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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Disponibilidade de ferro em ovo, cenoura e couve e em suas misturas / Iron availability in egg, carrot and cabbage and in them mixtures

Flavia Maria Vasques Farinazzi Machado 26 October 2005 (has links)
A anemia causada por deficiência de ferro é a forma mais comum de todas as anemias e afeta grande parcela da população mundial, especialmente o grupo materno-infantil: lactentes, pré-escolares, escolares, gestantes e nutrizes. A carência acarreta atraso no desenvolvimento psicomotor e cognitivo de crianças menores de dois anos, além de diminuição da eficiência da função imune, e agravamento de doenças infecciosas. O presente estudo teve por objetivos avaliar a disponibilidade de ferro em alimentos fontes deste e de vitamina A, ovo (o), cenoura (c) e couve (cv), bem como verificar a interação do ferro com α e ß-caroteno, e com outros interferentes. As misturas foram de ovo com cenoura e ovo com couve em diferentes proporções (1:1), (1:1,5), (1:2), (1:2,5) e (1:3) e também dos 3 alimentos sozinhos, totalizando 13 amostras. As amostras, após pré-preparo e cocção, foram submetidas às análises de composição centesimal, ferro, taninos, ácido fítico, ácido oxálico, α- e β- caroteno e ferro dialisável. Os dados foram submetidos à análise estatística empregando o teste de Tukey, regressão polinomial e correlação, utilizando o software SAS (1996). Os valores para umidade variaram de 83,93 a 95,74 g/100g, apresentando diferenças significativas entre as distintas amostras, assim como para proteínas (0,55 a 7,22g /100g) e extrato etéreo (0,21a 5,94 g/100g). Foi observado que em relação à umidade, extrato etéreo, proteínas, cinzas e β-caroteno houve correlação significativa para o ferro dialisável, sendo que para umidade e β-caroteno essa correlação foi positiva e para os demais componentes foi negativa. Os teores para taninos, fitatos e oxalatos variaram de 0,78 a 1,40 mEqcatequina/g, 0,17 a 0,42 mg/g, e 0,06 a 0,30% respectivamente. A amostra 2 (1o:1,5c) apresentou teores mais elevados de taninos (1,40 mEqcatequina/g), e as amostras 6 (1o:1cv) e 7 (1o:1,5cv) apresentaram teores mais elevados de oxalato e teores de ferro dialisável mais baixo, em relação às outras misturas. O teor de α-caroteno para as amostras contendo cenoura variou de 2.435,27 a 4.609,83 µg/100g. Quanto ao β-caroteno observou-se variações de 2.406,75 a 7.881,55 µg/100g, sendo evidenciado valores mais elevados para as amostras com cenoura. Numericamente, as misturas com maior proporção de cenoura e couve apresentaram os maiores resultados para o ferro dialisável, que variou entre 0,99 a 7,43%, sendo que a amostra 5 (1o:3c) apresentou o melhor resultado, seguida pelas amostras 1, 2, 3, 4, 8, 9 e 10. Pelos resultados obtidos pode-se concluir que as misturas com maior proporção de cenoura e couve aumentaram a disponibilidade do ferro, principalmente pelo maior conteúdo de ß-caroteno. Não houve interferência significativa dos antinutricionais sobre o ferro dialisável, embora os taninos e ácido oxálico atuaram como fatores limitantes quando observados os valores numéricos nas amostras com maiores concentrações de cenoura e couve. O ß-caroteno apresentou correlação positiva significativa com o ferro dialisável, exercendo influência na redução do efeito dos antinutricionais, especialmente dos fitatos, na disponibilidade do ferro, principalmente nas amostras com cenoura. Assim, pode ser recomendada a utilização de misturas de alimentos como ovo e cenoura, sendo que este último deve estar em maiores proporções em refeições destinadas a populações carentes em ferro. / The anemia caused by iron deficiency, is the form more common of all the anemias and it affects large portion of the world population, especially the maternal-infantile group: infants, child-school, children, pregnant woman and nutrizes, carting delay in the development psicomotor and cognitive of smaller children two years old, besides decrease of the efficiency of the immune function, and worsening of infectious diseases. This research aims to estimate the iron availability in food iron sources and vitamin A, egg (e), carrot (c) and cabbage (cb), as well as to verify the interaction of the iron with α, ß-carotene and with other interferents, being mixed the foods in study, resulted 13 food mixtures in different proportions (1:1), (1:1.5), (1:2), (1:2.5) and (1:3) include three food alone. The food mixtures, after prepare and cooking, was submitted the analyses of centesimal composition, levels of iron, tannin, phytic acid, oxalic acid, α, ßcarotene and in vitro iron dialysability. The statistical analysis was determinate by SAS System include polynomial regression and correlation. The values for moisture varied from 83.93 to 95.74 g/100g, showing significant differences among the different mixtures, as well as for proteins (0.55 to 7.22 g/100g) and fat (0.21 to 5.94 g/100g). There was significant correlation with regard to moisture, fat, protein, ash and ß-carotene to in vitro iron dialysability, being positive correlation to moisture and ß-carotene, and negative to other components. The levels of tannins, phytate and oxalates ranged 0.78 to 1.40 mEqcatequina/g, 0.17 to 0.42mg/g and 0.06 to 0.30%, respectively. The mixture 2 (1e:1.5c) showed high levels of tannins (1.40mEqcatequina/g), and the mixtures 6 (1e:1cb) and 7 (1e:1.5cb) high levels of oxalates, and lower levels of in vitro dialysability iron, in relation to the other mixtures. The values for α- carotene to mixtures with carrot ranged 2,435.27 to 4,609.83 µg/100g. With regard to ß-carotene, ranged variations to 2,406.75 from 7,881.55 µg/100g, being observed higher levels for the mixtures with carrot. The numbers showed that the mixtures with larger carrot and cabbage proportion showed the bigger results for the in vitro dialysability iron, ranges to 0.99 from 7.43 %, and the sample 5 (1e:3cb) it presented the bigger value, proceeded by the mixtures 1, 2, 3, 4, 8, 9 and 10. It’s concluded that the mixtures with larger carrot and cabbage proportion increased the iron availability, especially for the largest content of ß-carotene. There was not significant interference of antinutritional in the in vitro iron dialysability, although tannins and oxalates were an inhibitor when observed the numeric values in the mixtures with larger carrot and cabbage concentrations. The ß-carotene showed significant positive correlation with in vitro iron dialysability, increasing influence in the reduction of the antinutritional factors effect, especially phytates, in the iron availability, mainly in the mixtures with carrot. Therefore, the use of food mixtures as egg and carrot can be recommended, and this last one should be in larger proportions in meals destined to lacking populations in iron.
42

Combining Cover Crops, Strip Tillage, and Novel Mulches to Manage Weeds in Vegetable Cropping Systems

Puka-Beals, Jesse Jor-El January 2020 (has links)
Vegetable producers may benefit from integrating living mulches into their operations to manage weeds and improve soil quality. Living mulches, however, can reduce vegetable yield through competition. Here we investigate strip tilling into living mulches and then direct seeding a vegetable crop in the strip till zone as a production practice to limit competition. We further investigate the use of two surface-applied mulches, a newsprint hydromulch and a compost blanket, for weed control within the strip till zone. In field conditions, living mulches reduced vegetable yield by 49-84% and the use of the newsprint hydromulch and compost blanket reduced weed biomass by 84% and 85% respectively. In greenhouse conditions, a 50% reduction in the hydromulch application rate used in the field experiment achieved similar weed control, suggesting an application rate of 6.4 L m-2 or a mulch strength of 0.6 MPa may be sufficient for weed control with a hydromulch.
43

Využívání ekonomických mechanismů v zahraniční politice Ruské federace: případ Arménie / The Use of Economic Mechanisms in the Foreign Policy of the Russian Federation: the Case of Armenia

Motúzová, Diana January 2019 (has links)
The thesis analyses Russian economic statecraft in relation to Armenia. The thesis is focused on two areas, namely the Russian response to the foreign policy orientation of Armenia and its significant internal political changes. The aim of the thesis is to compare the extent to which Russia uses economic mechanisms on both levels. The thesis draws on Baldwin's concept of economic statecraft, focusing on the Russian "carrot and stick" policy. In the foreign policy area, the economic tools that Russia used in attempt to influence Armenia's decision in its dilemma between European and Eurasian integration are analysed. In the internal policy area, the thesis is focused on major events from 2015 to 2018, which to some extent also affected the Russian side. Positive incentives and coercive methods applied by Russia during this period are also examined. An analysis of the Russian "carrot and stick" policy has pointed out that Moscow is more strongly involved in foreign policy of Armenia if it feels an immediate threat to its interests. Russia applies positive incentives in situations when it needs to reduce internal tensions in Armenia, which may also be directed against Moscow. If there are major internal political changes in this South Caucasus republic, yet without serious foreign policy implications,...
44

Host selection behavior of the adult parasitoid Microctonus hyperodae Loan (Hymenoptera:Braconidae:Euphorinae) and the egg parasitoid Anaphes victus Huber (Hymenoptera:Mymaridae), parasitoids of the carrot weevil, Listronotus oregonensis LeConte (Coleoptera:Curculionidae)

Cournoyer, Michel, 1976- January 2003 (has links)
No description available.
45

Evaluation of strains of Bacillus thuringiensis as biological control agents of the adult stages of the carrot weevil, Listronotus oregonensis (Coleoptera:Curculionidae)

Saade, Fabienne Eugenie Joseph January 1993 (has links)
No description available.
46

Mathematical models for the population dynamics and management of the carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera:Curculionidae)

Zhao, Dingxin January 1990 (has links)
No description available.
47

Insects as a Sustainable Food Ingredient – Utilization of Carrot Pomace, Identification of Early Adopters, and Evaluation of Mealworm Acceptability

Rovai, Dominic 01 June 2021 (has links) (PDF)
Insects have been proposed as a sustainable alternative to livestock to help feed the growing population. Edible insects such as mealworms require less land and resources and can utilize food by-products to grow. While insects are consumed by over 2 billion people worldwide, they are not widely accepted in developed countries like the United States because of their unfamiliarity and the perception of disgust associated with entomophagy. The objectives of this research are to 1) grow mealworms using carrot pomace and determine an optimum diet for growth and nutritional composition, 2) identify and classify early adopters of insects, and propose a product form, and 3) assess the acceptability of frozen, ready-to-cook mealworms with early adopters. A response surface design was used to evaluate the use of carrot pomace in various percentages in the substrate and as the moisture source in a mealworm growing system. Mealworms were grown under controlled conditions in a climate chamber until they began to pupate, and statistical models were fitted to predict mealworm mortality, weight, days to pupation, protein content, fat content, and moisture content. An algorithm in Design Expert was used to optimize mealworm growth based on maximizing mealworm weight and minimizing mortality and days to pupation, and the optimum diet was found to be 36% carrot pomace in the substrate with carrot pomace as the moisture source. Early adopters of insects were identified through a survey using Red Jade Sensory Software. Participants were segmented using partitioning around medoids clustering algorithm based on responses to questions on willingness to consume insects in a variety of forms. Four segments were identified: No-thank-you’s, Hideaways, Daredevils, and Peekaboo’s. Daredevils, Peekaboo’s, and Hideaways are early adopters of insects in the nonvisible form, and Daredevils and Peekaboo’s are also early adopters of insects in the visible form. Based on these insights, frozen, ready-to-cook mealworms were selected to target Daredevils and Peekaboo’s as a product to serve as a sustainable alternative to traditional livestock protein. Participants from each of the four segments were shown a video of mealworm cooking and asked their willingness to buy the product and the motivation behind their response. The majority of respondents were unwilling to buy this product, driven by unfamiliarity and the perception of disgust. However, over half of Daredevils were willing to buy the product, driven by the novelty and ease of preparation. Marketing a product towards this group may be a feasible route for entry into the market and increase the familiarity of edible insects, thereby contributing to long-term acceptability.
48

Approaches for Enhancing Lethality of Bacterial Spores Treated by Pressure-Assisted Thermal Processing

Ratphitagsanti, Wannasawat 01 October 2009 (has links)
No description available.
49

Pineapple Vinegar to Enhance Shelf Life of Carrot and Mango in Tanzania

Matunda, Aldegunda Sylvester 09 July 2015 (has links)
Fruits and vegetables are highly perishable, produced seasonally, and large quantities (about 50-60% of production) are wasted during high season due to poor handling and lack of cold storage in Tanzania. Processing excess pineapple into vinegar which can be used for preservation of other fruits and vegetables may be a helpful strategy for reducing losses. Vinegar was produced from pineapple juice supplemented with sugar to produce different degrees of Brix (13, 20 and 30) and was fermented with Saccharomyces cereviciae, Acetobacter pasteurianus, and Gluconobacter oxydans. Levels of acetic acid were measured in the vinegar produced. High production (5.8%) of acetic acid was observed with pineapple juice concentrated to 130 Brix with the combination of Saccharomyces cerevisiae, A. pasteurianus and G. oxydans. The pineapple vinegar produced was used for preservation of carrot and mango. The pH of carrot pickle and mango chutney was monitored for three months. The pH of preserved carrot and mango was below 4 and no significant changes in pH were observed during three months storage at 29-320C. Chemical analysis of vitamin A and vitamin C showed high losses of Vitamin A in carrot and increased vitamin A in mango, but losses of about 74% and 85% of vitamin C were observed in carrot and mango after processing. Consumer sensory testing of pineapple vinegar, carrot pickle and mango chutney showed no significance different on overall consumer acceptability of products during storage. Pineapple vinegar can be used to rescue mango and carrots that would otherwise be lost, producing highly acceptable food products in Tanzania. / Master of Science in Life Sciences
50

Effect of Standard Post-harvest Interventions on the Survival and Regrowth of Antibiotic-Resistant Bacteria on Fresh Produce

Pulido, Natalie Anne 19 December 2016 (has links)
Raw vegetables can sometimes be the source of outbreaks of human illness; however the potential for fresh vegetables to serve as a vehicle for antibiotic -resistant bacteria is poorly understood. Antibiotics and antibiotic-resistant bacteria have been shown to persist in manure of animals administered antibiotics, and in compost generated from this manure, where there is the potential for their transfer to produce. The purpose of this study was to determine the survival of antibiotic-resistant bacteria on raw, peeled, carrots after washing with commonly used chemical sanitizers. Multi-drug resistant E. coli O157:H7 and Pseudomonas aeruginosa were inoculated into a compost slurry of composted manure from dairy cattle, with and without prior administration of antibiotics, and used to inoculate carrot surfaces prior to the washing studies. This approach provided defined model antibiotic-resistant pathogens present within a background microbial community simulating potential carry over from manure-derived fertilizer. Carrots (n=3, 25g) were air-dried and stored at 4 °C until washing with tap water, XY-12 (sodium hypochlorite, 50 ppm free chlorine) or Tsunami 100 (peroxyacetic acid/hydrogen peroxide, 40 ppm free paracetic acid), according to manufacturer's directions. A second batch of carrots representing each inoculation x wash condition (n=3) were individually packaged for storage at 2 °C for 1,7, and 14 days, or 10 °C for 7 days and enumerated on those day intervals to recover bacteria from the surfaces of washed carrots. The resulting previously washed and stored carrots were subject to serial dilution and plated onto corresponding agar to enumerate total aerobic bacteria (R2A), aerobic bacteria tolerant or resistant to antibiotics (antibiotic-supplemented R2A), E. coli (Eosin Methylene Blue), and Pseudomonas spp. (Pseudomonas Isolation Agar). In addition, the tetA gene was quantified from the carrot samples as a measure of the effect of sanitizers and storage on an antibiotic resistance gene known to be carried by the inoculated bacteria.Inclusion of sanitizer in the wash water significantly reduced the absolute numbers of inoculated bacteria (E.coli and Pseudomonas) as well as populations of bacteria capable of growth on the R2A media containing cefotaxime (10μg/mL), sulfamethoxazole (100μg/mL), or tetracycline (3μg/mL). Comparable reductions in the inoculated P. aeruginosa resistant to tetracycline (PIA T, 4μg/mL), bacteria resistant to cefotaxime (10μg/mL) and tetracycline (3μg/mL) occurred after washing with XY-12 or Tsunami 100. The sanitizer effectiveness may be bacterial dependent, as evident by larger absolute reductions of the inoculated E. coli (EMB) and bacteria grown on sulfamethoxazole (100μg/mL)-amended plates after washing with Tsunami 100 compared to washing with tap water or XY-12. Re-growth of both the inoculated and native compost-associated bacteria was inhibited by storage at 2 °C, as there were no significant differences in the log CFU/g values on the various media (total aerobic bacteria, bacteria on antibiotic-amended plates, E. coli inoculum, P. aeruginosa inoculum) during the 14-day storage period. However, temperature abuse at 10 °C resulted in significant re-growth of native Pseudomonas, compared to storage at 2 °C. A sanitizer-associated interaction between re-growth and temperature was also observed for bacteria resistant to clindamycin (25μg/mL) and cefotaxime (10μg/mL), with substantial re-growth occurring only on carrots washed with Tsunami 100. There was no significant re-growth of the inoculated E. coli O157:H7 at either temperature. Results indicate that some bacterial populations are reduced by post-harvest washes and that temperature abuse of fresh produce may result in increases in antibiotic-resistant bacterial populations. / Master of Science in Life Sciences

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