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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.
61

Radiação gama aplicada para estender a vida útil da carne de cordeiro embalada a vácuo e armazenada sob refrigeração / Gamma radiation applied to extend the shelf-life of lamb meat vacuum packed and stored under refrigeration

Raul Pereira Fregonesi 28 February 2013 (has links)
O Estado de São Paulo vem experimentando nos últimos anos um expressivo aumento da produção, oferta e consumo de carne ovina. Com a tendência atual de procura por produtos de maior conveniência, com rapidez e facilidade de preparo, vislumbra-se a necessidade do mercado investir na oferta de carne ovina na forma de cortes resfriados. Nesse sentido, a irradiação com energia ionizante poderia ser uma alternativa viável para a comercialização dos cortes resfriados de cordeiro. O objetivo deste trabalho foi estudar a aplicação de diferentes doses de radiação gama visando estender a vida útil microbiológica da carne de cordeiro embalada a vácuo e armazenada sob refrigeração. Para isso, primeiramente foi realizado um experimento preliminar visando se estabelecer parâmetros como a dose e o tempo de estocagem. As amostras foram irradiadas com doses de 1,0, 3,0 e 5,0 kGy e submetidas a análises microbiológicas por um período de 60 dias a uma temperatura de 1 °C. De acordo com os resultados pôde-se concluir que a dose de 3,0 kGy deve ser utilizada como dose máxima. Assim, iniciou-se o experimento final, e para isso, as amostras de lombo de cordeiro foram embaladas a vácuo e irradiadas com as doses zero (controle), 1,5 kGy e 3,0 kGy e estocadas sob refrigeração a 1 °C. Foram realizadas nos tempos de zero, 14, 28, 42 e 56 dias análises microbiológicas e análises físico-químicas. Também foi realizado um teste sensorial de aceitação com 63 provadores, no qual foram avaliados os atributos de aroma, textura, suculência, sabor e qualidade global. Todos os dados foram estatisticamente avaliados através de contrastes entre as médias, com um nível de significância de 5%. Os resultados obtidos para os testes microbiológicos foram de ausência de Salmonella sp., contagens esporádicas de coliformes a 45 °C e Staphylococcus aureus (< 10 (est) UFC/g) para todas as amostras. Para as demais análises microbiológicas houve efeitos significativos (p<0,05) de tratamento e tempo. Entretanto, nas características físico-químicas, houve apenas efeitos significativos (p<0,05) ao longo do tempo de zero a 28 dias, para pH e cor b* (amarelo), os quais decaíram e aumentaram, respectivamente. Na aceitação sensorial, as amostras não diferiram (p>0,05) em nenhum dos atributos avaliados. Assim, pôde-se concluir que a irradiação gama nos lombos de cordeiro foi eficiente em diminuir a proliferação de microrganismos sem prejudicar as características físico-químicas, e ainda, que a aceitação do consumidor também não foi prejudicada pela irradiação. Ao final do experimento, foi possível afirmar que a dose 3,0 kGy foi a mais indicada, pois conseguiu estender a vida de prateleira de 14 para 56 dias do lombo de cordeiro irradiado e armazenado a 1°C. / The State of São Paulo has experienced in recent years a significant increase in production, supply and consumption of lamb meat. With the current trend of demand for products of greater convenience, with speed and ease preparation, there is the need to invest in the market supply of refrigerated lamb cuts. Accordingly, irradiation with ionizing energy could be a viable alternative for the marketing of refrigerated cuts of lamb meat. The aim of this work was to study the application of different doses of gamma radiation in order to extend the stability of lamb meat vacuum packed and stored under refrigeration. For this, first a preliminary experiment was conducted aiming to determine parameters such as irradiation dose and storage time. The lamb loins (Longissimus dorsi) were vacuum packed, irradiated with doses of 1,0, 3,0 and 5,0 kGy and stored under refrigeration in cooling chamber at 1 °C. According to the results, a dose of 3,0 kGy may be indicated as the maximum dose of irradiation. After establishing these parameters, the final experiment began, and for that, the lamb loin samples were vacuum packaged and irradiated with doses zero (control), 1,5 kGy and 3,0 kGy and stored under refrigeration at 1 °C. In predetermined periods (zero, 14, 28, 42 and 56 days) microbiological and physicalchemical analysis were carried out. Also, a sensory acceptance test was conducted, with 63 consumers, which evaluated aroma, texture, juiciness, flavor and overall quality atributes. All data were statistically evaluated using contrasts between means, with a significance level of 5%. The results obtained for microbiological testing of all samples were absence of Salmonella sp. and sporadic counts of coliforms at 45 °C and Staphylococcus aureus (<10 (est) CFU/g). For other microbiological analysis there were significant effects (p <0,05) of treatment, and time. However, for the physicochemical characteristics, there were only differences (p <0,05) of time from zero to 28 days for pH and color b * (yellow), which declined and increased, respectively, over this period. In the sensory acceptance test, the samples did not differ (p> 0,05) in any of the evaluated attributes. Thus, it was concluded that gamma irradiation in the lamb loins was effective in decreasing the proliferation of microorganisms without damaging its physical and chemical characteristics. At the end of the experiment, it was possible to say that the 3.0 kGy dose was indicated because could extend the shelf life of 14 to 56 days of loin of lamb irradiated and stored at 1 °C.
62

Caracteriza??o e estudo da vida ?til de vinagreira cultivada em Serop?dica-RJ / Characterization and study of the shelf life of vinagreira cultivated in Serop?dica-RJ

REZENDE, Ana L?gia Panain de Souza 26 July 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-08-23T18:01:56Z No. of bitstreams: 1 2016 - Ana L?gia Panain de Souza Rezende.pdf: 2352671 bytes, checksum: 2325a74ffef5675199939b7af3f37d60 (MD5) / Made available in DSpace on 2017-08-23T18:01:56Z (GMT). No. of bitstreams: 1 2016 - Ana L?gia Panain de Souza Rezende.pdf: 2352671 bytes, checksum: 2325a74ffef5675199939b7af3f37d60 (MD5) Previous issue date: 2016-07-26 / CAPES / Vegetables are a source of nutrients essential to human health and have low caloric value. Among these, non-conventional vegetables also have other advantages such as hardiness and the lowest price, but lacks information on these species which prevents an increase in its production and consumption. Thus, the objective of this study was to cultivate the species Hibiscus sabdariffa, better known as vinagreira, characterize some of its constituents and estimate its shelf life potential when stored in polypropylene packaging with different perforations and stored at 5 ? 1 ?C. The vinagreira remained for approximately 120 days in field conditions in the Horticultural Sector UFRRJ. The branches were collected and transported to the Embrapa Food, which were washed, selected, arranged in bunches of about 150g and subjected to treatment consisting of the conical packaging polypropylene, perforated (P), not perforated (NP), micro perforated (MP) and control (C) in which the packs were stored without use of packaging. They were carried physical, physicochemical and chemical every two days storage. The design was completely randomized in split plots, and treatments in the plots and the days of storage in the subplot. The results were analyzed using SPSS. It was the homogeneity and normality of the data, followed by analysis of variance and significance according to Tukey test and/or regression analysis. For control, the analyzes were performed only until the fourth day of storage due to reduction of apparent quality such as wilting and color changes of the leaves, while those packaged in decreased the apparent quality, with symptoms of senescence the eighth day of storage. The leaves have a high levels of titratable acidity and carotenoids, being the predominant malic acid and the major carotenoid, the ?-carotene. It was concluded that vinagreira is well adapted Climate conditions Serop?dica-RJ, showing the source of compounds with antioxidant activity. With regard to cold storage, the use of plastic polypropylene packaging provided greater potential life for vegetables, because in these conditions the bunches could be sold for up to seven days after harvest without loss of quality, while the control bunches potential shelf life was less four days. / As hortali?as s?o fonte de nutrientes essenciais ? sa?de humana e possuem baixo valor cal?rico. Dentre estas, as hortali?as n?o-convencionais apresentam ainda outras vantagens como a rusticidade e o menor pre?o, por?m faltam informa??es sobre estas esp?cies o que impossibilita um aumento da sua produ??o e consumo. Desse modo, o objetivo do presente trabalho foi cultivar a esp?cie Hibiscus sabdariffa, mais conhecida como vinagreira, caracterizar alguns dos seus constituintes e estimar a sua vida ?til potencial, quando acondicionada em embalagens de polipropileno com diferentes perfura??es e armazenadas a 5 ? 1 ?C. A vinagreira permaneceu por aproximadamente 120 dias em condi??es de campo no Setor de Horticultura da UFRRJ. Os ramos foram colhidos e transportados para a Embrapa Agroind?stria de Alimentos, onde foram lavados, selecionados, arranjados em ma?os de aproximadamente 150 g e submetidos aos tratamentos, constitu?dos pelas embalagens c?nicas de polipropileno, perfurada (P), n?o perfurada (NP), micro perfurada (MP) e o controle (C) em que foram armazenados sem o uso de embalagens. Foram realizadas an?lises f?sicas, f?sico-qu?micas e qu?micas a cada dois dias do armazenamento. O delineamento utilizado foi o inteiramente casualizado, em esquema de parcelas subdivididas, tendo os tratamentos nas parcelas e os dias de armazenamento na subparcela. Os resultados foram submetidos a an?lises estat?sticas pelo programa SPSS. Verificou-se a homogeneidade e normalidade dos dados, com posterior an?lise de vari?ncia e de acordo com a signific?ncia procedeu-se o teste Tukey e/ou an?lise de regress?o. Para o controle, as an?lises foram realizadas somente at? o quarto dia do armazenamento, devido ? redu??o da qualidade aparente, como murchamento e altera??es de cor das folhas, enquanto para os ma?os acondicionados nas embalagens houve redu??o da qualidade aparente e sintomas de senesc?ncia ao oitavo dia do armazenamento. As folhas apresentaram elevado teor de acidez total titul?vel e de carotenoides, sendo o ?cido predominante o m?lico e o carotenoide majorit?rio, o ?-caroteno. Concluiu-se que a vinagreira se adapta bem as condi??es clim?ticas de Serop?dica-RJ, mostrando-se fonte de compostos com atividade antioxidante. Em rela??o ao armazenamento refrigerado, a utiliza??o de embalagens pl?sticas de polipropileno proporcionou maior vida ?til potencial para a hortali?a, pois nestas condi??es os ma?os poderiam ser comercializados por at? sete dias ap?s a colheita, sem preju?zo da qualidade, enquanto os ma?os do controle a vida ?til potencial foi inferior a quatro dias.
63

Utiliza??o de pel?cula de f?cula de mandioca e ?leo de canela na conserva??o p?s-colheita de tomate cereja / Use of cassava starch film and cinnamon oil in postharvest conservation of cherry tomato

OLIVEIRA, Cristiana Maia de 23 July 2013 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-11-12T20:55:15Z No. of bitstreams: 1 2013 - Cristiana Maia de Oliveira.pdf: 2253824 bytes, checksum: 0c49afa03412e03e8ba8d8d9e8b01029 (MD5) / Made available in DSpace on 2018-11-12T20:55:15Z (GMT). No. of bitstreams: 1 2013 - Cristiana Maia de Oliveira.pdf: 2253824 bytes, checksum: 0c49afa03412e03e8ba8d8d9e8b01029 (MD5) Previous issue date: 2013-07-23 / CNPq / The tomato has been widely cultivated in the state of Rio de Janeiro mainly by smallholders and family farmers that make use of organic agriculture as a way to add value to the culture. After harvest, the tomato presents itself as a highly perishable fruit, being a climacteric fruit, the ripening involves a number of changes in it physical and chemical characteristics. The main goal of this work was to evaluate the conservation and postharvest quality of cherry tomatoes Perinha ?gua Branca and Mascot cultivars, stored at room and controlled conditions. Three experiments were carried out: 1) postharvest longevity of fruits cherry tomato, 2) evaluation of the effect of cassava starch film on postharvest quality of fruits and 3) use of cinnamon essential oil to control pathogens. We carried out the following physico-chemical analyzes: weight loss, color, pH, titratable acidity, soluble solids, ascorbic acid and pectin methyl esterase activity. In the first experiment, we used fruits in the intermediate, pinky, red and mature stages to both cultivars. At room temperature, the post-harvest longevity of fruits in Perinha cultivar was 20 days in the pinky and 15 days to red and mature stages. ?Mascot? longevity was 24 days to the intermediate stage, 20 days for pinky and 15 days to red and mature stage. In controlled temperature postharvest longevity of fruits in Perinha cultivar was 24 days in the intermediate and pinky stages, 20 days to red and 15 days to mature. ?Mascot? longevity was 27 days in the intermediate and pinky stages, 24 days to red and to mature. In the second experiment, was used cassava starch coating in the following concentrations: 1%, 3% and 5%. It was observed that at room and controlled conditions cassava starch coating at a concentration of 3% promoted the best results, delaying the ripening and senescence while maintaining fruit quality. The concentration of 1% was similar to the control almost all the experimental period, while starch coating at 5% prevented the normal maturation process and showed high levels of infected fruits by fungi which affect the appearance and quality. The average activity of PME was higher in ?Mascot? fruits. The third experiment consisted in a combination of distilled water and starch coating at 3% associated with 0.1% and 0.3% concentrations of cinnamon essential oil. The cinnamon essential oil made changes on the fruit surface, causing stains and burns affecting the fruit quality. The oil was not effective in diseases control. / O tomate cereja vem sendo amplamente cultivado no Estado do Rio de Janeiro principalmente por pequenos produtores e pela agricultura familiar que fazem uso da agricultura org?nica como forma de agregar valor a cultura. O tomate ap?s a colheita apresenta-se como um fruto altamente perec?vel, sendo um fruto climat?rico seu amadurecimento acarreta uma s?rie de transforma??es em suas caracter?sticas f?sicas e qu?micas. Este trabalho teve por objetivo avaliar a conserva??o e qualidade p?s-colheita de tomates cereja cultivares Perinha ?gua Branca e Mascot, armazenados em condi??es ambiente e controlada. Foram realizados tr?s experimentos: 1) longevidade p?s-colheita de frutos de tomate cereja; 2) Avalia??o do efeito da pel?cula de f?cula de mandioca na qualidade p?s-colheita e 3) utiliza??o de ?leo essencial de casca de canela no controle de podrid?es. Foram realizadas as seguintes an?lises f?sicas e qu?micas: perda de massa fresca, cor, pH, acidez total titul?vel, s?lidos sol?veis, ?cido asc?rbico e atividade de pectinametilesterase. No experimento 1 foram utilizados frutos nos est?dios de vez, rosado, vermelho e maduro de ambas as cultivares. Em ambiente controlado, a longevidade p?s-colheita dos frutos da cultivar Perinha foi de 20 dias para os est?dios de vez e rosado e 15 dias para vermelho e maduro. Para ?Mascot? a longevidade foi de 24 dias para o est?dio de vez, 20 dias para rosado e 15 dias para vermelho e maduro. Em temperatura controlada, a longevidade p?s-colheita dos frutos da cultivar Perinha foi de 24 dias para de vez e rosado, 20 dias para vermelho e 15 dias para maduro. Para ?Mascot? a longevidade foi de 27 dias para de vez e rosado e 24 dias para vermelho e maduro. No experimento 2 foram utilizados revestimentos de f?cula de mandioca nas concentra??es de 1%, 3% e 5%. Foi observado que em condi??es ambiente e controlada, o revestimento de f?cula de mandioca na concentra??o de 3% foi o que promoveu melhores resultados retardando o processo de amadurecimento e senesc?ncia al?m de manter a qualidade dos frutos. A concentra??o de 1% se assemelhou ao controle durante quase todo per?odo experimental, enquanto que f?cula 5% impediu o processo normal de amadurecimento e mostrou alto ?ndice de frutos infectados por fungos comprometendo a apar?ncia e qualidade. A atividade m?dia de PME foi maior nos frutos de ?Mascot?. O experimento 3 consistiu da combina??o ?gua destilada e f?cula 3% associada a concentra??es de 0,1% e 0,3% de ?leo essencial de canela. O ?leo essencial de casca de canela promoveu altera??es na superf?cie dos frutos, provocando manchas e queimaduras afetando sua qualidade. O ?leo n?o foi efetivo no controle de podrid?es.
64

Effects of Processing and Packaging Modifications on the Quality and Shelf Life in Meats

Khan, Abdulla 01 May 2014 (has links)
Shelf life of meat and meat products depends on the quality of meat and packaging stability. Meat color change, lipid oxidation, pH, and microbial contamination are the main causes that affect the nutritional, sensory, and physical characteristics by forming toxic compounds, off flavors, off odors, and undesirable color. The first objective of this study was to examine the effect of newly developed CO2 generating absorbent pads on beef, tuna and chicken meats. The second objective was to compare the effect of Type I (radical quenching) antioxidants eugenol and rosmarinic acid (RA) to that of Type II (metal chelating) antioxidants milk mineral (MM), phytate, and sodium tri-polyphosphate (STPP) in raw ground chicken patties. In the first study samples of beef semitendinosus muscle, boneless and skinless chicken breast, and yellowfin tuna loins were chosen and packaged with four different pad types. Red meats and chicken exhibited trends as would normally be expected during storage. Specifically, color became less appealing (beef and tuna color changed from red to brown, and chicken changed from yellow–pink to grey); pH increased, microbial counts increased, and lipid oxidation (rancidity) increased. Lightness (L*) values for chicken were within 46 – 54, for tuna L* value range was 21-26. Redness/greenness (a*) is an indicator of freshness in red meats, and for beef steaks an average value of 12.32 was noted on day 8, indicative of fresh red color. Recorded average lipid oxidation (TBA values in mg/kg of meat) for chicken (< 0.19 mg/kg) and tuna were low (< 0.16 mg/kg) and for beef (1.06 mg/kg). Even though there was a significant effect of storage time (P < 0.05) as expected, no significant (P >0.05) differences were observed between the four tested pad types over the 8-day testing period. In study 2, (Chapter 4) a significant antioxidant effect (P < 0.05) was observed in L* values of ground chicken color between treatments. Milk mineral effectively preserved fresh color and slowed lipid oxidation in chicken patties by day 10. Inverse correlations (P < 0.001) were observed between pH (increasing), and lightness, redness values (decreasing) from day 1 through 10. Increased pH levels from slightly acidic to basic or physiological pH resulted in high numbers for total aerobic plate-counts. There was a significant antioxidant effect on lipid oxidation values by day 10; eugenol and MM were more effective (P < 0.05) than STPP in controlling lipid oxidation measured as thiobarbituric acid reactive substances (0.198 mg/kg, 0.198 mg/kg, and 0.268 mg/kg, respectively). In conclusion, CO2 generating absorbent pads did not have a positive effect on meat quality, while the antioxidant milk mineral efficiently maintained color, and pH, and controlled lipid oxidation and limited the growth of aerobic bacteria when compared to other antioxidants.
65

Produção e qualidade de batata sob influência de fertilização, massa de tubérculos sementes e regimes hídricos /

Viana, Jonathan dos Santos January 2019 (has links)
Orientador: Rogério Teixeira de Faria / Resumo: Os efeitos do manejo da irrigação, dos tubérculos sementes e fertilização na produção e qualidade da batata são discutidos como relevantes para o desenvolvimento do crescimento da cultura. A cultura da batata apresenta ótimas respostas a irrigação localizada, porém para que se obtenha sucesso se fazem necessários mais estudos. Dada a importância que essa cultura tem na mesa dos consumidores objetivou-se com essa pesquisa avaliar a produção e qualidade de batata sob influência de fertilização, massa de tubérculos sementes e regimes hídricos. O estudo foi realizado com batata cultivar Orchestra, em delineamento experimental de blocos aos acaso com seis repetições com parcelas subdivididas em fertilizações na parcela e massa de tubérculos sementes na subparcela, no qual incluiu 3 níveis de formas de fertilização: F1 – adubação convencional, F2 – fertirrigação de acordo com a marcha de absorção da cultura, F3 – fertirrigação parcelada em três vezes; 2 níveis de massas de tubérculos sementes: TS1 < 50g e TS2 > 50g. Maior produtividade (48,18 Mg ha-1) e batata graúda (43,67 Mg ha-1) foram obtidas no tratamento fertirrigação (marcha de absorção) e massas de tubérculos sementes > 50 g (48,61 Mg ha-1 e 42,78 Mg ha-1) no regime hídrico (RH) 100%ETc. Porém para as plantas submetidas ao RH 50%ETc para a variável produtividade de tubérculos não foi verificado diferença (P>0,05) nos fatores fertilização e massa de tubérculos sementes. Maior eficiência do uso da água é atribuída ao RH 50%ET... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The results of nutrient analysis and fertilization in potato production and quality are discussed as relevant to the development of crop growth. The potato crop presents excellent responses to localized irrigation, but to be successful. Given the opportunity that culture in the table of customers was aimed at that survey the production and quality of potato under influence of fertilization, mass of tubers, seeds and water regimes. The study was conducted with potato to crop Orchestra. The experimental design was a randomized block design with six replications in subdivided plots with fertilizations in the plot and mass of seed tubers in the subplot, which included 3 levels of fertilization: F1 - conventional fertilization, F2 - fertigation according to uptake of the crop, F3 - fertigation in three times; 2 levels of tuber seed masses: TS1 <50g and TS2> 50g. Higher productivity (48.18 Mg ha-1) and large potato (43.67 Mg ha-1) were obtained in the fertigation treatment and mass of tubers seeds> 50 g (48.61 Mg ha-1 and 42.78 Mg ha-1) in the water regime (RH) 100% ETc. However, for the plants submitted to RH 50% ETc for the variable yield of tubers, no difference (P> 0.05) was observed in the factors of fertilization and mass of seed tubers. Greater efficiency of water use is attributed to RH 50% ETc for tubers seeds greater than 50 g of 39.82 kg m-3 of water. The highest coverage ratio is attributed to tubers under 100% ETc regime with 89 days of cycle length. There was variatio... (Complete abstract click electronic access below) / Mestre
66

Consumers' attitudes regarding the link between frozen and fresh vegetables and health / Emdri Maria van der Walt

Van der Walt, Emdri Maria January 2003 (has links)
Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2004.
67

Effect Of High Hydrostatic Pressure Treatment On Some Quality Properties, Squeezing Pressure Effect And Shelf Life Of Pomegranate (punica Granatum) Juice Against Thermal Treatment

Gultekin, Necmiye Busra 01 September 2012 (has links) (PDF)
The aim of this study was to investigate the effect of high hydrostatic pressure (HHP) treatment (200, 300, 400 MPa / 5
68

Survival Of Probiotic Microorganisms During Storage After Marketing

Kose, Iskin 01 September 2011 (has links) (PDF)
Probiotics are viable microorganisms that show beneficial effects on the health of the host by improving their intestinal microflora. The microorganisms applied as probiotics mainly include Lactobacillus and Bifidobacterium species. Probiotics can inhibit the bacterial pathogens, reduce serum cholesterol levels, improve lactose tolerance and stimulate the immune response. They also have other properties such as / tolerance to acid and bile salts, adherence to gastrointestinal cells for colonization, resistance to antibiotics and &beta / -galactosidase acitivity. The properties of probiotic products are determined by the characteristics of the microorganisms they contain. For that reason, isolation and characterization of new strains having probiotic properties is an important issue. New strains are generally isolated from their natural habitats which are fermented dairy products such as kefir. In order to exert beneficial health affects in the digestive system, commercial probiotic products should contain adequate numbers of viable cells. Probiotic microorganisms should protect their viability during their shelf storage. Therefore, the viability of probiotics is especially important for food manufacturers that search for new probiotic strains with good survival and stability properties upon storage. In this study, probiotic microorganisms were isolated from traditional kefir grains known as a &lsquo / complex probiotic&rsquo / . The isolates were firstly identified using biochemical tests, then the putative species belonging to &lsquo / Lactobacillus acidophilus group&rsquo / were identified with 16S rRNA gene sequencing. Analysis of sequencing resulted in differentiation of &ldquo / L. acidophilus group&rdquo / organisms, namely L. amylovorus and L. acidophilus. Moreover, typing of commercial and traditional L. acidophilus strains and L. amylovorus strains were performed with RAPD-PCR by using primer M13. While several L. acidophilus strains showed different RAPD fingerprints most of the L. acidophilus and L. amylovorus strains could not be differentiated due to high similarity of their RAPD fingerprints. Following identification, survival of these isolates in probiotic yogurt preparations were investigated and compared to the survival of commercial probiotics. Consequently, although the survival of kefir grain isolates were less than commercial probiotics, they sustained the minimum recommended level for probiotics (106 cfu/ml) during cold storage. Such level of survival makes them considerably good candidates to be used as commercial probiotic cultures.
69

Preservation And Shelf Life Extension Of Anchovy (engraulis Encrasicolus) And Haddock (gadus Merlangus Euxinus) By High Hydrostatic Pressure

Akhan, Ceyda 01 June 2012 (has links) (PDF)
High Hydrostatic Pressure (HHP) application, alone or in combination with refrigeration, ambient or moderate heating temperatures / inactivates pathogenic and spoilage microorganisms and conserves the product &bdquo / &bdquo / freshness
70

Consumers' attitudes regarding the link between frozen and fresh vegetables and health / Emdri Maria van der Walt

Van der Walt, Emdri Maria January 2003 (has links)
Vegetables and fruit appear to confer protection against various diseases, but most adults in South Africa eat substantially less than the recommended amounts. Many barriers and factors that influence vegetable consumption have been identified in the literature. One major barrier is the perishability of vegetables. Frozen vegetables can be a useful way in encouraging greater intakes. Some consumers are, however, of the opinion that processing destroy nutrients to a large extent. There is, therefore, a lack of understanding of the freezing process. Research on the attitudes of consumers towards frozen vegetables in South Africa is limited. Objective: The purpose of this study was to determine the attitudes of consumers regarding the link between frozen and fresh vegetables and health and the attributes of frozen vegetables. Subjects/Setting: One thousand nine hundred and ninety seven South African respondents, representative of the four major race groups of South Africa (whites, blacks, coloureds and Indians) were randomly chosen from metropolitan areas from the nine provinces in South Africa. Questionnaires, existing of 17 food-related sections, including subsections on vegetables and health, were designed by researchers in co-operation with business partners. MARKINOR, a market research company, was contracted to collect the data. Respondents were questioned regarding their attitudes towards the link between frozen and fresh vegetables and health. Statistical analysis performed: The quantitative data produced by the survey was analysed by using the StatisticaⓇ-programme in order to generate the relevant tabulations, descriptive statistics and statistical tests. Results: Overall, the attitudes of consumers towards frozen vegetables were found to be negative. Practical and statistically significant attitude differences towards frozen vegetables were found between most variables. Results from this study revealed that different levels of education, age and gender do not have a big influence on consumer's attitudes towards frozen vegetables. However, practical and statistically significant differences were found between the various LSM (Living Standards Measure) groups, especially with regard to the convenience of frozen vegetables. Results also indicated that Indians, the age group 61+ and males were the most negative towards frozen vegetables. Almost 75% of all consumers indicated that they never eat frozen vegetables. Only 1% of consumers in the LSM group 2 own a fridge/freezer. An alarmingly 26% of all consumers indicated that they are not convinced that vegetables are healthy. Application/Conclusions: Nutrition professionals should use these findings to target messages in health-promotion programmes to increase the overall consumption of vegetables. The use of frozen vegetables by consumers with frozen storage facilities should be promoted aggressively. Consumers also need practical advice on how to overcome the barriers to dietary change. Nutrition counseling efforts should also be aimed specifically at increasing frozen vegetable consumption among targeted subgroups, particularly Indians, males and the age group 61+. It is strongly recommended that suitable measuring instruments be developed for assessing the knowledge and attitude of South Africans towards vegetable and fruit consumption and the ability of individuals to improve their health. The results of this study may prove to be very useful in this regard. / Thesis (M.Sc. (Dietetics))--North-West University, Potchefstroom Campus, 2004.

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