Measurement of available lysine in processed beef muscle by various laboratory procedures

Protein extraction from biomass in a bioethanol refinery – Possible dietary applications: Use as animal feed and potential extension to human consumption

“…Among amino acids, some are known to be particularly sensitive to harsh conditions and hence more labile than others: it is the case of lysine, cysteine and glycine (Rayner and Fox, 1978). Heat damage can be studied directly, for instance by periodically monitoring the amount of amino acids present in biomass samples that have been placed in an autoclave for variable times (Fontaine et al, 2007).…”

In‐vitro determination of nitrogen digestibility and lysine availability in meat and bone meals and comparison with in‐vivo ileal digestibility estimates

“…A pronase in-vitro digestibility assay (Rayner and Fox 1978; method B) and a multi-enzyme pHdrop assay (Hsu et a1 1977;method C) were also included for comparison with the in-vivo data. The pronase assay is commonly used in commercial practice, and the pHdrop method was chosen for investigation because of its inherent simplicity.…”

“…As an alternative, several in-vitro digestibility assays have been developed, some of which have shown considerable promise (Satterlee et ul 1981). Earlier Rayner and Fox 1978; Johnston and Coon 1979) relied upon single enzyme digests. However, multi-enzyme assays more closely simulating conditions found in the live animal have been developed, and high correlations with in-vivo digestibility data have been reported (Akeson and Stahmann 1964; Saunders and Kohler 1972; Saunders t't crl 1973; Hsu et a1 1977;Buchmann 1979; Clunies and Leeson 1984).…”

“…The aim of the present study was to compare values of crude protein digestibility generated by the modified pepsin/pancreatin method (Metz and Van der Meer 1985) (method A) with true ileal crude protein digestibility coefficients determined with thegrowing rat. A pronase in-vitro digestibility assay (Rayner and Fox 1978; method B) and a multi-enzyme pHdrop assay (Hsu et a1 1977;method C) were also included for comparison with the in-vivo data. The pronase assay is commonly used in commercial practice, and the pHdrop method was chosen for investigation because of its inherent simplicity.…”

Development of a novel bioassay for determining the available lysine contents of foods and feedstuffs

“…The most well-known method is the FDNB method 60 which uses the Sanger reaction to convert lysine to dinitrophenyl-lysine which is extracted and measured spectrophotometrically or by HPLC. This method has been applied to animal feedstuffs 34 , 57 , breakfast cereals 24 , 25 , 31 , 61 , meat 61 , 62 and milk 61 . However, the method underestimates the reactive lysine content of foods since some of the dinitrophenyl-lysine may be destroyed during the acid-hydrolysis step used to liberate the dinitrophenyl-lysine from the protein 63 , necessitating the use of correction factors.…”