• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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.
1

Estudo da estabilidade de presunto cozido fatiado em atmosfera modificada / Study of the stability of sliced cooked ham in modified atmosphere

Bedendi, Rafaela Ferrari 24 May 2004 (has links)
Orientador: Expedito Tadeu Facco Silveira / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T22:51:31Z (GMT). No. of bitstreams: 1 Bedendi_RafaelaFerrari_M.pdf: 1078798 bytes, checksum: 4d00a8483869fd9a13387496464d8a85 (MD5) Previous issue date: 2003 / Resumo: Este trabalho teve como objetivo avaliar a eficiência de sistemas de embalagem com atmosfera modificada na preservação da qualidade de presunto cozido fatiado. Para tanto, acompanhou-se a estabilidade do produto a 4 :t 1°C, acondicionado em uma embalagem barreira a gases denominada "master pack" , com três tipos de atmosferas modificadas (100% CO21 60% CO2 I 40% N2 e 25% CO2 I 75% Nz). Comparativamente, foi avaliada a estabilidade do produto no sistema convencional sob vácuo. Bandejas de poliestireno não expandido contendo cerca de 200g de presunto cozido fatiado foram acondicionadas em embalagens de um filme poliolefínico selado a quente, sendo denominadas como embalagens primárias. Em seguida, seis embalagens primárias, de presunto cozido fatiado, foram colocadas dentro de um saco barreira a gases chamado de "master pack" (embalagem secundária), constituído de polietileno de baixa densidade e copolímeros de etileno e álcool vinílico. A taxa de permeabilidade ao oxigênio do material foi de 1,87 cm3 (CNTP)/m2/atm/dia a 23°C e a seco. No produto convencional, as bandejas foram envoltas em um filme termo-encolhível. Periodicamente, os produtos foram avaliados quanto à qualidade sensorial (aparência e odor), qualidade microbiológica (contagens de enterobactérias, psicrotróficas aeróbias, bactérias lácticas e Pseudomonas sp.) e características físicas e químicas (coloração e pH). As embalagens com atmosfera modificada foram periodicamente avaliadas quanto à composição gasosa do espaço-livre. Não foram verificadas alterações físicas e químicas no presunto cozido fatiado, nos diversos sistemas de acondicionamento, durante os períodos estudados. A estabilidade do produto para cada sistema de acondicionamento foi determinada com base em alterações sensoriais, tendo sido definidas como limitantes as classificações: cor característica do presunto fresco e odor característico de presunto fresco moderados. A vida útil do presunto no sistema convencional sob vácuo foi de 15 dias e no final deste período, as contagens de enterobactérias, psicrotróficas aeróbias, bactérias lácticas e Pseudomonas sp. foram de 4,0 109 UFC/g, 5,1 109 UFC/g, 4,5 109 UFC/g e < 1 109 UFC/g, respectivamente. No produto em atmosfera de 25% CO2/75% N2, o período de vida útil foi de 22 dias, ao final da qual, o presunto apresentava contagens de enterobactérias, psicrotróficas aeróbias, bactérias lácticas e Pseudomonas sp. de < 1, 5,1, 4,5 e < 1 log UFC/g, respectivamente. Contudo, constatou-se um prolongamento significativo da durabilidade do presunto cozido fatiado quando acondicionado sob atmosferas contendo altas concentrações de gás carbônico, em relação ao sistema convencional, uma vez que o período de estabilidade determinado foi de 29 dias (aumento de 93,3%), para os produtos em atmosfera 100% CO2 e 60% CO2/ 40% N2. Quanto à ação bacteriostática do gás carbônico, comprovou-se retardamento no desenvolvimento de bactérias psicrotróficas aeróbias e inibição do crescimento de enterobactérias e Pseudomonas sp. quando a atmosfera foi de 100% CO2. Quando esta atmosfera foi de 60% CO2 I 40% N2, houve um retardamento tanto no desenvolvimento de psicrotróficas aeróbias como no de Pseudomonas sp., sendo que a contagem de Pseudomonas sp. foi de 4,7 log UFC/g, no 50° dia de estocagem e inibição do crescimento de enterobactérias. Com base nos resultados obtidos confirmou-se o efeito positivo do acondicionamento sob atmosfera modificada com gás carbônico na extensão da vida útil de presunto cozido fatiado, sendo mais eficiente o seu efeito quanto maior for a concentração desse gás no espaço-livre / Abstract: The purpose of this study was to evaluate the efficiency of packaging systems with modified atmosphere to preserve the quality of sliced cooked ham. Thus the quality stability of the product at 4 +/_:t 1°C, packed in a gas barrier package with three kinds of modified atmosphere (100% CO2, 60% CO2/40% N2 and 25% CO2 I 75% N2), was studied. The shelf-life of each condition of atmosphere was analysed. Comparatively, the shelf-life of the same product packed in conventional under vacuum was also evaluated. No expanded polystyrene trays with about 200g of sliced cooked ham were placed in a hot sealed poliolefinic film packages, nominated as primary packages. After that, six primary packages of sliced cooked ham were placed inside a barrier bag called "master pack" (secondary packages), formed of low density polyethylene and copolymer of ethylene vinylindene alcohol. The material permeability rates to oxygen was 1,87 cm3 (CNTP)/m2/atmlday at 23°C and dry. For the conventional product, the trays were wrapped in a thermoform film. The products were periodically evaluated as to their organoleptie quality (appearance and odour), microbiological quality (counts of Enterobacteriaceae, aerobic psychrotrophic microorganisms, lactic acid bacteria and Pseudomonas sp.) and physical and chemical characteristics (colour and pH). The headspace gas composition of the modified atmosphere packages were periodically evaluated. The cooked ham did not present any physical or chemical alteration in any of the packaging systems during the analysed period. The shelf-life for each packaging system was established based on organoleptic alterations that defined as the limitin classification: characteristic collor of the fresh ham and characteristic odour of the fresh ham moderates. The shelf life of the ham in the conventional under vacuum was 15 days. At the end of this period, the counts of Enterobacteriaceae, aerobic psychrotrophie microorganisms, ladie acid bacteria and Pseudomonas sp. were 4,0 log CFU/g, 5,1 log CFU/g, 4,5 log CFU/g and < 1 CFU/g, respectively. The product placed in a 25% CO2/75% N2 atmosphere, the shelf-life of the was 22 days and during this period, the counts of Enterobacteriaceae, aerobic psychrotrophie microorganisms, lactic acid bactería and Pseudomonas sp. were < 1, 5,1, 4,5 and < 1 109 CFU/g, respectively. higher it's effect. However, it was verified a significant shelf-life increase of sliced cooked ham in atmospheres with high concentrations of carbon dioxide in relation to the conventional under vacuum, as fo 11 ows: 29 days (93,3% increase) for products in 100% CO2 and 60% CO21 40% N2 atmosphere. Due to the bacteriostatic action of the carbon dioxide, the development of aerobic psychrotrophics microorganisms was retarded and the growth of Enterobacteriaceae and Pseudomonas sp. was inhibited in the 100% CO2 atmosphere. When the atmosphere was 60% CO2 I 40% N2, the development of both aerobic psychrotrophic microorganisms and Pseudomonas was retarded, and the counts of Pseudomonas sp. was 4,7 log CFU/g, after 50 days of storage and the development of Enterobacteriaceae was inhibited. Based on the obtained results, it was confirmed the positive effect of the packaging in modified atmosphere with carbon dioxide on the shelf-life increase of sliced cooked ham. It has been proved that, the higher the concentration of carbon dioxide in the headspace / Mestrado / Mestre em Tecnologia de Alimentos
2

Bidrar lokala avfuktare till en kontrollerad miljö för sterilt material? / Do local dehumidifiers contribute to a controlled environment for sterile material?

Johansson, Susan January 2020 (has links)
Introduktion Hög luftfuktighet har i flera år orsakat problem i sterilförråd på svenska sjukhus. Sterila förpackningar ska enligt standard förvaras i en temperatur på 22±3 ˚C och i en luftfuktighet på 30-70 %. För att relativt enkelt och kostnadseffektivt få bukt med fuktighetsproblemet installeras avfuktare. Inga studier finns på hur avfuktare fungerar i sterila miljöer. Elimineras risken för fuktiga emballage utan tillväxt av mikroorganismer i förråd med sterilt material. Syfte Syftet med studien är att undersöka om den lokala avfuktaren Dantherm kan bidra till en kontrollerad miljö genom att antal bakteriebärande partiklar, dvs. colony forming units (cfu) i protesförråd och sterilförråd håller sig inom godkända nivåer relaterat till rekommendationerna i den tekniska standarden SIS TR 57:2020, dvs. 100 cfu/m3 när avfuktaren är installerad och aktiverad. Metod Studien är en kvantitativ pilotstudie. Aktiv och passiv luftprovtagning utfördes i två förråd med två olika sorters Danthermavfuktare samt i två andra förråd, dvs. ett förråd med avfuktare av märket Wood’s och ett förråd helt utan avfuktning. Åtta mättillfällen gjordes per förråd mellan slutet av juni till mitten av oktober år 2020. Resultat Resultatet visar att de allra flesta värdena låg inom referensvärden enligt standard. Slutsats Dantherm avfuktaren verkar bidra till en kontrollerad miljö i förråd med sterilt material. De gånger avfuktaren var aktiv kontaminerade den inte miljön med mikroorganismer. Således kommer den att installeras i fler förråd med sterilt material på Hallands sjukhus och utvärderas kontinuerligt nästkommande år. / Introduction High humidity has been a problem for a long time in sterile storage rooms in Swedish hospitals. According to standards temperature in sterile storage rooms should be within 22±3˚C and the relative humidity 30-70 %. In order to achieve these conditions in a relatively easy and cost effective way, local dehumidifiers have been installed. No previous studies on eliminating the risk of moist packaging without microbial growth in sterile storage rooms have been carried out. Aim The aim of the study is to evaluate whether the dehumidifier Dantherm could contribute to a controlled environment by keeping colony forming units (cfu) in the storage rooms called protesförråd (prostheses storage room) and sterilförråd (sterile storage room) within recommendations according to the standard technical report SIS TR 57:2020 written by Swedish institute of standards, i.e. 100 cfu/m3 when the dehumidifiers are installed and running. Method This study is a quantitative pilot study. Active and passive air sampling were made in two sterile storage rooms with two different kinds of Dantherm dehumidifiers. Two other sterile storage rooms were sampled of which one had a Wood’s dehumidifier installed and the other one lacked totally a dehumidifier. Eight measurements per storage room were made from the end of June to mid-October in the year 2020. Results The results show that almost all rates were within recommended limits. Conclusion The Dantherm dehumidifier seems to contribute to a controlled environment in sterile storage rooms as it did not introduce additional microbiological contamination. Consequently, it will be installed in several more sterile storage rooms at Halland’s hospitals and will be continuously evaluated next year.

Page generated in 0.0692 seconds