Sucrose chloride salts effect

Fig. 13.—The effect of chloride salts on sucrose reaction rate.

In a study of the pectinesterase from bananas,64,85,102 three pectinesterase fractions were obtained after respective extraction with water, 150 mM sodium chloride, and 150 mM sodium chloride of pH 7.5. The fractions obtained were further purified by fractional salting-out with ammonium sulfate, and chromatography on columns of DEAE- and CM-cellulose. A 50-fold purification was achieved, and the individual, purified fractions were characterized with respect to different effects of cations, inhibition by sucrose, and reaction kinetics. 

The effect of inert solutes, such as calcium chloride, magnesium chloride and sucrose, can also be employed judiciously and efficaciously in the development of solutions to difficult extraction problems by allowing efficient extractions from the water into such solvents as acetone, ethanol and methanol that are found to be completely miscible with water in the absence of salt. Matkovitch and Cristian found the above three inert solutes to be the best agents for salting acetone out of water. It has been observed that the acetone layer that separated from a saturated aqueous solution of CaCl2 exclusively contained 0.32 0.01% water (v/v) and 212 ppm salt (w/w) at equilibrium. 

Proceeding on the same line, Hagerdal et al. reported that perfluorinated resin supported sulfonic sites (NATION 501) can hydrolyze disaccharides [25]. In particular, these authors studied the effect of the addition of sodium chloride in the hydrolysis of cellobiose, a subunit of cellulose much more resistant to hydrolysis than sucrose. They observed that the presence of sodium chloride in water dramatically increased the conversion of cellobiose. Indeed, in the presence of 10 wt% of sodium chloride, 80% of cellobiose was converted at 95°C after 6 h. For comparison, when 1% of sodium chloride was added, only 50% of cellobiose was hydrolyzed. It should be noted that without addition of sodium chloride only 15% conversion was achieved, thus pushing forward the key role of sodium chloride on the reaction rate. Effect of salt on the reaction rate was attributed to a change of the pH caused by the release of proton in the reaction medium (due to an exchange of the supported proton by sodium). 

Additives had substantial effects on the aeration properties of bromelain-modified succinylated fish protein (50). Foam volume was increased with up to 2% sodium chloride in the system however there was a decrease in foam stability when greater than 0.3% salt was used. Sucrose, at concentrations up to 50%, increased foam stability. When fat was added to treated fish protein dispersions... 

Other physical phenomena that may be associated, at least partially, with complex formation are the effect of a salt on the viscosity of aqueous solutions of a sugar and the effect of carbohydrates on the electrical conductivity of aqueous solutions of electrolytes. Measurements have been made of the increase in viscosity of aqueous sucrose solutions caused by the presence of potassium acetate, potassium chloride, potassium oxalate, and the potassium and calcium salt of 5-oxo-2-pyrrolidinecarboxylic acid.81 Potassium acetate has a greater effect than potassium chloride, and calcium ion is more effective than potassium ion. Conductivities of 0.01-0.05 N aqueous solutions of potassium chloride, sodium chloride, potassium sulfate, sodium sulfate, sodium carbonate, potassium bicarbonate, potassium hydroxide, and sodium hydroxide, ammonium hydroxide, and calcium sulfate, in both the presence and absence of sucrose, have been determined by Selix.88 At a sucrose concentration of 15° Brix (15.9 g. of sucrose/100 ml. of solution), an increase of 1° Brix in sucrose causes a 4% decrease in conductivity. Landt and Bodea88 studied dilute aqueous solutions of potassium chloride, sodium chloride, barium chloride, and tetra-... 

Figure 4. The effect of different alkali metal chlorides on thylakoid function during freezing to —20°C. Washed thylakoids were suspended before freezing in a solution containing 0.1 M sucrose and alkali metal chlorides, as indicated. The sucrose served as cryoprotectant and was added to prevent freeze-inactivation of the membranes in the presence of low salt concentrations. The suspensions were slowly frozen for 3 hours at —20°C. After thawing in a water bath at room temperature, the activity of cyclic photophosphorylation was measured.

Characteristics of this membrane include 30 to 40% sodium chloride rejection, 85 to 90% magnesium sulfate rejection, 98% sucrose rejection, and 99% raffinose rejection. Water flux is 15 to 25 gfd at 35 to 50 psi, depending on feed-water composition. The effect of increasing salinity on salt rejection and water flux is similar to the behavior observed for NF-40 membrane as was illustrated in Figures 5.8 and 5.9. 

There are also chemical additives that can preserve food. Salted meat and fruit in a concentrated sugar solution are protected from microorganisms. The dissolved sodium chloride or sucrose creates a hypertonic solution in which water flows by osmosis (page 245) from the microorganism to its environment. Thus, salt and sucrose have the same effect on microorganisms as dryness both dehydrate them. 

This process is based on the separation of a water-soluble solvent from aqueous solution through the salting-out effect. Initially, polymer and drug are dissolved in a solvent such as acetone and then the polymer solution is emulsified into an aqueous solution containing electrolytes (such as magnesium chloride, calcium chloride and magnesium acetate), non-electrolytes (such as sucrose), and a colloidal stabilizer such as poly(vinyl pyrrolidone) or hydroxyethylcellulose. Finally, the oil/water emulsion is diluted with a sufficient volume of water to enhance the diffusion of acetone into the aqueous phase by inducing the formation of nanospheres. Both the... 

Salty substances exhibit a variety of pharmacological effects, whose character depends on the type of cation and anion. Some substances are toxic at higher concentrations. The compound consumed in the largest amount is sodium chloride. The daily intake of salt in developed countries is estimated at 8 15g. Sodium chloride supports the perception of taste of foods at the required intensity and fullness, stimulates not only receptors for salty taste, but significantly increases the perception of the sweet taste of sucrose and some other sweet substances, as well as sour taste perception, and suppresses the sensation of metaUic taste and some other... 

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