Temperature vinegar production

Various species and many strains oiyAcetobacter are used in vinegar production (48,49). Aeration rates, optimum temperatures and nutrient requirements vary with individual strains. In general, fermentation alcohol substrates require minimal nutrient supplementation whde their addition is necessary for distilled alcohol substrates. 

Temperature is an important factor in vinegar production. Like all bacteria, vinegar bacteria prefer warm conditions. Temperatures around 25°C are essential for rapid and effective fermentation. If the temperature of the vinegar falls markedly during fermentation, the fermentation process is interrupted and may start again later. The temperature in the vinegar vat should therefore never drop below 25°C. 

Submerged fermentation processes are currently considered to be the best methods of vinegar production. The bacteria are active in the liquid, no mother of vinegar is produced, and continuously controlled aeration is guaranteed. This means that temperature control and thus carefully... 

Submerged culture oxidizers can also be operated on a continuous basis. Continuous monitoring of ethanol and acetic acid concentrations, temperature, and aeration rates permit control of feed and withdrawal streams. Optimum production, however, is achieved by semicontinuous operation because the composition of vinegar desired in the withdrawal stream is so low in ethanol that vigorous bacterial growth is impeded. Bacterial... 

Originally, acetic acid was produced by fermentation this is still the major process for the production of vinegar. Modern production is by acetaldehyde oxidation, liquid phase hydrocarbon oxidation and preferentially by methanol carbonylation. The latter process is to be preferred because of the low raw material and energy costs. As early as 1913 BASF described the carbonylation of methanol at high temperature and pressure ... 

In this process the acetic fermentation takes place in a more or less open container (usually a vinegar vat in the cellar). The primary product stays in the open container until acetic fermentation starts, i.e. a mother of vinegar, or film consisting of vinegar bacteria, moulds and slime fungi, is formed. In this method it is not possible to control the fermentation or the temperature. The quality of the vinegar produced does not always meet current sensory and analytical requirements. 

For larger scales, shallow trays made of corrosion-resistant metal or plastic placed in portable trolleys may be used for efficient liquid-air contact. The trolleys are placed in a sterile room with frequent sterile air changes under closely controlled temperature and humidity conditions. Efficient air-liquid contact may also be obtained from a loosely packed, moist, solid medium permeated with air. For instance bran is used as the substrate for enzyme production by Aspergillus oryzal. Wine vinegar (acetic acid) is produced by trickling wine (basically ethanol in water) over a short tower of wood chips, which are used both as a support and to provide air to Acetobacter aceti [13] (Eq. 16.15). By law, the acetic acid (3-5% in water) in vinegar must be produced by fermentation, and not by petrochemical methods. 

Pasteurized fish products made of fresh, deep-frozen or frozen fish or fish portions have shelf lives, even without cold storage, of at least 6 months. These products are prepared by prolonged heat treatment of fish at temperatures below 100 °C. They are then tightly sealed in a container. Such products are salted or soaked in vinegar prior to pasteurization. 

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