An almond-and-wheat blend (about 1:2.5, dry basis) was extruded through a co-rotating twin-screw extruder with a barrel diameter of 25 mm. The effects of barrel temperature (69.77-120.23°C), dough moisture (26.64-33.36%) and screw speed (13.85-38.50 rad s )1 ) on specific mechanical energy, oil loss that occurs during extrusion process, pressure at the die and on complexing index, break strength, porosity and expansion ratio of extrudates were investigated using response surface methodology. The only variable that had a significant influence on oil loss was barrel temperature (the lowest oil loss, i.e. 0.06%, was obtained with the minimum barrel temperature). The worst product structure was obtained at barrel temperature less than 100°C. Yet, the highest values of porosity (18.47%) and expansion ratio (158.76%) were obtained at a barrel temperature of 120°C. Regression results showed a positive correlation (r 2 = 0.94) between oil loss, porosity and expansion degree values.
The extrusion of fatty flour at temperatures less than 100C on the one hand favors less leakage of oil from plant and products, but on the other hand reduces the degree of expansion unless suitable technological coadjuvants are used.Enzymes are generally used in the preparation of bread to mellow gluten and to soften texture. At the moment, there is little information about the use of enzymes to improve the texture of extruded products.The effect of two commercially available enzymes (GRINDAMYL Amylase 1000 and GRINDAMYL Protease 41) on the texture of products obtained from wheat and almond flours extruded at low temperature (54C) was studied.GRINDAMYL Protease 41 was found to affect the rheological characteristics of dough by rapid decreasing the consistency during farinographic analyses and by improving the structure of extrudates with a high lipid content (reduced breaking strength, high% porosity and high water solubility index).
Cereal Chem. 82(5):494-498Doughs made from wheat and almond flours, water, and five types of emulsifiers commonly used in confectionary and bakery products (soy lecithin, sucrose esters, mono-glycerides, mono-and di-glycerides of fatty acids, and diacetyl tartaric acid esters of monoglycerides [DATEM]) were studied. To evaluate the additive ability to retain the fatty fraction during the extrusion process, electrical conductivity was measured and fat loss (%) that occurs during extrusion processing was determined. The electrical conductivity measurements showed that the lower and better concentration of soy lecithin and mixed mono-and di-glycerides of fatty acids to obtain an oil-water emulsion was 0.2 g/100 g of dough, while for sucrose esters and mono-glycerides of fatty acids, it was 0.7 g/100 g of dough. No efficacy for DATEM was observed. The fat loss results showed that sucrose esters were the most suitable emulsifiers for retaining the fatty fraction during extrusion processing, even at a very low amounts (2 g/kg of dough).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.