Juice flavour

Evaluation of pervaporation process for recovering a key orange juice flavour compound modeling and simulation... 

Evaluation ofPervaporation Process for Recovering a Key Orange Juice Flavour Compound Modeling and Simulation... 

Formation of intense flavours during the ripening period of fruit is traditionally well known. In many cases the characteristic flavours are only produced during the auto-lytic decomposition or during mechanical destruction of plant tissue (apple juice flavour from mash, woodruff in withered clove). The cause of this post-mortem flavour liberation is always a hydrolytic process mediated by plant-borne enzymes. 

In chapter 3.2.2.1 the manufacturing of juice flavours from fruit is described in more detail. 

A commercial design of the UF-RO process for membrane concentration of orange juice was described by Cross (1989). After that, the Separasystems LP, a joint venture between FMC and Du Pont, developed a combined membrane process, named FreshNote system, able to produce concentrated orange juice at 60 °Brix retaining the fresh juice flavours. The... 

The corrosive effects to be considered (mainly simple corrosion of metals) are, as would be expected from the edible nature of foodstuffs which are not excessively either acidic or basic but which may contain sulphur, less severe than those often encountered with inedible materials containing reactive substances. The importance of corrosive efiects where foodstuffs are concerned lies not so much in the action of the foodstuffs on the metal involved as in the resultant metal contamination of the foodstuff itself, which may give rise to off-flavours, in the acceleration of other undesirable changes (by the Maillard reaction for example), and in the possible formation of toxic metallic salts. Metal ions generally have threshold values of content for incipient taste effect in different liquid foodstuffs. Except in the case of the manufacture of fruit juices and pickles, process plant failure through corrosion must be rare. Nevertheless all foodstuffs, particularly liquid ones, should be regarded as potentially corrosive and capable of metal pick-up which may be undesirable. 

The important commercial feature of these juices, especially significant with blackcurrant and tomato juices, is their ascorbic acid (or vitamin C) content, of which loss by oxidation is known to be accelerated both by heat and by metal (particularly copper) contamination. The effect of copper has been carefully investigated for pure ascorbic acid", and more recently ascorbic acid in blackcurrant juice and model systems. There are, however, oxidation inhibitors of different kinds (which may themselves be heat-sensitive) present in various fruits, which give differing results. The presence of metals will also affect flavours", may cause discoloration, and may give rise to clouding effects, as in apple juice. ... 

Ice lollies are made from juice (water, sugar, citric acid, flavour and colour) and are frozen into shape using moulds immersed in a cold brine solution, in a similar manner to can ice making (see Section 12.4). The moulds are made from stainless steel or nickel, and pass in rows through a brine bath at - 45°C. Different layers of confection may be built up by allowing one outside layer to freeze, sucking out the unfrozen centre and refilling with another mix. The sticks are inserted before the centre freezes solid. The moulds finally pass... 

FAD. FMN AND RF CONCENTRATION (juG/L) FOR WINES. BEERS AND FRUIT JUICES AND THE ESTIMATE OF THE AVERAGE INTENSITY OF THE DEFECT SUNLIGHT FLAVOUR AFTER EXPOSURE TO LIGHT OF SAMPLES... 

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). 

About two thirds of the citrus produced worldwide is consumed as fresh fruit. Unfortunately, citrus utilised as fresh fruit cannot constitute a source of commercial flavours. However, in certain high-production countries such as the USA (Florida) and Brazil, the majority of the citrus crop is processed. In Florida over 90% of the orange crop is processed and is a major source for citrus flavouring material. Citrus fruits are processed primarily into juice, but oil from the outer layer of the peel, flavedo, and the condensate from making concentrated juice are also major sources of flavour products from citrus fruit. 

The typical flavour of sour cherries is produced during processing into wine, liqueur, juice, jam or fruit sauce. Benzaldehyde has been determined to be the most important aroma compound in sour cherries [82], but benzyl alcohol, eu-genol and vanillin are also important flavour compounds (Table 7.2, Fig. 7.5) [83]. Growing and storage conditions affect the concentration of benzaldehyde, benzyl alcohol, eugenol and vanillin [83, 84], and cold and rainy weather produces sour cherries with a less delicate sour cherry aroma [83]. 

Important aroma compounds of black currant berries have been identified mainly by GC-O techniques by Latrasse et al. [119], Mikkelsen and Poll [115] and Varming et al. [7] and those of black currant nectar and juice by Iversen et al. [113]. The most important volatile compounds for black currant berry and juice aroma include esters such as 2-methylbutyl acetate, methyl butanoate, ethyl butanoate and ethyl hexanoate with fruity and sweet notes, nonanal, /I-damascenone and several monoterpenes (a-pinene, 1,8-cineole, linalool, ter-pinen-4-ol and a-terpineol) as well as aliphatic ketones (e.g. l-octen-3-one) and sulfur compounds such as 4-methoxy-2-methyl-butanethiol (Table 7.3, Figs. 7.3, 7.4, 7.6). 4-Methoxy-2-methylbutanethiol has a characteristic catty note and is very important to blackcurrant flavour [119]. 

The fruity-sweet flavours in elderberry juice and products have primarily been associated with aliphatic esters such as ethyl 2-methylbutanoate, ethyl 3-methylbutanoate, methyl heptanoate, methyl octanoate, methyl nonanoate, alcohols (2-methyl-l-propanol, 2-methyl-1-butanol and 3-methyl-1-butanol) and the aldehydes pentanal, heptanal and octanal [127, 129, 130, 132],... 

Essences of pink and white fresh guava obtained by direct extraction of flesh juices with dichloromethane revealed that the total amount of Cs aldehydes, alcohols, and acids comprised 20 and 44% of the essence of fresh white and pink guavas, respectively [49]. The flavour of the Costa Rican guava has been described as sweet with strong fruity, woody-spicy, and floral notes [53]. One hundred and seventy-three volatile compounds were isolated by simultaneous steam distillation-solvent extraction. The terpenes and terpenic derivatives were found in this fruit in major concentrations and were strong contributors to tropical fruit notes (Fig. 8.1). The aliphatic esters contributed much to its typical flavour. 

Pineapple, one of the most popular tropical fruits in the world, has been cultivated in South America since the fifteenth century [61]. It has been very popular throughout the world for many years [16]. Native to Central America and South America, pineapples grow in several tropical countries, such as Hawaii, India, Malaysia, the Philippines, and Thailand [12]. Owing to its attractive sweet flavour, pineapple is widely consumed as fresh fruit, processed juice, canned fruit, and as an ingredient in exotic foods. The volatile constituents of pineapple have been studied for over 60 years by many researchers. More than 280 compounds have been found among volatiles of pineapples so far [60]. 

The volatile compounds of juices made from freshly cut pineapple fruits from different cultivars from Costa Rica, Ghana, Honduras, Cote d Ivoire, the Philippines, Reunion, South Africa, and Thailand were studied in comparison to that of commercial water phases/recovery aromas, juice concentrates as well as commercially available juices [12]. The qualitative pineapple fruit flavour profile showed several methyl esters, some characteristic sulfur-containing esters, and various hydroxy esters were responsible for the typical pineapple flavour profile. 

Gupuacu is an Amazonian forest tree from Para state, Brazil. The fruits are 15-25 cm in length, 10-12 cm in diameter, and weigh between 0.8 and 2 kg. They are oblong fruits with a hard skin. The seeds contain caffeine and theobromine, alkaloids with stimulant properties. The seeds contain about 48% of a white fat similar to cocoa butter. The creamy-white pulp has an attractive and characteristic aroma and flavour. The fruits are consumed mainly as juice. 

The bacuri tree grows in the south of the Amazonian forest in Para state, Brazil. The fruits are ovoid to subglobose, are 7-15 cm in diameter and weigh 200-1,000 g. They have a creamy white mucilaginous, fibrous, juicy pulp with a very attractive exotic flavour. The fruit is consumed as such, as a juice, or in ice cream or jellies. 

Cachaqa and aguardente de cana are the most consumed distilled spirits in Brazil exclusively made from cane-sugar juice. Sugar and caramel maybe added for colour adjustment. The total content of congeners is between 200 and 650 mg 0.1 L p.e. Like other spirits, the flavour of cacha a is mainly characterised by the presence of fermentation by-products such as higher alcohols, esters, carboxylic acids, and carbonyl compounds [41-43]. 

Apfelkorn Apple juice, Korn, apple flavour... 

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