Influence of Process Variables on the Characteristics of a High Moisture Fish Soy Protein Mix Texturized by Extrusion Cooking

• Published in: Food science & technology 1996, Vol.29 (5), p.526-535
• Main Authors: Thiébaud, Maryse, Dumay, Eliane, Cheftel, Jean Claude
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; color; extrusion; fish; Fish and seafood industries; Food industries; food processing; food processing equipment; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; soy protein; texture; texturization; water content
• ISSN: 0023-6438; 1096-1127
• DOI: 10.1006/fstl.1996.0080

A two level factorial experimental design was used to study the influence of process variables (feed rate, 33 – 38 kg/h; screw speed, 70 – 100 rpm; extruder barrel temperature, 173 – 177 °C; feed moisture, 630 – 650 g/kg) on the resistance to stretching, colour and final water content (after immersion in water) of extrudates from a mix of fish surimi and soy protein concentrate texturized by extrusion cooking. The relationship between process variables and system parameters (product temperature before the cooling die, mean and peak residence times in the extruder + die) was also investigated. Extrusion cooking was carried out on a long barrel (1500 mm) corotative twin screw extruder equiped with an 800 × 40 × 3 mm cooling die. Extrudate texture was found to depend mainly on feed moisture, screw speed and barrel temperature, in this decreasing order. Extrudate colour depended most significantly on feed moisture and barrel temperature, while the final water content of extrudates (after immersion in water) was most affected by barrel temperature and screw speed. Within the experimental domain, the feed rate and mean residence time had no significant effect on the characteristics of extrudates.