Acid degree value

Gholson, J. H., Gelpi, A. J., Jr. and Frye, J. B., Jr. 1966A. Effect of a high-level and a low-level milk pipeline on milk fat acid degree values. J. Milk Food Technol. 29 248-250. 

Duncan, S.E., Christen, G.L., Penfield, M.P. 1991. Rancid flavor of milk relationship of acid degree value, free fatty acids, and sensory perception. J. Food Sci. 56, 394-397. 

Assessment of rancidity in potato crisps is usually done by the Rancimat or acid degree value tests, but these are labor-intensive. Electronic noses based on mass spectrometry or gas sensors were used to assess rancidity without oil extraction steps [35]. This removes the need for sample preparation, avoids the use of solvents, and reduces the analysis time from several hours to about 25 minutes. The nose based on MS had a 100% success rate in determining rancidity while that based on GC was 68%. 

This suggests that an analytical method that measures total free fatty acids (e.g., acid degree value) may be a poor measure of the off-flavor potential of these fatty acids. 

Acid dyes are normally applied to wool at acidic pH values but are washed under neutral or mildly alkaline conditions. Forces of affinity between dye and substrate tend to retard desorption. The higher the degree of sulphonation in a series of naphthylazo-2-naphthol dyes (Table 3.39), the higher is the rate of desorption into sodium borate solution at 40 °C. With a series of monosulphonated acid dyes the desorption rate under these conditions was inversely related to the affinity of the dye for wool at pH 3 and 60 °C (Table 3.40). 

Similarly, good results were obtained with poly-(i)-alanine, poly-(L)-leucine and poly-(i)-isoleucine, whereas with poly-(i)-vahne or random copolymers reduced chemical yields as weU as asymmetric induction were obtained. Chemical and optical yields are closely related in all cases. The enantiomeric excesses obtained increased as the average chain length of the catalyst increased varying from 10 to 30 amino acids (ee values between 50 to 99%). For high ee values it seems to be essential that the polymer chain is at least 10 units. The degree of asymmetric induction decreases as the temperature is raised. The amount of catalyst only influences the chemical yield, not the optical yield of... 

A wide range of calcium-containing PE waxes with different acidity index values and calcitxm contents have been obtained by the proper choice of the OXPE wax type, i.e. the oxidation degree, and the proportion of the added Ca(0H)2 ... 

The degree of heteromolecular association of esters in reaction [9.121 ] is higher than for acids when values are equal. Thus the change of equihbrium constant according to [9.121] depends on electrostatic component. for these reactions also depends on exponentially reciprocal 8. 

Studies of polyelectrolytes, using DjO as solvent to enhance the contrast between polymer and solvent, have been carried out using carboxymethyl cellulose (CMQ and poly(methacrylic acid) (PHA). Values of the radius of gyration have been determined as a function of the degree of polymerization (N), the degree of neutralization of the carboxylic acid groups (a,), and the poly-electrolyte concentration (C). In the case of PMA in which N = 15 it was found that... 

Numerous studies have dealt with the epithelium of the small intestine. Entry of fat from the bowel lumen into the mucosal cells appears to proceed as evidenced by the extreme degree of fat accumulation in these cells. Steatorrhea may result when the maximal absorptive capacity of these cells is exceeded. There is no evidence of selective absorption of certain fats, as could be shown by analysis of mucosal lipids and feces. In particular, the lowering of plasma linoleic acid concentration in a-jff-lipoproteinemia and other forms of malabsorption does not appear to be due to impairment of absorption of, essential fatty acids. After administration of diets rich in polyenoic acids Ways and Parmentier (1963) found more linoleic acid in mucosal phospholipids and triglycerides than was found with the normal diet. There was a simultaneous increase in the proportion of linoleate in plasma cholesterol esters. Linoleic acid, given for a period of three years, was absorbed to about 97 per cent (Frezal et al. 1966). Its administration resulted in a significant increase of the proportion of linoleic acid in the plasma lipid fatty acids. Normal values were reached in the triglyceride and phospholipid fractions (see table 6). 

The ratio of CHj to CONH groups, the hydrogen ion concentration in the acid (pH-value), diffusion rate, temperature, and the degree of crystallization are decisive factors for the hydrolysis of polyamides. The smaller the CH2/CONH ratio, the more... 

Systematic studies of the acid-catalysed hydrolysis of esters in the presence of sulphonated polystyrene showed an increase in the value of q with decreasing solubility of the esters in water [17, 22]. Correspondingly, for soluble macromolecular acids the values of q have been found to decrease with increasing degree of sulphonation of the polymer. These effects are consistent with hydrophobic interaction between resin and substrate and its effect on the value of Ar. The importance of hydrophobic interaction can be reduced if, for example, acetone is added to the solvent. Such solvent changes have the opposite effect on hydrophilic substrates [26]. 

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