The objective of this study was to establish conditions for the texturization of soy protein isolate and peanut flour mixture using a single‐screw extruder. The effects of feed moisture, screw‐speed, and barrel temperature on the characteristics of the texturized products were studied. Feed moisture was the most important factor affecting the texture. Feeding ingredients with 22% moisture had the highest water absorption and expansion indices, and Hunter L value (P < 0.05). When the screw speed was above 180 RPM, the meat analog had a 12% decrease in the expansion index and a 5% decrease in moisture content (P < 0.05). When the barrel temperature was increased to 165C, there was a 12% decrease in the water absorption index, and a 23% decrease in the expansion index of the meat analogs (P < 0.05). Overall, an acceptable meat analog could be successfully produced with 22% moisture in the raw ingredient, screw speed at 140 RPM, and barrel temperatures at 150, 155, and 160C for the three temperature zones respectively.

Tetrahymenapyriformis strain E was used to compare the nutritive value of globin before and after peptic hydrolysis. In addition, the nutritive value was determined for shy protein, peanut protein, casein and gluten both as a sole source of nitrogen and combined with globin in isonitrogenous amounts. The nutritive value of casein ranked the highest followed by peanut protein, soy protein, globin and gluten. Peptic hydrolysis of globin, gluten and soy protein increased the cellular growth of T. pyriformis while hydrolysis had no effect on cellular growth when casein or peanut protein were used as the amino acid source. The ranking of nutritive values after peptic hydrolysis was as follows: casein, soy protein, gluten, peanut protein and globin. This indicates a difference in the availability of amino acids from some intact proteins. The nutritive value of globin was increased by blending the globin with other proteins. The Tetrakymena assay with peptic hydrolysis is an excellent procedure for the rapid screening of the quality of individual proteins or blends.