Study on Interaction Among Extrusion‐cooking Process Variables and Enzyme Activity: Evaluation of Extrudate Structure

Abstract

A blend of wheat flour (moisture content 11.61%) and different amounts of two commercial enzymes like GRINDAMYL (GA) amylase 1000 (0–0.1 g/kg) and GA protease 41 (0–1.0 g/kg) were extruded through a co‐rotating twin‐screw extruder. The effects of barrel temperature (60–120C), dough moisture (20–36%), screw speed (100–400 rpm) and different amounts of enzymes on structure of extrudates (porosity and break strength) were studied using response surface methodology. Results showed that the highest value of porosity (62.47% ± 4.07) was obtained at the highest value of barrel temperature (120C) and at the largest amounts of GA protease 41 (1.0 g/kg) or GA amylase 1000 (0.1 g/kg). However, the simultaneous addition of large amounts of both enzymes caused a negative effect on expansion degree (porosity < 30%). Large amounts of moisture dough and GA amylase 1000 resulted in a high value of break strength (25.7 N/mm2) and in stiff‐textured extrudates. PRACTICAL APPLICATIONS This research could provide some information about the effects of and the interactions between extrusion parameters and enzyme activities, which are commonly used to produce bakery products, in order to improve the texture of extrudates processed at low barrel temperatures, i.e., 60C, for example, extrudates with thermolabile components like vitamins or extrudates with high lipid fraction like breakfast cereals, pet food, etc.

Dynamics of rapid starch gelatinization and total phenolic thermomechanical destruction moderated via rice bio-extrusion with alpha-amylase activation

“…20,23,24 This dilemma was somewhat reversed when the thermostable a-amylase was introduced into cereal extrusion (mainly to achieve a high degree of starch gelatinization and liquefaction in the industries of starch saccharication, cake making, ethanol fermentation and liquor brewing) because the phenolics seem to be indirectly protected both in free and bound forms. 3,19,25,26 The mechanism of rapid starch gelatinization coupled with total phenolic retention during bioextrusion is still ambiguous, in spite of the otherwise complex impact of extrusion processing (without an enzyme catalyst) on the chemical and antioxidative prole, considering the multiple operating factors of temperature, moisture content, shear force, local friction and mechanical energy. 18 Thus it is worth following the idea of modeling reaction kinetics for food ingredients in extrusion cooking that have been developed separately for starch gelatinization and degradation, 15,16,[27][28][29] amino acid loss, 30 vitamin destruction 31,32 and phenolic compounds.…”

Effect of Flaxseed Oil Inclusion and Extrusion Cooking Parameters on Extruded Snack-food Physical and Functional Properties

“…It can be well correlated with texture of extrudate [20,29]. Moreover, it correlates with simulation of incisors impact during biting [30,31]. It is evident from Fig.…”

Optimization of Extrusion Conditions for GABA Tea Powder/Corn Grit Blend Extrudates

“…; Saxena and Rao ; De Pilli et al . , ). The basic principle of RSM is to relate product properties of regression equations that describe interrelations between input parameters and product properties (Colonna et al .…”