Grape table wine

In addition to alcohoHc fermentation, a malolactic fermentation by certain desirable strains of lactic acid bacteria needs to be considered. Occasionally, wild strains produce off-flavors. Malolactic fermentation is desirable in many red table wines for increased stabiUty, more complex flavor, and sometimes for decreased acidity. Selected strains are often added toward the end of alcohoHc fermentation. AH the malic acid present is converted into lactic acid, with the resultant decrease of acidity and Hberation of carbon dioxide. Obviously this has more effect on the acidity the more malic acid is present, and this is the case in wine from underripe, too-tart grapes. Once malolactic fermentation has occurred, it does not recur unless another susceptible wine is blended. 

Maturation regimes vary from as tittle change as possible in many white and pink wines (stainless steel tanks, cool storage, minimum time) to considerable modification in red table and a few white table wines. Fermentation and storage in fairly new 200-L barrels for about 6 mo is not uncommon for Chardoimay and white Burgundy wines. Many robust red table wines such as those from Cabernet Sauvignon grapes are often stored similarly, after fermentation and initial clarification, for up to about 3 yr in such barrels. 

As discussed above, the development of mild MS techniques has led to further progress in the determination of proanthocyanidin size distribution. In particular, ESI-MS studies have demonstrated that prodelphinidin and procyanidin units coexist within the polymers, where they seem distributed at random. A list of mass signals attributed to proanthocyanidins detected in grape or wine extracts is given in Table 5.2. 

The procedures used in winery operations vary greatly, depending on the types of products produced and their market. A small winery producing only one type of red wine may need only a few different analyses. A winery producing grape juice, grape concentrate, table wines, dessert wines, special natural (flavored) wines, vermouth, fruit wines, high-proof spirits, and commercial brandy will require many different types of analyses. 

Naphthalene- and anthracene-derived phenols did, however, almost uniformly precipitate (Table VI). In natural materials (not grapes or wines) which contain them they would be included in the formaldehyde precipitable group. Several primary amines capable of SchifFs base formation reacted with formaldehyde to lose their F-C oxidizability, but only the resorcinol analog, 3-aminophenol, precipitated (Table VIII). Sulfite also reacted but did not precipitate with formaldehyde, and the F-C oxidizability was suppressed (Table IX). The resorcinol derivative, 2,4-dimethoxycinnamic acid, formed a precipitate with formaldehyde, but it did not react appreciably in the F-C assay. 

The quick or competitive procedure for making sweet table wines depends on sweetening a dry table wine with a very sweet blending wine or with sugar or grape concentrate and some procedure of sterilization which ensures that no viable yeast cells are present in the closed bottle. The simplest is pasteurization of the blend after it has been bottled. This technique, however, is not favored as it tends to give the wine a cooked aroma and taste. 

B Zimmerli, R Dick. Ochratoxin A in table wine and grape-juice occurrence and risk assessment. Food Add Contain 13(6) 655-668, 1996. 

Zimmerli B, Dick R (1996) Ochratoxin A in Table Wine and Grape-Juice Occurrence and Risk Assessment. Food Addit Contam 13 655... 

TABLE 2.3 Maximum residue limits (mg/L) in grape and wine... 

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