The use of lactic acid bacteria adjunct cultures to decrease the incidence of gas defects in Cheddar cheese...

Area of Science:

• Food Microbiology
• Dairy Science
• Bacteriology

Background:

• Heterofermentative lactic acid bacteria (LAB) produce CO2 from 6-carbon sugars, leading to gas defects like slits, cracks, and blown packaging in Cheddar cheese.
• Homofermentative LAB are explored as adjunct cultures for flavor modification and as bioprotective agents against gas-producing nonstarter LAB (NSLAB).

Purpose of the Study:

• To evaluate the efficacy of four specific galactose-positive, lactose-negative LAB (Lacticaseibacillus rhamnosus 20DK04, Lacticaseibacillus paracasei 20DK06, Pediococcus acidilactici 23F, and Latilactobacillus curvatus WSU1) as adjunct cultures.
• To determine their impact on gas production by known gas-producing NSLAB in Cheddar cheese.

Main Methods:

• Cheddar cheese was manufactured with a standard starter culture and inoculated with one of four adjunct LAB.
• Blocks were later comminuted and inoculated with one of four gas-producing NSLAB strains (Levilactobacillus brevis 277-1, Limosilactobacillus fermentum 305-1, Lentilactobacillus parabuchneri CC01, Paucilactobacillus wasatchensis WDCO4).
• Gas production was monitored non-destructively by package loosening over 16 weeks at 14°C; bacterial populations were enumerated.

Main Results:

• Gas production varied significantly among NSLAB strains, with Lev. brevis 277-1 > P. wasatchensis WDC04 > L. parabuchneri CC01 > L. fermentum 305-1.
• Adjunct LAB had differential effects: L. curvatus WSU1 and P. acidilactici 23F inhibited Lev. brevis 277-1 but stimulated P. wasatchensis WDC04.
• L. rhamnosus 20DK04 and L. paracasei 20DK06 inhibited P. wasatchensis WDC04 but had minimal effect on Lev. brevis 277-1; P. acidilactici 23F most inhibited L. parabuchneri CC01.

Conclusions:

• The effectiveness of bioprotective adjunct LAB in controlling gas production in Cheddar cheese is highly dependent on the specific NSLAB involved.
• Knowledge of the predominant NSLAB causing gas defects is essential for selecting appropriate adjunct cultures to mitigate these issues.