promissoras foram encontradas para os genÃtipos avaliados, tais como capacidade de absorÃÃo de Ãgua e Ãleo, geleificaÃÃo e espumabilidade, as quais apontam para uma possÃvel aplicaÃÃo da farinha de feijÃo-caupi na indÃstria alimentÃcia. Baseando-se nos Ãndices de qualidade nutricional por meio das caracterÃsticas nutricionais e bioquÃmicas, os trÃs genÃtipos sugeridos para serem usados como parentais em programas de melhoramento genÃtico e produÃÃo de sementes sÃo: G17 (MNC02-682F-2-6), G03 (BRS ARACÃ) e G01 (BRS- JURUÃ). / Cowpea [Vigna unguiculata (L.) Walp] conventional breeding aims to improve its agricultural characteristics. However, there is a global concern that besides considering the needs of farmers, entrepreneurs and exporters, it is also necessary to develop cultivars with higher nutritional quality for consumers. The aim of this study was to evaluate the effects of conventional breeding of cowpeas upon their nutritional attributes and functional properties of industrial significance. The nutritional attributes were initially evaluated by determination of proximate and minerals composition. The means (% dry basis) of total proteins, lipids, ashes, total dietary fiber and digestible carbohydrates content were 22.95; 1.60; 3.84; 17.80 and 53.87, respectively. Mean values for iron and zinc contents were 4.62 and 3.21 mg/100g of seeds, respectively. Genotypes with protein content over 25% showed good in vitro digestibility (ca. 70%) and amino acid profile, including sulfur amino acids, all being in higher levels than the requirements for 3-10 years old children. The levels of toxic and/or antinutritional factors in the genotypes with better contents of protein, iron and zinc were low to moderate compared to those of soybeans. There were reasonable variations in phenolic acid contents (11.18 to 94.60 mg/g of seeds), tannin (1.33 to 3.05 mg/g of seeds), trypsin inhibitor (30.15 to 40.47 UI/mg protein), chymotrypsin inhibitor (14.21 to 26.43 UI/mg protein) and lectin (20,000 to 80,000UH/kg seeds). By using nutritional quality indexes of cowpea genotypes it was observed that the contents of antinutrients may change the ranking position. Nevertheless, when cowpea genotypes are compared to soybeans, it is observed that these factors are not so relevant considering that this legume seed is safely consumed by animals and humans since there are methods to inactivate or remove them. Promising functional properties were detected in the analyzed genotypes, such as water and oil absorption capacity, gelation and foaming properties. These properties point to a possible utilization of cowpea flour in the food industry. Based upon the nutritional quality indexes, we conclude that the top three genotypes suggested to be used as parentals in cowpea breeding programs are G17 (MNC02-682F-2-6), G03 (BRS-ARACÃ) and G01 (BRS-JURUÃ).

This study investigated the feasibility of oxidative modification with glucose oxidase (GluOx) to enhance the rheological and gelling properties of myofibrillar protein. Differential oxidative modifications of myofibrillar protein (MP) by hydroxyl radicals generated in an enzymatic system with glucose oxidase (GluOx) in the presence of glucose/FeSO4 compared to a Fenton system (H2O2/FeSO4) were investigated. Firmer and more elastic MP gels were produced by the GluOx-oxidizing system than by the Fenton system at comparable H2O2 levels due to an altered radical reaction pathway. The study further explored the effect of GluOx-mediated oxidation on the efficacy of transglutaminase (TGase) cross-linking of MP in 0.6 M NaCl and the rheological properties of GluOx oxidation/TGase treated MP in MP–lipid emulsion composite gels. The GluOx-mediated oxidation promoted the formation of both soluble and insoluble protein aggregates via disulfide bonds and occlusions of hydrophobic groups. The subsequent TGase treatment converted protein aggregates into highly cross-linked polymers. MP–lipid emulsion composite gels formed with such polymers exhibited markedly enhanced gelling capacity: up to a 4.4-fold increase in gel firmness and a 3.5-fold increase in gel elasticity over untreated protein. Microstructural examination showed small oil droplets dispersed in a densely packed gel matrix when MP was oxidatively modified, and the TGase treatment further contributed to such packing. Comparison of the modification of MP via GluOx oxidation/TGase cross-linking pathway under different salt concentrations (0.3 and 0.6 M NaCl) showed different patterns of MP cross-linking, resulting in different extents of aggregation. Under low-salt condition (0.3 M NaCl), the GluOx/TGase treatment increased the gel strength to the same level as those treated with TGase in 0.6 M NaCl, suggesting a potential application of GluOx/TGase for improving gel strength in low ionic strength conditions. Finally, the application of GluOx oxidation in the development of emulsion-type sausages was studied. The GluOx oxidation/TGase cross-linking improved the textural properties (firmness, chewiness, and rupture force) of emulsion-type sausages under both salt levels (P < 0.05). Under low-salt condition (1.5% NaCl), GluOx/TGase treatment can increase the sausage binding strength to the same level as the control sample under high-salt condition (3% NaCl). The GluOx oxidation/TGase treatment shows promise to improve the textural properties of emulsified meat products. However, the significant decrease of a* value and increase of b* value indicated GluOx-induced color deterioration.

Gold nanoparticles produced using the Turkevich method were able to have their hydrophobicity modified using octanethiol in a novel method for SERS application. Both amphiliphic GNPs and hydrophobic GNPs were produced and differentiated by Raman signals. The amphiliphic GNPs were able to enhance the SERS signals of the protein emulsifier in the emulsion in situ and the hydrophobic GNPs were able to enhance the SERS signals from canola oil. Further purification of the hydrophobic GNPs proved to have higher enhancement and sensitivity, but still poor consistency which is typical of SERS. Monitoring lipid oxidation using Raman and SERS using alternative approaches was the primary objective of the thesis. The purified GNPs were capable of enhancing the canola oil over two weeks, but the poor consistency led to no major trends. Using normal Raman, a triphenylphosphine oxidation reaction was capable of producing a peroxide value correlation in a very simple and rapid manor. Using a gold nanoparticle modified stainless steel wire, the headspace volatiles from canola oil oxidation were able to be enhanced, but with poor consistency. Silver dendrites were used to enhance the canola oil signal but with poor resolution. A combination of silver dendrites and GNPs were used to slightly improve enhancement, but not as strong as GNPs alone.

Emulsion-based delivery systems offer many potential benefits for incorporating omega-3 oils into foods and beverages. Nanoemulsions are emulsion-based delivery systems that are gaining popularity because of their ease of preparation, small particle size, relatively high stability, high bioavailability, and production of optically transparent emulsions. Fish oil (FO) nanoemulsions are potentially more susceptible to lipid oxidation because of their high degree of lipid unsaturation, high surface area of exposed lipids, and greater light penetration. In the first study, spontaneous emulsification, a low-energy method, was used to fabricate FO nanoemulsions. The influence of surfactant-to-oil-ratio (SOR) on particle size, turbidity, and physical stability was evaluated. Furthermore, the oxidative stability of these nanoemulsions was compared to emulsions produced by microfluidizer, a high-energy method. The effect of particle size and SOR on oxidation was monitored by measuring lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS). Optically transparent nanoemulsions were formed and maintained physical stability after being held at 37 °C for 14 days. FO nanoemulsions produced by high- and low-energy methods had similar oxidative stabilities at 55 °C for 14 days. These results demonstrate that spontaneous emulsification can produce fish oil nanoemulsion that are physically stable and oxidize at similar rates as traditionally prepared nanoemulsions, and are therefore potentially suitable for fortification of clear food systems. Additionally, carrier oils can also impact the physical and oxidative stability of FO nanoemulsions. Medium chain triglycerides, lemon oil, and thyme oil were chosen as carrier oils and added to the oil phase at different ratios of FO to carrier oil for emulsions produced by the microfluidizer. Medium chain triglycerides and lemon oil produced stable FO nanoemulsions but the thyme oil only produced stable FO nanoemulsions at lower concentrations of carrier oil. On the other hand, at FO to carrier oil ratios of 75/25, lemon oil and thyme oil nanoemulsions had high oxidative stability because of natural of their antioxidants. These findings suggest that lemon oil and thyme oil can produce FO nanoemulsions that are physically and chemically stable and can be used for food system fortification.

In this study, we determined the effect of nutritive sweeteners at 0 to 0.50 moles/kg on lipid oxidation in a model cookie system. Confocal microscopy using Bodipy 493 as a fat soluble dye showed that the fat formed a continuous phase surrounding the starch granules regardless of sugar type. The impact of glucose concentration on lipid oxidation was monitored by lipid hydroperoxides and headspace hexanal during storage at 55°C. Low concentrations of glucose (0.09) were strong inhibitors. At equal molar concentrations, reducing sugars (glucose and fructose) inhibited lipid oxidation, greater than a two months increase in lag phase compared to the control. Sucrose inhibited lipid oxidation, but to a much lesser extent than reducing sugars. The inhibition of lipid oxidation is potentially due to sugar’s ability to bind water. Additionally, reducing sugars may exhibit this effect due to their ability to act as a hydrogen donor which could inactivate free radicals or due to the production of Maillard reaction products (MRPs). For example, the l-values were lower and b-values were higher for cookies with non-reducing sugars compared to cookies with sucrose indicating that there were more MRPs. The addition of cysteine, sulfites, and ascorbic acid acted as a strong browning inhibitors however cysteine was showed to be antioxidative. When compared to synthetic antioxidants, glucose proved to be a strong natural alternative. These results could be utilized to develop effective means of controlling water activity and extending shelf-life of low moisture baked goods.

The objective of this research was to study the impact of ripening inhibitor level and type on the formation, stability, and activity of antimicrobial thyme oil nanoemulsions formed by spontaneous emulsification. Oil-in-water antimicrobial nanoemulsions (10 wt%) were formed by titrating a mixture of essential oil, ripening inhibitor, and surfactant (Tween 80) into 5mM sodium citrate buffer (pH 3.5). Stable nanoemulsions containing small droplets (d < 70 nm) were formed. The antimicrobial activity of the nanoemulsions decreased with increasing ripening inhibitor concentration, which was attributed to a reduction in the amount of hydrophobic antimicrobial constituents transferred to the separated hydrophobic domain, mimicking bacterial cell membranes, by using dialysis and chromatography. The antimicrobial activity of the nanoemulsions also depended on the nature of the ripening inhibitor used: palm ≈ corn > canola > coconut which also depended on their ability to transfer hydrophobic antimicrobial constituents to the separated hydrophobic domain.

Unsaturated fats undergo a process known as oxidation by which they are degraded into undesirable compounds. Therefore it is important for food manufacturers to employ antioxidant strategies. Crackers were used as a model in these studies because of their dietary contribution to saturated, and because the properties of crackers are translatable to other low moisture foods. The objective of this thesis was to determine if there was a significant variance in rates of oxidation between surface and total lipids in crackers and how solid fat content, synthetic antioxidants, and reduction of headspace oxygen affect those rates. It was hypothesized that lipids on the surface of a cracker would be more prone to oxidation than those on the interior. Experiments consisted of treatments to monitor total lipid oxidation and surface lipid oxidation. In the first experiment, crackers were formulated with soy oils of varying solid fat content. The second experiment monitored the effects of two synthetic antioxidants, BHT and TBHQ. The third experiment involved flushing the headspace of cracker storage vials with different blends of nitrogen and oxygen to inhibit lipid oxidation. Overall, significant differences did not exist in the rates of oxidation between surface and interior lipids. The lower the solid fat content of an oil, the more prone it was to oxidation. Antioxidants of greater hydrophobicity have increased efficacy in low moisture foods. Greater than 70% oxygen reduction is necessary to impart any antioxidant effect on crackers.