Kinetics of the Formations of Gelatinized and Melted Starch at Extrusion Cooking Conditions

Qu, Di; Wang, S. S.

doi:10.1002/star.19940460605

Cited by 27 publications

(11 citation statements)

References 8 publications

(7 reference statements)

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“…Humans and other monogastric species cannot easily digest ungelatinised starch. Extrusion cooking is somewhat unique because gelatinisation occurs at much lower moisture levels (12–22%) than is necessary in other forms of food processes (Qu & Wang, 1994).…”

Section: Nutritional Changesmentioning

confidence: 99%

Nutritional aspects of food extrusion: a review

Singh

Gamlath

Wakeling

2007

Int J of Food Sci Tech

633

489

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Extrusion cooking, as a multi-step, multi-functional and thermal/mechanical process, has permitted a large number of food applications. Effects of extrusion cooking on nutritional quality are ambiguous. Beneficial effects include destruction of antinutritional factors, gelatinisation of starch, increased soluble dietary fibre and reduction of lipid oxidation. On the other hand, Maillard reactions between protein and sugars reduce the nutritional value of the protein, depending on the raw material types, their composition and process conditions. Heat-labile vitamins may be lost to varying extents. Changes in proteins and amino acid profile, carbohydrates, dietary fibre, vitamins, mineral content and some non-nutrient healthful components of food may be either beneficial or deleterious. The present paper reviews the mechanisms underlying these changes, as well as the influence of process variables and feed characteristics. Mild extrusion conditions (high moisture content, low residence time, low temperature) improve the nutritional quality, while high extrusion temperatures (P200°C), low moisture contents (<15%) and/or improper formulation (e.g. presence of high-reactive sugars) can impair nutritional quality adversely. To obtain a nutritionally balanced extruded product, careful control of process parameters is essential.

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Section: Nutritional Changesmentioning

confidence: 99%

Nutritional aspects of food extrusion: a review

Singh

Gamlath

Wakeling

2007

Int J of Food Sci Tech

633

489

View full text Add to dashboard Cite

show abstract

“…By regarding the gelatinization of starch in sufficient water as a first-order reaction (Eq. 1) (Kubota et al 1979, Bakshi and Singh 1980, Pravisani et al 1985, Riva et al 1991, Kokini et al 1992, Qu and Wang 1994, Okechukwu and Rao 1996, the temperature dependence of the gelatinization rate constant can be described by an Arrhenius equation (Eq. 2):…”

Section: Calculation Of Gelatinization Kinetic Constantsmentioning

confidence: 99%

“…The activation energies of gelatinization found in this study are reasonably larger and more precise than those determined by isothermal methods. However, this nonisothermal method is unsuitable for elucidating the kinetic parameters for crystallite melting in limited water systems which presumably follows a zero-order reaction (Bhattacharya and Hanna 1987, Wang et al 1989, Qu and Wang 1994.…”

Section: Thermal Kinetics Of Starch Gelatinizationmentioning

confidence: 99%

Effects of Modulated Differential Scanning Calorimetry (MDSC) Variables on Thermodynamic and Kinetic Characteristics During Gelatinization of Waxy Rice Starch

Lai

Lii

1999

Cereal Chem

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The total, reversing, and nonreversing thermal properties during gelatinization of waxy rice starch (starch‐to‐water ratio = 1:2, w/w) were examined by modulated differential scanning calorimetry (MDSC). The effect of MDSC operating variables (i.e., the amplitude and frequency of temperature modulation and the underlying heating rate) on these thermal properties was determined by response surface methodology (RSM) and statistical analysis. The frequency of temperature modulation and the underlying heating rate significantly influenced the gelatinization temperatures and enthalpy changes in total and nonreversing endotherms. In addition, the combination of 0.025Hz and 4–8°C/min with a properly low degree of oscillation was suitable for characterization of starch gelatinization by MDSC. The enthalpy changes in the reversing (thermodynamic) endotherms increased, but those in the nonreversing (kinetic) endotherms decreased with increasing periods (i.e., decreasing frequencies) and underlying heating rates. However, the total enthalpy changes were only slightly influenced by the MDSC variables studied. In addition, the activation energies for the total and nonreversing events were 281.8–417.3 and 386.3–739.7 kJ/mol, respectively, depending on the MDSC conditions. From the compensation relationship between the activation energy and frequency factor, we concluded that the total and nonreversing endotherms were linked to the same single transition.

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“…In starch cooking with limited amounts of water, Qu and Wang (1994) followed the kinetics of the formations of gelatinized starch (GEL) and melted starch (MELT) separately. The reaction rate of GEL formation was faster than that of MELT at a specified temperature.…”

Section: Effects Of Additives On Kinetics Of Starch Conversionmentioning

confidence: 99%

Starch Cooking with Limited Water as Affected by Zein and Guar Gum

Kim

Wang

1999

Journal of Food Science

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DSC (Differential Scanning Calorimetry) peak temperature of starch was decreased by adding zein, but was increased by adding guar gum. Adding zein increased the initial rate of starch cooking, but adding guar gum decreased it. Kinetic studies were carried out at 115, 125, and 1358C. At 258C, zein absorbed less water than waxy corn starch, especially at water activities .0.6 where guar gum absorbed more water than starch. The strong binding of water by guar gum increased DSC-peak-temperature and decreased the initial rate of starch cooking. The relatively weak binding of water by zein decreased DSC peak temperature and increased the initial rate of starch cooking. Although water sorption data at cooking temperatures are difficult to measure, the kinetic data at these temperatures and DSC data could be used to supplement the sorption data.

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Kinetics of the Formations of Gelatinized and Melted Starch at Extrusion Cooking Conditions

Cited by 27 publications

References 8 publications

Nutritional aspects of food extrusion: a review

Nutritional aspects of food extrusion: a review

Effects of Modulated Differential Scanning Calorimetry (MDSC) Variables on Thermodynamic and Kinetic Characteristics During Gelatinization of Waxy Rice Starch

Starch Cooking with Limited Water as Affected by Zein and Guar Gum

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