Floral Aromas and Funky Flavors : An Analysis of the X-zyme Brewing Adjunct and its Associated Enzyme Activity

Color poster with text, charts, photographs, and graphs.Adjuncts have been used for centuries to improve various qualities of beer. Enzyme adjuncts work by facilitating specific chemical reactions to attain results that would normally take much longer or not be possible at all without the adjunct. The X-zyme enzyme adjunct is intended to act as a beta-glucosidase and release glycosidically bound volatile terpene alcohols (VOC’s) to improve aroma and flavor. When performing GCMS analysis to look for increased VOC profiles we also saw an increase in the level of 4-vinylguaiacol (4-VG). 4-VG is a “funky”, clove-like, off flavor in beer that is usually undesirable. It has been characterized in the brewing community as a Phenolic Off Flavor (POF) which has been shown to rely on enzymatic decarboxylation to be derived from ferulic acid. With the knowledge that 4-VG is a derivative of ferulic acid, spectroscopic and HPLC ferulic acid esterase assays for in vitro and in situ X-zyme activity were developed. Both showed consistently higher ferulic acid content with X-zyme treatment. Results from our test brews suggest that there is little increase in terpene alcohols but when coupled with specific strains of yeast strains there is a large increase in the “funky” 4-VG aroma.University of Wisconsin--Eau Claire Office of Research and Sponsored Program

The impact of cardiopulmonary bypass management on outcome: a propensity matched comparison between minimally invasive and conventional valve surgery

Abstract OBJECTIVES Research concerning cardiopulmonary bypass (CPB) management during minimally invasive cardiac surgery (MICS) is scarce. We investigated the effect of CPB parameters such as pump flow, haemoglobin concentration and oxygen delivery on clinical outcome and renal function in a propensity matched comparison between MICS and median sternotomy (MS) for atrioventricular valve surgery. METHODS A total of 356 patients undergoing MICS or MS for atrioventricular valve surgery between 2006 and 2017 were analysed retrospectively. Propensity score analysis matched 90 patients in the MS group with 143 in the MICS group. Logistic regression analysis was performed to investigate independent predictors of cardiac surgery-associated acute kidney injury in patients having MICS. RESULTS In MICS, CPB (142.9 ± 39.4 vs 101.0 ± 38.3 min; P &amp;lt; 0.001) and aortic cross-clamp duration (89.9 ± 30.6 vs 63.5 ± 23.0 min; P &amp;lt; 0.001) were significantly prolonged although no differences in clinical outcomes were detected. The pump flow index was lower [2.2 ± 0.2 vs 2.4 ± 0.1 l⋅(min⋅m2)−1; P &amp;lt; 0.001] whereas intraoperative haemoglobin levels were higher (9.25 ± 1.1 vs 8.8 ± 1.2; P = 0.004) and the nadir oxygen delivery was lower [260.8 ± 43.5 vs 273.7 ± 43.7 ml⋅(min⋅m2)−1; P = 0.029] during MICS. Regression analysis revealed that the nadir haemoglobin concentration during CPB was the sole independent predictor of cardiac surgery-associated acute kidney injury (odds ratio 0.67, 95% confidence interval 0.46–0.96; P = 0.029) in MICS but not in MS. CONCLUSIONS Specific cannulation-related issues lead to CPB management during MICS being confronted with flow restrictions because an average pump flow index ≤2.2 l/min/m2 is achieved in 40% of patients who have MICS compared to those who have a conventional MS. This study showed that increasing the haemoglobin level might be helpful to reduce the incidence of cardiac surgery-associated acute kidney injury after minimally invasive mitral valve surgery. </jats:sec