TY - JOUR
T1 - Influence of microflora on texture and contents of amino acids, organic acids, and volatiles in semi-hard cheese made with DL-starter and propionibacteria
AU - Rehn, Lina Ulrika Ingeborg
AU - Vogensen, Finn Kvist
AU - Persson, S.-E.
AU - Saedén, K. Hallin
AU - Nilsson, B.F.
AU - Ardö, Ylva Margareta
PY - 2011/3
Y1 - 2011/3
N2 - The microflora of semi-hard cheese made with DL-starter and propionic acid bacteria (PAB) is quite complex, and we investigated the influence of its variation on texture and contents of organic acids, free amino acids, and volatile compounds. Variation in the microflora within the normal range for the cheese variety Grevé was obtained by using a PAB culture in combination with different DL-starters and making the cheeses at 2 dairy plants with different time and temperature profiles during ripening. Propionic acid bacteria dominated the microflora during ripening after a warm room period at levels of log 8 to log 9 cfu/g, which was about 1 log unit higher than the total number of starter bacteria and about 2 log units higher than the number of nonstarter lactic acid bacteria. Eye formation was observed during the warm room period and further ripening (at 8 to 10°C). The amounts of acetate, propionate, total content of free amino acids, 2-propanol, and ethyl propionate in the ripened cheeses were related to the number of PAB. A decrease in the relative content of Asp and Lys and increase of Phe over the ripening time were different from what is observed in semi-hard cheese without PAB. The occurrence of cracks was higher in cheeses with more hydrolyzed αS1- and β-casein, higher content of free amino acids, lower strain at fracture (shorter texture), and a greater number of PAB.
AB - The microflora of semi-hard cheese made with DL-starter and propionic acid bacteria (PAB) is quite complex, and we investigated the influence of its variation on texture and contents of organic acids, free amino acids, and volatile compounds. Variation in the microflora within the normal range for the cheese variety Grevé was obtained by using a PAB culture in combination with different DL-starters and making the cheeses at 2 dairy plants with different time and temperature profiles during ripening. Propionic acid bacteria dominated the microflora during ripening after a warm room period at levels of log 8 to log 9 cfu/g, which was about 1 log unit higher than the total number of starter bacteria and about 2 log units higher than the number of nonstarter lactic acid bacteria. Eye formation was observed during the warm room period and further ripening (at 8 to 10°C). The amounts of acetate, propionate, total content of free amino acids, 2-propanol, and ethyl propionate in the ripened cheeses were related to the number of PAB. A decrease in the relative content of Asp and Lys and increase of Phe over the ripening time were different from what is observed in semi-hard cheese without PAB. The occurrence of cracks was higher in cheeses with more hydrolyzed αS1- and β-casein, higher content of free amino acids, lower strain at fracture (shorter texture), and a greater number of PAB.
KW - Former LIFE faculty
KW - Cheese texture
KW - Propionic acid bacteria
KW - Microflora
KW - DL-starter
U2 - 10.3168/jds.2010-3146
DO - 10.3168/jds.2010-3146
M3 - Journal article
C2 - 21338776
SN - 0022-0302
VL - 94
SP - 1098
EP - 1111
JO - Journal of Dairy Science
JF - Journal of Dairy Science
IS - 3
ER -