Beer, flavor compounds

Buchardt O, Jensen RB, Hansen HF, Nielsen PE, Andersen D, Chinoin I (1986) Thermal chemistry of podophyllotoxin in ethanol and a comparison of the cytostatic activity of the thermolysis products J Pharm Sci 75 1076-1080 Charalambous G, Bruckner KJ, Hardwick WA, Linneback A (1973) Determination of beer flavor compounds by high pressure liquid chromatography Tech Quart, Master Brew Assoc Am 10(2) 74-78... 

Sugita, Y.H., Flavor enhancers. Food Sci. Technol., 116, p. 409, 2002. Charalambous, G., K.J. Buckner, W.A. Hardwick, T.J. Weatherby, Determination of beer flavor compounds by high pressnre liqnid chromatography IV. Nncleotides, Tech. Quart.-Master Brew. Assn. Am., 12(4), p. 203, 1975. 

Carbonyl compounds, particular aldehydes, are considered to play an important role in the deterioration of beer flavor and aroma during storage. 

Lawrence, W. C., Volatile Compounds Affecting Beer Flavor, Wallerstein... 

The evaluation of only one GC run has an important drawback. Since it is not possible to exactly evaluate the intensity of the odor during sniffing, the results cannot be used to decide whether a compound is a key odorant in beer flavor or contributes little to the overall odor. Furthermore, the number of the compounds detected depends on accidental factors, e.g., the amount of die food used for the isolation of the volatile fraction or the degree of the concentration. 

A review of HPLC techniques which have been used to study flavors in a wide variety of foods and flavorings is presented. Specific examples of how HPLC has been used to study nonvolatile flavor compounds 1n beer, beef, tea, grapefruit juice, vanilla, soy bean etc., are presented. Relative advantages and disadvantages of using HPLC vs GLC are discussed. 

Unfortunately the relative contribution of each of the 58 compounds to beer flavor 1s known only for a few. There are also many compounds which were separated by not identified which might be flavor active. Additional work needs to be done to determine the relative contribution of the identified compounds to beer flavor and to identify those unknown compounds which are flavor active. 

Review of Ascorbic Acid Mechanisms of Action. Ascorbic acid and AP have antioxidant activity in fats, oils, vitamin A, and carotenoids. In these systems AP is a better antioxidant than are the phenolic antioxidants BHT and BHA, both from these data and others (29,35). Ascorbic acid protects against oxidation of flavor compounds in wine, beer, fruits, artichokes, and cauliflower (29) presumably by oxygen scavenging. The well-known formation of nitric oxide from nitrites by ascorbic acid is used not only for inhibition of nitrosamine fortnation, but also to promote... 

Separation of aroma and flavor compounds in fresh and aged beer. 

Especially in the large-scale production of beer, of highest significance is not ethanol production but a balanced flavor to obtain the desired taste. One unpleasant off-flavor compound is diacetyl, which is a nonenzymatically degraded product of a-acetolactate. Diacetyl is then enzymatically converted to ace-toin and subsequently to 2,3-butanediol. The nonenzymatic-degradation step is very slow and requires long lager periods. 

The most easily definable hop contribution to beer aroma is a floral flavor note that certain hop varieties (not necessarily the traditional "aroma hop" varieties) impart to beer ( ). Indications are (Table I) that the floral compounds linalool and ger-anlol are responsible for this aroma note. Geranyl isobutyrate, though present in the more floral beers, is probably in too low concentration to have a major effect on beer flavor. a-Terplneol is eliminated from consideration for the same reason. Linalool has been reported in beer at an estimated concentration of 34ppb ( 3) by Lindsay and at a concentration of 470ppb ( 7) by Tressl. 

In fact, processed foods are better regulated in this area than are natural ones. Safrole, for example, is a compound found in oil of sassafras, isolated from the bark of the sassafras tree. Health food advocates often recommend sassafras tea as a restorative. At one time, manufacturers used safrole as a root-beer flavoring, but they stopped when safrole was found to cause cancer in test animals. Processed foods, you see, are not allowed to contain known carcinogens — but natural foods are. 

Safrole (25) and isosafrole were once important as the flavoring for root beer. These compounds are present in the plant extracts used to make this beverage. By the 1950s, however, most root beer was flavored with synthetically derived safrole. Both safrole and isosafrole were shown to be weakly carcinogenic and now have been banned for this purpose (Fishbein et al., 1967). These compounds have a methylenedioxy structure and are known to inhibit mixed-function oxidase enzymes. Two compounds of similar structure, piperonal (26) (naturally occurring) and piperonyl bu-toxide (27) (synthetic) are mixed function oxidase inhibitors and are used as synergists for insecticides such as pyrethrins, rotenoids, and Sevin (a carbamate insecticide) (Fishbein et al., 1967). 

This section is based on the flow injection methodology developed for the analysis of total phosphorus in beer, reported by Fernandes et al. (2000) As those authors mentioned in their work, phosphorus-containing compounds (inorganic and organic phosphorus) from water used in the brewing process have a considerable impact on the final flavor and physical appearance of the product. The measurement of its concentration in all phases of beer production can be used to help track metabolic products of fermentation and correlate beer flavor trends. Prior to the analysis of total phosphorus, all phosphorus compounds present in the food matrix must be converted into an analyzable form such as orthophosphate (total phosphorus), and therefore, undergo a digestion procedure. 

With respect to the food business, it has to be pointed out that ethyl lactate is a flavor compound found naturally in small quantities in a wide variety of foods such as meat, some fruits, soy products and fermented foods, such as wine or beer. Thus, ethyl lactate is... 

The same quality control parameters described for beer ingredients, enzymes, and the various processing steps are applied for alcoholic spirits and fuel ethanol. Since most distilled beverages are aged, the quantification of flavorful compounds via... 

Beta acids Resins from hops that are the precursors of aroma and flavor compounds in beer. Includes lupulone, colupulone, and related compounds. 

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