The effect of site of supplementation of a mixture of two crude preparations (Enzyme C and Enzyme X) of exogenous polysaccharide-degrading enzymes (EPDE) was studied in vivo using four ruminally and duodenally cannulated heifers (Exp. 1). The treatments were as follows: control (no EPDE), EPDE supplied through the diet (EF, 47.0 g/d), and EPDE infused continuously into the abomasum (EA, 41.6 g/...

The effects of proteolytic enzymes, ribonuclease, and deoxyribonuclease upon a fibrous component of chick embryo mitochondria, which was previously shown to have many fixation and staining properties characteristic of the bacterial nucleoplasm, are reported. Pepsin digestion of formaldehyde-fixed tissues removed the membranes and matrices of mitochondria, but a pepsin-resistant fibrous material...

An analytical procedure was proposed to estimate bioaccessibility of copper and zinc in Spirulina Pacifica tablets with respect to that of copper and zinc in gluconate complexes. Spirulina is the common name for diet supplements produced primarily from two species of cyanobacteria, namely Arthrospira platensis and Arthrospira maxima. Spirulina tablets are an excellent source of proteins, vitami...

Bioaccessibility studies should be taken into account when evaluating the physiological effects of ingested compounds at the intestine level. Several in vitro digestion protocols have been described, with a wide range of experimental conditions but no optimised protocol exists. In order to fill in this gap, we evaluated the influence of three continuous factors (pH, incubation time, and enzyme ...

The control of gastric pepsin secretion continues to excite controversy. The diversity in the results obtained by different investigators may be due, at least in part, to the varying techniques employed to estimate pepsin activity. Thus, edestin (Polland and Bloomfield, 1929), gelatin (Gilman and Cowgill, 1930), egg albumen (Vineberg and Babkin, 1931), beef haemoglobin (Anson and Mirsky, 1932),...

1. Adult female rats given a diet containing 200 g casein/kg showed an increase in heat production which reached a maximum in 10--20 min after completion of food intake. 2. Replacement of casein in the diet by enzymic hydrolysates of casein of different extents of hydrolysis (pepsin for 1 or 3 h and pancreatin for 6, 12 or 24 h) resulted in a decrease in metabolic rate (stimulation) in the rat,...

Stability in simulated gastric fluid is regarded as an important parameter for the estimation of food allergenicity. In this study, the digestive stability of allergenic protein tropomyosin (TM) and other food proteins from mud crab in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) digestion assay system was investigated and compared by SDS-PAGE and Western blot. In SGF syst...

The aim of the present study is to characterise the influence of gluten structure on the kinetics of starch hydrolysis in pasta. Spaghetti and powdered pasta were prepared from three different cultivars of durum semolina, and starch was also purified from each cultivar. Digestion kinetic parameters were obtained through logarithm-of-slope analysis, allowing identification of sequential digestio...

1. The effect of the addition of acid on the amount of ionized protein has been compared with the effect on the rate of digestion of gelatin, casein, and hemoglobin by pepsin. 2. A similar comparison has been made of the addition of alkali in the case of trypsin with gelatin, casein, hemoglobin, globin, and edestin. 3. In general, the rate of digestion may be predicted from the amount of ionize...

Previously reported experiments (Winand, R. J., and Kohn, L. D. (1970) J. Biol. Chem. 245, 967-975; Kohn, L. D., and Winand, R. J. (1971) J. Biol. Chem. 246, 6570-6575) have demonstrated that partial pepsin digestion of bovine thyrotropin preparation yields a fragment of the thyrotropin molecule which is exophthalmogenic but has negligible or no thyroid-stimulating activity. In the present repo...