Cheeses with blowing defect
Blowing defect of cheeses refers to undesirable openness of the cheeses interior. It is a result of unwanted microbial metabolism. Production of hard- and semi-hard chesses require methods and/or preservatives to make sure that blowing defect is prevented. Most dairy industries have developed proper...
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| Formato: | First cycle, G2E |
| Lenguaje: | sueco Inglés |
| Publicado: |
2015
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| Acceso en línea: | https://stud.epsilon.slu.se/8424/ |
| _version_ | 1855571348956381184 |
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| author | Alvenäs, Amanda |
| author_browse | Alvenäs, Amanda |
| author_facet | Alvenäs, Amanda |
| author_sort | Alvenäs, Amanda |
| collection | Epsilon Archive for Student Projects |
| description | Blowing defect of cheeses refers to undesirable openness of the cheeses interior. It is a result of unwanted microbial metabolism. Production of hard- and semi-hard chesses require methods and/or preservatives to make sure that blowing defect is prevented. Most dairy industries have developed proper methods for this purpose, but it still remain a big problem for many cheese-producers.
In this study problematics behind blowing defect was investigated. Preventing methods are compiled and the magnitude of the problem in the dairy industry was evaluated. Five Swedish large-scale dairy industries as well as two Italian tradition-al cheese producers have contributed with information about the importance of managing blowing defect at their factories.
Cheeses frequently affected by blowing defect include brine-salted cheeses, cheeses ripened at hot temperatures and hard cheeses that are ripened for extensive periods. Low salt content, high levels of moisture content, water activity and pH as well as high initial amount of spores and/or somatic cell count favours spoilage. Swiss-type-, Dutch-type-, very hard Italian-type-, and Swedish Herrgård- and Grevé-type-cheeses are examples of cheeses susceptible for blowing defect.
Pasteurization of cheese milk is the most common method for the prevention of spoilage bacteria. It inhibits non-sporulating microorganisms causing blowing defect; heterofermentative lactic acid bacteria, propionic acid bacteria, coliform bacteria and yeasts. However, it is not a guarantee for safe dairy products without spoilage organisms since thermoduric microorganisms and enzymes survives the process and sterilized milk is a good substrate for a lot of spoilage microorganisms.
Endospores survive pasteurization and can germinate in the cheese during ripening if environmental conditions are favourable. Endospores are normally reduced by membrane filtration and/or bactofugation of the cheese milk. Sodium nitrate and lysozyme are common additives for the inhibition of spore-forming bacteria as well as other spoilage bacteria. More severe methods for the removal of spores exist, but they normally alter the cheese-making properties too much to be applied in the industry.
Further development of processing techniques of cheese milk and research about combining different methods are needed to be investigated in order to ensure a cheese production without blowing defect, and without altering the cheese-making properties. |
| format | First cycle, G2E |
| id | RepoSLU8424 |
| institution | Swedish University of Agricultural Sciences |
| language | Swedish Inglés |
| publishDate | 2015 |
| publishDateSort | 2015 |
| record_format | eprints |
| spelling | RepoSLU84242015-10-23T13:40:50Z https://stud.epsilon.slu.se/8424/ Cheeses with blowing defect Alvenäs, Amanda Food science and technology Blowing defect of cheeses refers to undesirable openness of the cheeses interior. It is a result of unwanted microbial metabolism. Production of hard- and semi-hard chesses require methods and/or preservatives to make sure that blowing defect is prevented. Most dairy industries have developed proper methods for this purpose, but it still remain a big problem for many cheese-producers. In this study problematics behind blowing defect was investigated. Preventing methods are compiled and the magnitude of the problem in the dairy industry was evaluated. Five Swedish large-scale dairy industries as well as two Italian tradition-al cheese producers have contributed with information about the importance of managing blowing defect at their factories. Cheeses frequently affected by blowing defect include brine-salted cheeses, cheeses ripened at hot temperatures and hard cheeses that are ripened for extensive periods. Low salt content, high levels of moisture content, water activity and pH as well as high initial amount of spores and/or somatic cell count favours spoilage. Swiss-type-, Dutch-type-, very hard Italian-type-, and Swedish Herrgård- and Grevé-type-cheeses are examples of cheeses susceptible for blowing defect. Pasteurization of cheese milk is the most common method for the prevention of spoilage bacteria. It inhibits non-sporulating microorganisms causing blowing defect; heterofermentative lactic acid bacteria, propionic acid bacteria, coliform bacteria and yeasts. However, it is not a guarantee for safe dairy products without spoilage organisms since thermoduric microorganisms and enzymes survives the process and sterilized milk is a good substrate for a lot of spoilage microorganisms. Endospores survive pasteurization and can germinate in the cheese during ripening if environmental conditions are favourable. Endospores are normally reduced by membrane filtration and/or bactofugation of the cheese milk. Sodium nitrate and lysozyme are common additives for the inhibition of spore-forming bacteria as well as other spoilage bacteria. More severe methods for the removal of spores exist, but they normally alter the cheese-making properties too much to be applied in the industry. Further development of processing techniques of cheese milk and research about combining different methods are needed to be investigated in order to ensure a cheese production without blowing defect, and without altering the cheese-making properties. Feljäsning av ostar orsakas av mikrobiell metabolism och resulterar i oönskad öppen struktur av ostens innanmäte. Produktionen av hårda- och halvhårda ostar kräver metoder och/eller tillsatser för att förhindra problemet. De flesta mejerier har utvecklat lämpliga metoder för detta ändamål men trots detta utgör feljäsning av ostar fortfarande ett problem för många ostproducenter. I denna studie undersöktes problematiken angående feljäsning av ostar. Förebyggande metoder är sammanställda och omfattningen av problemet i mejeriindustrin utvärderades. Fem svenska storskaliga ostproducenter samt två italienska traditionella ostproducenter har bidragit med information angående omfattningen av feljäsning på deras ystningsverksamhet. Osttyper som ofta drabbas av feljäsning inkluderar saltlakesaltade ostar, ostar som mognar vid höga temperaturer och hårdostar som lagras under långa perioder. Lågt saltinnehåll, hög fuktighet, vattenaktivitet och pH samt höga initiala halter av sporer och/eller somatiska celltal gynnar feljäsning. Schweiziska osttyper-, holländska osttyper-, hårda italienska osttyper-, samt Svensk Grevé och Herrgårdsost är exempel på ostar som är särskilt mottagliga för feljäsning. Pastörisering är en metod som förhindrar mikrobiell tillväxt och den tillämpas vanligen på ystmjölk. Pastörisering inhiberar icke-sporulerande mikroorganismer som orsakar feljäsning; heterofermentativa mjölksyrebakterier, propionsyrabakterier, koliforma bakterier och jäst. Metoden kan dock inte garantera helt säkra produkter eftersom termoresistenta mikroorganismer och enzymer överlever processen. Steriliserad mjölk är även ett bra näringssubstrat för flertalet mikroorganismer. Endosporer överlever pastörisering och om omgivande faktorer tillåter det kan sporerna gro i osten under lagringsperioden. Endosporer reduceras vanligen genom membranfiltration och/eller baktofugering av ystmjölken. Natriumnitrat och lysosym är vanliga tillsatser som både inhiberar sporulerande bakterier och andra förstörande mikroorganismer. Mer omfattande metoder för att få bort sporer finns men de försämrar ofta ystningsegenskaperna vilket gör att de inte används i industrin idag. Ytterligare forskning angående kombinationen av metoder och utveckling av processandet av ystmjölk behöver utföras för att kunna säkerställa en ostproduktion utan feljäsning samt utan att försämra dess ystningsegenskaper. 2015-08-25 First cycle, G2E NonPeerReviewed application/pdf sv https://stud.epsilon.slu.se/8424/7/alvenas_a_151023.pdf Alvenäs, Amanda, 2015. Cheeses with blowing defect : problematics and preventable methods. First cycle, G2E. Uppsala: (NL, NJ) > Dept. of Food Science <https://stud.epsilon.slu.se/view/divisions/OID-550.html> urn:nbn:se:slu:epsilon-s-4785 eng |
| spellingShingle | Food science and technology Alvenäs, Amanda Cheeses with blowing defect |
| title | Cheeses with blowing defect |
| title_full | Cheeses with blowing defect |
| title_fullStr | Cheeses with blowing defect |
| title_full_unstemmed | Cheeses with blowing defect |
| title_short | Cheeses with blowing defect |
| title_sort | cheeses with blowing defect |
| topic | Food science and technology |
| url | https://stud.epsilon.slu.se/8424/ https://stud.epsilon.slu.se/8424/ |