Yeast proteinase in beer

Dreyer, Thomas; Biedermann, Kirsten; Ottesen, Martin

doi:10.1007/bf02907771

Cited by 40 publications

(17 citation statements)

References 14 publications

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“…Losses of hydrophobic polypeptides are more pronounced in high gravity brewing 4 , due to a poorer extraction during mashing of high gravity grists and disproportionate losses during kettle boil and fermentation 7 . Decrease in beer foam stability due to proteinase A activity has been reported by several research groups 8,10,14,15,20,22 . Proteinase A (EC 3.4.23.25) is a vacuolar aspartic proteinase, which is encoded by the PEP4 gene.…”

Section: -2863(9'8-32mentioning

confidence: 84%

The Effect of Proteinase A on Foam-Active Polypeptides During High and Low Gravity Fermentation

Brey

Costa

Rogers³

et al. 2003

Journal of the Institute of Brewing

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The ability of beer to produce good foam is influenced by the level of foam-active polypeptides. Specific polypeptides with hydrophobic domains, such as Lipid Transfer Protein (LTP1), are important components of beer foam. Although, high gravity brewing is a commercially viable technique, it has the disadvantage of producing beer with less foam stability compared to lower gravity brewed counterparts. It is thought that proteinase A plays a key role in the degradation of these hydrophobic polypeptides responsible the beer foam stability. The object of this study was to compare and quantify the loss of hydrophobic polypeptides and specifically foam-LTP1 during high gravity (20°Plato) and low gravity (12°Plato) wort fermentations and to evaluate the effect of proteinase A on these polypeptides. The losses of hydrophobic polypeptides and foam-LTP1 were generally greater in high gravity brews. Furthermore, the results obtained suggest that proteinase A alters the hydrophobicity of these polypeptides rather than their molecular size. Approximately 20% of hydrophobic polypeptides and approximately 57% of foam-LTP1 appeared to be proteinase A resistant. These differential losses of hydrophobic polypeptide and foam-LTP1 could have implications for the foam stability of the finished product.

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Section: -2863(9'8-32mentioning

confidence: 84%

The Effect of Proteinase A on Foam-Active Polypeptides During High and Low Gravity Fermentation

Brey

Costa

Rogers³

et al. 2003

Journal of the Institute of Brewing

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“…The HPLC system consisted of a SCL-6B system controller, a SIL-6B auto injector, a LC-9A pump, a RF-55OA spectrofluoromctric detector, and a C-R4AX integrator (Shimadzu Corporation, Kyoto, Japan). The column of Nova-Pak C18, 3.9x150 mm, (Waters, Millipore Corporation, MA, USA) and the eluant composed of 15 mM sodium phosphate (pH 6.8):acetonitrile (1:1) was used. The flow rate was 0.6ml/min and the eluate was monitored with excitation at 380 nm and emission at 460 nm.…”

Section: Methodsmentioning

confidence: 99%

A Fluorometric Assay for Proteinase a in Beer and Its Application for the Investigation of Enzymatic Effects on Foam Stability

Yokoi

Shigyo

Tamaki

1996

Journal of the Institute of Brewing

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A previously developed fluorometric assay using synthetic substrate, Succinyl-Arg-Pro-Phe-His-LeuLeu-Val-Tyr-4-methylcoumaryl-7-amide, for yeast proteinase A (PrA) was modified for the accurate and quick determination for the activity in unpasteurized beer. Employing simple HPLC for the deter mination of 7-amino-4-methylcoumarine (AMC), a final degradation product on this assay, the activity of PrA in beer was measured without the interference of the fluorogenic and photosensitive substance present in beer. The assay for common unpasteurized beers was completed within 5 hours without any concentration procedure. Its linearity and reproducibility were satisfactory for quanti tative purposes. Using a purified PrA from brewer's yeast, the effect of the PrA activity on foam stability during storage was furthermore clarified. The exclusive effect of PrA on foam stability was also demonstrated by proteinase inhibitor test.

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“…3 However, the haemoglobin substrate was non-tritiated and consequently the products of the proteolytic reaction (the acid-soluble peptides) in the final supernatent were determined by their absorbance at 280 nm.…”

Section: Experimental Materials and Methodsmentioning

confidence: 99%