Palate Fullness Research Articles

Enhancing the mouthfeel of non-alcoholic beers: The influence of dextrin and arabinoxylan on perceived viscosity and body

Carbohydrates in beer are recognized for enhancing viscosity. Increasing their levels during the production of non-alcoholic beers (NABs) may serve as a valuable strategy to compensate for the loss in viscosity and palate fullness due to dealcoholization. This study assessed the effectiveness of dextrin and arabinoxylan (AX) in this respect, within their content range and with the structural characteristics found in commercial beers. The addition of purified dextrin and AX isolates to water, pilsner beer, and NAB revealed that 30 g/L dextrin or 1.5 g/L high-molecular-weight AX (HMW AX) was required to compensate for the dealcoholization-induced viscosity loss. Evaluating the effect of both components on perceived palate fullness and mouthfeel involved producing eight NABs with varying dextrin and HMW AX levels and assessing them by a trained sensory panel (n = 12). Dextrin and HMW AX combined significantly increased palate fullness (p < 0.10), while solely increasing either was insufficient to achieve this effect. Increasing beer viscosity by itself could not fully compensate for palate fullness loss due to dealcoholization. Thus, adjusting NAB production to elevate HMW AX and dextrin levels simultaneously emerges as a viable strategy for improving palate fullness, offering valuable insights for brewers towards enhanced NAB quality.

Effective strategies to maximise dextrin formation in brewing

Why was the work done: Dextrin is the non-fermentable product of starch hydrolysis and plays a role in enhancing the perceived palate fullness of beer. Therefore, increasing dextrin formation is a promising strategy to improve palate fullness, particularly in non-alcoholic and low-alcohol beers. How was the work done: This study investigated the impact of adjusting the mashing profile of a 100% barley malt mash on the dextrin content and molecular weight distribution in the wort. Mash thickness, heating rate, and mashing-in temperature with and without the addition of a thermostable α-amylase were adjusted during mashing to evaluate the impact on dextrin content and molecular weight distribution. To benchmark this work, the dextrin content and molecular weight distribution was determined in five pilsener beers and their non-alcoholic counterparts. What are the main findings: With the exception of one non-alcoholic beer which contained 72 g/L, the concentration of dextrin ranged from 15 to 30 g/L in the five commercial pilsner-type beers and their non-alcoholic equivalents. The molecular weight distribution of dextrin among the beers was similar, with 85-98% of the dextrin population characterised by a degree of polymerisation below 35. Various strategies were applied during mashing to evaluate the impact on the content and the molecular weight distribution of dextrin. A strategy that promoted dextrin formation was mashing with a lower water-to-grist ratio. This resulted in delayed starch gelatinisation influenced by increased solid extract content in wort. Furthermore, at a low water-to-grist ratio, faster mash heating (up to 2°C/min) or isothermal mashing at temperatures below 72°C had no impact on dextrin formation. Isothermal mashing at 78°C supplemented with thermostable α-amylase increased the dextrin level in wort up to 60 g/L, while the molecular weight distribution of dextrin was similar to that found in commercial beers. Why is the work important: This study demonstrates that increased dextrin formation is achievable in beer but requires significant changes to the mashing process. These insights will enable brewers to enhance the palate fullness of beers, especially those which are non-alcoholic or low in alcohol.

Influence of dextrins and β-glucans on palate fullness and mouthfeel of beer

Palate fullness (PF) and mouthfeel are important sensory attributes influencing beer quality. The molar mass of starch (dextrins) and non-starch (β-glucans) polysaccharides may influence PF (pleasant) or mouthfeel (sliminess, unpleasant), respectively. Therefore, this research aims to generate beer with wide physico-chemical responses based on various raw material characteristics to study its relation to PF and mouthfeel. To accomplish this, ten barley varieties (two harvest locations and years) were classified into three groups based on their modification characteristics. To intensify response variation, barley was malted at two modification levels (parameter steeping degree), generating 55 independent malts used to brew the same number of standardized bottom fermented beers. A trained sensory panel evaluated PF (intensity and quality) and mouthfeel (e.g., slimy) descriptors. Additionally, beers were fractionated by asymmetrical flow field-flow fractionation (AF4) in three different fractions and their molar masses were determined. The average molar mass of big size (> 10 nm) dextrins and β-glucans AF4 fraction increased analogously to barley modification characteristics. For sensory data evaluation, only beer samples brewed with malts inside the recommended brewing specifications were considered (β-glucan content in malt < 350 mg/L, ISO 65 °C). PF quality was lower on samples with β-glucan content < 100 mg/L. This group also contained fewer dextrins (attenuation > 87.4 ± 1.5%), suggesting that the balance of β-glucans and dextrins is important for PF quality. This work indicates that molar mass of starch and non-starch polysaccharides, affected by barley variety and its modification level, influences sensory perception, and hence, beer quality.Graphical

Filtration enzymes applied during mashing affect beer composition and viscosity

Why was the work done: Filtration enzymes that target the degradation of arabinoxylan and β-glucan are widely used in the brewing industry to improve wort and beer filtration. Although these enzymes have proven their effectiveness in improved lautering efficiency and beer filterability, the effect of varying dosage and type of enzyme preparations on beer composition and quality has not been described.&#x0D; How was the work done: The impact of dosage of different filtration enzyme preparations (Laminex®750, Laminex®C2K, and Laminex®MaxFlow4G) was investigated on the free ferulic acid content in the wort, chemical composition and viscosity of beer, together with an emphasis on the content and structure of arabinoxylan and β-glucan.&#x0D; What are the main findings: The structural features of arabinoxylan and β-glucan in beer were strongly influenced by the dosage and type of filtration enzyme. In general, the high-molecular weight (HMW) arabinoxylan and HMW β-glucan content, and total β-glucan content in beers decreased with increasing enzyme dosage, while the total arabinoxylan levels increased. The HMW arabinoxylan content was strongly related to beer viscosity. The use of filtration enzymes led to a decreased HMW arabinoxylan content and decreased beer viscosity, which could affect the palate fullness of beers. Overdosing filtration enzymes resulted in more ferulic acid, the precursor (in the presence of phenolic yeast) to the clove-like 4-vinyl guaiacol.&#x0D; Why is the work important: This work provides brewers with insight on how filtration enzymes affect beer composition and viscosity. It can help make an informed choice of the type of filtration enzyme and the dosage applied during mashing.

Comparative Analysis of the Essential Oil Contents of Azadrichta indica and Humulus lulpulus: Could Azadrichta indica Substitute Humulus lulpulus in Beer Brewing?

Hops (Humulus lulpulus) give beer its brewing qualities (iso-alpha acid and essential oil). Hop acid is responsible for bitterness while hop essential oil is responsible for aroma and palate fullness. The aim of the study is to investigate the potentiality of substituting hop oil with neem (Azadrichta indica) oil in beer brewing. The oils were analyzed using Fourier-Transform Infrared (FTIR) spectroscopic technique after extracting the oil by solvent extraction. Hydrocarbon and Sulphur contents were also investigated using their standard methods. FTIR results show that both oils contain similar functional groups. It was observed that some hydrocarbons (myrcene, ocimene and α and β-pinene) present in essential oil of hop were also present in neem leaf oil. Volatile sulphur compounds such as dimethyl sulphide, dimethyl disulphide and dimethyl trisulphide present in hop oil were also found in neem oil. This study revealed that neem oil could be used as a substitute for hop oil in aroma enhancement in beer.

Effect of molar mass and size of non-alcoholic beer fractions and their relevance toward palate fullness intensity

Palate fullness intensity and mouthfeel descriptors are essential sensory characteristics of non-alcoholic beers (NABs). The descriptor’s perception might be influenced by the molar distribution of the non-volatile matrix in cereal-based beverages like NABs. However, only limited information is available on the molar mass of different substances in NABs. This study investigated the role of weight average molar mass (Mw) and size of NABs fractions and their relation to sensory perception. Industrialized bottom-fermented NABs (n = 28) from the German market and NABs produced by different methods were used in this study. A trained sensory panel evaluated palate fullness intensity, mouthfeel, and basic taste descriptors (as additional quality parameters). Asymmetric flow field-flow fractionation was used to fractionate NABs, while Mw was determined by multi-angle light scattering and differential refractive index detectors. The NABs were fractionated into three groups containing different substances: proteins, proteins-polyphenol complexes (P-PC) and low molar mass (non-)starch polysaccharides (LN-SP), and high molar mass (non-)starch polysaccharides (HN-SP). The Mw range of proteins was 18.3–41 kDa, P-PC and LN-SP 43–122.6 kDa, and HN-SP 0.40–2.18·103 kDa. Harmony, defined as the sweet and sour ratio, influenced the palate fullness intensity perception. In the harmonic samples (sour/sweet sensory balanced), the size of HN-SP (> 25 nm) showed a positive correlation to palate fullness intensity. The results suggest the importance of dextrins, arabinoxylan, and β-glucan in modulating the sensory characteristics of harmonic bottom-fermented NABs.

Mouthfeel of Beer: Development of Tribology Method and Correlation with Sensory Data from an Online Database

Soft tribology has recently gained momentum as a technique to measure friction properties of food that can be correlated to mouthfeel. The mouthfeel of beer is an important driver of acceptance and liking of consumers, and especially non-alcoholic beers are often rated poorly in terms of palate fullness. In the present work, frictional parameters of ten beers (five alcoholic and their non-alcoholic counterpart) were measured, and a range of variables was extracted and subjected to dimension reduction analysis (Principal Component Analysis, clustering, and correlation analysis). Sensory data consisting of a numeric mouthfeel rating and written reviews from an online beer-rating website (www.ratebeer.com) were compiled, transformed, and correlated with the tribology data. Based on frictional parameters of the beers, clear differences were observed between alcoholic and non-alcoholic beers, as well as those beers with high or low mouthfeel rating. Text-mining and clustering of the written reviews led to the development of seven overall sensory descriptors ("watery", "smooth", "thick", "bitter", "foam", "astringent", and "sour") related to mouthfeel. Frictional parameters related to the static, boundary and beginning of the mixed regime were correlated with "watery", "smooth", and "thick", while "bitter", "foam", "astringent", and "sour" were represented later in the mixed regime. These results are significant in two ways; firstly, they indicate that online beer reviews represent a valuable resource when gathering large amounts of sensory data, and secondly, they demonstrate tribology as a tool to instrumentally determine important mouthfeel parameters of beer.

Chemometric modeling of palate fullness in lager beers

Palate fullness and mouthfeel of beer are key attributes of sensory beer quality. Non-volatile substances and molar mass fractions influence sensory perceptions of palate fullness and mouthfeel. However, systematic correlations between sensory attributes and native beer compounds have not been evaluated within the concentration range found in lager beer. This article reports a chemometric analysis of 41 lager beers by evaluating analytical data of beer compositions, palate fullness, and mouthfeel descriptors. AF4-MALS-dRI indicated high variability in the macromolecular compositions of classical lager beers. Screened beers were clustered into groups differing significantly in palate fullness intensity and macromolecular distribution. Significant correlations were found between palate fullness and macromolecular fractions and beer composition parameters: original gravity, viscosity, indices of macromolecular distribution, total nitrogen (p < 0.001), and β-glucan (p < 0.01). Thus, a model was built using partial least square regression (PLS) analysis to predict the palate fullness intensity in beers (R2C = 0.7993). This model can be used as a guideline by brewers to control palate fullness and mouthfeel.

Influence of malt modification and the corresponding macromolecular profile on palate fullness in cereal-based beverages

The sensory attribute palate fullness of cereal-based beverages was shown to be affected by polymeric compounds and their macromolecular profile. During malting, the enzymatic degradation of polymers is technologically controlled by the malting parameters, namely the degree of steeping, germination time, and germination temperature. The macromolecular profile of a fermented cereal-based beverage consists of non-fermentable substance classes. Therefore, the macromolecular composition of a final beverage is originally dominated by the raw material, if conventional production methods are used. We investigated the influence of different cytolytic and proteolytic malt modifications on the macromolecular profile of lactic acid-fermented cereal-based beverages (a strain was selected that did not produce exopolysaccharides) and their resultant effect on the sensory perception of the attributes of palate fullness and mouthfeel. Asymmetrical-flow field-flow fractionation coupled with multi-angle light-scattering detection and refractive index detection is an analytical tool for macromolecular characterization to indicate differences in the macromolecular profile, molar mass, and molar mass distribution. The beverages produced using different modified malts demonstrated a considerable variation in their final composition, particularly in the composition of their macromolecular compounds. A higher level of malt modification led to a decrease in the high-molar-mass fraction and a consequent shift toward fractions with a lower molar mass. Malts produced from barley with increased crude protein contents resulted in a greater range within the macromolecular profile. The variation of germination time significantly influenced the number average molar mass, the total refractive index detection (dRI) peak area, and the high-molar-mass fraction, which contained cell wall polysaccharides (60–1200 kDa). The perception of the intensity of palate fullness was significantly correlated with specific macromolecular fractions, which were influenced by the malting parameter degree of steeping and the resultant modification. The perception of the mouthfeel descriptor watery varied significantly for different crude protein contents. Our results are beneficial for a targeted design of beverage composition based on the macromolecular profile by an improved selection of raw materials and malting technology.

Potential use of Starmerella bacillaris as fermentation starter for the production of low-alcohol beverages obtained from unripe grapes

To obtain beverages with reduced alcohol content, the use of unripe grapes, with low sugar and high malic acid concentration, was recently explored. Due to the low sugar, ethanol and glycerol production is limited during fermentation affecting important sensory aspects such as the palate fullness of these beverages. The high acidity influences their organoleptic quality, as well.So far, only S. cerevisiae starter, used in conventional fermentations, have been tested in this condition, and no selection has been performed to identify alternative yeasts suitable for unripe grape fermentation. S. bacillaris is known for the low ethanol tolerance, high glycerol and moderate volatile acidity production. Therefore, this non- Saccharomyces yeast have been investigated to improve the quality of low-alcohol beverages. Seven S. bacillaris strains were tested in synthetic musts with different sugar and malic acid levels, mimicking natural ripe and unripe grape musts. In all the tested conditions, S. bacillaris produced higher glycerol than S. cerevisiae. In single-strain fermentation at low sugar and high malic acid no S. bacillaris strains was able to transform all the sugars, although the produced ethanol was lower than that at high sugar condition. Therefore, sequential fermentations with S. cerevisiae were evaluated at low sugar and high malic acid. In this condition all the sugars were consumed and a significant glycerol increase was found. These results were confirmed when sequential fermentations were run in natural unripe grape must. Moreover, an increase in malic acid degradation, with respect to EC1118 single-strain fermentation, was observed.

Characterization of the macromolecular and sensory profile of non-alcoholic beers produced with various methods

Due to changing consumer habits, non-alcoholic beer is the fastest-growing market within the beverage industry. Different processing technologies for limiting the alcohol content of beer yield in completely different matrix compositions and sensory profiles. Especially the specific sensory attributes of palate fullness, mouthfeel, and the perception of harmony (ratio harmony between sweetness and sourness) of non-alcoholic beers are often described as atypical and unbalanced by the consumer. In addition to technological aspects, the matrix components represent a significant factor. Cereal-based beverages contain a complex mixture of various polymers that includes proteins, polyphenols, and polysaccharides. These polymers affect the sensory perception of beverages in terms of mouthfeel depending on their substance properties.This article reports the analytical characterization of the macromolecular profile of non-alcoholic beers to predict sensory differences in palate fullness and mouthfeel that arise because of variations in polymer profile and processing method. Therefore, asymmetric flow-field-flow-fractionation (FFF/AF4), multi-angle light-scattering (MALS), and refractive index measurements were used to characterize polymers in non-alcoholic beers. We observed significant differences in the ratio of low- to high-molar-mass polymers. These differences included a shift of the molar mass distribution towards higher molar masses for beers subjected to higher thermal loads during dealcoholization in a rectification column. Limited fermentation beers tended to be composed of more low-molar-mass polymers.Highly discriminating sensorial assessment schemes demonstrate the correlations between differences in macromolecular profile and specific sensory impressions like sweetness (basic taste), palate fullness and harmony. This trend is verified in the present study with spiking experiments using substances that are known to influence mouthfeel and palate fullness, such as beta-glucans, dextrins, isomaltulose, and other low-molar-mass sugars, may be controlled during the production process. These results confirm that the particular sensory attributes can be influenced by different classes of cereal-based substances, especially by varying their molar mass fractions and concentrations. Maltodextrins and β-glucan are shown to enhance palate fullness. Spiking with maltodextrin caused a lasting, smooth, and pleasant perception of mouthfeel; spiking with β-glucan resulted in a more viscous, thick perceived mouthfeel. However, spiking with isomaltulose led solely to a sweet taste (basic taste).These tests show more generally that AF4-MALS is a suitable analytical tool for understanding how the macromolecular fractions in cereal-based beverages are linked to sensory impressions. This type of assessment can be used to target the composition of polymer profiles, which can be a technological possibility to produce sensorily appealing high-quality non-alcoholic beers.

Analytical Characterization of the Hydrolysis of Barley Malt Macromolecules During Enzymatic Degradation Over Time Using AF4/MALS/RI.

The changes on the molecular weight distribution (MWD) and particle size distribution (PSD) during hydrolysis of barley malt in isothermal mashing procedures were determined using asymmetrical flow field flow fractionation coupled to multiangle laser light scattering and refractive index (AF4/MALS/RI). Mash/trials were focused on amylolytic starch degradation. Therefore, temperatures (65, 70, and 75 °C) were selected according to α- and β-amylases range of activity. Samples were produced by triplicate, tracking amylolytic processes over time periods from 10 to 90 min in each mash/trial. AF4/MALS/RI analysis demonstrated significant differences on the values of the MWD and PSD according to the temperature/time profile used. At mashing times over 30 min at a temperature of 65 °C, when α- and β-amylase are both active, the decrease over time of the MWD and PSD was significantly higher (P < 0.005) than at 70 °C when mainly α-amylase is active. At 75 °C, also the activity of α-amylase decreased and the MWD and PSD were significantly lower (P < 0.005) than at 70 or 65 °C at any time of the procedure. The MWD and PSD of beer components influence beer palate fullness, thus AF4/ MALS/RI would be a powerful tool for breweries to adapt their technological processes to obtain beers with particular sensorial attributes.

ФОРМИРОВАНИЕ И РАЗВИТИЕ ОТЕЧЕСТВЕННОГО РЫНКА ПИВА С ПОЗИЦИЙ МЕЖДУНАРОДНЫХ ТРЕБОВАНИЙ

The analysis of the domestic beer market is made. It is determined that nowadays despite of the intensive development of the malting and brewing industry in our country there is a problem of providing brewing companies with a traditional raw material of high quality. Therefore, an increasing number of companies turn to the use of the unmalted grains as corn, rice, barley, wheat, rye, oat, grain sorghum, millet and triticale as well as solid and liquid non-grain materials. As a result of testing assessment of 20 samples of beer of different composition we found out that the introduction of malt-free materials reduces the organoleptic parameters of beer, it worsens the palate fullness, makes it rather tasteless and hop bitter becomes weaker, the flavor is flat. The increasing competition in the brewing market puts forward new demands to food producers. Within this framework satisfaction of the consumers by the quality of beer plays an important role. We can’t solve this problem in all sectors of food industry and especially in the dynamically developing brewing industry without improving the organoleptic evaluation of food products on the basis of international standards. The German Purity Decree, which is the oldest and well-known in the world, controls the brewing process and states that the beverage is considered to be beer only if it contains water, barley malt and hop, as well as yeasts which are subsequently removed from beer. In this regard we offer a technological solution consisting in the production of beer within the requirements of the Purity Decree due to the use of microwave treatment at the barley malting stage. This solution will make it possible to produce beer according to the classical technology of high quality.

Reducing Properties of Fermentable and Nonfermentable Carbohydrates in Beverages and Brewing Process

An optimized method to ascertain the reduction potential of sugars against Fe3+ at low pH range was applied to get a deeper insight into the reduction properties of carbohydrates in beverages and during the brewing process. Our investigations have clearly shown that the behavior of carbohydrates at low pH is different compared with the generally known reduction properties described by Fehling using NaOH. At a low pH range, the formation of the open-chain aldehyde structure of glucose is more inhibited and fructose has a higher ability to generate the open structure, resulting in stronger reducing properties. At typical beer pH range of approx. 4.3, the analyses showed the strongest reduction potential caused by the nonfermentable carbohydrate isomaltulose, which is commercially used to increase the palate fullness of beverages. On the side of fermentable carbohydrates, fructose showed the strongest reduction potential followed by maltotriose and maltose. The detected higher reduction potential of the “nonreducing” sucrose contrary to the so-called “reducing sugar” glucose can be explained by the acid hydrolyzation of carbohydrates. Furthermore, the demonstrated pH-dependent changes of the reduction potentials of carbohydrates, are notable and help to explain the influences of carbohydrates on oxidative processes at different pH ranges of beverages. Analogous to the latest publications about influences of substances with typical reductone or enediol structure on the acceleration of oxidative processes, the increasing reduction potential of carbohydrates is responsible for an accelerated oxygen activation and radical generation. Especially during the wort boiling process, where all carbohydrate reactions are accelerated, the carbohydrates with the stronger reduction potential are responsible for a stronger acceleration of oxidative processes and vice versa.

Influence of the range of molecular weight distribution of beer components on the intensity of palate fullness

The effect of the molecular weight distribution (MWD) of the beer components on the intensity of palate fullness was studied. The range of MWD for different types of maltodextrin and for nine commercial pilsner beers was determined using AF4/MALLS/RI. Sensory analysis (DIN 10952, DIN ISO 4120 and DIN 10963/ISO 8587) was carried out by a trained Deutsche Landwirtschafts-Gesellschaft, German Agriculture Society (DLG) tasting panel. The intensity of the palate fullness of a spiking trial (beer + maltodextrin) and the threshold concentration of the maltodextrins in beer was determined. The association between the ranges of MWD and the intensity of the palate fullness of the commercial pilsner beers was studied. AF4/MALLS/RI and sensory analysis were used to study the effect of variations of the brewing process on the range of MWD and the palate fullness of beer. The intensity of the palate fullness differed significantly (p < 0.0001) within commercial pilsner beers. Strong associations were found between the range of MWD of the commercial beers and intensity of the palate fullness (p < 0.05). The range of MWD of the commercial pilsner beers (3–13 kDa) corresponded to those found for maltodextrins with intermediated range of MWD (3.4–22.3 kDa). The threshold concentration was higher (p < 0.0001) for those maltodextrins with lower range of MWD (2.7–8.9 kDa). Beers produced with malted barley with Kolbach Index of 36 % exhibited a higher range of MWD (2.9–13 kDa) compared to those with Kolbach Index of 41 % (1.7–11.6 kDa). Slight differences in the palate fullness were perceived according to variations on the initial temperature of the mashing process among those beers produced using Kolbach Index of 36 %, whereas a great difference (p < 0.0001) was perceived using Kolbach Index of 41 %. The intensity of the palate fullness of the pilsner beer was influenced by the range of MWD of the beer components which would vary according to differences in the mashing process and of the quality of the malted barley.

ON BARLEY AMYLASE AND PROTEINASE

In view of the significance of albumin degradation products in relation to beer foam and palate fullness, and the apparent localization of amylase in the albumin fraction of barley, it appears desirable to develop means for accurate determination of barley amylase, including both free and total amylase. A suitable method for this purpose involves extraction of barley meal with 0.1 M sodium chloride solution for free amylase determination and by sodium chloride in presence of cystein for total amylase, it having been shown that the inactive enzyme is activated by reducing substances; the effect is probably independent of any influence on proteolytic enzymes. Further, proteinase activity in barley can be determined by a modification of the Anson method, using haemoglobin as substrate, and determining proteolysis either spectrophotometrically or by applying Kjeldahl's method to the soluble products formed.