Coefficients of digestibility

Coefficient of digestibility = (lipid ingested - lipid excreted)/ lipid ingested x 100. Results taken from Carroll, 1958 Carroll and Richards, 1958. 

If the substance has been dosed using a vehicle, the water solubility of the vehicle and the vehicle/water partition coefficient of the substance may affect the rate of uptake. Compounds delivered in aqueous media are likely to be absorbed more rapidly than those delivered in oils, and compounds delivered in oils that can be emulsified and digested, e.g., com oil or arachis oil are likely to be absorbed to a greater degree than those delivered in nondigestible mineral oil (liquid petrolatum). 

Species Digestion Procedure % Recovery % Coefficient of Variance... 

Solid-phase sediment digestions were analyzed in triplicate, with one duplicate digestion and a spike recovery or analysis of reference material every 10 samples. Coefficients of variation (C.V.) for triplicates fell within 0.5-11.5% [n = 60, mean C.V. = 3.6% 2.4% (std)], and spike recoveries were within 90-103% [n = 3, mean = 96% 7%]. Eight replicates of standard reference material [National Institute of Standards and Technology (NIST) Tennessee River sediment, Catalog No. 8406] were within 10% (0.053 0.004 xg/g, C.V = 7.2%) of the recommended value of 0.06 xg/g. A standard reference for Hg in natural water was not available. Typical duplicates of small-volume pore waters (<30 mL) had an average C.V of 30.8% 22% (n = 30). 

Joseph Lister introduced phenol (carbolic acid) as a disinfectant in 1967. It has been the standard disinfectant to which other disinfectants are compared under the same conditions. The result of this comparison is the phenol coefficient. Salmonella typhi, a pathogen of the digestive system, and Staphlococcus aureus, a common wound pathogen, are typically used to determine phenol coefficients. A disinfectant with a phenol coefficient of 1.0 has the same effectiveness as phenol (Dorland s Illustrated Medical Dictionar). A coefficient less than 1.0 means that the disinfectant is less effective than phenol and greater than 1.0 is more effective than phenol. Phenol coefficients are reported separately for the different test organisms. 

Zduhczyk et ol. (1996) studied the nutritive value of low-alkaloid varieties of white lupin and found that the lysine contents were relatively low (4.70-5.25g/16g N), with methionine as the limiting AA. Roth-Maier and Paulicks (2004) studied the digestibility and energy contents of the seeds of sweet blue lupins (L. angustifolius) and found digestibility coefficients of 0.43-0.5 for organic matter, 0.36-0.43 for protein, 0.69-0.83 for fat, 0.46-0.58 for NFE and an ME concentration of 7.54-8.22 MJ. 

Shao et al. recommended the use of a simultaneous fluorimetric method for the determination of the dissolution rate of dipyridamole and aspirin tablets [34]. The powdered tablets (equivalent to weight of one tablet) of dipyridamole and aspirin were dissolved in simulated digestive fluids at 37°C, cooled, and diluted to 1 L with simulated digestive juice. The solution was filtered, and a 1 mL portion of the filtrate was mixed with 0.1 M sodium hydroxide and then set aside at room temperature for 1 h. The solution was mixed with 8 mL of phosphoric acid buffer (pH 6.8) and fluorimetrically detected for dipyridamole at 493 nm (excitation at 418 nm). The coefficients of variation for within-day and within 5 days were 2% for both dipyridamole and aspirin. 

The coefficient of fat absorption is defined as the amount of fat absorbed as a percentage of the ingested amount. This coefficient normally exceeds 93% and is used (rather than crude fecal fat excretion) to indicate efficacy of luminal fat digestion following different dietary lipid intakes. By contrast, fecal carbohydrate measurements do not fully reflect the extent of starch malabsorption because carbohydrates are metabolized by the intracolonic microbial flora. Since intracolonic metabolism of carbohydrates... 

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