摘要:

This paper describes the use of a fuel cell sensor combined with dynamic headspace analysis as the basis of a new method for the determination of ethanol in alcoholic beverages. The success of the procedure has led to the production of a commercially available instrument for ethanol measurement, specifically targeted at the alcoholic beverage industry. This instrument, the Lion Laboratories Ltd. Drinks Alcolmeter DA-1, is a portable unit capable of continuous operation for up to 8 hr using integral, rechargeable batteries and has a precision better than±1% of the displayed value.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-47-0001

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Three isomeric humulene epoxides (I–III) were oxidized withm-chloroperbenzoic acid to their corresponding diepoxides (A–E) to determine the positions of the epoxide rings of the five known diepoxides. Humulene epoxide I gives three diepoxides designated A, B, and C. Epoxide II gives diepoxides A, B, D, and E. Epoxide III gives C, D, and E. Therefore, diepoxides A and B have epoxide rings in the positions of the monoepoxides I and II, diepoxide C in positions I and III, and diepoxides D and E in positions II and III. X-ray analysis of purified humulene diepoxide A showed it to have the epoxide rings trans, therefore the rings of B must be cis.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-47-0004

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

A gas chromatographic technique for the determination of free and bound sulfur dioxide in beer was developed. Bound SO2was decomplexed in alkaline medium in the presence of mercuric chloride. Free SO2evolved on acidification was quantified by gas chromatography with a flame photometric detector. Sodium bisulfite was used as an external standard. The method showed good correlation with both the distillation and colorimetric methods. Recovery of SO2and reproducibility by this gas chromatographic technique were high. Because the procedure does not use pararosaniline dye, it is safer than the colorimetric method and is equally applicable to rapid analysis of SO2in both pale and dark beer samples.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-47-0006

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

Bisulfite addition complexes were utilized in a method devised to obtain extracts suitable for the relatively rapid isolation and identification of beer carbonyl components as their oxime derivatives by combined gas chromatography-mass spectrometry. Analysis of a commercial lager revealed that the aldoximes in the extracts included alkanals, 3-hydroxyalkanals, and 2-methyl-2-alkenals. Hexenal and nonenal were determined to be present in beer ascis-3 isomers. Under the acid conditions used in other analyses, these may isomerize totrans-2-alkenals. Thecis-3-alkenals observed are expected products of the oxidative degradation of linoleic and linolenic acids. The 2-methyl-2-alkenals may be derived from aldol condensations involving propanal, which itself is an oxidative cleavage product of linolenic acid. A scheme is proposed for the formation of the identified beer carbonyls from linoleic and linolenic acids derived from malt.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-47-0009

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

The methods of analysis generally used for malt extract involve filtration of the mash at room temperature. We have shown that filtration at 75°C is a useful method able to provide information relevant to the performance of malt in industrial liquid-solid separations. Systematic study allowed determination of the discriminating parameters for filtration, which permitted filtration time and pressure to be optimized during various steps of the filtration and sparging process. A model equation was developed.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-47-0014

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor

摘要:

There is plentiful evidence that both the composition of the essential oil of hops and hop flavor in beer are influenced by variety. However, correlating these analytical and sensory data, and relating them to the varietal factor, are difficult because many of the major constituents of hop oil are not normally found in finished beer. The present studies sought to differentiate between a number of hop varieties on the basis of flavor attributes used to describe hoppy flavor in beer and to search for correlations between the latter and individual hop oil-derived flavor constituents found in beer. For this purpose, a series of pilot-scale beers was brewed using four domestically grown U.S. hop varieties and four imported European hop varieties. Sensory and compositional data were collected using experimental protocols specially devised for the purpose and were examined using a number of multivariate statistical techniques. The beers brewed with domestic hops were readily distinguishable from those brewed with imported hops, on the basis of either sensory or instrumental data. Using the technique of partial least squares analysis, a number of strong statistical correlations were noted to exist between particular hoppy flavor attributes and certain hop oil components.

ISSN:0361-0470    

DOI:10.1094/ASBCJ-47-0018

出版商:Taylor&Francis    

年代:1989

数据来源: Taylor