The Effect of Moisture Content on Mechanical Properties and Texture Profile Parameters of Corn Meal Extrudates

Abstract

Two corn meal extrudates with initial moisture contents of 22% and 31% W.B. were partially dried to moisture contents from 7% to 31% W.B. and stored in hermetically sealed containers to allow redistribution of the water. Compressive strength, compressive relaxation and instrumental texture profile analyses (fracturability, cohesiveness, springiness, gumminess and chewiness) were measured. Compressive strength increased with decrease in moisture content from 31‐15%, reached a maximum between 15‐10% and then decreased below 10%. Stiffness showed a similar relationship, with the maximum occurring between 10‐6%. Relaxation modulus increased with decrease in moisture content over the range studied. Relaxation time was a minimum at 15% moisture content. Fracturability had a similar relationship to moisture content as that of compressive strength. The textural behavior was ductile and chewy at moisture contents above 15% but became crisp or crunchy and collapsed with brittle fractures at lower moisture contents. Both compressive properties and texture profile parameters of the corn meal extrudates changed considerably with changes in moisture content.

Nutritional, physical and sensory properties of extruded products from high-amylose corn grits

“…In this study, the instrumental frangibility was expressed using the force value corresponding to the first apparent peak (point A in Fig. 3a and b) in the force-time texture profile curve (Halek et al, 2007;Szczesniak and Hall, 2007). The size of the cell as well as the thickness and toughness of a cell wall can affect the rupture of the cells and, indirectly, the frangibility (Bouvier et al, 1997).…”

“…However, the sensory chewiness of the HACG extrudate was rated at a significantly higher (P≤ 0.05) value than that of the NCG extrudate. Halek et al (2007) determined that the moisture content of the extrudate significantly affects the texture properties. In this study, the difference in the chewiness evaluation could be due to the difference in chewiness caused by the addition of saliva upon tongue stirring during the sensory evaluation.…”

Effect of deep-fat frying on sensory and textural attributes of pellet snacks

“…Uniaxial compression test, by a 35 mm diameter plastic cylinder, was made on the snacks which were mounted over a platform. Samples were compressed to 30 % strain at a constant speed of 25 mm/min (Halek et al 1989). The texture of snacks was expressed as fracture force (highest peak followed by a sudden drop [g]), hardness (peak compression force [g] at target deformation), apparent modulus of elasticity or initial target modulus (sample rigidity that is the linear part of the force-deformation curve [g/s]), adhesiveness (negative force area during withdrawal [g.s]), and compressive energy (area under the curve for the compression that is the work [g.s] required to attain deformation indicative of internal strength of bonds within product) (Halek et al 1989;Ahmed et al 2005;Anton and Luciano 2007;Kim et al 2009).…”

“…Literature review shows that there have been many researches into the textural quality of different kinds of snacks (Katz and Labuza 1981;Halek et al 1989;Liu et al 2000;Pamies et al 2000;Rampersad et al 2003;Veronica et al 2006;Ainsworth et al 2007;Ravi et al 2007;Nath and Chattopadhyay 2008;Greve et al 2010;Lazou and Krokida 2010). However, to our knowledge, there is no or little study available concerning the effects of different combinations of time and temperature of deep-fat frying on sensory and textural properties of pellet snacks.…”

Instrumental Texture Evaluation of Extruded Snack Foods: A Review Evaluación Instrumental De Textura en Alimentos Extruidos: Una Revisión

“…Instrumentally, texture parameters such as fracturability, cohesiveness, adhesiveness, hardness and chewness were calculated based on a compression test. The procedure described by Halek et al (1989) was used to the instrumental settings, which were applied on a TA-XT2 texture analyzer. Briefly, the sample was compressed twice at 70 % of its original height and the force deformation curve was recorded.…”