Seminar Presentation

Please join us for seminar today at noon presented by John Larsen entitled “Strategies to Inhibit the Formation of Biogenic Amines in Ripened Cheeses” 

Time: 12:05-12:55

Location: Room 205, Babcock Hall 

ABSTRACT

Biogenic amines (BA) may form during cheese ripening due to decarboxylation of free amino acids (FAA) by bacteria containing amino acid decarboxylase enzymes (AADC). Accumulation of BA in cheese (>200 mg/kg) may cause off-flavors, gas formation and allergic-like reactions in sensitive consumers. Levels of BA in cheese can be reduced by controlling ripening temperature (RT; <10°C) or preventing the growth of BA-producing bacteria. Nisin, an antibacterial peptide produced by some adjunct cultures, has been used in cheese to prevent the growth of undesirable bacteria. We hypothesized that the combined use of a nisin-producing adjunct culture (PC) and low RT would prevent the accumulation of histamine (hist), a common BA, in cheese. Gouda cheeses (20 L scale) were made using milk with/without PC and with/without contamination with Lentilactobacillus parabuchneri (LP; a common Hist producer) at a level of 1.0 × 101 CFU/mL. CR proceeded at low (LT; 4°C) or high RT (HT;10°C) for 9 mo (n = 4). Levels of Hist were reduced in cheeses with LP when stored at LT (238 versus 1035 mg/kg at 9 mo; P<0.05). Quantification of DNA sequences corresponding to histidine decarboxylase (hdc) indicated that RT had no impact on hdc counts in LP cheeses after 9 mo (P>0.05), but cheeses made with PC ripened at LT had significantly decreased counts of hdc (P<0.05). These findings indicate PC and LT ripening reduce levels of Hist in cheese, but both together are more effective in preventing accumulation of Hist in cheese containing LP.