Comparison of the total protein, nitrogen, and amino acid composition of selected additives and ingredients used in composite meat products

Comparison of the amino acid composition and protein contents of two northern adapted asparagus cultivars

“…These values were determined using the conventional Kjeldahl nitrogen procedure. Such differences in protein content were also noted among other products evaluated by Zarkadas et al (1988a). These data suggest that a substantial quantity of Kjeldahl nitrogen is derived from non-protein nitrogenous compounds present in asparagus and that the usefulness of the conventional Kjeldahl nitrogen conversion factor, N X 6.25 (Morries, 1983), for an accurate assessment of the total protein is limited.…”

“…Total protein on a dry weight basis for Jersey Centennial and Lucullus Midseason averaged 23.08 and 24.40%, respectively. The constants, weight equivalent (WE, micrograms per nanomole) and conversion factors (CF and CF', micrograms per nanomole), for each of the asparagus cultivare (Table I) or asparagus protein fractions investigated (Tables II and III) have been determined and can be used in all subsequent quantitations of these plant tissues following standard procedures as described by Horstmann (1979) and Zarkadas et al (1988a).…”

“…Previous studies (Zarkadas et al, 1988a) have shown that a method of calculating the amount of a specific protein (j) in plant tissues from the quantitative determination of a given unique amino acid i known to occur exclusively in that specific protein (j) is where P¡ is the concentration of a specific primary cell wall glycoprotein j, i.e., extensin, expressed in grams per kilogram of total protein, c¡ is the mean concentration of a unique proteinbound amino acid, i.e., 4-hydroxyproline, in grams per kilogram of total protein, n¡ is the number of amino acid residues, i, per 1000 amino acid residues, WEp¡ is the weight equivalent of a specific protein j determined from its known amino acid composition according to the method of Horstmann (1979), and , is the anhydrous molecular weight of 4-hydroxyproline.…”

Comparison of the Protein Quality of Five New Northern Adapted Natto Soybean Cultivars by Amino Acid Analysis

“…Complete amino acid analyses were carried out on each of the four replicate soybean samples (50.0 mg) according to the standard procedures described previously (Zarkadas et al, 1988a(Zarkadas et al, ,b, 1993a. Each of the four replicates was divided into two subsamples, i.e., A and B, which were then hydrolyzed under vacuum (below 10 µmHg) with 10 mL of triple glassdistilled constant-boiling HCl (6.0 M; 20.5% v/v) at 110.0 ( 0.5 °C in duplicate for 24, 72, and 96 h as described previously (Zarkadas et al, 1988a,b).…”

“…A conversion factor CF (in micrograms per nanomole) for determining the protein mass in each sample analyzed in the absence of tryptophan, methionine, and cyst(e)ine was also calculated as described previously (Horstmann, 1979;Zarkadas et al, 1988a) as The protein content P (in micrograms) of each sample was calculated by multiplying CF by the nanomoles of total amino acids in each acid hydrolysate as follows:…”