Oxidative Enzyme Effects in Malt for Brewing

Malted barley is an important beer‐brewing material that strongly affects brewing processes, the aroma, and the taste of beer. In addition to imparting a good aroma, malt not only generates substrates and enzymes, such as starches and some amylase, for alcohol production but also generates beer‐quality‐degrading substances and enzymes. Four oxidases are specifically addressed in this chapter. First, thiol oxidase in malt is described. The activity of thiol oxidase decreases during malt storage. Next, ascorbate peroxidase was investigated. It has been detected in the acrospires and aleurones of germinating barley. The enzyme has extremely high affinity for hydrogen peroxide. Also, ascorbic acid oxidase (AAO) was investigated. It is developed in the embryo tissues of barley during steeping and during the initial stages of germination. The addition of ascorbic acid to mash leads to the survival of higher levels of polyphenol and thiols into wort and a reduced color in that wort. Finally, oxalate oxidase in barley kernels is described. It is probably less important than other oxidases in scavenging oxygen from mashes, because the enzyme has low affinity for oxygen. Beer quality is expected to be improved by the regulation of oxidant enzymes, such as thiol oxidase or AAO, oxalate oxidase, or substrates, such as oxygen

Energy management in industry : a case study on the brewing industry

The industrial sector is the main energy user in South Africa, using about half the national total, and compared to most other industrialised countries South Africa has a high in_dustrial energy intensity, thus necessitating improved industrial energy management. The malt brewing industry was chosen as a case study industry to illustrate the potential for improved energy management in industry. Ohlsson's brewery in Cape Town was analysed in detail and energy management improvements identified for that brewery were ·expanded to include the malt brewing industry in general, by comparing Ohlsson's brewery to other breweries in South Africa. It was found that energy requirements at Ohlsson's Brewery could be reduced by 12-20%, by the implementation of economically feasible energy management schemes. However, mainly because of discrepancies in coal prices between Ohlsson's Brewery and most other breweries in South Africa, energy requirements for the brewing industry in general can be reduced by 7-13%. This translates to be a monetary saving of R242 000-R486 000/month, which is evenly spread between coal, electricity, and maximum demand savings. No single large energy saving scheme was identified, but the potential. savings are due to a number of schemes. The potential energy savings identified in this study exclude the savings as a result of the implementation of process sensitive schemes, which were considered beyond the scope of this study. Nevertheless some process sensitive schemes, associated with boiling in the brewhouse, could result in substantial savings. The energy usage target identified for South African breweries is higher than current energy requiiements for breweries in the Britain and Germany when climatic and operational constraints are taken into account. This is because Britain and Germany have higher energy costs relative to production costs, government incentive schemes for reducing energy usage, and more stringent environmental legislation often necessitating the recovery of brewhouse vapours

Interactions between macromolecules and membranes: their effects on beer quality

When filtering beer at pore sizes of 0.45 μm and below, some desirable components may be lost, even though they are orders of magnitude smaller than the pores. In this work, a model beer solution of pure components has been filtered through 0.2 μm membranes to investigate this problem. Starch (a model for the long chain carbohydrates) at a concentration of 1500 mg.l-1 and casein (a model for the protein fraction) at a concentration of 150 mg.l-1 were found to result in reduced permeate fluxes in the region of 20–40 l.m-2.h-1. [Continues.

Low pressure microfilter design aspects and filtration performance

A microfilter should retain micron sized material yet provide minimal resistance to liquid flow. A slotted pore surface microfilter was oscillated whilst filtering yeast cells under constant rate. At shear rates over 7760 s-1, a pore blocking model fitted the data. The operating pressure was very low (<1000 Pa), but particle retention was limited by the 4 micron pore slot width. A sintered glass micro-bead coating improved yeast rejection: 95% at 1.7 microns at a shear rate of 5000 s-1, with a 1.2 kPa transmembrane pressure. Two models were validated to assist with the design of future micro-bead coatings constructed from spherical particles

Effects of physical parameters in mashing on lautering performance

This thesis investigates performance parameters of unit operations in the brewery. It describes effects of the parameters temperature and agitation during mashing on mash properties. Mainly two properties are influenced by these parameters, the viscosity and the particle size distribution in the fines. It could be shown that both factors have significant influence on filterability of mash. In pilot scale and laboratory trials particle size effects in mash were investigated systematically. The importance of fine particles for lautering performance could be confirmed and quantified. The precipitation and aggregation of fine particles with increasing temperatures in the mash could be monitored for the first time. It could be shown that this parameter is not malt dependent. Mashes from different malts react in the same way. In laboratory trials it could be proved that the particle size parameter is more important than viscosity for filterability of mash. The parameters described above have been quantified and correlated with mash filtration parameters. This work provided a basis for the development of a computer model which describes mash separation in a lauter tun

An exploratory investigation of crossflow microfiltration for solid/liquid separation in biological wastewater treatment

This thesis contains the results and discussion of an exploratory investigation into the application of Crossflow Microfiltration (CFMF) for solid/liquid separation in biological wastewater treatment systems. The principal objective of the study was to assess the influence of CFMF on the performance of identified biological wastewater treatment systems. It was not the objective to optimise filtration performance. A literature review indicated that the crossflow mode of filtration has been widely accepted as a unit operation in the fermentation industry. The filtration mode is now being applied not only for solid/liquid separation but also for separations on a molecular and ionic level. Very few applications of crossflow filtration in the context of biological wastewater treatment solid/liquid separation are reported in the literature. The reasons for this limited experience would appear to be the scale involved and the perceived high costs; separations in the fermentation industry are usually conducted at relatively small scale (laboratory or pilot-scale) and involve high-value products, justifying high capital and operating costs. Also, the high level of separation performance attained is perhaps not necessary for many wastewater treatment applications. No doubt these reservations are largely valid. However, these arguments cannot be applied equally to all filtration methods and wastewater treatment schemes. For example, the costs of microfiltration are substantially less than ultrafiltration or reverse osmosis, and in certain cases effluents with extremely low suspended solids contents may be required. In the light of these observations an investigation of CFMF for solid/liquid separation in biological wastewater treatment systems appears justified. Two biological treatment systems were selected for study: the Upflow Anaerobic Sludge Bed (UASB) reactor and the Activated Sludge system. The envisaged benefits accruing from the application of CFMF were different in each case

Improvement of the microbiological quality of a beer filtration system

This work addresses the improvement of the microbiologic quality of beer in the BBT (Bright Beer Tanks), after the filtration of green beer, which is the final step of beer production before packaging. The objective was to improve the KPI to achieve a 91.00% Micro BBT FTR indicator in the end of the team’s work, starting from 85.42% in the beginning of the work. A multidisciplinary improvement team inside the brewery was formed to study and implement changes that would improve the FTR (First-Time Right) Microbiology Indicator for the BBT. The designed team was routed in the TPM (Total Productive Management) structure of the brewery, using the 5S’s philosophy, and following a microbiological defect reduction route. The team improved the indicator up to 87.05% by the conclusion of its work, thus falling short of its goal. Despite this, several improvements were made, such as the removal of dead legs on the CIP Circuit and the creation of an integrated Cleaning, Inspection, Lubrication and Tightening plan. Besides this, important studies regarding BBT usage and beer recovery alternatives in filtration were also carried out, and these could have a very significant impact in the overall Micro BBT FTR in the future