Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk
Traditional hard Xinotyri cheese was manufactured using raw or pasteurized goat milk, without starter cultures, and the changes in microbiological and biochemical characteristics were studied during ripening and storage. Mesophilic lactic acid bacteria (LAB) predominated (>8.5 log CFU/g) in fresh...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Fermentation |
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| Online Access: | https://www.mdpi.com/2311-5637/8/1/20 |
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| author | Eleni C. Pappa Thomas G. Bontinis John Samelis Kyriaki Sotirakoglou |
| author_facet | Eleni C. Pappa Thomas G. Bontinis John Samelis Kyriaki Sotirakoglou |
| author_sort | Eleni C. Pappa |
| collection | DOAJ |
| description | Traditional hard Xinotyri cheese was manufactured using raw or pasteurized goat milk, without starter cultures, and the changes in microbiological and biochemical characteristics were studied during ripening and storage. Mesophilic lactic acid bacteria (LAB) predominated (>8.5 log CFU/g) in freshly fermented Xinotyri cheeses (pH 4.5–4.6), regardless of milk pasteurization. Enterobacteria, pseudomonads and staphylococci were suppressed below 6 and 4–5 log CFU/g in fresh cheeses from raw and pasteurized milk, respectively. <i>Salmonella</i> and <i>Listeria</i> spp. were absent in 25 g cheese samples. Coagulase-positive staphylococci exceeded the 5-log safety threshold in fresh raw milk cheeses, which also had 10-fold higher levels of enterococci than pasteurized milk cheeses. Non-LAB groups declined <100 CFU/g, whereas yeasts increased to 5–6 log CFU/g in both cheeses during ripening. Milk pasteurization affected the protein, fat, ash, moisture, nitrogen fractions, total free fatty acids and total free amino acids content of cheeses. Primary proteolysis, detectable by urea-PAGE, was more intense in raw milk cheeses than in pasteurized milk cheeses. However, the hydrophilic and hydrophobic peptides and their ratio in the water-soluble fraction were similar in both cheeses. Cheeses discriminated clearly according to the milk kind (raw, pasteurized) and the stage of ripening, based on the examined biochemical characteristics. |
| first_indexed | 2024-03-10T01:30:42Z |
| format | Article |
| id | doaj.art-82c89779a4d844f38f5a23221405183e |
| institution | Directory Open Access Journal |
| issn | 2311-5637 |
| language | English |
| last_indexed | 2024-03-10T01:30:42Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Fermentation |
| spelling | doaj.art-82c89779a4d844f38f5a23221405183e2023-11-23T13:43:04ZengMDPI AGFermentation2311-56372022-01-01812010.3390/fermentation8010020Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat MilkEleni C. Pappa0Thomas G. Bontinis1John Samelis2Kyriaki Sotirakoglou3Dairy Research Department, Institute of Technology of Agricultural Products, ELGO-DIMITRA, Katsikas, 45221 Ioannina, GreeceDepartment of Chemistry, University Campus of Ioannina, University of Ioannina, 45110 Ioannina, GreeceDairy Research Department, Institute of Technology of Agricultural Products, ELGO-DIMITRA, Katsikas, 45221 Ioannina, GreeceLaboratory of Mathematics and Statistics, Department of Natural Resources Management & Agricultural Engineering, Agricultural University of Athens, 75 Iera Odos, 11855 Athens, GreeceTraditional hard Xinotyri cheese was manufactured using raw or pasteurized goat milk, without starter cultures, and the changes in microbiological and biochemical characteristics were studied during ripening and storage. Mesophilic lactic acid bacteria (LAB) predominated (>8.5 log CFU/g) in freshly fermented Xinotyri cheeses (pH 4.5–4.6), regardless of milk pasteurization. Enterobacteria, pseudomonads and staphylococci were suppressed below 6 and 4–5 log CFU/g in fresh cheeses from raw and pasteurized milk, respectively. <i>Salmonella</i> and <i>Listeria</i> spp. were absent in 25 g cheese samples. Coagulase-positive staphylococci exceeded the 5-log safety threshold in fresh raw milk cheeses, which also had 10-fold higher levels of enterococci than pasteurized milk cheeses. Non-LAB groups declined <100 CFU/g, whereas yeasts increased to 5–6 log CFU/g in both cheeses during ripening. Milk pasteurization affected the protein, fat, ash, moisture, nitrogen fractions, total free fatty acids and total free amino acids content of cheeses. Primary proteolysis, detectable by urea-PAGE, was more intense in raw milk cheeses than in pasteurized milk cheeses. However, the hydrophilic and hydrophobic peptides and their ratio in the water-soluble fraction were similar in both cheeses. Cheeses discriminated clearly according to the milk kind (raw, pasteurized) and the stage of ripening, based on the examined biochemical characteristics.https://www.mdpi.com/2311-5637/8/1/20Xinotyricheesegoat milkrawpasteurizedlactic acid bacteria |
| spellingShingle | Eleni C. Pappa Thomas G. Bontinis John Samelis Kyriaki Sotirakoglou Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk Fermentation Xinotyri cheese goat milk raw pasteurized lactic acid bacteria |
| title | Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk |
| title_full | Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk |
| title_fullStr | Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk |
| title_full_unstemmed | Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk |
| title_short | Assessment of the Microbiological Quality and Biochemical Parameters of Traditional Hard Xinotyri Cheese Made from Raw or Pasteurized Goat Milk |
| title_sort | assessment of the microbiological quality and biochemical parameters of traditional hard xinotyri cheese made from raw or pasteurized goat milk |
| topic | Xinotyri cheese goat milk raw pasteurized lactic acid bacteria |
| url | https://www.mdpi.com/2311-5637/8/1/20 |
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