Ultra-high pressure homogenization treatment combined with lysozyme for controlling Lactobacillus brevis contamination in model system

Journal of the Institute of Brewing

2011

J. Inst. Brew. 117(4), 634-638, 2011Inactivation of Lactobacillus brevis in beer by high-pressure homogenization (HPH) and lysozyme addition was evaluated. The minimum inhibitory concentration of lysozyme against L. brevis was determined and found to be 100 mg.L -1 . The effects of the homogenization process on lysozyme antimicrobial activity and muramidase activity, and the microbial reduction promoted by HPH, and by HPH associated with lysozyme, were evaluated. A significant reduction in lysozyme muramidase activity was observed under 250 MPa, however, no reduction in antimicrobial activity was observed after homogenization up to 300 MPa. The HPH at 100, 140 and 150 MPa promoted 1, 3 and 6 decimal reductions in L. brevis microbial counts, respectively. The HPH and lysozyme association had an additive effect on microbial inactivation, immediately after homogenization, and the lysozyme remained active during 10 days of storage, increasing the inactivation of L. brevis up to a 6 decimal reduction. Therefore, the application of lysozyme with HPH has the potential to reduce the level of pressure required for beer processing, improving the economic costs when utilizing HPH.

Section: Pressure (Mpa)mentioning

confidence: 96%

Section: Inactivation Of Lactobacillus Brevis In Beer Utilizing a Commentioning

confidence: 99%

“…The MIC determination was performed as previously described 24 . It was tested using lysozyme concentrations ranging from 0.5 to 1,000 mg.L -1 .…”

Section: Lysozyme Minimum Inhibitory Concentration (Mic)mentioning

confidence: 99%

Section: Pressure (Mpa)mentioning

confidence: 99%

See 2 more Smart Citations

Inactivation of Lactobacillus brevis in Beer Utilizing a Combination of High-Pressure Homogenization and Lysozyme Treatment

Franchi

Journal of the Institute of Brewing

2011

“…High pressure homogenization (HPH) is a continuous process in which the fluid is forced under pressure through a narrow gap, where it is subjected to rapid acceleration (200 m/s at 340 MPa) 7 , after which it undergoes an extreme drop in pressure 7 , causing shear, cavitation, turbulence and friction 12,18 , which can promote microbiological inactivation 4,18 and molecular conformational changes mainly in proteins 13 and polysaccharides 12 .…”

Section: Introductionmentioning

confidence: 99%

Effects of High Pressure Homogenization on Beer Quality Attributes

Franchi¹,

Journal of the Institute of Brewing

2011

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The aim of the present study was to evaluate the use of high pressure homogenization (HPH) as an alternative to thermal pasteurization for beer stabilization and to evaluate the effect of processing on colour, haze and redox potential immediately after the process and during the product shelf-life (100 days). The results obtained showed good colour retention, changes in the redox potential and greater values for turbidity, presenting a higher value for the product treated by HPH than for the thermally treated samples reported in literature. The evaluation of the results indicated that the HPH process is a promising process for beer treatment in terms of guaranteeing better colour retention. However to make this product stable, it would be necessary to perform stabilization treatments to minimize the negative effects of processing on the haze of the final product.

High-pressure homogenization: a non-thermal process applied for inactivation of spoilage microorganisms in beer

Franchi¹,

2013

J. Inst. Brew.

Self Cite

The inactivation of spoilage microorganisms in beer using high-pressure homogenization (HPH) was studied with the aim of evaluating the possibility of changing the conventional pasteurization process using this particular process. The homogenization pressure required for the inactivation of lactic acid bacteria, acetic bacteria and yeasts was investigated. For the most resistant microorganisms, the pressure inactivation kinetics and the effects of multiple process passes, initial temperature of the beer and the CO 2 concentration were studied. The results indicated that Lactobacillus delbrueckii was the most resistant microorganism tested, requiring 250 MPa to reach a six decimal reduction. Additionally, results showed that L. delbrueckii inactivation followed a second-order kinetic process. A multi-pass process and the use of a high initial beer temperature increased inactivation by HPH with L. delbrueckii, allowing the use of 150 MPa to achieve a five log cycle of inactivation. In contrast, a high CO 2 concentration reduced the efficacy of the HPH process. The results that were obtained are useful for high-pressure homogenization applications in breweries and help to elucidate the effect of this new technology in a beverage that is both alcoholic and carbonated.