Natural meat flavours

In applications to sausage products which are produced in cellulose casings, the coagulation of surface proteins is an essential functional effect of smoke solutions. While the above mentioned carbonyl-amine reaction is one of two mechanisms of surface modifications, the acidity of natural smoke flavourings is an even more valuable processing aid for meat surface protein coagulation. 

Snack foods include a vast array of food items ranging from cereal-based crackers and com chips to high-protein snacks such as beef sticks and jerky. In past years, smoking of snack foods was limited primarily to meat snacks, as other snack foods were difficult to handle in the traditional smokehouse. With the development of natural smoke flavourings, snack food manufacturers can now incorporate these flavourings into a variety of products to produce smoked, barbecued, roasted or grilled flavours. 

The production of a closely related furanone starts with natural 5-oxo-glu-conic acid production from glucose with Gluconobacter suboxydans the acid is recovered by precipitation as the calcium salt for flavour applications, it is converted by heating to 4-hydroxy-5-methyl-2H-furan-3-one, a typical savoury reaction flavour with a meat-like taste [70] (Scheme 23.19). 

Cloves are best used whole. The flavour deteriorates quickly once it is powdered. Whole and ground cloves are used to enhance the flavour of meat and rice dishes. They are used widely in curry powders and masalas. In North Indian cuisine, cloves are used in almost every sauce or side dish made, mostly mixed with other spices. In South India, they find extensive use in biriyanis to enhance the flavour of the rice. They are highly valued in medicine as a carminative and stimulant. Cloves are said to be a natural anthelmintic. 

The other commonly occurring amino acid with an acidic side-chain is glutamic acid. This compound is probably best known as its monosodium salt (monosodium glutamate or MSG). This salt is added to foods (especially oriental food) to enhance the flavour and impart a meat-like taste to the food. Interestingly, both the d enantiomer of glutamic acid and the naturally occurring l form are used as food additives. Use of the nonnatural d isomer may account for some of the adverse reactions experienced by consumers of MSG in food. 

Contrary to microbial flavour generation directly in the food by starter cultures, the technical bioreactions for flavour production with micro-organisms do not use the complete food raw material as substrate. Isolated and purified single components of food are used as substrates for the micro-organisms. Examples are butterfat from butter, proteins from meat, carbohydrates from plant food materials. Microbial material syntheses may lead to chemically defined pure substances (cf. chapter 3.2.1.1.2). It is also possible to obtain complex mixtures of different compounds. Polysaccharides, natural colours and also complex flavour extracts belong to this category. Figure 3.17 outlines the principle of such processes. 

Application of natural aqueous smoke flavourings to meat is done in large part for the purpose of producing smoked colour. Smoke solutions are applied to the surface of meat where smoked product colour is desired. The carbonyls are known to be the initiators of a brown smoked colour. While aqueous smoke solutions are innately a reddish brown colour, virtually none of this colour is imparted to the product through a staining effect. Rather, carbonyls first react with amines to produce Schiff bases which eventually end up as mealnoidins through complex, multiple-step reactions which are driven by heat and dehydration. 

Although drenching, spraying or atomisation may find limited application in the food industry, they are by far the major methods used for surface applied natural liquid smoke flavourings in the meat and fish industries. Drenching and spraying are widely accepted practices on continuous line operations where large volumes of product are produced in tunnel-type ovens. 

The systematic use of gas chromatography coupled with olfactometry [27, 28] in the last 20 years has resulted in a number of new high-impact aroma chemicals found in natural extracts, food products and reaction flavours. In general, sulphur-containing odorants play a particularly important role in food products and savoury flavours [30]. Some of them are shown in Fig. 5.54. Usually, the odour threshold is one key attribute showing the potential impact of the odorant. This may be as low as 0.00002 pg/L water reported for bis-(2-methyl-3-furyl)disulphide (BMFD) (Fig. 5.55) found in cooked meat with a typical meaty, sulphury note. 

A wide range of flavouring substances is used in powdery or pasty convenience foods. Reaction flavours based on hydrolysed plant proteins, natural flavours, artificial flavours and meat, vegetable, yeast and spice extracts are added to the products to generate the desired flavour profile. The most common savoury flavour types used for dehydrated convenience foods are chicken, beef and vegetable flavours. However various other flavour types are used while formulating dehydrated convenience foods. Amongst them are mutton, crawfish, fish, wine and various spice and herb flavours. 

Alkylpyrazines occur frequently as flavour constituents in foodstuffs that undergo heating, e.g. coffee and meat. They are probably formed by a Maillard reaction between amino acids and carbohydrates. Alkylpyrazines also act as alarm pheromones in ants. Coelenterazine 35, a bioluminiscent natural product isolated from a jelly fish, is used in bioassays [159]. 

The technique, being non-destructive, not only allows the preparation of low-cholesterol and low-fat products but also allows the use of the extracted components, that is, the fat for edible use, or the cholesterol for pharmaceutical use. Flavour components extracted from meat fat could be added to products as natural flavourings. 

The oleoresins have some advantages over natural spices (Table 8.36), because of their low microbial contamination, uniformity in flavour, colour and pungency, easy storage and transport. Oleoresins as such or deposited on suitable media (such as starch or flour) have several applications such as in preparation of beverages, soup powders, confectionary, curries, noodles, sauces, canned meat and meat products. 

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