Critical stages of the brewing process for changes in antioxidant activity and levels of phenolic compounds in ale

Samples were taken at each stage of brewing (malt, milling, mashing, wort separation, hop addition, boiling, whirlpool, dilution, fermentation, warm rest, chill-lagering, beer filtration, carbonation and bottling, pasteurization, and storage). The level of antioxidant activity of unfractionated, low-molecular-mass (LMM) and high-molecular-mass (HMM) fractions was measured by the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfortic acid) radical cation (ABTS(.+)) and ferric-reducing antioxidant power (FRAP) procedures. Polyphenol levels were assessed by HPLC. The LMM fraction (<5 kDa) was responsible for similar to80% of the level of antioxidant activity of the unfractionated malt and beer samples. In the unfractionated samples, significant decreases (P < 0.001) in antioxidant activity levels were observed after milling and beer filtration, with the decrease after beer filtration being accompanied by a significant decrease (P > 0.001) in catechin and ferulic acid levels. Increases in antioxidant activity levels were observed after mashing, boiling, fermentation, chill-lagering, and pasteurization, in line with previous studies on lager. Additionally, increases in the level of antioxidant activity occurred after wort separation and carbonation and bottling and were accompanied by increases in levels of most monitored polyphenols. Data from the ABTS(.-) and FRAP assays indicated that the compounds contributing to the levels of antioxidant activity responded differently in the two procedures. Levels of ferulic, vanillic, and chlorogenic acids and catechin accounted for 45-61% of the variation in antioxidant activity levels.

Predicting the thermal inactivation of bacteria in a solid matrix: simulation studies on the relative effects of microbial thermal resistance parameters and process conditions

A combined mathematical model for predicting heat penetration and microbial inactivation in a solid body heated by conduction was tested experimentally by inoculating agar cylinders with Salmonella typhimurium or Enterococcus faecium and heating in a water bath. Regions of growth where bacteria had survived after heating were measured by image analysis and compared with model predictions. Visualisation of the regions of growth was improved by incorporating chromogenic metabolic indicators into the agar. Preliminary tests established that the model performed satisfactorily with both test organisms and with cylinders of different diameter. The model was then used in simulation studies in which the parameters D, z, inoculum size, cylinder diameter and heating temperature were systematically varied. These simulations showed that the biological variables D, z and inoculum size had a relatively small effect on the time needed to eliminate bacteria at the cylinder axis in comparison with the physical variables heating temperature and cylinder diameter, which had a much greater relative effect. (c) 2005 Elsevier B.V All rights reserved.

Seasonal changes in olive fruit characteristics and oil accumulation during ripening process

Olive fruits of three of the most important Spanish and Italian cultivars, 'Picual', `Hojiblanca' and 'Frantoio', were harvested at bi-weekly periods during three crop seasons to study their development and ripening process. Fresh and dry weights and ripening index were determined for fruit, while dry matter, oil and moisture contents were determined in both fruit and pulp (flesh). Fruit growth rate and oil accumulation were calculated. Each olive cultivar showed a different ripening pattern, 'Hojiblanca' being the last one to maturate. Fruit weight increased, decreasing its growth rate from the middle of November. Dry matter and moisture contents decreased during ripening in pulp and fruit, 'Hojiblanca' showing the highest values for both. Oil content, when expressed on a fresh weight basis, increased in all cultivars, although for the last time period showed variations due to climatic conditions. During ripening, oil content on a dry weight basis increased in fruit, but oil biosynthesis in flesh ceased from November. Olive fruits presented lower oil and higher dry matter contents in the year of lowest rainfall. Therefore fruit harvesting should be carried out from the middle of November in order to obtain the highest oil yield and avoid natural fruit drop. (C) 2004 Society of Chemical Industry.

Preventing drug related morbidity: a process for facilitating changes in practice

Aim: To describe how quantitative data obtained from applying a series of indicators for preventable drug related morbidity (PDRM) in the electronic patient record in English general practice can be used to facilitate changes aimed at helping to improve medicines management. Design: A multidisciplinary discussion forum held at each practice facilitated by a clinical researcher. Subjects and setting: Eight English general practices. Outcome measures: Issues discussed at the multidisciplinary discussion forum and ideas generated by practices for tackling these issues. Progress made by practices after 1, 3, and 6 months. Results: A number of clinical issues were raised by the practices and ideas for moving them forward were discussed. The issues that were easiest and most straightforward to deal with (for example, reviewing specific patient groups) were quickly addressed in most instances. Practices were less likely to have taken steps towards addressing issues at a systems level. Conclusions: Data generated from applying PDRM indicators can be used to facilitate practice-wide discussion on medicines management. Different practices place different priority levels on the issues they wish to pursue. Individual practice "ownership'' of these, together with having a central committed figure at the practice, is key to the success of the process.

An empirical study of process-related attributes in segmented software cost-estimation relationships

Parametric software effort estimation models consisting on a single mathematical relationship suffer from poor adjustment and predictive characteristics in cases in which the historical database considered contains data coming from projects of a heterogeneous nature. The segmentation of the input domain according to clusters obtained from the database of historical projects serves as a tool for more realistic models that use several local estimation relationships. Nonetheless, it may be hypothesized that using clustering algorithms without previous consideration of the influence of well-known project attributes misses the opportunity to obtain more realistic segments. In this paper, we describe the results of an empirical study using the ISBSG-8 database and the EM clustering algorithm that studies the influence of the consideration of two process-related attributes as drivers of the clustering process: the use of engineering methodologies and the use of CASE tools. The results provide evidence that such consideration conditions significantly the final model obtained, even though the resulting predictive quality is of a similar magnitude.

The importance of the relationship between scale and process in understanding long-term DOC dynamics

Concentrations of dissolved organic carbon have increased in many, but not all, surface waters across acid impacted areas of Europe and North America over the last two decades. Over the last eight years several hypotheses have been put forward to explain these increases, but none are yet accepted universally. Research in this area appears to have reached a stalemate between those favouring declining atmospheric deposition, climate change or land management as the key driver of long-term DOC trends. While it is clear that many of these factors influence DOC dynamics in soil and stream waters, their effect varies over different temporal and spatial scales. We argue that regional differences in acid deposition loading may account for the apparent discrepancies between studies. DOC has shown strong monotonic increases in areas which have experienced strong downward trends in pollutant sulphur and/or seasalt deposition. Elsewhere climatic factors, that strongly influence seasonality, have also dominated inter-annual variability, and here long-term monotonic DOC trends are often difficult to detect. Furthermore, in areas receiving similar acid loadings, different catchment characteristics could have affected the site specific sensitivity to changes in acidity and therefore the magnitude of DOC release in response to changes in sulphur deposition. We suggest that confusion over these temporal and spatial scales of investigation has contributed unnecessarily to the disagreement over the main regional driver(s) of DOC trends, and that the data behind the majority of these studies is more compatible than is often conveyed.

The tendering process and performance analysis of a public building project in Ghana

A case study on the tendering process and cost/time performance of a public building project in Ghana is conducted. Competitive bids submitted by five contractors for the project, in which contractors were required to prepare their own quantities, were analyzed to compare differences in their pricing levels and risk/requirement perceptions. Queries sent to the consultants at the tender stage were also analyzed to identify the significant areas of concern to contractors in relation to the tender documentation. The five bidding prices were significantly different. The queries submitted for clarifications were significantly different, although a few were similar. Using a before-and-after experiment, the expected cost/time estimate at the start of the project was compared to the actual cost/time values, i.e. what happened in the actual construction phase. The analysis showed that the project exceeded its expected cost by 18% and its planned time by 210%. Variations and inadequate design were the major reasons. Following an exploration of these issues, an alternative tendering mechanism is recommended to clients. A shift away from the conventional approach of awarding work based on price, and serious consideration of alternative procurement routes can help clients in Ghana obtain better value for money on their projects.

Risk accountability in the tender process of contractors in Ghana and UK

The process of how contractors take account of risk when calculating their bids for construction work is investigated based on preliminary investigations and case studies in Ghana and UK. Ghana and UK were chosen, more or less arbitrarily, for the purpose of case studies, and to test the idea that there are systematic differences between the approaches in different places. Clear differences were found in the risk pricing approaches of contractors in the two countries. The difference appeared to emanate from the professional knowledge and competence of the bid team members, company policy, corporate accountability and the business environments in which the contractors operate. Both groups of contractors take account of risk in estimates. However, risk accountability was found to be higher on the agenda in the tender process of UK contractors, documented more systematically, and assessed and managed more rigorously with input from the whole bid team. Risk accountability takes place at three levels of the tender process and is dictated strongly by market forces and company circumstances.

New developments in batch process input profile optimisation

A novel algorithm for solving nonlinear discrete time optimal control problems with model-reality differences is presented. The technique uses dynamic integrated system optimisation and parameter estimation (DISOPE) which achieves the correct optimal solution in spite of deficiencies in the mathematical model employed in the optimisation procedure. A new method for approximating some Jacobian trajectories required by the algorithm is introduced. It is shown that the iterative procedure associated with the algorithm naturally suits applications to batch chemical processes.

Liquidity in commercial property markets: deconstructing the transaction process

This paper draws from a wider research programme in the UK undertaken for the Investment Property Forum examining liquidity in commercial property. One aspect of liquidity is the process by which transactions occur including both how properties are selected for sale and the time taken to transact. The paper analyses data from three organisations; a property company, a major financial institution and an asset management company, formally a major public sector pension fund. The data covers three market states and includes sales completed in 1995, 2000 and 2002 in the UK. The research interviewed key individuals within the three organisations to identify any common patterns of activity within the sale process and also identified the timing of 187 actual transactions from inception of the sale to completion. The research developed a taxonomy of the transaction process. Interviews with vendors indicated that decisions to sell were a product of a combination of portfolio, specific property and market based issues. Properties were generally not kept in a “readiness for sale” state. The average time from first decision to sell the actual property to completion had a mean time of 298 days and a median of 190 days. It is concluded that this study may underestimate the true length of the time to transact for two reasons. Firstly, the pre-marketing period is rarely recorded in transaction files. Secondly, and more fundamentally, studies of sold properties may contain selection bias. The research indicated that vendors tended to sell properties which it was perceived could be sold at a ‘fair’ price in a reasonable period of time.