Flavour preference

Smoke flavourings may be added directly to the salt solution used for brining fish or fillets. The final level of flavouring usage will depend on the flavour preference of specific market areas. 

Mention should also be made of glutamic acid and invert sugar which are used in foodstuffs and demand the use of hydrochloric acid-resistant material in manufacture, and of the essential flavouring oils which should preferably be stored and prepared in stainless steel and aluminium equipment. 

Crockery preferably is made from ceramic materials, although it is brittle and can break rather easily. Properties of ceramics, such as resistance to absorb flavours and low heat conductivity, however, are superior compared to metals and plastics. Therefore, we defined a task to design crockery with improved mechanical strength. 

The market for table ducks is steadily increasing, but egg layers are declining because of the strong flavour of the eggs. From four weeks onwards, ducks are reared outside, preferably on light sandy soils, as found in parts of Norfolk. Once again the outdoor system, particu-... 

Yolk colour plays a role in consumer acceptance, but the preferred colour varies in different countries. Yolk colour has no relation to nutrient content, flavour or freshness, but is often enhanced in conventional production systems by addition of synthetic pigments to the animal feed. In organic production, synthetic yolk pigments are prohibited and this normally results in paler yolks, but may also lead to greater variability in yolk colour intensity. In many European countries paler yolk colour is perceived by consumers as being associated with less natural production systems, an issue that clearly needs to be addressed by improved consumer information. 

The preferred solvent is supercritical CO2. The reasons for this choice are many and various. Firstly, the CO2 is not hot (CO2 first becomes critical at 31 °C and 73 atm pressure see Figure 5.5), so no charring of the coffee occurs during decaffeination. Furthermore, at such a low temperature, all the components within the coffee that impart the flavour and aroma remain within the solid coffee - try soaking coffee beans in cold water and see how the water tastes afterwards Caffeine is removed while retaining a full flavour. 

Flavour is of increasing importance when food is sufficiently abundant for consumers to exert choice. Sensory analysis, using trained laboratory panels, has been developed to profile fruit flavours, and describe relationships between products with a marked de ee of confidence but is time-consuming, requiring d icated obs ers who appreciate the nuances of individual character. Many, if not most, consumers, however, do not discriminate between fruit flavours. In dried orange juices, sweetness has been shown to be the major factor determining preference in canned juices, sourness and in frozen juices the interaction between sweetness and sourness is the significant factor (77). 

Owing to their unique and delicate flavour, species of the genus Passiflora have been the subject of intensive research on their volatile constituents [13]. The purple passion fruit (Passiflora edulis Sims) is a tropical fruit native to Brazil but is now grown in most tropical and subtropical countries [50]. Purple passion fruit is cultivated in Australia, India, Sri Lanka, New Zealand, and South Africa [48]. Yellow passion fruit (Passiflora edulis t flavicarpa) is one of the most popular and best known tropical fruits, having a floral, estery aroma with an exotic tropical sulfury note [62]. Yellow passion fruit is cultivated in Brazil, Hawaii, Fiji, and Taiwan [48]. Because of its more desirable flavour, the purple passion fruit is preferred for consumption as fresh fruit, whereas the yellow passion fruit is considered more suitable for processing [28]. 

Although quite often these flavour chemicals can be prepared from petrochemical sources, renewable resources are preferred by the flavour industry, because access to these renewable resources is very good and already existed when these companies were started. In addition, chemicals from renewable resources are natural, so they can be used in natural flavours and offer the possibility to be used for the production of natural secondary products. 

Vanilla is an excellent example in which a flavourist has to understand the market the flavour is to be created for. The Americans, for example, prefer the... 

As a direct result of this so-called food-minus trend some of the ingredients have to replaced or reduced. Owing to their role as preference drivers in food consumption, it is important to retain the whole flavour and taste profile of the original product, which can be done in most cases using a mixture of flavours, tastants, taste modifiers and texturants. 

Lipolysed milk fat was one of the first flavours produced with the help of enzymes. The original process was based on the controlled lipase-catalysed hydrolysis of cream [18]. For instance, Mucor miehei lipase possesses a high selectivity towards flavour-active short-chain fatty acids. Additionally, lipases that prefer long-chain fatty acids or lipases without particular preferences can be found. The free fatty acids produced can be isolated by steam distillation and further purified. Thus, it is possible to obtain pure short-chain fatty acids like butanoic, hexanoic, octanoic and decanoic acid. 

Esters are widespread in fruits and especially those with a relatively low molecular weight usually impart a characteristic fruity note to many foods, e.g. fermented beverages [49]. From the industrial viewpoint, esterases and lipases play an important role in synthetic chemistry, especially for stereoselective ester formations and kinetic resolutions of racemic alcohols [78]. These enzymes are very often easily available as cheap bulk reagents and usually remain active in organic reaction media. Therefore they are the preferred biocatalysts for the production of natural flavour esters, e.g. from short-chain aliphatic and terpenyl alcohols [7, 8], but also to provide enantiopure novel flavour and fragrance compounds for analytical and sensory evaluation purposes [12]. Enantioselectivity is an impor-... 

Fig. 23.3 a Ester formation via alkyl-CoA alcoholysis with yeasts (preferably Geotrichum fragrans) according to [85], exemplarily shown for ethyl-2-methylbutanoate and ethyl tiglate. b Some possible flavour esters producible depending on amino acid and alcohol used as substrates... 

Phenylethanol has a rose-like odour and makes the chemically produced compound the most used fragrance chemical in perfume and cosmetics, with a world market of about 7,000 t year [107, 108]. 2-Phenylethanol is also found in many foods as a characteristic flavour compound rounding off the overall aroma, especially in foods obtained by fermentation, such as wine, beer, cheese, tea leaves, cocoa, coffee, bread, cider and soy sauce [109]. In food applications, natural 2-phenylethanol is preferred rather than its nature-identical counterpart from chemical synthesis and it has a market volume of 0.5-11 year . This product is sold at market prices of up to US 1,000 per kiklogram and is mainly produced by yeast-based bioprocesses since its isolation from natural sources, e.g. rose oil, would be too costly [109]. 

Malic acid finds use in a variety of products, mostly in fruit-flavoured carbonates. It is the preferred acidulant in low-calorie drinks and in cider and apple drinks, enhancing flavour and stabilising colour in carbonated and non-carbon-ated fruit-flavoured drinks. Malic acid may also be used to mask the off-taste of some sugar substitutes. Blends of malic and citric acids are said to exhibit better taste characteristics than either acidulant individually. 

A first prototype can then be put together with the decided carbohydrate system and with salts added to approximate to the target electrolyte levels. Sweetness must be adjusted, probably by adding non-nutritive sweetener(s), an acidity level must be selected and flavour, colour and preservative must be added at appropriate levels. If the drink is to be carbonated a level must be chosen (a low level is preferable). 

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