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

Y1 - 2011

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 a(S1)- and ß-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 a(S1)- and ß-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

VL - 94

SP - 1098

EP - 1111

JO - Journal of Dairy Science

JF - Journal of Dairy Science

SN - 0022-0302

IS - 3

ER -