56 Abstracts / Cerevisia 38 (2013) 51–60

Impact of Various Levels of Unmalted Oats(Avena sativa L.) on the Quality andProcessability of Mashes, Worts, and Beers

Journal of the American Society of BrewingChemists, 2012, 70 (3): 142–149.B. Schnitzenbaumer, R. Kerpes, J. Titze, F. Jacobs,E.K. Arendt

The brewing industry is facing an ever increasing challenge tobecome more cost-effective, while at the same time maintainingor improving product quality. Brewing with unmalted oats (Avenasativa L.) has the potential to reduce the costs of raw materials.However, the replacement of malted barley with unmalted oatscan also adversely affect the quality and processability of mashes,worts, and beers. In this study, brewing with unmalted oats (0–40%)and malted barley was carried out in a 60-L pilot plant. The impactof various levels of oats on mashing, lautering, and fermentationperformance was monitored in detail and the quality of the finalbeers was evaluated. It has been found that the �-glucan con-tent and viscosity of mashes and worts increased significantly withincreasing amounts of oats. In addition, the use of 20% or more oatadjunct resulted in a clearly increased lautering time. The replace-ment of barley malt with unmalted oats also had adverse effects ontotal soluble nitrogen (TSN), free amino nitrogen (FAN), and extractlevels in worts. The foam stability of the final beers decreased sig-nificantly using 20% oats or more. However, their sensory qualityimproved with increasing levels of oat adjunct.

http://dx.doi.org/10.1016/j.cervis.2013.09.020

A Review of Molecular Methods for MicrobialCommunity Profiling of Beer and Wine

Journal of the American Society of BrewingChemists, 2012, 70 (3): 150–162.N.A. Bokulich, C.W. Bamforth, D.A. Mills

Recent advances in molecular biotechnology have introducedan array of powerful techniques for studying the microbial ecol-ogy of beverage and food fermentations. Molecular tools such asdenaturing gradient gel electrophoresis, terminal restriction frag-ment length polymorphism, fluorescent in situ hybridization, clonelibraries, and quantitative polymerase chain reaction are sensitivemethods for microbial community analysis and have several advan-tages over traditional, culture-based techniques. Some of thesetools have far-reaching benefits, not only for fermentation researchbut also for rapid quality-assurance applications in the beveragefermentation industry. Additionally, the increasing accessibility ofnext-generation sequencing technologies is bringing some of thesepowerful new tools within reach of researchers for food or fermen-tation analysis. This promises high-resolution studies revealingdeep community structure in fermentation and processing envi-ronments, endeavors with obvious benefits to understanding andcontrolling mixed microbial fermentation systems and processhygiene. This review presents an overview of the current technolo-gies available for microbial community analysis and considers theirspecific application for fermentation research and industrial pur-poses, as well as providing an outlook on the future of communityprofiling in beer and wine.

http://dx.doi.org/10.1016/j.cervis.2013.09.021

Chemometric Investigation of Barley and MaltData

Journal of the American Society of BrewingChemists, 2012, 70 (3): 163–175.K.J. |Siebert, A. Egi, R. Mccaig

Several hundred samples of barleys and corresponding pilotscale malts were analyzed for eight barley parameters and 15malt parameters. Principal components analysis (PCA) was appliedto the barley and malt data sets. The barley data had three sig-nificant PCs, corresponding to kernel size, germination rate andprotein content, and moisture. The malt data had 5 significant com-ponents, largely corresponding to modification, extract, enzymeactivity, nitrogenous substances, and wort pH. Pattern recogni-tion of the barley and malt data sets was carried out with LinearDiscriminant Analysis (LDA), k-Nearest Neighbor analysis (k-NN)and SIMCA. Classification of the barley samples into 2- or 6-row,winter or spring, origin country and cultivar was fairly successful.Classification of the malt samples into hulled or hull-less barleys,country of origin, and cultivar was quite successful; classificationby crop year and 2- or 6-row barley was less successful. Modelsof malt parameters as a function of multiple barley measurementswere constructed using partial least squares regression (PLSR). Anexcellent model of malt total protein was obtained. Fair models offriability, fine and coarse extract, soluble protein, Kolbach index,diastatic power and alpha-amylase activity were produced. Onlypoor models of the other parameters were obtained.

http://dx.doi.org/10.1016/j.cervis.2013.09.022

Sensory Descriptive Analysis and Free-ChoiceProfiling of Thirteen Hop Varieties as WholeCones and After Dry Hopping of Beer

Journal of the American Society of BrewingChemists, 2012, 70 (3): 176–181.B.A. Donaldson, C.W. Bamforth, H. Heymann

Sensory descriptive analysis and free choice profiling have beenapplied to the characterization of aroma in thirteen hop varieties,both in the whole cone form and after the hops had been used todry hop beer. One hundred and eighty terms were identified andused for the classification of hops. Only two of the varieties dis-played closely similar profiles. Varieties could, however, be broadlygrouped into those with overriding citrus notes and those with sub-stantial green tea, hay and wet wood nature. Dry hopping tends tocompress varieties when evaluated for aroma, perhaps indicating adegree of masking by other beer components. However the aromanotes detected are similar whether assessed in whole cones or inbeers.

http://dx.doi.org/10.1016/j.cervis.2013.09.023

Characterization of Mutagenicity Test andIdentification of N-Nitroso Mutagens in SomeSoju Alcoholic Spirits

Journal of the American Society of BrewingChemists, 2012, 70 (3): 182–185.K.H. Kim, Y. Bae, K.S. Lee, Y. Moon, C.H. Kwon, J.H.Ahn

Although chronic exposure to alcohol or its contaminantsis the main carcinogenic risk factor in the high prevalence