DERIVATION OF A PROFILE METHOD FOR SENSORY ANALYSIS OF BEER FLAVOUR

Flavour assessment ultimately depends on sensory methods of analysis. Profile methods are considered to offer the best current solution to the problem of describing, and as far as possible quantifying, beer flavour. The sensory characteristics of flavour must be identified and described systematically and objectively, without prejudice due to preferences. A flavour ‘vocabulary’ is needed which is applicable to all types of beer. This involves selection of significant terms which have the same meaning for different people. Any system universally applicable to all types of beer must necessarily be complex, but such a “universal” system is essential for research. It also provides a “dictionary” from which terms can be selected for simpler profiles for quality control of particular products. The steps in the development of a profile system are described. Development has depended and will continue to depend on the collaboration of a large number of individuals and groups of people within the industry. Profile systems cannot be static but must continuously evolve.     

ESTER CONTROL IN HIGH GRAVITY BREWING

Pilot brewing trials have shown that beers of good flavour can be produced using a high gravity brewing system in which worts of 1080° gravity are fermented and the resulting beers diluted to give an O.G. of 1040°. The flavour can differ from that of the control beers in that the diluted beers retain more ester and strong ale character. Trials have been carried out to study possible methods for control of ester production to permit product matching. A promising approach is controlled contact with oxygen during fermentation.     

MALT FLAVOUR — TRANSFORMATION OF CARBONYL COMPOUNDS BY YEAST DURING FERMENTATION

Laboratory and pilot scale fermentations have been carried out using worts spiked with a range of carbonyl compounds, many of which are derived from malt. Aldehydes and vinyl ketones were chemically reduced during fermentation and could not be detected in the resulting beers; on the other hand certain saturated and non-conjugated unsaturated ketones were only partially reduced. The corresponding saturated alcohols and acetate esters were usually detected as transformation products.     

无盐酸菜在发酵和贮藏过程中品质的变化

目的:探究无盐并接种乳酸菌发酵酸菜过程及低温贮藏过程中品质变化规律。方法:分析无盐酸菜发酵过程中的基本理化指标及贮存期间的品质变化。结果:无盐酸菜在发酵第5天达到成熟,发酵过程中,pH值、亚硝酸盐含量、还原糖含量和维生素C含量显著下降(P<0.05),其中维生素C含量减少了88.62%,总酸和总有机酸水平显著上升(P<0.05)。发酵成熟时,亚硝酸盐含量极低,达(0.23±0.10) mg/kg;其中有机酸主要为乳酸、草酸和醋酸,除琥珀酸外,其他有机酸如草酸、柠檬酸等发酵后均有增加,乳酸含量增加了26.5倍。4℃贮藏60 d,无盐酸菜的pH值、总酸含量无明显变化,亚硝酸盐含量持续降低。结论:发酵过程有效提高了无盐酸菜的酸味和鲜味,并保证了其优良的感官品质,且4℃下的贮藏性能良好,贮藏期为60 d。     

The production of pork with garlic flavour notes using garlic essential oil

Garlic essential oil (GEO) added directly to pork mince or to the diet of pigs was evaluated for its effectiveness in masking undesirable mutton flavour. Pork was from 31 female pigs (Duroc × (Large White × Landrace)) grown on diets containing either animal-plus-plant products (AP diet) or plant products only (P diet) with four levels of GEO: 0, 0.55, 1.44 and 1.84 g/kg feed and 0, 0.55, 1.44 and 2.15 g/kg feed in the AP and P diet, respectively. Garlic flavour increased and mutton flavour decreased in pork from pigs that consumed more than about 150 g and 220 g of GEO in P and AP diets, respectively over the 57-day feeding period. The garlic flavour was stronger and the mutton flavour less intense for pork from pigs on the P diet. When GEO was added to pork mince at 125 ppm, it significantly reduced mutton flavour.     

Phenolic acids composition and antioxidant activity of canola extracts in cooked beef,chicken and pork

Crude polyphenol extracts (15 or 100 mg gallic acid equivalents (GAE)/kg meat) from canola meal reduced the formation of 2-thiobarbituric acid-reactive substances (TBARS) in pre-cooked beef (66–92%), pork (43–75%) and chicken (36–70%). The canola extract contained sinapic (99.7%), ferulic (0.28%) and p-hydroxybenzoic acids (0.07%).     

Perception of Beer Flavour Associates with Thermal Taster Status

Beer flavour, and thus much of the consumer experience of beer, is determined by the sensations elicited when it is taken into the mouth. Thus, individual differences in the perception of these oral sensations may contribute to the variation in consumer behaviour. A new taste phenotype shown to associate with the intensity of oral sensations elicited by simple solutions is thermal taster status (TTS). Thermal tasters (TTs) perceive ‘phantom’ tastes with thermal stimulation of the tongue, while thermal non‐tasters (TnTs) do not. Here, we investigate the effect of TTS on the perceived intensity of bitterness, sourness, sweetness, fullness, carbonation and overall flavour intensity elicited by seven beers representing classic styles — wheat beer, brown ale, pale ale, low‐alcohol lager, standard lager, high‐alcohol lager and stout. A strong trend was observed for TTs (n = 20) to rate attributes higher than TnTs (n = 20) for all beers except the stout, with these differences significant in many instances (ANOVA or binomial analysis). It is concluded that TTS may be an important determinant of individual differences in the perception of beer flavour, but beer liking and preference are more complex phenomena than can be accounted for by this phenotype alone.     

多菌种混合发酵对主食风味的影响

随着经济的发展和生活水平的不断提高,对主食的质量提出了更高的要求。传统主食发酵剂属于混合菌种发酵,发酵的馒头风味独特,深受人们的青睐。近年研究发现混合菌种发酵的酸面团能够改善面包产品的风味和质构,增加谷物产品的营养价值,延长货架期等。对多菌种混合发酵主食产生的风味物质进行了研究,包括风味物质的组成、影响因素和检测等。     

The Influence of Heavy Metal Ions on Beer Flavour Stability

In this study, the importance of iron and copper ions and their radical formation via the respective Fenton and Haber‐Weiss reactions was confirmed. Of the other heavy metals present in the brewing process in relevant concentrations, the impact of manganese ions on beer flavour stability has been elucidated. In contrast to iron and copper, manganese ions are not removed from wort or beer to any great extent during the process. Additionally, manganese shows a similar radical‐promoting effect to that seen with iron and copper. Its reactivity, and typically higher concentration than the other two metals in beer, appear to make manganese an especially potent pro‐oxidant in beer. The results of the investigation clearly indicate that there are other heavy metals influencing the stale flavour characteristics of beer, in addition to the well‐known metals, iron and copper. In contrast to the aforementioned ions, manganese does not enter the product by being leached out of a tank or from piping materials, but rather comes from the cereals employed in brewing. This finding, concerning the importance of manganese as a redox system in beer staling, can serve as a basis for a different approach in the choice of raw materials.     

A Review of Flavour Formation in Continuous Beer Fermentations*

The attractive prospect of a continuous beer fermentation system consists mostly of the accelerated transformation of wort into beer. Although continuous beer fermentation has been studied as a promising technology for several decades, the number of industrial applications is still limited. The major obstacle hindering the extensive industrial exploitation of this technology is the difficulty in achieving the correct balance of sensory compounds in the short time typical for continuous systems. This paper offers an integral view on the particularities of continuous systems, which may impart beer a sensorial character distinct from conventionally fermented counterparts. The main groups of flavour active compounds are discussed from the perspective of possible control strategies by means of process parameters and strain selection.