title: Enhanced lactose cheese milk does not guarantee calcium lactate crystals in finished cheddar cheese.
abstract: Three experimental batches of Cheddar cheese were manufactured in duplicate, with standardization of the initial cheese-milk lactose content to high (5.24%), normal (4.72%, control), and low lactose (3.81%). After 35 d of aging at 4.4 degrees C, the cheeses were subjected to temperature abuse (24 h at 21 degrees C, unopened) and contamination (24 h at 21 degrees C, packages opened and cheeses contaminated with crystal-containing cheese). After aging for 167 d, residual cheese lactose (0.08 to 0.43%) and L(+)-lactate concentrations (1.37 to 1.60%) were high and D(-)-lactate concentrations were low (<0.03%) for all cheeses. No significant differences in lactose concentrations were attributable to temperature abuse or contamination. No significant differences in L(+)- or D(-)-lactate concentrations were attributable to temperature abuse. However, concentrations of L(+)-lactate were significantly lower and D(-)-lactate were significantly higher in contaminated cheeses than in control cheeses, indicating inoculation (at d 35) with heterofermentative nonstarter lactic acid bacteria able to racemize L(+)-lactate to D(-)-lactate. The fact that none of the cheeses exhibited crystals after 167 d demonstrates that high cheese milk or residual lactose concentrations do not guarantee crystal formation. Contamination with nonstarter lactic acid bacteria can significantly contribute to D(-)-lactate accumulation in cheese.
authors.affiliation: Department of Food Science and Human Nutrition, Washington State University, Pullman, 99164-6376, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Blake
authors.forename: J R
authors.initials: JR
authors.lastname: Powers
authors.forename: L O
authors.initials: LO
authors.lastname: Luedecke
authors.forename: S
authors.initials: S
authors.lastname: Clark
mesh_terms: D000818:Animals; D017610:Calcium Compounds / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D002611:Cheese / Q000032:analysis* / Q000382:microbiology; D003460:Crystallization; D005285:Fermentation; D005511:Food Handling / Q000379:methods; D018857:Food Packaging; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism; D019344:Lactic Acid / Q000032:analysis / Q000378:metabolism; D013294:Lactococcus lactis / Q000502:physiology; D007785:Lactose / Q000032:analysis* / Q000378:metabolism; D008892:Milk / Q000737:chemistry*; D014462:Ultrafiltration
chemical_list: D017610:Calcium Compounds; D007773:Lactates; C110051:calcium lactate; D019344:Lactic Acid; D007785:Lactose