•A low-cost portable e-nose was developed integrating nine different gas sensors.•The e-nose was able to effectively discriminate different beer samples from gases.•An accurate machine learning model ...was developed to predict beer aromas.•Another accurate machine learning model was able to predict sensory characteristics.•This method is cost-effective, rapid, reliable and accurate applicable for other foods.
The assessment of aromas in beer is critical to assess its quality since it could be used as an indicator of contamination or faults, which will directly influence consumers’ acceptability. Traditional techniques to evaluate aromas are time-consuming, require special training, costly equipment, and trained personnel. Therefore, this study aimed to develop a portable, low-cost electronic nose (e-nose) coupled with machine learning modeling to predict aromas in beer. Nine different gas sensors were used i) ethanol, ii) methane, iii) carbon monoxide, iv) hydrogen, v) ammonia/alcohol/benzene, vi) hydrogen sulfide, vii) ammonia, viii) benzene/alcohol/ammonia and ix) carbon dioxide. Output data were assessed for significant differences using ANOVA and least significant differences as post hoc test (α = 0.05). Two artificial neural network (ANN) models were also developed to predict i) the peak area of 17 different volatile aromatic compounds (Model 1) obtained from gas chromatography–mass spectroscopy (GC–MS) and ii) the intensity of ten sensory descriptors acquired from a sensory session with 12 trained panelists. Results from the ANOVA showed that there were significant differences between the samples used, which showed that the e-nose was able to discriminate samples. The resulting ANN models were highly accurate with correlation coefficients of R = 0.97 (Model 1) and R = 0.93 (Model 2). The combined method using the developed e-nose and the ANN models could be used by the industry as a low-cost, rapid, reliable and effective technique for beer quality assessment within the production line. This may also be calibrated for its use in other foods and beverages.
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•AFB1 lowered yeast counts in the first 48 h of sweet wort fermentation.•Wheat craft beer quality parameters were not compromised by AFB1.•Different organic acid profiles were ...detected in AFB1-contaminated beer.•Beer contaminated with AFB1 had lower levels of gallic acid, catechin, and procyanidins.•Levels of AFB1 were 0.22 µg/L in the wheat beer produced.
Levels of aflatoxin B1 (AFB1) were measured during the production of wheat craft beer made with wheat malt contaminated with AFB1 (1.23 µg/kg). A wheat craft beer made with non-contaminated wheat malt was produced for comparison purposes. AFB1 was measured after mashing (malt after the mashing process), and in spent grain (spent grains are filtered to collect the wort - remaining sugar-rich liquid), sweet wort, green beer, spent yeast, and in beer. Physicochemical parameters (pH, titratable acidity, color parameters, total soluble solids), sugars, organic acids, alcohols, and phenolics were evaluated after mashing, and in sweet wort, green beer, and beer samples. Density and yeast counts were determined over 120 h of sweet wort fermentation every 24 h. The AFB1 levels in the final beer were 0.22 µg/L, while the spent grains and spent yeasts contained 0.71 ± 0.17 and 0.11 ± 0.03 µg/kg of AFB1, respectively. AFB1 contamination did not influence the final product's physicochemical parameters, density during fermentation, fructose, or glycerol content. Higher yeast counts were observed during the first 48 h of non-contaminated wheat craft beer fermentation, with higher ethanol, citric acid, and propionic acid contents and lower glucose, malic acid, and lactic acid contents compared with beer contaminated with AFB1. Non-contaminated wheat craft beer also had higher concentrations of gallic acid, chlorogenic acid, catechin, procyanidin A2, and procyanidin B1. AFB1 contamination of wheat malt may not affect basic quality parameters in wheat craft beer but can influence the final product's organic acid and phenolic contents. Our findings show that if wheat craft beer is made with contaminated malt, AFB1 can remain in the final product and may pose a risk to consumers.
The production of alcoholic beverages is intrinsically linked to microbial activity. This is because microbes such as yeast are associated with the production of ethanol and key sensorial compounds ...that produce desirable qualities in fermented products. However, the brewing industry and other related sectors face a step-change in practice, primarily due to the growth in sales of no- and low-alcohol (NoLo) alternatives to traditional alcoholic products. Here we review the involvement of microbes across the brewing process, including both their positive contributions and their negative (spoilage) effects. We also discuss the opportunities for exploiting microbes for NoLo beer production, as well as the spoilage risks associated with these products. For the latter, we highlight differences in composition and process conditions between traditional and NoLo beers and discuss how these may impact the microbial ecosystem of each product stream in relation to microbiological stability and final beer quality.
Foam-related parameters greatly influence other sensory attributes of beer such as aromas, flavors and mouthfeel; therefore, the visual assessment of beers is one of the most important quality ...traits, since it creates the first impression of consumers in determining the willingness to taste the product and perceived quality. Sensory analysis has been extensively used to assess consumers acceptability; however, this can only obtain their self-reported conscious responses. Therefore, biometric techniques have been used to assess the subconscious responses, which provide more information from consumers when integrated with sensory evaluation questionnaires. In this study, non-invasive biometrics along with a sensory questionnaire were used to assess consumers perception to visual attributes of 15 beers from pouring videos obtained using the RoboBEER (automatic robotic pourer). The sensory session was conducted with 30 participants using an integrated camera system, which consists of an infrared thermal camera and video recording coupled with a Bio-sensory computer application (App) and an eye tracking device. Objective physical parameters from beer pouring were obtained using the RoboBEER and computer vision algorithms. Results from the Just About Right (JAR) and acceptance tests showed that consumers preferred top fermentation beers, which have a medium foam height and stability, and tend to highly penalize bottom fermentation beers with lower foam. The principal components analysis explained a total of 52% of data variability. A correlation matrix was developed to assess significant correlations between the conscious, subconscious and physical data such as the positive correlation between perceived quality and heart rate, and the negative correlation between foam stability liking and foam drainage. Furthermore, an artificial neural network model (ANN) with 82% accuracy was developed using 28 parameters from the subconscious and objective physical data as inputs to classify beers per participant according to their level of liking of foam height (low and high). The combined use of these techniques showed to be an accurate and rapid tool to assess the visual sensory perception of beers based on the RoboBEER and biometric outputs from consumers with significant potential applications for fast screening within the beer industry.
•Performed sensory evaluation of beer visual acceptability based on foam parameters.•Non-invasive biometrics applied to assess consumers visual perception of beer.•Biometrics and RoboBEER data used to classify foam liking with machine learning.•Significant correlations found between subconscious, conscious and objective data.
Rhubarb (
L.) is a valuable source of active components responsible for laxative, antibacterial, diuretic, anti-inflammatory and anti-cancer properties. On the other hand, ozone being an allotropic ...form of oxygen, due to its potential is a powerful antimicrobial agent. Treatment of rhubarb petioles with gaseous ozone, especially at a concentration of 50 ppm, for 30 minutes had a positive result on the microbiological stability and quality of the finished material. Sensory evaluation of prepared beers enriched without ozonated and ozonated rhubarb pulp showed that wheat beer with the addition of ozonated (50 ppm) rhubarb pulp was characterized by a balanced aroma and taste. The physico-chemical analysis of wheat beers demonstrated that the increasing concentration of ozone had an impact on, among others, increased the degree of final real attenuation (by 21.97%), decreased pH (by 18.43%) and energy value (by 36.30%), but had a negative impact on the content of ethyl alcohol (by 17.32%) compared to the control beer. Among the analyzed beers enriched with rhubarb, the beer product with the addition of ozonated (50 ppm) rhubarb was the most microbiologically stable. The research shows that wheat beers enriched with fragmented rhubarb can be a new trend to expand the range of wheat beers, and the use of gaseous ozone, especially at a concentration of 50 ppm for 30 minutes, can be a trend to extend the microbiological stability of beers, especially craft beers.
•Maiorca malt possesses the technological parameters required for brewing cereals.•Maiorca malt has adequate enzymatic activity resulting in better extraction values.•Brewing with 100 % Maiorca malt ...offers a novel approach in the brewing sector.
This study explores the potential of Maiorca wheat malt as an alternative ingredient in beer production, investigating its impact on the brewing process and beer quality at different recipe contents (50 %, 75 %, 100 %). The study encompasses a comprehensive analysis of key malt parameters, revealing Maiorca malt’s positive influence on maltose, glucose, filterability, extract, free amino nitrogen, and fermentability. Notably, the malt exhibited heightened levels of α-amylase and β-amylase enzymes compared to conventional commercial malt. Furthermore, the analysis of aroma compounds and subsequent sensory evaluations unveiled a significant correlation between the proportion of Maiorca malt in the formulation and intensified estery, fruity, malty, honey, complemented by a reduction in attributes such as aromatic compounds, phenolic, yeasty, sulfury, oxidized, and solvent-like odors. This research underscores the favorable contribution of Maiorca wheat malt to enhancing both the brewing process and final beer quality, highlighting its potential as an innovative ingredient in brewing practices.
Beers are among the most popular drinks all over the world. The introduction of beers to the market must be preceded by lengthy physicochemical studies, which are essential to ensure the food safety ...of consumers. Studying the rheological and electrical properties of beers can not only speed up the product launch, but also improve technological processes. Craft wheat beers enriched with lemongrass and fruit (addition of kamchatka berry and haskap fruits) were used in this study. Beer samples were subjected to density, dynamic viscosity, conductivity and impedance analyses and the values obtained were compared with the results of physicochemical analyses. The coefficient of determination reflects the correctness of the proposed model describing the detected dependence in the best way. The closer its value is to 1, the more accurate the model. The addition of lemongrass extract was found to reduce density, and coefficients of determination had high values in the interval (0.9927 - 0.9961). Beers enriched with berry extract had higher density than the control sample, and coefficients of determination have very high values in the interval (0.9955 - 0.9976). The control beers have the highest conductivity. The lemongrass and fruit extract with which the beer samples were enriched introduced sugar into the beer and these samples had lower conductivity (R
for beers with lemongrass is situated in interval 0.7772 - 0.9256 and for samples of beers with berries 0.6884 - 0.9846). Based on the impedance, it was possible to distinguish between types of beers, mainly at 50 kHz or 100 kHz.
•A recent case of diethylene glycol contamination in beer echoed in Brazilian press.•This case resulted in seven deaths and dozens of intoxicated people.•PLS-DA and portable NIRS were combined to ...detect diethylene glycol in beer.•The developed screening method is rapid, direct and environmentally friend.•It can be applied for quality control in breweries or on-site forensic analysis.
A recent case of contamination of some batches of a Brazilian beer brand with diethylene glycol (DEG) had great repercussion, resulting in at least seven deaths. In this article, a direct method was developed for the rapid detection of DEG in beer samples based on portable near-infrared spectroscopy combined with partial least squares discriminant analysis (PLS-DA). The discriminant model was built with 100 uncontaminated beer samples and 100 samples containing DEG in a concentration range between 10 and 1000 mg L−1, totalizing 200 samples of different brands and styles. The method was validated by estimating figures of merit, such as false positive and false negative rates, sensitivity, specificity, accuracy, accordance, and concordance. The decision limit (CCα) of the method was 52 mg L−1 and the detection capability (CCβ) was 106 mg L−1. This method does not consume reagents/solvents and can be suitable for the beer industry quality control or forensic investigations.
Beer is a popular drink and represents the most widely consumed alcoholic beverage in the world. In recent years, there has been a significant growth of independent craft breweries, even in countries ...without a brewing tradition.
A craft brewery is usually defined as a small, independent and traditional brewery.
Nowadays, consumers are looking for genuine, singular, different and high-quality products. Craft beer manufacturers have responded to this with the introduction of a novel combination of raw or malted cereals and have modified the beer flavours and taste with the addition of fruit, spices, etc.
This work presents an analysis of the different aspects related to craft beer. Its characteristics and brewing singularities are analyzed. The quality and safety standards used are examined and future trends of craft beer are also discussed.
