Riccarton, United Kingdom
Riccarton, United Kingdom

Time filter

Source Type

Agu R.C.,Scotch Whisky Research Institute | Walker J.W.,Scotch Whisky Research Institute | Okolo B.N.,University of Nigeria | Olabanji O.G.,Lake Chad Research Institute | And 3 more authors.
Journal of the American Society of Brewing Chemists | Year: 2016

An adapted, landrace Nigerian Arupo S barley was malted in the laboratory following the standard malting method developed for malting elite barleys. Our results showed that Arupo S barley showed both fast and even germination during the malting process. Friability results further established that Arupo S malted barley produced flours with high amounts of husks. This is an advantage for both the brewing and distilling industries in terms of wort filtration for the brewing industry or phenol retention during peating or kilning for the distilling industry. The proteolysis achieved when Arupo S barley was malted by using standard malting procedures for malting elite barleys showed that a progressive increase in the pattern of release of soluble nitrogen materials in terms of free amino nitrogen (FAN) and amino acid production was achieved. FAN released in Arupo S malt was 118 mg/L on day 4 of the germination period and was sufficient to support yeast fermentation. The amino acids released into the worts of mashed Arupo S malt were generally high. Extracts from mashed Arupo S malt produced a similar range of reducing sugars (glucose, sucrose, fructose, maltose, and maltotriose) found in standard (elite) malted barley varieties. Fermentability results showed that Arupo S malted barley produced maximum predicted spirit yield on day 4 of malting. This study also showed that for the brewing industry, Arupo S malted barley produced good head retention. Our results clearly showed that although the Arupo S six-row barley studied was grown in a hot tropical environment with irrigation (drought and flooding) and was malted using methods developed for malting temperate-grown elite barleys, it still produced overall results comparable to those obtained for adequately researched barleys. A genetic variability that enabled Arupo S barley to grow and produce crops under these harsh environmental conditions, as well as to produce malt, is worth exploring. © 2016 American Society of Brewing Chemists, Inc.


Agu R.C.,Scotch Whisky Research Institute | Chiba Y.,Heriot - Watt University | Goodfellow V.,Heriot - Watt University | MacKinlay J.,Heriot - Watt University | And 6 more authors.
Journal of Agricultural and Food Chemistry | Year: 2012

This study examined the performance of rice and buckwheat when malted under various temperature conditions and for different lengths of time. The mashed malts produced from both rice and buckwheat contained a wide spectra of sugars and amino acids that are required for yeast fermentation, regardless of malting temperature. At the germination temperatures of 20, 25, and 30 °C used, production of reducing sugars and free amino nitrogen (FAN) followed similar patterns. This implies that temperature variations, experienced in different countries, will not have an adverse effect on the production and release of amino acids and sugars, required by yeast during fermentation, from these grains. Such consistency in the availability of yeast substrates is likely to reduce differences in processing when these malts are used for brewing. This study revealed that, while rice malt consistently produced more maltose than glucose, buckwheat malt gave several times more glucose than maltose, across all germination temperatures. Buckwheat malt also produced more soluble and free amino nitrogen than rice malt. Unlike sorghum, which has gained wide application in the brewing industry for the production of gluten-free beer, the use of rice and buckwheat is minimal. This study provides novel information regarding the potential of rice and buckwheat for brewing. Both followed similar patterns to sorghum, suggesting that they could play a similar role to sorghum in the brewing industry. Inclusion of rice and buckwheat as brewing raw materials will increase the availability of suitable materials for use in the production of gluten-free beer, potentially making it more sustainable, cheaper, and more widely available. © 2012 American Chemical Society.


Chiba Y.,Heriot - Watt University | Bryce J.H.,Heriot - Watt University | Goodfellow V.,Heriot - Watt University | MacKinlay J.,Heriot - Watt University | And 4 more authors.
Journal of Agricultural and Food Chemistry | Year: 2012

Our study showed that sorghum and millet followed a similar pattern of changes when they were malted under similar conditions. When the malt from these cereals was mashed, both cereal types produced wide spectra of substrates (sugars and amino acids) that are required for yeast fermentation when malted at either lower or higher temperatures. At the germination temperatures of 20, 25, and 30 °C used in malting both cereal types, production of reducing sugars and that of free amino nitrogen (FAN) were similar. This is an important quality attribute for both cereals because it implies that variation in temperature during the malting of sorghum and millet, especially when malting temperature is difficult to control, and also reflecting temperature variations, experienced in different countries, will not have an adverse effect on the production and release of amino acids and sugars required by yeast during fermentation. Such consistency in the availability of yeast food (substrates) for metabolism during fermentation when sorghum and millet are malted at various temperatures is likely to reduce processing issues when their malts are used for brewing. Although sorghum has gained wide application in the brewing industry, and has been used extensively in brewing gluten-free beer on industrial scale, this is not the case with millet. The work described here provides novel information regarding the potential of millet for brewing. When both cereals were malted, the results obtained for millet in this study followed patterns similar to those of sorghum. This suggests that millet, in terms of sugars and amino acids, can play a role similar to that of sorghum in the brewing industry. This further suggests that millet, like sorghum, would be a good raw material for brewing gluten-free beer. Inclusion of millet as a brewing raw material will increase the availability of suitable materials (raw material sustainability) for use in the production of gluten-free beer, beverages, and other products. The availability of wider range of raw materials will not only help to reduce costs of beer production, but by extension, the benefit of reduced cost of production can be gained by consumers of gluten-free beer as the product would be cheaper and more widely available. © 2012 American Chemical Society.


Agu R.C.,Scotch Whisky Research Institute | Okolo B.N.,University of Nigeria | Okoro P.M.,Crop and Soil Systems Research Group | Goodfellow V.,Heriot - Watt University | Bryce J.H.,Heriot - Watt University
Journal of the American Society of Brewing Chemists | Year: 2016

The major climatic limitations associated with barley production in the tropics are temperature, humidity, and soils. Arupo S is a six-row landrace barley variety successfully grown in Nigeria, where environmental conditions are often unfavorable. Arupo S is a semi-dwarf, medium maturity with very high yield potential under favorable conditions. It has excellent lodging resistance and good levels of resistance to most diseases, for example, stem rust, leaf rust, and so on. It has good malting quality. Arupo S barley malted at a wide range of temperature conditions (16- 25°C) produced malts that met the requirements for brewing purposes. The results of this study showed that the growing conditions of Arupo S barley under irrigation (flooding) did not have any observed negative impact on the quality of malt made from Arupo barley. Arupo S barley steeped and germinated in the temperature range 16-25°C developed good levels of amylolytic enzymes (α-amylase and β-amylase) and produced good hot water extracts (HWE), free amino nitrogen (FAN), amino acids, and reducing sugars. Although the malt made at 25°C developed the least amount of amylolytic enzymes and FAN products, it produced the highest levels of HWE and reducing sugars (glucose and maltose). On the other hand, Arupo S malt made at 18°C developed higher levels of amylolytic enzymes but gave lower amounts of HWE, especially at day 4 of germination. In terms of amino acid distribution in the worts of malted Arupo S barley, the malts made at the lower temperatures of 16 and 18°C gave higher levels of the individual amino acids. The malt made at higher temperatures also produced reasonable amounts of individual amino acids. These results show the difficulties of using only a few parameters in assessing malt quality, indicating that a holistic approach is required when assessing barley and malt quality. Furthermore, this study showed that using a higher malting temperature to produce malt from Arupo S barley in hot countries where malting temperature is difficult to control will not have much detrimental effect on the quality of the malt produced. This is an advantage because use of refrigeration during malting would be expensive. © 2016 American Society of Brewing Chemists, Inc.


Hess L.,Crop and Soil Systems | Hess L.,Scotch Whisky Research Institute | Hess L.,University of Edinburgh | Meir P.,University of Edinburgh | And 2 more authors.
Annals of Applied Biology | Year: 2015

The drought-sensitivity of oilseed rape (OSR, Brassica napus cv. SW Landmark) was investigated, using the more widely studied crop species wheat (Triticum aestivum cv. Tybalt) as a benchmark. The water relations of OSR and wheat were compared in lysimeter and controlled environment experiments to test the hypothesis that the growth of OSR is restricted to a greater extent by soil drying than wheat and to determine whether the greater sensitivity results from differences in root or shoot traits. Plants were grown, with or without irrigation, in 1.2 m tall lysimeters packed with a sandy clay loam soil. The experiment was conducted in an open-sided glasshouse to encourage air flow and to resemble a field environment as far as possible; plant population densities were equivalent to commercial crops. Irrigated OSR (evapo)transpired more water than wheat (498 vs. 355 mm), but had a comparable water use efficiency (WUE; 4.1 vs. 4.4 g DW mm-1 H2O). Oilseed rape showed a greater reduction in above-ground growth (52% vs. 21%) and a smaller increase in WUE (27% vs. 45%) when water was withheld. Oilseed rape also responded to soil drying at a lower soil moisture deficit than wheat; transpiration rates fell below the potential of irrigated plants when plant available water remaining in the soil profile declined from 54 to 23% compared to 38 to 9% for wheat. The root hydraulic conductivity of young OSR plants, measured on root surface area basis, was about twice that of wheat, and was comparable on a root length basis. The results show that OSR was more sensitive to a restricted water supply than the benchmark species wheat and that the greater sensitivity resulted from differences in shoot, rather than root, characteristics. The root system of OSR was at least as efficient as wheat at extracting water from soil. © 2015 Association of Applied Biologists.


Okolo B.N.,University of Nigeria | Agu R.C.,Scotch Whisky Research Institute | Agu R.C.,University of Nigeria
Journal of Solid Waste Technology and Management | Year: 2013

This study investigated the potential of waste materials from yam as a viable alternative and cheaper source of raw material for bio-ethanol production. In a world where the population continues to expand rapidly and high levels of poverty, there may be a conflict in our application of food quality raw materials. Use of human grade raw materials for bio-ethanol production can limit these resources. Rotten yam will not compete as a human food source. Their conversion into bio-ethanol could provide a more appropriate alternative. Good and rotten parts of yam tuber produced alcohol yields of 533 and 528 litres of alcohol per tonne (LA/t) on a dry weight basis (dwb). Yam with varying degrees of rot - "slight," "medium" and "excessive" gave alcohol yields of 518 LA/t, 512 LA/t and 478 LA/t (dwb) respectively. Yam peel and extremely rotten yam tuber produced alcohol at 240 LA/t and 300 LA/t respectively. Benefit to be gained from this study is that good quality yam flour will be available as food for humans, while use of rotten yam for bio-ethanol production will provide a cleaner environment by eliminating their dumping into the environment thereby reducing environmental pollution and health hazards associated with their decay.


Agu R.C.,Scotch Whisky Research Institute | Agu R.C.,University of Nigeria | Walker J.W.,Scotch Whisky Research Institute | Okolo B.N.,University of Nigeria | And 3 more authors.
Journal of Solid Waste Technology and Management | Year: 2014

This study examined the potential of waste materials from the tuber of Dioscorea bulbifera ("Aduegbe ") as a viable alternative and cheap source of renewable raw material for bio-ethanol production. Use of renewable waste materials will reduce competition in the use of human grade raw materials for bio-ethanol production. World population continues to expand rapidly with high levels of poverty. Use of human grade raw materials for bio-ethanol production can limit these resources. "Aduegbe" will not compete as a human food source as it is a waste ma- terial and is in abundance. Their conversion into bio-ethanol could provide a more appropriate alternative. Peeled "Aduegbe " and the peel produced alcohol yields of 425 and 251 litres of al- cohol per tonne (LA/t) on a dry weight basis (dwb) respectively. Rice and sorghum studied for comparison produced higher alcohol yields at 507LA/t and 452 LA/t respectively while millet and buckwheat produced much lower alcohol yields than "Aduegbe" at 392 LA/t and 294 LA/t respectively. Benefit to be gained from this study is that food materials will be available for humans, whilst waste materials will provide renewable raw materials for bio-ethanol production and will provide a cleaner environment by eliminating their dumping or burning into the environment.


Harrison B.,Scotch Whisky Research Institute | Fagnen O.,Scotch Whisky Research Institute | Jack F.,Scotch Whisky Research Institute | Brosnan J.,Scotch Whisky Research Institute
Journal of the Institute of Brewing | Year: 2011

In Scotch malt whisky production, the use of copper for the construction of the pot stills for distillation is regarded as having an important effect on whisky aroma. During distillation in cop- per pot stills, the copper acts to reduce sulphury aromas in the resultant spirit by reducing the levels of sulphur compounds such as dimethyl trisulphide (DMTS). This work has shown that the copper is more effective in this role in some parts of the pot stills than others. This information can be used to help distillers maintain or, indeed, to alter new make spirit aroma. It was also noted that in addition to DMTS, other, as yet unidentified, com- pounds make a significant contribution to sulphury aromas, so future research efforts should focus on identifying such com-pounds. © 2011 The Institute of Brewing & Distilling.

Loading Scotch Whisky Research Institute collaborators
Loading Scotch Whisky Research Institute collaborators