Starters concentration

It has been shown, in vitro that proflavine (30 pM) inhibits bacterial DNA polymerase by 85 per cent and RNA polymerase by 30 per cent (Hurwitz et al,y 1962). Some typical data are shown in Fig. 10.4. The inset graph (of the reciprocal of the velocity plotted against the reciprocal of the DNA-starter concentration) points to the site of action of proflavine as being mainly on this starter, thus inhibiting DNA (or RNA) synthesis in the living bacterium. The intercalating mechanism by which amino-acridines combine with DNA helices and impede strand separation is outlined in the next Section (10.3b). 

The individual starter battery separator systems have been described here they are evaluated comparatively. There are no standards for evaluating separators Therefore the comparison will be concentrated primarily on the effects on the performance of the starter battery, with other decisive criteria such as cost structure and effects on productivity indicated. 

Electronic Grade Silicon (EGS). As the first step in the production of electronic grade silicon (EGS), an impure grade of silicon is pulverized and reacted with anhydrous hydrochloric acid, to yield primarily tricholorosilane, HSiClg. This reaction is carried out in afluidizedbed at approximately 300°C in the presence of a catalyst. At the same time, the impurities in the starter impure silicon reactto form their respective chlorides. These chlorides are liquid at room temperature with the exception of vanadium dichloride and iron dichloride, which are soluble in HSiCl3 at the low concentration prevailing. Purification is accomplished by fractional distillation. 

Figure 10.24 Concentration of individual amino acids in 60-day-old Cheddar cheese, made with a single-strain starter Lactococcus lactis ssp. cremoris AM2, G11/C25 or HP (from...

Apart from public health impacts, residual antimicrobials in animal products can bring about technoeconomic losses in the food processing industry. It has long been known that the presence of some antimicrobial compounds in milk can dramatically affect the production of fermented dairy products such as yogurt, cheese, buttermilk and sour cream (72, 73). As shown in Table 10.2, even minute concentrations of antibiotics in milk can cause inhibition of the growth of commonly used dairy starter cultures (74). 

Table 10.2 Minimum Inhibitory Concentrations of Antibiotics for Common Dairy Starter Cultures and B cillus ste rothermophilus...

Hydrolytic rancidity flavor defects in Swiss, brick, and Cheddar cheeses have been linked to high concentrations of individual short chain free fatty acids (Woo et al 1984). Lipases from psychrotrophic bacteria have been implicated in causing rancidity in cheese (Cousin 1982 Kuzdzal-Savoie 1980), although most starter streptococci and lactobacilli isolated from cheese are also capable of hydrolyzing milk fat (Paulsen et al. 1980 Umemoto and Sato 1975). Growth of Clostridium tyrobutyricum in Swiss cheese causes the release of butyric acid and subsequent rancid-off flavors (Langsrud and Reinbold 1974). The endogenous lipoprotein lipase is also responsible for hydrolytic rancidity in nonpasteurized milk. 

Lamprech, E. D. and Foster, E. M. 1963. The survival of starter organisms in concentrated suspensions. J. Appl Bacteriol. 26, 359-369. 

Salji, J. P. and Kroger, M. (1981). Proteolysis and lipolysis in ripening Cheddar cheese made with conventional bulk starter and with frozen concentrated direct-to-the-vat starter culture. ]. Food Sci. 46,1345-1348. 

Another remarkable positive effect on GFPuv expression was the storage of the starter culture at 4°C for 24 (x, = -1) and 48 h (x, = +1). Expression of the highest concentrations of GFPuv was shown to be independent of the time in storage. 

In the fermentations under the cellar conditions, higher ethanol concentrations were reached compared with those under the vinsantaia temperature conditions. This could be due to the combined stress effects on the yeasts of alcohol and high temperatures during the summer period in the vinsantaia aging. In the Vin Santo obtained without inoculation with the commercial starter, satisfactory ethanol levels were however reached (13.7-15.3%, v/v). 

You can play with the dilution. I recommend 1 part of concentrate to 50 parts of water for starters. Dilute 1 + 50 and use the same initial developing times as D-76 1 1. 

The starter and non-starter bacteria appear to attach, via filaments from their cell walls, to the casein matrix (Kimber et al., 1974) and are concentrated near the fat-casein interface (Laloy et al., 1996 Haque et al.,... 

Using the relations given in Table 5.1, along with similar equations for FeO and ZnO in the alkaline regions, the ionic concentrations are plotted as a function of pH in Fig. 5.2 for the major oxides of practical interest. The choice of these oxides (and similarly hydroxides) is dictated by the fact that they are starter powders in syntheses of common commercial CBPC products. One may make the following observations from Fig. 5.2 ... 

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