ABSTRACT PILOT SCALE WHEAT GERM STABILIZATION IN A SPOUTED BED OYMAK, Mert Mehmet M.S., Department of Chemical Engineering Supervisor: Prof. Dr. N. Suzan KINCAL Co-Supervisor: Dr. Cevdet &Ouml / ZTiN April 2006, 97 pages Wheat germ, a nutritionally rich by product of wheat milling, has poor storage stability due to its content of essential fatty acids along with oxidative enzymes. A pilot scale conventional spouted bed was designed and constructed as a high temperature &amp / #8211 / short time treatment unit to bring about drying and roasting effects. By facilitating the use of high temperature inlet air, yet maintaining the bed solids at a temperature below the degradation temperature, spouted bed dryers achieve thermal efficiencies unachievable by other dryers. The inlet diameter, diameter of the column and the angle of the cone were 6.2 cm, 16 cm and 65&deg / respectively. Thermocouples were placed on the inlet, exit and discharge gate of the column. Temperature profiles were recorded during drying, roasting and cooling of wheat germ. The drying temperatures ranged between 201 and 243&deg / C, operation times between 6.5 and 12 minutes, and air flow rate between 55 and 65 m3/h. It was seen that the degree of roasting was closely related to the exit temperature of the air. The exit air temperature range was determined as 155-160&deg / C. Sensory evaluation tests were carried out. Wheat germ processed at 60 m3/h &amp / #8211 / 209&deg / C for 12 min and 55 m3/h &amp / #8211 / 216&deg / C for 7 min were selected as the samples for storage studies, on the basis of the results of sensory evaluation tests. Reproducibility runs were carried out for the selected conditions. The bed height increase study was carried out at 60 m3/h &amp / #8211 / 240 to 243&deg / C. The processed and raw wheat germ was stored in paper pouches at 40&deg / C, to estimate the shelf life on the basis of earlier studies. Peroxide values of both raw and processed samples were followed during the storage period. The initial peroxide values of raw germ, processed samples, and reproducibility samples were 1.1 meq peroxide / kg oil. The peroxide value formation data were found to follow zero order rate kinetics. Comparison of the peroxide value changes in the processed and raw samples indicated that in the studied range of 55-60 m3/h &amp / #8211 / 209-216&deg / C &amp / #8211 / 7-12 min, about 8&amp / #8211 / 10 fold increase in the shelf life due to stabilization was achieved. The color parameters of each run were determined using the CIELAB (L*, a*, b*) system. Total color difference (&amp / #8710 / E*) values due to processing were calculated using L*, a* and b* values, to be between 2.3 and 58.6.

Darbo tikslas - įvertinti Lietuvoje gaminamų fermentinių sūrių ir sūrio produktų riebalų kokybės rodiklius. Darbo uždaviniai: 1. Fermentinių sūrių ir sūrio produktų riebalų rūgščių nustatymas dujų chromatografijos metodu; 2. Fermentinių sūrių ir sūrio produktų riebalų kokybės rodiklių analizė ir nustatymo metodų įsisavinimas; 3. Fermentinių sūrių ir sūrio produktų riebalų peroksidų skaičiaus nustatymas ir duomenų statistinis apdorojimas; 4. Fermentinių sūrių ir sūrio produktų rūgštingumo skaičiaus nustatymas ir duomenų statistinis apdorojimas; 5. Fermentinių sūrių ir sūrio produktų juslinių savybių įvertinimas, taikant juslinių savybių profilius. Tirti Lietuvoje pagaminti sūriai: fermentiniai kieti; fermentiniai puskiečiai; sūrio produktai; lydyti sūriai. Tyrimas atliktas Lietuvos sveikatos mokslų universiteto Lietuvos veterinarijos akademijos Maisto saugos ir gyvūnų katedroje ir Kauno technologijos universiteto Maisto instituto Chemijos laboratorijoje. Riebalų rūgštys buvo nustatytos dujų chromatografijos metodu, peroksidų skaičius, riebalų rūgštingumas nustatytas titruojant, aktyvusis rūgštingumas nustatytas potenciometru „CyberScan pH510“. Juslinė analizė fermentinių kietų, fermentinių puskiečių sūrių ir sūrio produktų atlikta taikant juslinių savybių profilius. Išvados: 1. Fermentiniuose kietuose sūriuose buvo nustatytas didesnis sočiųjų riebalų rūgščių kiekis, lyginant su fermentiniais puskiečiais sūriais, sūrio produktais ir lydytais sūriais (p<0,05 visais atvejais)... [toliau žr. visą tekstą] / The aim of the work – evaluate fat quality indicators in Lithuania fermented cheeses and cheese products. Objectives: 1. Determination of fatty acids in fermented cheeses and cheese products by gas chromatography method; 2. Analysis of fat quality indicators and uptake of detection methods in fermented cheeses and cheese products; 3. Determination of the peroxide value and statistical processing of data in fermented cheeses and cheese products; 4. Determination of the acidity and statistical processing of data in fermented cheeses and cheese products; 5. Sensory properties of fermented cheeses and cheese products. Investigated Lithuania cheeses: fermented hard, fermented semi-hard, cheese products and processed cheeses. Analysis of fatty acids in the Lithuanian cheeses and their products was carried out of Lithuania Health Science University Veterinary Academy of Food and Animal Safety department and Kaunas University of Technology, Institute of Food Chemistry Laboratory. Fatty acids were determined by gas chromatography, peroxide and fat acidity were determined by titration, active acidity was determined by potentiometer „CyberScan pH510“. Organoleptic analysis was performed in fermented hard cheeses, fermented semi-hard cheeses and cheese products. Conclusions: 1. The higher amount of saturated fatty acids were found in hard cheeses compared to the semi-hard cheese, cheese products and processed cheese (p <0.05 in all cases). Polyunsaturated fatty acids have been found... [to full text]

Master of Science / Grain Science and Industry / Greg Aldrich / Rendered protein meal is an important source of dietary protein and fat in pet food. However, fats in rendered meals can oxidize rapidly if not protected. The most common measurement of oxidation is the peroxide value (PV), but the analysis is highly variable. Additionally, the incorporation of oxidized protein further shortens its shelf life. Therefore, our objectives were to evaluate methods to measure fat quality in rendered protein meals and to determine the effect of increasingly oxidized protein meals on the shelf life of extruded pet foods. In Experiment 1, samples of five chicken byproduct meals (CBPM) from each of three locations and five beef meat and bone meals (BMBM) from each of two locations were analyzed for PV, anisidine value (AV), and thiobarbituric acid reactive substances (TBARS). The PV varied by method and location (P < 0.05). The alternative oxidation analytical methods, AV and TBARS, were not strongly correlated to PV (R² > 0.01). In Experiment 2, one metric ton of each unpreserved CBPM and unpreserved BMBM were collected and left unpreserved (U) or preserved with either ethoxyquin (E) or mixed tocopherols (T). These were held at ambient conditions (25°C, 51% RH) and monitored for PV and AV until values plateaued (41 and 63 days for CBPM and BMBM, respectively). Each “aged” meal was then incorporated into a model extruded cat food diet (~30% protein). Samples of kibble for each treatment were collected and stored at an elevated temperature and humidity (40°C, 70% RH) for 18 weeks and an ambient temperature and humidity (~22°C, 45% RH) for 12 months. The initial reduction (P < 0.05) in PV of the U (highly oxidized) BMBM and CBPM after processing suggests oxidation levels were diluted by food production. The oxidized meal led to a shorter shelf life (P < 0.05) in the finished food by PV analysis; but, sensory analysis by quick assessment did not completely corroborate these findings. These results suggest that PV doesn’t fully describe rendered protein meal stability or have a direct impact on shelf life for consumers; but may have a negative impact on pets due to oxidized lipid consumption.

This diploma thesis deals with characterization of sea buckthorn oil. The sea buckthorn oil is frequently used as a food supplement and in dermatology. The first part summarizes the literature on sea buckthorn oil and its biological effects. In the experimental part, the thesis deals with the comparison of three commercially available preparates of sea buckthorn oils. We employed the basic characteristics of these oils, including the determination of peroxide value, iodine value, saponification value and acid value using titration methods. Spectroscopic measurements were used to further characterize the oils. The comparised sea buckthorn oil samples differed strongly in the peroxide value and in the stability during storage. In this respect, the oil from Relikt - Art Engel company had significantly lower value (2,95 mekv/kg) compared to other two oil samples studied from Elith Phito and Virde companies with peroxide values 12,68 and 8,97 mekv/kg. This value was also much less prone to increase during storage. A similar difference was also found in spectral and colorimetric characteristics of the oil samples, where this oil displayed much less optical density then the other two samples. This might be a result of different technology used for production of oils, or it may reflect some adulteration,...

A formulação de dietas para ruminantes pode alterar o perfil de ácidos do leite, potencializando o valor nutritivo e nutracêutico do mesmo. Estas alterações podem, no entanto, aumentar a susceptibilidade do leite à oxidação, perdendo qualidade em sabor e tempo de prateleira. O objetivo deste trabalho consistiu em avaliar o efeito do fornecimento de dieta com alto teor de soja integral extrusada, associada ou não à suplementação com selênio orgânico, sobre a produção, a composição, a concentração de CLA, o perfil de ácidos graxos e a estabilidade oxidativa do leite. Vinte e quatro vacas holandesas foram agrupadas em três blocos, de acordo com o número de lactações e alimentadas com dieta total contendo 56% de volumoso e 44% de concentrado. Os animais foram distribuídos aleatoriamente nos seguintes tratamentos: A) dieta controle, B) dieta contendo 21% de soja extrusada e C) dieta contendo 21% de soja extrusada + 5 mg de selênio orgânico. As dietas foram balanceadas para obtenção dos mesmos níveis de energia e proteína. O fornecimento de soja extrusada não afetou o consumo de matéria seca, o peso vivo dos animais e a produção de leite. As vacas alimentadas com soja extrusada produziram leite com menor (P<0,01) porcentagem de gordura, menor (P<0,01) concentração de ácidos graxos de cadeias curta e média e maior (P<0,01) concentração de ácidos graxos de cadeia longa, quando comparadas às vacas alimentadas com a dieta controle. Com relação ao teor de saturação, produziram leite com menor (P<0,01) concentração de ácidos graxos saturados e maior (P<0,01) concentração de ácidos graxos poliinsaturados e de ácido linoléico conjugado (CLA). A concentração de colesterol total foi maior (P<0,01) no soro sanguíneo das vacas alimentadas com soja extrusada, quando comparado ao controle. A suplementação com selênio aumentou (P<0,05) significativamente a concentração do mineral no leite e retardou a oxidação do mesmo, avaliada pelo índice de peróxido (P<0,01). O fornecimento da dieta contendo 21% de soja alterou o perfil de ácidos graxos do leite, diminuindo a concentração de ácidos graxos saturados e aumentando a concentração de ácidos graxos poliinsaturados e ácido linoléico conjugado, no entanto, produziu um leite mais susceptível à oxidação. O enriquecimento do leite com selênio conseguiu minimizar este efeito influenciando positivamente a estabilidade do leite. / The manipulation of ruminant diet can modify the fatty acid profiles increasing its nutritive and therapeutic value. However, this change in fatty acid composition can increase milk oxidation and can affect its flavor and shelf life. The objective of this study was to evaluate the effect of extruded soybean diet and organic selenium supplementation on milk composition, CLA content, fatty acid profiles and oxidative stability of milk. Twenty four Holstein cows were grouped into three blocks according to number of parturition and were fed diets containing 56% forage and 44% concentrate. The animals were allocated to three treatments: A) control diet, B) 21% extruded soybean diet and C) 21% extruded soybean diet + 5 mg of organic selenium. The diets were formulated to provide the same energy and protein levels. The extruded soybean did not affect the dry matter intake, body weight and milk production. The cows fed extruded soybean diet produced milk with lower (P<0,01) concentration of fat, lower (P<0,01) concentration of short and medium chain fatty acids and higher (P<0,01) concentration of long chain fatty acids when compared to control group. Regarding to saturation level, those animals produced milk with lower (P<0,01) concentration of saturated fatty acids and higher (P<0,01) concentration of polyunsaturated fatty acids and CLA content. The serum concentration of cholesterol was higher (P<0,01) for treatments containing extruded soybean when compared to control. The organic selenium supplementation increased (P<0,05) milk selenium concentration and delayed milk oxidation measured by peroxide value (P<0,01). The inclusion of 21% of extruded soybean in dairy cattle diet resulted in production of milk fat with modified fatty acid profile with lower concentration of saturated fatty acids and higher concentration of polyunsaturated fatty acids and CLA content. However the milk fat was more susceptible to oxidation. The organic selenium supplementation was efficient to overcome this problem and therefore could maintain the stability of milk.

A formulação de dietas para ruminantes pode alterar o perfil de ácidos do leite, potencializando o valor nutritivo e nutracêutico do mesmo. Estas alterações podem, no entanto, aumentar a susceptibilidade do leite à oxidação, perdendo qualidade em sabor e tempo de prateleira. O objetivo deste trabalho consistiu em avaliar o efeito do fornecimento de dieta com alto teor de soja integral extrusada, associada ou não à suplementação com selênio orgânico, sobre a produção, a composição, a concentração de CLA, o perfil de ácidos graxos e a estabilidade oxidativa do leite. Vinte e quatro vacas holandesas foram agrupadas em três blocos, de acordo com o número de lactações e alimentadas com dieta total contendo 56% de volumoso e 44% de concentrado. Os animais foram distribuídos aleatoriamente nos seguintes tratamentos: A) dieta controle, B) dieta contendo 21% de soja extrusada e C) dieta contendo 21% de soja extrusada + 5 mg de selênio orgânico. As dietas foram balanceadas para obtenção dos mesmos níveis de energia e proteína. O fornecimento de soja extrusada não afetou o consumo de matéria seca, o peso vivo dos animais e a produção de leite. As vacas alimentadas com soja extrusada produziram leite com menor (P<0,01) porcentagem de gordura, menor (P<0,01) concentração de ácidos graxos de cadeias curta e média e maior (P<0,01) concentração de ácidos graxos de cadeia longa, quando comparadas às vacas alimentadas com a dieta controle. Com relação ao teor de saturação, produziram leite com menor (P<0,01) concentração de ácidos graxos saturados e maior (P<0,01) concentração de ácidos graxos poliinsaturados e de ácido linoléico conjugado (CLA). A concentração de colesterol total foi maior (P<0,01) no soro sanguíneo das vacas alimentadas com soja extrusada, quando comparado ao controle. A suplementação com selênio aumentou (P<0,05) significativamente a concentração do mineral no leite e retardou a oxidação do mesmo, avaliada pelo índice de peróxido (P<0,01). O fornecimento da dieta contendo 21% de soja alterou o perfil de ácidos graxos do leite, diminuindo a concentração de ácidos graxos saturados e aumentando a concentração de ácidos graxos poliinsaturados e ácido linoléico conjugado, no entanto, produziu um leite mais susceptível à oxidação. O enriquecimento do leite com selênio conseguiu minimizar este efeito influenciando positivamente a estabilidade do leite. / The manipulation of ruminant diet can modify the fatty acid profiles increasing its nutritive and therapeutic value. However, this change in fatty acid composition can increase milk oxidation and can affect its flavor and shelf life. The objective of this study was to evaluate the effect of extruded soybean diet and organic selenium supplementation on milk composition, CLA content, fatty acid profiles and oxidative stability of milk. Twenty four Holstein cows were grouped into three blocks according to number of parturition and were fed diets containing 56% forage and 44% concentrate. The animals were allocated to three treatments: A) control diet, B) 21% extruded soybean diet and C) 21% extruded soybean diet + 5 mg of organic selenium. The diets were formulated to provide the same energy and protein levels. The extruded soybean did not affect the dry matter intake, body weight and milk production. The cows fed extruded soybean diet produced milk with lower (P<0,01) concentration of fat, lower (P<0,01) concentration of short and medium chain fatty acids and higher (P<0,01) concentration of long chain fatty acids when compared to control group. Regarding to saturation level, those animals produced milk with lower (P<0,01) concentration of saturated fatty acids and higher (P<0,01) concentration of polyunsaturated fatty acids and CLA content. The serum concentration of cholesterol was higher (P<0,01) for treatments containing extruded soybean when compared to control. The organic selenium supplementation increased (P<0,05) milk selenium concentration and delayed milk oxidation measured by peroxide value (P<0,01). The inclusion of 21% of extruded soybean in dairy cattle diet resulted in production of milk fat with modified fatty acid profile with lower concentration of saturated fatty acids and higher concentration of polyunsaturated fatty acids and CLA content. However the milk fat was more susceptible to oxidation. The organic selenium supplementation was efficient to overcome this problem and therefore could maintain the stability of milk.

Oxidation limits the shelf life of many food products. Adding antioxidants to foods is the most common way to solve this problem. Reports on safety issues of synthetic food additives have raised consumer interest in "all natural" foods, without added antioxidants or with synthetic replaced with natural antioxidants. The natural antioxidants now in use are much more expensive and less potent than the synthetic antioxidants. Thus, effective and economical natural antioxidants are of great interest to researchers. Teng Cha is a type of herbal tea found in China that has reported high levels of antioxidants. Antioxidant activity of Teng Cha extract and its major component dihydromyricetin has been reported, but no studies have provided clear evidence for the antioxidant effectiveness of Tech Cha extracts. The goal of this study was to measure the antioxidant activity of Teng Cha extract and dihydromyricetin (DHM), a major component of Tech Cha extract. The DPPH assay was conducted and antioxidant activities of the crude extract and dihydromyricetin were evaluated in soybean oil based on the peroxide value, anisidine value, Totox value, headspace volatiles and headspace oxygen. Antioxidant effectiveness was also evaluated in a cooked beef model system. DHM was more potent than BHA in preventing soybean oil oxidation. The crude extract was not as effective as BHA and DHM, possibly because it contained transition metals. In cooked beef, DHM and the crude extract showed lower activity than BHA, possibly due to their low solubility. Overall, Teng Cha extract and DHM are potential natural food antioxidants for future applications. / Master of Science in Life Sciences