Literature Data Compilation of WAI and WSI of Extrudate Food Products

Abstract

Published data on water absorption index and water solubility index of food materials are selected from the literature and organized into a database. Useful information such as the characteristics of the database and the statistics of the included data are presented. Researchers report that the values of the latter properties are affected by extrusion process variables.

Keywords:

• Water absorption index
• Water solubility index
• Cereal mixtures
• Legumes
• Extrusion parameters

INTRODUCTION

High temperature sort time extrusion cooking has found many applications in producing a wide variety of food materials such as: breakfast cereals, snacks, weaning foods, pet and aquatic foods, confectionery products, and texturized vegetable proteins. Researchers have shown that the most important chemical reactions which occur during extrusion processes involve starch gelatinization, protein denaturation and inactivation of many native enzymes.[1,2,3,4] The qualitative features of the extruded products are characterized by several functional properties such as water absorption index (WAI), water-oil absorption index, water absorption capacity, water solubility index (WSI), protein solubility index, nitrogen solubility index, gelatinization capacity, foam expansion index, emulsion solubility index, emulsion activity index, water holding capacity, and swelling index. In particular, the WAI and WSI can be used to estimate the functional characteristics of foods and predict how the materials may behave if further processed.[5,6,7] Moreover, these indices give information of the physicochemical changes of the biopolymers as a result of extrusion processing.[8,9,10,11]

Water absorption indicates the amount of water immobilized by the extrudate, while water solubility indicates the amount of small molecules solubilized in water so process molecular damage.[12] Anderson et al.[13] recorded a method to estimate the amount of material that can be extracted by water from an extruded product. The method involves milling the extruded product and then adding a known weight of powder to distilled water. The samples are then stirred and the suspension is washed into a tare centrifuge tube. After centrifugation the supernatant is dried and the weight of solids in the supernatant was used to calculate the WSI as a percentage of dry weight of the extrudate. The weight of the sediment in the centrifuge tube was used to calculate the WAI as a percentage of the water bound per 100 g of dry extrudate. The WAI and WSI can be used to characterize extruded products and these methods are simple, easy to apply and the results are consistent when precise methodology is applied. The use of WAI and WSI is justified at the practical level in that they readily yield the ‘degree of cook’ without requiring time-consuming biochemical extraction, isolation and characterization of complex mixtures.[8] The raw materials which are soluble include unmodified or gelatinized starch, natured globular proteins, inorganic ions and small sugars. During extrusion the morphological changes of above materials determine the functional characteristics of final product. When the initial materials contains mainly starch, the WAI measures the volume occupied by the starch polymer after swelling in excess water, or the dispersion of starch in excess water. The dispersion of starch is increased by the degree of starch damage due to gelatinization. High WAI values indicate the presence of large starch fragments in the final product. The WSI determines the amount of free polysaccharide or polysaccharide released from the granule on addition of excess water. Moreover, the WSI reflect the macromolecular degradation of starch. High WSI values indicate the presence of dextrinized starch molecules. The value of WSI is an important measure on proteinaceous blends because is an indicator of the status of the proteins. During extrusion proteins suffer partial denaturation and the value of index are used often to decide the technological usefulness of the blend.[14,15,9,16 –17,6,18]

The WAI and WSI values of extruded products depend on several factors. The later can be classified into two major groups. The first group consists of the factors which are related to the properties of the raw materials, such as the initial composition of raw materials, the formulations of raw materials, the pre-processing treatments, the initial particle size of milled materials, the milling procedure.[6] The second group consists of the process input variables which are related to the extruder conditions, such as extruder type, last section barrel temperature, feed moisture content, feed rate, screw speed, screw configuration, screw compression ratio, die dimension, and die configuration.[19] Many studies have related the final state of raw materials transformation during extrusion to such processing parameters as barrel temperature, water content, feed rate, or screw speed without discuss about the influence of the others factors on the final product.

In the recent literature, there exist few available experimental data of WAI and WSI values mainly for certain cereals, legumes or mixtures of them.[13,20,14,21,2,22–45,3,46–49,8,50–57,15,58,4,50,9,5,12,60–62,16,63–69,10,70–77,11,78–83,6,7,84,18,85–90] The scope of this work is to collect, update and classify the experimental data, which concern only products for human consumptions, of the above articles. It should be noted that although there exist a large number of available articles reporting WAI and WSI values determined by statistical methods, these values have not been taken into account in the present work.

DATA

An exhaustive literature search was made in the most popular food engineering and food science journals during the recent years as indicated in Table 1.

Table 1 Science journals and the number of papers which retrieved from them

Journal	Number of papers
Carbohydrate Polymers	5
Cereal Chemistry	8
Food Chemistry	4
Food Control	1
Food Research International	2
Industrial Crops and Products	4
Int. J. of Food Properties	2
Int. J. of Food Science and Technology	6
J. of Agricultural and Food Chemistry	3
J. of Cereal Science	1
J. of Food Engineering	11
J. of Food Process Engineering	2
J. of Food Processing and Preservation	3
J. of Food Quality	1
J. of Food Science	12
J. of the Science of Food and Agriculture	4
J. of Vinyl & Additive Technology	1
LWT- Food Science and Technology	8
Nahrung/Food	4
Plant Foods for Human Nutrition	3
Starch/Stärke	2

DATABASE DESCRIPTION

The selected data were organized into a database developed in Excel. In Tables 2, 3, and 4, every record includes the following fields:

•	Category: The food category
•	Material: The material name
•	Water absorption index: The measured value of the water absorption
•	Water solubility index: The measured value of the water solubility
•	Die temperature: The temperature at the die or the final section of extruder
•	Feed moisture content: The quantity of water in the materials at the first stage of extrusion process
•	Feed rate: The feed rate of materials in the extruder through the screw feeder
•	Screw speed: The rotary speed of the main extruder screw
•	Recorded type of the data: The presentation format of the experimental data, table, or graph
•	Type of extruder: Single screw or twin screw extruder
•	Effect or not effect: The effect of extrusion parameters on WAI and WSI respectively. Table 2 The values of WAI and WSI vs. die temperature, feed moisture content, feed rate and screw speed of extruded materials Material WAI WSI % Die temper. (°C) Feed moisture content % (wb) Feed rate (kg/h) Screw speed (rpm) Cereal products Adlay cv. 5.4 26.4 140 – 25 50 6.1 21.4 140 – 25 50 5.3 27.4 140 – 25 50 5.8 24.3 140 – 25 50 5.1 30.8 140 – 25 50 Barley flour cv. 2.3 – 170 17 6 100 2.5 – 170 17 6 100 2.8 – 160 17 6 100 2.5 – 170 17 6 50 2.5 – 170 17 6 75 2.5 – 170 17 6 100 2.6 – 170 17 6 125 2.7 – 170 17 6 150 1.3 – 170 17 5 100 1.4 – 170 17 6 100 1.6 – 170 17 6 100 2.3 – 170 17 6 100 2.7 – 170 17 6 100 3.4 – 160 17 6 100 2.2 – 170 17 6 50 2.2 – 170 17 6 75 2.8 – 170 17 6 100 3.2 – 170 17 6 125 3.3 – 170 17 6 150 2.9 35.2 135 14 23 195 4.7 21.8 185 14 29 195 4.6 13.9 135 14 29 125 4.3 26.9 185 14 14 125 4.9 27.7 160 18 21 230 4.5 14.8 160 18 21 90 4.6 15.2 160 18 36 160 2.9 38.9 160 18 6 160 5.4 18.6 210 18 21 160 5.0 50.2 110 18 21 160 4.8 15.9 160 26 21 160 3.2 35.4 160 10 21 160 4.8 13.0 160 18 21 160 4.7 12.5 160 18 21 160 5.1 19.7 160 18 21 160 5.1 19.6 160 18 21 160 Barley flour (hull less) cv 2.5 – 170 17 6 100 2.0 – 170 17 6 100 3.1 – 170 17 6 100 1.3 – 160 17 6 50 1.5 – 170 17 6 75 1.7 – 170 17 6 100 2.5 – 170 17 6 125 2.5 – 170 17 6 150 1.2 – 170 17 5 100 1.4 – 170 17 6 100 1.6 – 170 17 6 100 2.4 – 170 17 6 100 1.7 – 170 17 6 100 2.7 – 160 17 6 100 1.5 – 170 17 6 50 1.6 – 170 17 6 75 1.6 – 170 17 6 100 1.7 – 170 17 6 125 2.1 – 170 17 6 150 Corn flour and grids 2.4 – 70 28 4 30 3.4 – 100 28 4 30 2.7 – 70 28 4 30 3.5 – 100 28 4 30 2.8 – 70 28 4 80 3.2 – 100 28 4 80 3.0 – 70 28 4 80 3.3 – 100 28 4 80 3.0 – 60 28 4 55 3.6 – 110 28 4 55 2.9 – 85 28 4 55 2.9 – 85 28 4 55 2.9 – 85 28 4 97 3.3 – 85 28 4 55 3.1 – 85 28 4 55 3.1 – 85 28 4 55 3.1 – 85 28 4 55 3.1 – 85 28 4 55 7.2 16.2 130 8 6 750 6.6 27.1 110 14 6 750 5.3 30.2 110 15 6 750 5.8 35.9 110 19 6 750 – 46.0 90 24 6 750 6.1 41.2 155 – 75 200 6.7 50.8 155 – 75 300 5.5 64.8 155 – 75 500 5.9 42.8 130 15 75 200 5.1 39.7 130 15 75 200 5.9 41.7 130 15 75 200 4.1 38.0 130 15 75 200 4.0 37.8 130 15 75 200 3.8 39.2 130 15 75 200 5.5 15.8 170 19 3 200 5.5 14.7 170 19 3 200 5.4 9.8 170 19 5 200 6.1 8.4 170 19 5 200 5.8 9.3 170 19 6 200 5.1 8.4 170 19 6 200 5.5 17.2 170 16 3 200 5.4 12.6 170 16 3 200 5.5 13.9 170 16 5 200 5.3 12.6 170 16 5 200 5.4 15.1 170 13 3 200 5.9 17.7 170 13 3 200 5.6 15.0 170 13 3 200 6.7 6.5 170 19 5 200 5.1 12.2 170 13 4 200 5.3 15.0 170 13 4 200 5.3 11.8 170 19 3 200 5.3 12.2 170 19 3 200 5.1 9.7 170 19 5 200 5.0 9.2 170 19 5 200 5.1 14.8 170 16 3 200 5.3 17.0 170 16 3 200 5.0 8.6 170 19 7 200 5.1 9.7 170 19 7 200 5.0 12.5 170 16 5 200 4.9 23.2 170 13 3 200 5.3 25.3 170 13 3 200 4.8 12.3 170 16 4 200 5.0 23.3 170 13 3 200 4.9 20.0 170 13 3 200 5.9 18.6 200 19 3 200 6.1 19.9 200 19 3 200 5.7 14.0 200 19 5 200 5.6 15.1 200 19 5 200 5.4 27.8 200 16 3 200 5.5 27.1 200 16 3 200 5.5 18.5 200 16 5 200 5.6 16.9 200 16 5 200 5.2 11.9 200 16 7 200 5.4 11.5 200 16 6 200 5.2 9.6 200 19 7 200 5.2 12.3 200 19 7 200 5.0 11.0 200 16 6 200 5.3 25.6 200 13 3 200 5.4 18.6 200 13 5 200 5.2 16.1 200 13 5 200 5.3 18.3 200 13 5 200 5.3 24.8 200 13 3 200 5.4 17.7 200 13 5 200 5.7 23.6 200 19 3 200 5.8 24.2 200 19 3 200 5.3 13.7 200 19 5 200 5.5 13.9 200 19 5 200 5.4 27.4 200 16 3 200 5.5 25.8 200 16 3 200 5.4 17.6 200 16 5 200 5.2 16.8 200 16 5 200 5.2 11.1 200 19 7 200 5.1 10.4 200 19 7 200 4.7 36.7 200 13 3 200 4.8 35.1 200 13 3 200 5.1 27.2 200 13 4 200 5.3 16.8 200 16 6 200 5.2 15.4 200 16 6 200 5.9 17.0 230 19 5 200 5.9 18.8 230 19 5 200 5.7 18.4 230 16 5 200 5.2 12.1 230 16 7 200 5.4 12.6 230 16 7 200 5.7 17.7 230 16 5 200 5.5 21.8 230 13 5 200 5.4 29.3 230 13 3 200 5.5 30.4 230 13 3 200 5.4 16.7 230 13 6 200 5.4 17.3 230 13 6 200 5.8 27.4 230 16 3 200 5.9 29.7 230 16 3 200 5.3 10.7 230 19 7 200 6.1 29.3 230 19 3 200 6.1 25.7 230 19 3 200 5.5 10.4 230 19 7 200 5.5 32.4 230 16 3 200 4.8 39.7 230 16 3 200 4.4 42.6 230 13 3 200 5.2 27.2 230 13 5 200 5.2 25.3 230 13 5 200 5.7 31.6 230 19 3 200 5.6 31.6 230 19 3 200 5.6 19.4 230 19 5 200 5.8 18.2 230 19 5 200 5.1 10.2 230 19 7 200 5.3 10.7 230 19 7 200 5.5 21.6 230 16 5 200 5.6 23.4 230 16 5 200 5.4 18.8 230 16 6 200 5.2 16.1 230 16 6 200 5.0 37.0 230 13 3 200 5.2 28.1 230 13 5 200 4.7 20.6 125 – – 300 5.3 22.6 87 11 10 840 6.2 18.7 155 15 52 400 5.4 20.7 115 15 52 400 9.0 14.3 155 22 52 220 3.8 17.7 115 15 52 220 6.8 16.7 135 18 52 310 5.7 18.0 135 12 52 310 7.4 12.6 135 25 52 310 5.6 18.5 115 22 52 400 6.5 17.0 135 18 52 159 6.9 16.9 135 18 52 310 7.2 18.0 155 15 52 220 6.1 15.8 115 22 52 220 6.5 16.2 135 18 52 310 7.1 19.4 169 18 52 310 6.2 15.9 135 18 52 310 3.4 19.7 101 18 52 310 6.6 16.7 135 18 52 310 6.6 16.4 135 18 52 310 6.7 14.0 155 22 52 400 5.6 17.0 135 18 52 461 4.1 19.3 132 6 7 700 1.1 – 100 11 – 120 1.1 – 100 15 – 120 1.0 – 100 20 – 120 1.1 – 120 11 – 120 1.1 – 120 15 – 120 1.0 – 120 20 – 120 1.0 – 150 11 – 120 1.1 – 150 15 – 120 1.0 – 150 20 – 120 4.8 8.0 125 14 5 300 4.8 7.0 125 11 5 300 5.6 – 160 15 – 100 4.8 – 160 22 – 100 5.3 – 210 15 – 100 4.8 – 210 22 – 100 5.6 – 250 15 – 100 5.6 – 250 22 – 100 8.6 18.7 200 18 10 200 5.0 15.7 90 18 25 200 4.9 11.9 90 20 25 200 5.1 9.7 90 22 25 200 5.1 11.4 90 24 25 200 5.0 20.5 110 18 25 200 5.0 15.1 110 20 25 200 5.3 13.0 110 22 25 200 5.2 11.4 110 24 25 200 5.4 20.5 130 18 25 200 5.1 16.2 130 20 25 200 5.0 15.1 130 22 25 200 5.0 14.1 130 24 25 200 5.8 34.6 150 20 25 200 6.1 33.5 150 22 25 200 6.2 29.7 150 24 25 200 5.7 27.0 90 18 25 200 5.8 21.6 90 20 25 200 5.6 18.9 90 22 25 200 5.5 15.1 90 24 25 200 5.9 28.6 110 18 25 200 6.0 24.3 110 20 25 200 5.8 21.6 110 22 25 200 5.2 25.4 110 24 25 200 5.9 29.7 130 18 25 200 6.2 24.9 130 20 25 200 6.1 21.6 130 22 25 200 5.2 27.6 130 24 25 200 3.2 60.0 150 18 25 200 4.7 45.9 150 20 25 200 5.5 37.8 150 22 25 200 6.1 33.5 150 24 25 200 5.7 35.7 90 18 25 200 6.3 29.2 90 20 25 200 6.1 29.2 90 22 25 200 6.1 26.5 90 24 25 200 5.1 41.1 110 18 25 200 5.9 34.1 110 20 25 200 6.3 29.7 110 22 25 200 6.2 28.6 110 24 25 200 3.8 52.4 130 18 25 200 4.3 47.0 130 20 25 200 5.2 40.0 130 22 25 200 6.2 29.7 130 24 25 200 3.5 56.2 150 18 25 200 3.5 57.8 150 20 25 200 4.4 46.5 150 22 25 200 5.5 38.4 150 24 25 200 5.1 40.5 90 18 25 200 5.9 31.3 90 20 25 200 5.9 28.6 90 22 25 200 5.8 29.7 90 24 25 200 4.5 47.6 110 18 25 200 5.7 36.8 110 20 25 200 5.9 35.1 110 22 25 200 5.8 33.5 110 24 25 200 3.8 53.0 130 18 25 200 4.5 45.9 130 20 25 200 5.0 41.1 130 22 25 200 5.5 36.8 130 24 25 200 2.9 60.5 150 18 25 200 3.5 55.1 150 20 25 200 4.5 45.9 150 22 25 200 5.0 41.6 150 24 25 200 5.3 16.0 150 13 1 200 5.5 16.2 150 13 1 300 5.7 16.2 150 13 1 400 5.6 20.0 150 13 1 200 5.7 19.7 150 13 1 300 5.7 20.8 150 13 1 400 5.4 15.2 150 13 1 200 5.7 18.3 150 13 1 300 5.7 22.2 150 13 1 400 5.0 32.0 110 15 4 150 7.2 17.0 110 20 4 150 5.9 32.1 110 15 4 150 7.8 17.3 110 20 4 150 Corn flour degermed – 7.7 130 23 5 300 – 11.8 130 28 5 300 – 11.9 130 28 5 300 – 13.1 130 28 5 300 – 13.2 130 28 5 300 – 12.8 130 28 5 300 6.5 16.4 130 16 4 130 6.7 19.2 130 18 4 130 7.0 10.4 130 20 4 130 6.9 14.1 150 16 4 130 6.8 21.1 150 18 4 130 7.7 19.6 150 20 4 130 Oat grits 4.2 9.0 78 16 – 100 6.4 5.5 162 26 – 100 3.5 3.3 100 25 – 140 2.1 7.7 135 16 21 125 2.0 7.2 205 16 39 125 1.8 5.8 135 26 39 195 2.3 5.1 205 26 21 195 2.0 7.3 135 16 21 195 2.4 7.3 205 16 21 195 2.0 6.0 135 26 21 125 2.3 7.0 170 11 30 160 1.9 6.0 170 21 30 160 2.0 6.2 170 21 30 160 2.0 6.3 170 21 30 160 2.0 6.2 170 21 30 160 1.8 5.3 205 26 39 125 2.1 6.3 170 21 30 230 1.9 6.2 170 21 30 90 1.8 6.3 170 21 48 160 2.5 6.6 170 21 12 160 2.2 6.0 240 21 30 160 Sorghum flour 7.1 19.3 130 20 26 200 6.8 20.3 165 20 26 200 Rice ^1 flour cv. – 21.4 160 14 60 180 – 22.6 160 14 60 180 1.8 55.6 140 12 20 200 2.0 65.0 140 20 10 400 2.5 55.6 140 20 20 200 5.1 32.4 100 20 20 400 2.4 14.4 100 12 10 400 2.6 12.2 100 12 10 400 6.7 15.2 100 12 20 400 2.5 3.4 140 20 10 400 2.5 8.2 140 12 20 400 5.0 20.2 100 20 20 200 4.9 13.7 140 12 10 200 5.7 20.8 100 20 10 200 5.5 9.4 110 20 – 200 5.8 10.3 120 20 – 200 5.5 10.9 130 20 – 200 5.2 9.7 110 20 – 300 5.6 9.8 120 20 – 300 5.4 13.6 130 20 – 300 6.8 3.7 110 30 – 200 6.9 3.4 120 30 – 200 6.6 4.2 130 30 – 200 7.1 4.0 110 30 – 300 6.9 2.7 120 30 – 300 9.8 4.1 130 30 – 300 3.6 18.9 137 – 27 – 3.9 23.4 137 – 27 – 4.3 23.3 137 – 27 – 5.1 5.0 150 16 – – 6.0 5.9 150 16 – – 6.3 5.2 150 16 – – 6.5 11.5 150 16 – – 6.5 3.9 150 16 – – 6.9 10.2 150 16 – – 4.7 4.1 150 16 – – 5.6 4.7 150 16 – – 5.5 4.0 150 16 – – 6.1 4.8 150 16 – – 5.3 4.6 150 16 – – 6.3 5.0 150 16 – – 2.5 68.6 110 15 12 200 2.4 73.0 110 15 12 250 12.8 17.8 110 20 12 200 9.9 23.2 110 20 12 250 6.3 7.7 110 12 4 150 5.2 8.3 110 15 4 150 5.4 8.3 110 18 4 150 6.8 7.5 110 12 4 150 6.1 8.1 110 15 4 150 6.5 7.8 110 18 4 150 – 15.5 100 18 26 250 – 23.5 120 18 26 250 – 33.5 140 18 26 250 4.6 – 160 15 – 100 4.6 – 160 22 – 100 5.0 – 210 15 – 100 5.2 – 210 22 – 100 5.0 – 250 15 – 100 5.4 – 250 22 – 100 – 20.5 150 15 – 400 – 32.1 150 15 – 400 – 32.7 150 15 – 400 – 36.8 150 15 – 400 – 21.7 150 15 12 400 – 40.0 150 15 12 400 – 48.6 150 15 12 400 – 50.3 150 15 12 400 – 37.1 150 15 12 400 – 41.1 150 15 12 400 – 40.0 150 15 12 400 – 34.3 150 15 12 400 – 36.6 150 15 12 400 – 45.7 150 15 12 400 – 40.6 150 15 12 400 – 46.3 150 15 12 400 – 44.0 150 15 12 400 – 48.0 150 15 12 400 – 45.7 150 15 12 400 – 37.1 150 15 12 400 – 42.9 150 15 12 400 – 41.1 150 15 12 400 4.1 4.5 125 22 3 300 4.3 3.7 125 15 3 300 6.2 37.0 130 25 10 120 4.3 33.0 130 20 10 120 4.2 40.0 130 15 10 120 6.8 24.0 130 25 10 120 7.1 27.0 130 20 10 120 6.6 25.0 130 15 10 120 5.2 – 95 – 27 500 6.3 – 95 – 27 500 6.6 – 95 – 27 500 7.7 – 95 – 27 500 Rye flour 4.0 18.3 125 16 34 125 4.1 26.0 175 16 16 125 4.0 28.1 125 16 16 175 4.6 21.3 175 16 34 175 4.3 24.0 150 19 26 200 4.2 17.0 150 19 26 100 4.2 17.0 150 19 44 150 4.0 30.3 150 19 8 150 4.5 16.7 200 19 26 150 4.3 21.7 100 19 26 150 4.7 17.0 150 25 26 150 4.5 30.0 150 13 26 150 4.3 18.8 150 19 26 150 4.4 20.7 150 19 26 150 3.9 20.8 150 19 26 150 4.2 19.2 150 19 26 150 Wheat flour 5.8 22.9 130 15 75 200 6.0 25.6 130 15 75 200 5.9 23.6 130 15 75 200 6.0 26.1 130 15 75 200 5.9 28.6 130 15 75 200 6.1 29.4 130 15 75 200 3.7 – 250 15 – 100 4.3 – 250 22 – 100 6.0 23.1 155 – 75 200 6.4 28.0 155 – 75 300 6.5 30.4 155 – 75 500 3.9 10.4 135 14 30 180 3.8 15.6 185 14 18 180 3.4 5.2 160 14 24 140 3.4 5.7 160 14 24 140 3.3 4.7 160 14 24 140 3.5 6.0 160 14 24 140 3.3 5.7 160 14 24 140 3.3 5.9 160 14 24 140 3.2 8.5 185 14 30 100 3.7 11.4 160 14 24 220 2.5 4.4 160 14 24 60 2.5 6.3 160 14 36 140 3.6 16.3 160 14 12 140 3.5 6.9 140 24 14 160 3.3 6.9 140 24 14 210 7.7 4.6 120 14 – 150 7.4 7.0 120 14 – 250 7.1 9.1 120 14 – 350 Legumes Beans (Ph. Vulgaris L.) cv. 5.0 – 165 – 1 25 5.6 – 185 – 1 25 4.0 – 205 – 1 25 4.5 – 165 – 1 25 4.6 – 185 – 1 25 4.2 – 205 – 1 25 4.3 – 165 – 1 25 4.7 – 185 – 1 25 5.0 – 205 – 1 25 3.3 – 130 24 1 90 3.5 – 130 26 1 90 3.8 – 130 28 1 90 0.9 – 165 24 1 90 1.8 – 165 26 1 90 1.8 – 165 28 1 90 3.9 – 130 24 1 90 4.4 – 130 26 1 90 3.4 – 130 28 1 90 2.1 – 165 24 1 90 2.2 – 165 26 1 90 1.2 – 165 28 1 90 4.5 39.0 130 – – 85 3.5 49.0 130 – – 85 4.2 13.0 140 25 4 91 4.4 12.2 140 25 4 91 5.1 12.1 140 25 4 91 3.4 17.2 140 18 – 200 3.4 17.2 140 20 – 200 3.4 17.2 140 22 – 200 3.4 20.1 160 18 – 200 3.4 20.1 160 20 – 200 3.4 20.1 160 22 – 200 3.4 23.0 180 18 – 200 3.4 23.0 180 20 – 200 3.4 23.0 180 22 – 200 2.1 28.7 120 60 4 500 2.2 29.8 120 60 4 500 2.0 27.6 120 30 4 500 2.1 28.6 120 30 4 500 3.0 16.0 110 – 7 700 3.4 21.0 121 – 7 700 4.0 21.7 132 – 7 700 4.0 21.7 132 6 7 700 4.8 30.0 190 22 – 100 3.3 35.3 132 20 7 700 4.1 – 130 24 1 90 3.4 – 130 26 1 90 3.6 – 130 28 1 90 1.9 – 165 24 1 90 2.8 – 165 26 1 90 2.9 – 165 28 1 90 3.2 25.4 132 20 7 700 4.0 15.2 132 6 7 700 4.2 26.0 87 11 10 840 3.6 19.9 110 – 7 700 3.7 20.2 121 – 7 700 4.0 20.2 132 – 7 700 3.8 20.6 150 – 7 700 3.3 – 90 15 – 80 4.2 – 110 15 – 80 5.4 – 134 15 – 80 3.6 – 90 25 – 80 4.9 – 110 25 – 80 6.1 – 134 25 – 80 3.5 – 90 15 – 120 4.8 – 110 15 – 120 5.3 – 134 15 – 120 3.9 – 90 25 – 120 4.9 – 110 25 – 120 5.8 – 134 25 – 120 3.4 – 90 15 – 160 4.9 – 110 15 – 160 5.0 – 134 15 – 160 4.0 – 90 25 – 160 5.3 – 110 25 – 160 5.9 – 134 25 – 160 Chickpea (C. arietinum L.) cv 2.4 21.2 132 20 7 700 3.3 23.5 160 – 25 300 6.3 53.8 130 20 – 175 7.0 43.8 160 20 – 175 5.4 59.0 130 30 – 175 11.0 63.5 160 30 – 175 6.0 57.0 130 25 – 150 9.3 53.5 160 25 – 150 6.1 67.8 130 25 – 200 11.5 50.3 160 25 – 200 6.3 42.8 145 20 – 150 6.4 58.8 145 30 – 150 5.5 54.5 145 20 – 200 7.8 62.0 145 30 – 200 7.5 50.3 145 25 – 175 7.5 53.5 145 25 – 175 6.7 49.8 145 25 – 175 2.3 26.1 151 – – 190 3.3 20.1 151 – – 190 Cowpea (V. unguiculata L.) cv. 4.6 40.0 130 – – 85 3.3 41.0 130 – – 85 8.5 22.2 130 20 26 200 7.7 23.5 165 20 26 200 Soybean flour 2.1 15.2 150 21 – 200 Model Foods Banana starch – 62.8 102 20 – 58 – 90.7 138 20 – 58 – 21.6 102 35 – 58 – 81.2 138 35 – 58 – 43.8 102 20 – 82 – 90.8 138 20 – 82 – 33.0 102 35 – 82 – 72.1 138 35 – 82 – 55.2 90 28 – 70 – 92.4 150 28 – 70 – 95.8 120 15 – 70 – 29.7 120 40 – 70 – 78.3 120 28 – 50 – 81.5 120 28 – 90 – 82.3 120 28 – 70 – 80.6 120 28 – 70 – 84.6 120 28 – 70 – 88.9 120 28 – 70 – 83.9 120 28 – 70 – 82.8 120 28 – 70 Cassava starch 5.8 60.7 75 38 5 200 2.8 – 100 18 – 130 3.7 – 100 26 – 130 2.9 – 100 18 – 130 3.0 – 100 26 – 130 3.8 – 100 18 – 100 4.0 – 100 26 – 100 3.1 – 100 18 – 160 3.4 – 100 26 – 160 4.2 – 100 22 – 100 4.5 – 100 22 – 100 3.9 – 100 22 – 160 2.1 – 100 22 – 160 3.5 – 100 22 – 130 7.7 22.5 100 23 5 100 3.2 – 100 25 – 100 2.8 – 100 25 – 160 9.8 44.3 130 – 5 200 9.7 44.3 130 – 8 200 9.0 39.1 130 – 5 300 9.2 49.4 130 – 8 300 Corn starch 4.8 61.0 110 14 8 750 5.4 46.9 110 16 8 750 6.1 34.1 110 23 8 750 6.2 22.3 110 25 8 750 6.6 12.2 110 29 8 750 7.6 7.6 110 33 8 750 11.0 6.3 130 – 4 120 11.9 8.6 145 – 4 120 12.2 10.8 160 – 4 120 11.1 11.8 175 – 4 120 10.8 9.8 200 – 4 120 11.9 6.9 130 – 4 120 11.1 6.2 130 – 4 120 11.9 6.3 130 – 4 120 11.2 6.8 130 – 4 120 11.5 6.4 130 – 4 120 12.0 6.9 130 – 4 120 12.0 7.0 130 – 4 120 12.2 6.3 130 – 4 120 12.3 6.2 130 – 4 120 6.1 – 130 55 – 90 6.3 – 130 55 – 180 5.9 – 130 55 – 90 6.2 – 130 55 – 180 – 37.0 120 22 75 230 – 38.3 120 22 75 330 7.0 27.0 130 – – 140 6.7 – 130 40 – 40 6.7 – 130 40 – 90 6.7 – 130 40 – 140 6.0 – 130 55 – 40 6.3 – 130 55 – 90 6.4 – 130 55 – 140 6.0 – 130 70 – 40 5.5 – 130 70 – 90 5.7 – 130 70 – 140 7.0 – 130 23 42 350 8.4 – 130 23 42 350 8.8 – 130 23 42 350 – 27.0 130 – – 140 3.5 8.2 140 20 – 140 5.4 19.3 140 22 – 140 3.7 14.7 140 22 – 140 3.3 53.9 140 22 – 140 8.6 19.0 140 22 – 140 2.1 4.1 120 – – 140 2.1 2.8 120 – – 140 3.6 4.1 160 – – 140 3.6 2.8 160 – – 140 Rice starch 6.4 – 160 25 4 42 Soy protein isolate 3.0 – 160 25 4 42 Wheat starch 7.3 18.8 125 22 40 300 8.0 14.6 125 25 40 300 9.0 10.7 125 28 40 300 7.7 27.4 150 22 40 300 8.5 16.8 150 25 40 300 9.5 8.8 150 28 40 300 8.2 18.5 175 22 40 300 8.5 14.9 175 25 40 300 9.0 11.8 175 28 40 300 Vegetables Cassava root 3.7 44.2 122 11 17 540 3.8 43.2 122 12 17 540 3.9 42.6 122 13 17 540 4.0 41.5 122 14 17 540 4.1 40.7 122 15 17 540 4.1 39.6 122 16 17 540 4.0 35.8 122 12 18 – Onion white outer fleshy 11.9 0.8 100 40 – 100 12.3 0.5 100 60 – 100 12.7 0.1 100 80 – 100 9.5 3.3 120 60 – 100 8.7 4.0 140 60 – 100 8.4 4.4 160 60 – 100 8.7 4.1 140 60 – 250 Potato condyle 5.2 – 160 15 – 100 5.7 – 160 22 – 100 5.4 – 210 15 – 100 5.7 – 210 22 – 100 5.4 – 250 15 – 100 5.9 – 250 22 – 100 2.9 9.4 125 15 7 300 2.8 8.8 125 13 7 300 Yam D. rotundata condyle 1.9 21.1 150 21 – 200 – 25.5 100 18 4 100 – 14.0 100 26 4 100 – 37.0 100 18 4 200 – 20.0 100 26 4 200 – 33.5 125 22 4 150 – 31.5 125 22 4 150 – 30.4 125 22 4 150 – 33.0 125 22 4 150 – 32.5 125 22 4 150 – 32.0 125 22 4 150 – 34.4 125 15 4 150 – 33.4 125 29 4 150 – 28.0 125 22 4 66 – 35.5 125 22 4 234 – 29.6 150 18 4 100 – 30.5 150 26 4 100 – 30.0 150 18 4 200 – 36.4 150 26 4 200 – 37.0 167 22 4 150 1 Various levels of amylose; – not reported. Table 3 The range of values WAI and WSI vs. die temperature, feed moisture content, feed rate, screw speed and the mix lever of extruded blends Material WAI WSI (%) Die Temper. (°C) Feed moisture content % (wb) Feed rate (Kg/h) Screw speed (rpm) Lever (%) Cereal products Adlay cv. : rice 6.0 22.5 140 – 25 50 75/25 5.9 21.2 140 – 25 50 50/50 Corn flour and grits : DDG ^1 1.1 – 100 11 – 120 90/10 1.1 – 100 15 – 120 90/10 1.0 – 100 20 – 120 90/10 1.1 – 120 11 – 120 90/10 1.1 – 120 15 – 120 90/10 1.1 – 120 20 – 120 90/10 1.1 – 150 11 – 120 90/10 1.1 – 150 15 – 120 90/10 1.1 – 150 20 – 120 90/10 1.1 – 100 11 – 120 80/20 1.1 – 100 15 – 120 80/20 1.1 – 100 20 – 120 80/20 1.1 – 120 11 – 120 80/20 1.1 – 120 15 – 120 80/20 1.1 – 120 20 – 120 80/20 1.1 – 150 11 – 120 80/20 1.1 – 150 15 – 120 80/20 1.1 – 150 20 – 120 80/20 1.0 – 100 11 – 120 70/30 1.0 – 100 15 – 120 70/30 1.1 – 100 20 – 120 70/30 1.0 – 120 11 – 120 70/30 1.1 – 120 15 – 120 70/30 1.0 – 120 20 – 120 70/30 1.1 – 150 11 – 120 70/30 1.1 – 150 15 – 120 70/30 1.2 – 150 20 – 120 70/30 4.9 – 160 15 – 100 90/10 4.2 – 160 22 – 100 90/10 5.1 – 210 15 – 100 90/10 4.4 – 210 22 – 100 90/10 5.1 – 250 15 – 100 90/10 5.1 – 250 22 – 100 90/10 4.3 – 160 15 – 100 80/20 4.0 – 160 22 – 100 80/20 4.3 – 210 15 – 100 80/20 4.1 – 210 22 – 100 80/20 4.6 – 250 15 – 100 80/20 4.3 – 250 22 – 100 80/20 3.3 – 160 15 – 100 60/40 4.4 – 160 22 – 100 60/40 3.5 – 210 15 – 100 60/40 3.7 – 210 22 – 100 60/40 3.5 – 250 15 – 100 60/40 3.8 – 250 22 – 100 60/40 Corn grits: flaxseed 7.8 16.7 200 18 10 200 95/5 7.4 15.5 200 18 10 200 90/10 7.1 7.6 200 18 10 200 80/20 Corn flour : finger millet 3.8 12.9 180 13 – 200 – 3.8 20.6 180 15 – 170 – 3.8 13.7 180 15 – 230 – 4.7 11.7 180 19 – 200 – 4.0 16.3 180 19 – 160 – 3.7 18.3 180 19 – 242 – 3.9 13.2 180 19 – 200 – 3.7 14.0 180 19 – 200 – 4.0 13.6 180 19 – 200 – 4.0 14.3 180 19 – 200 – 3.7 17.5 180 19 – 200 – 3.9 15.8 180 23 – 170 – 3.8 15.1 180 23 – 230 – 3.9 16.1 180 25 – 200 – Corn flour : lentil 5.1 15.3 170 19 3 200 90/10 5.1 15.4 170 19 3 200 90/10 4.9 12.2 170 19 5 200 90/10 4.8 10.7 170 19 5 200 90/10 4.9 12.5 170 19 6 200 90/10 4.8 9.8 170 19 6 200 90/10 5.2 21.5 170 16 3 200 90/10 5.1 20.7 170 16 3 200 90/10 5.2 15.8 170 16 5 200 90/10 5.1 14.3 170 16 5 200 90/10 5.8 23.5 200 19 3 200 90/10 5.4 31.7 200 19 3 200 90/10 5.1 14.0 200 19 5 200 90/10 5.1 13.2 200 19 5 200 90/10 5.0 10.9 200 19 7 200 90/10 4.9 10.9 200 19 7 200 90/10 5.2 35.5 200 16 3 200 90/10 5.4 33.2 200 16 3 200 90/10 5.3 18.4 200 16 5 200 90/10 5.3 17.6 200 16 5 200 90/10 5.2 16.1 200 16 6 200 90/10 5.2 15.4 200 16 6 200 90/10 5.1 35.6 200 13 3 200 90/10 4.6 41.6 200 13 3 200 90/10 5.2 27.4 170 13 3 200 90/10 5.1 28.2 170 13 3 200 90/10 5.1 24.5 170 13 4 200 90/10 5.0 23.1 170 13 4 200 90/10 5.5 27.6 200 13 4 200 90/10 5.2 27.1 200 13 4 200 90/10 5.4 26.6 230 16 3 200 90/10 4.8 40.8 230 16 3 200 90/10 5.7 25.4 230 16 5 200 90/10 5.6 26.4 230 16 5 200 90/10 4.7 41.7 230 13 3 200 90/10 4.0 48.0 230 13 3 200 90/10 5.8 29.1 230 19 3 200 90/10 6.3 26.3 230 19 3 200 90/10 5.7 19.1 230 19 5 200 90/10 5.4 16.0 230 19 5 200 90/10 5.1 11.4 230 19 7 200 90/10 5.1 11.2 230 19 7 200 90/10 5.1 13.1 230 16 6 200 90/10 5.1 13.7 230 16 6 200 90/10 5.5 21.9 230 13 5 200 90/10 5.1 18.6 200 13 4 200 90/10 5.1 21.7 230 13 5 200 90/10 5.2 20.6 230 13 5 200 90/10 5.7 23.2 200 19 3 200 70/30 5.8 21.7 200 19 3 200 70/30 5.2 14.9 200 19 5 200 70/30 5.2 14.4 200 19 5 200 70/30 5.1 14.0 200 19 6 200 70/30 4.9 11.9 200 19 6 200 70/30 5.5 25.5 200 16 3 200 70/30 5.4 23.8 200 16 3 200 70/30 5.2 18.3 200 16 5 200 70/30 5.3 18.3 200 16 5 200 70/30 5.2 17.2 200 16 6 200 70/30 5.4 17.1 200 16 6 200 70/30 5.4 18.5 200 13 3 200 70/30 5.3 22.0 200 13 3 200 70/30 5.0 16.5 200 13 5 200 70/30 5.2 15.6 200 13 5 200 70/30 5.8 17.9 230 16 5 200 70/30 5.8 17.7 230 16 5 200 70/30 6.0 26.4 230 16 3 200 70/30 6.1 21.5 230 16 3 200 70/30 5.4 17.8 230 16 7 200 70/30 6.1 18.2 230 19 3 200 70/30 6.0 20.1 230 19 3 200 70/30 5.8 18.4 230 19 5 200 70/30 5.5 17.7 230 19 5 200 70/30 5.5 20.4 230 13 3 200 70/30 5.5 21.1 230 13 3 200 70/30 5.2 18.6 230 13 5 200 70/30 5.2 17.3 230 13 5 200 70/30 4.9 16.0 230 13 6 200 70/30 4.9 15.1 230 13 6 200 70/30 4.6 15.5 170 19 3 200 70/30 4.7 14.6 170 19 3 200 70/30 4.5 11.1 170 19 5 200 70/30 4.7 11.0 170 19 5 200 70/30 4.7 9.8 170 19 6 200 70/30 4.2 9.4 170 19 6 200 70/30 4.8 17.8 170 16 3 200 70/30 4.8 19.4 170 16 3 200 70/30 4.5 13.1 170 16 5 200 70/30 4.5 13.4 170 16 5 200 70/30 4.9 23.9 170 13 3 200 70/30 4.8 25.2 170 13 3 200 70/30 5.0 15.5 230 19 7 200 70/30 4.8 14.3 230 19 7 200 70/30 5.0 17.2 230 16 7 200 70/30 5.3 19.8 170 19 3 200 50/50 5.4 19.2 170 19 3 200 50/50 4.8 14.1 170 19 5 200 50/50 5.2 17.4 170 19 5 200 50/50 5.1 21.6 170 16 3 200 50/50 5.1 22.2 170 16 3 200 50/50 5.1 19.2 170 16 5 200 50/50 5.0 18.3 170 16 5 200 50/50 4.9 18.2 170 16 5 200 50/50 4.8 17.3 170 16 5 200 50/50 5.0 17.1 170 19 6 200 50/50 4.9 15.3 170 19 6 200 50/50 4.7 17.4 170 13 3 200 50/50 4.6 16.6 170 13 3 200 50/50 4.7 17.9 170 13 5 200 50/50 4.6 16.1 170 13 5 200 50/50 5.3 24.1 200 19 3 200 50/50 5.5 24.5 200 19 3 200 50/50 5.1 17.8 200 19 5 200 50/50 5.2 17.6 200 19 5 200 50/50 5.2 18.3 200 19 7 200 50/50 5.1 17.3 200 19 7 200 50/50 5.5 25.3 200 16 3 200 50/50 5.4 25.1 200 16 3 200 50/50 5.2 23.8 200 16 5 200 50/50 5.2 21.0 200 16 5 200 50/50 5.0 19.7 200 16 6 200 50/50 4.9 19.0 200 16 6 200 50/50 5.0 21.3 200 13 3 200 50/50 4.4 20.3 200 13 3 200 50/50 4.7 18.6 200 13 5 200 50/50 4.8 19.4 200 13 5 200 50/50 4.6 17.8 200 13 6 200 50/50 4.7 17.4 200 13 6 200 50/50 5.8 21.3 230 19 3 200 50/50 5.6 22.9 230 19 3 200 50/50 5.7 18.4 230 19 5 200 50/50 5.4 18.7 230 19 5 200 50/50 5.8 23.8 230 16 3 200 50/50 5.6 25.1 230 16 3 200 50/50 5.3 21.9 230 16 5 200 50/50 5.4 21.2 230 16 5 200 50/50 4.9 19.9 230 16 7 200 50/50 5.1 22.9 230 13 3 200 50/50 5.0 17.9 230 13 5 200 50/50 4.8 20.9 230 13 5 200 50/50 5.0 22.3 230 13 3 200 50/50 5.1 18.4 230 19 7 200 50/50 5.0 18.4 230 19 7 200 50/50 4.8 18.5 230 16 7 200 50/50 4.7 18.7 230 13 6 200 50/50 4.6 17.5 230 13 6 200 50/50 Corn flour : navy bean (Ph. Vulgaris L.) HPF ^2 4.6 20.3 132 6 7 700 90/10 4.6 20.5 132 6 7 700 80/20 2.8 13.3 132 6 7 700 70/30 2.6 13.5 132 6 7 700 60/40 4.5 16.3 132 6 7 700 90/10 3.5 12.5 132 6 7 700 80/20 Corn flour : sugar beet fiber 4.0 – 139 23 45 200 90/10 4.0 – 139 23 45 200 90/10 4.0 – 139 23 45 200 90/10 4.4 – 139 23 45 200 90/10 3.7 – 139 23 45 300 90/10 3.7 – 139 23 45 300 90/10 3.6 – 139 23 45 300 90/10 3.7 – 139 23 45 300 90/10 3.4 – 139 23 45 200 80/20 4.0 – 139 23 45 200 80/20 3.8 – 139 23 45 200 80/20 4.3 – 139 23 45 200 80/20 3.4 – 139 23 45 300 80/20 3.6 – 139 23 45 300 80/20 3.5 – 139 23 45 300 80/20 3.6 – 139 23 45 300 80/20 3.1 – 139 23 45 300 70/30 4.1 – 139 23 45 300 70/30 3.9 – 139 23 45 300 70/30 3.9 – 139 23 45 300 70/30 3.5 – 139 23 45 300 70/30 3.6 – 139 23 45 300 70/30 3.5 – 139 23 45 300 70/30 3.7 – 139 23 45 300 70/30 Corn flour : sweet whey solids 3.4 9.0 125 14 5 300 75/25 4.2 7.8 125 9 5 300 75/25 3.0 20.0 125 14 5 300 50/50 2.8 8.9 125 9 5 300 50/50 Corn flour : whey protein concentrate 3.9 11.0 125 6 5 300 50/50 4.3 14.0 125 14 5 300 75/25 4.6 6.0 125 10 5 300 75/25 4.2 21.0 125 17 5 300 50/50 3.9 11.0 125 6 5 300 50/50 5.2 15.0 125 – – 300 75/25 Corn flour : wheat bran 4.8 15.9 125 – – 300 95/5 4.7 12.1 125 – – 300 87,5/12,5 Corn grits ^7 : fatty acids – 24.6 150 19 35 165 99,8/0,2 – 22.9 150 19 35 165 99,6/0,4 – 17.4 150 19 35 165 99,4/0,6 – 16.6 150 19 35 165 99,2/0,8 – 23.4 150 19 35 165 99,8/0,2 – 19.7 150 19 35 165 99,6/0,4 – 18.2 150 19 35 165 99,4/0,6 – 22.9 150 19 35 165 99,2/0,8 – 41.8 150 19 35 165 99,8/0,2 – 30.0 150 19 35 165 99,6/0,4 – 19.7 150 19 35 165 99,4/0,6 – 21.3 150 19 35 165 99,2/0,8 Corn degermed yellow : calcium hydroxide 6.6 12.4 130 16 4 130 99,85/0,15 6.8 12.8 130 18 4 130 99,85/0,15 6.6 11.7 130 20 4 130 99,85/0,15 6.3 12.8 150 16 4 130 99,85/0,15 6.0 12.8 150 18 4 130 99,85/0,15 6.4 11.8 150 20 4 130 99,85/0,15 5.5 8.4 130 16 4 130 99,75/0,25 7.4 21.3 130 18 4 130 99,75/0,25 6.5 13.2 130 20 4 130 99,75/0,25 6.5 5.6 150 16 4 130 99,75/0,25 6.2 8.8 150 18 4 130 99,75/0,25 5.9 14.8 150 20 4 130 99,75/0,25 6.4 15.6 130 16 4 130 99,65/0,35 6.7 16.4 130 18 4 130 99,65/0,35 6.9 18.8 130 20 4 130 99,65/0,35 6.9 5.6 150 16 4 130 99,65/0,35 5.6 7.2 150 18 4 130 99,65/0,35 6.9 5.6 150 20 4 130 99,65/0,35 Corn degermed : whey protein isolate – 12.2 130 23 5 300 75/25 – 11.7 130 23 5 300 75/25 – 12.8 130 23 5 300 75/25 – 12.9 130 23 5 300 75/25 – 13.5 130 23 5 300 75/25 Oat flour : corn bran 3.6 4.3 100 25 – 140 90/10 3.7 4.1 100 25 – 140 80/20 3.8 5.0 100 25 – 140 70/30 3.9 5.7 100 25 – 140 60/40 4.1 5.6 100 25 – 140 50/50 Sorghum red : cowpeas (V. Unguiculata) ^3 cv. 7.3 20.7 130 20 26 200 70/30 6.7 20.7 165 20 26 200 70/30 7.8 20.9 130 20 26 200 50/50 7.4 21.2 165 20 26 200 50/50 8.1 21.9 130 20 26 200 30/70 7.5 22.8 165 20 26 200 30/70 Rice flour : Euryale ferox Salisb. 2.2 69.9 110 15 12 200 95/5 2.3 75.3 110 15 12 250 95/5 12.5 18.4 110 20 12 200 95/5 10.5 27.2 110 20 12 250 95/5 2.5 68.2 110 15 12 200 90/10 2.3 68.3 110 15 12 250 90/10 13.4 18.3 110 20 12 200 90/10 9.0 25.4 110 20 12 250 90/10 2.4 68.1 110 15 12 200 85/15 2.3 74.8 110 15 12 250 85/15 14.4 19.3 110 20 12 200 85/15 8.6 27.6 110 20 12 250 85/15 Rice flour : sweet whey solids 3.5 6.0 125 9 3 300 75/25 3.1 8.2 125 11 3 300 75/25 3.8 18.0 125 12 3 300 50/50 3.0 11.8 125 9 3 300 50/50 Rice flour : DDG ^1 4.4 – 160 15 – 100 90/10 4.4 – 160 22 – 100 90/10 4.6 – 210 15 – 100 90/10 5.0 – 210 22 – 100 90/10 4.6 – 250 15 – 100 90/10 5.1 – 250 22 – 100 90/10 4.5 – 160 15 – 100 80/20 4.3 – 160 22 – 100 80/20 3.9 – 210 15 – 100 80/20 4.5 – 210 22 – 100 80/20 4.2 – 250 15 – 100 80/20 5.0 – 250 22 – 100 80/20 3.3 – 160 15 – 100 60/40 4.4 – 160 22 – 100 60/40 3.7 – 210 15 – 100 60/40 5.1 – 210 22 – 100 60/40 3.9 – 250 15 – 100 60/40 4.5 – 250 22 – 100 60/40 Rice flour : legumes (Fabaceae) ^8 6.7 12.9 60 – 9 – 75/25 7.2 19.6 95 – 9 – 75/25 6.3 12.5 60 – 15 – 75/25 5.7 17.0 95 – 15 – 75/25 7.0 9.9 60 – 17 – 75/25 7.8 13.8 95 – 17 – 75/25 5.9 13.0 60 – 9 – 75/25 6.6 20.5 95 – 9 – 75/25 6.3 12.2 60 – 15 – 75/25 6.2 17.8 95 – 15 – 75/25 5.4 9.5 60 – 17 – 75/25 6.0 13.2 95 – 17 – 75/25 5.8 11.4 60 – 15 – 75/25 6.6 16.1 95 – 15 – 75/25 6.2 9.0 60 – 17 – 75/25 6.5 13.0 95 – 17 – 75/25 Rice flour : soybean (full fat) 5.8 8.7 60 – 9 – 75/25 6.5 11.5 95 – 9 – 75/25 5.3 8.5 60 – 15 – 75/25 6.0 10.4 95 – 15 – 75/25 5.5 8.3 60 – 17 – 75/25 6.1 9.3 95 – 17 – 75/25 Rice flour : soybean (deffated) 5.4 7.1 80 24 3 120 83/17 7.9 8.0 120 24 3 120 83/17 5.1 9.1 80 24 3 120 60/40 5.3 13.1 120 24 3 120 60/40 5.7 8.2 100 24 3 120 70/30 5.8 6.7 100 24 3 120 70/30 5.8 9.5 100 24 3 120 70/30 5.6 8.0 100 24 3 120 70/30 5.8 8.2 100 24 3 120 70/30 6.5 10.5 128 24 3 120 70/30 4.9 8.6 72 24 3 120 70/30 Rice flour : banana powder 5.7 23.4 120 – 16 220 60/40 5.6 24.1 120 – 16 260 60/40 5.5 24.3 120 – 16 220 60/40 5.3 25.8 120 – 16 260 60/40 5.2 25.4 120 – 16 220 60/40 5.1 26.2 120 – 16 260 60/40 Rice flour : whey protein concentrate 3.8 14.0 125 19 3 300 75/25 2.8 4.7 125 19 3 300 75/25 3.9 12.5 125 25 3 300 50/50 4.0 16.0 125 24 3 300 50/50 Wheat flour : BSG ^4 5.9 11.3 120 12 25 200 90/10 5.9 10.2 120 13 25 200 90/10 6.4 6.8 120 14 25 200 90/10 6.0 6.6 120 15 25 200 90/10 6.5 5.7 120 16 25 200 90/10 6.8 5.0 120 17 25 200 90/10 5.7 9.7 120 14 – 150 90/10 5.6 12.1 120 14 – 250 90/10 5.4 15.7 120 14 – 350 90/10 6.3 6.3 120 14 – 150 80/20 6.0 9.0 120 14 – 250 80/20 6.0 10.4 120 14 – 350 80/20 4.9 6.1 120 14 – 150 70/30 4.7 7.5 120 14 – 250 70/30 6.5 7.2 120 14 – 350 70/30 Wheat flour : DDG ^1 2.2 – 160 15 – 100 90/10 2.2 – 160 22 – 100 90/10 2.8 – 210 15 – 100 90/10 3.1 – 210 22 – 100 90/10 3.4 – 250 15 – 100 90/10 3.6 – 250 22 – 100 90/10 2.2 – 160 15 – 100 80/20 2.1 – 160 22 – 100 80/20 2.8 – 210 15 – 100 80/20 2.8 – 210 22 – 100 80/20 3.0 – 250 15 – 100 80/20 3.4 – 250 22 – 100 80/20 2.4 – 160 15 – 100 60/40 2.2 – 160 22 – 100 60/40 2.4 – 210 15 – 100 60/40 3.2 – 210 22 – 100 60/40 2.6 – 250 15 – 100 60/40 3.2 – 250 22 – 100 60/40 Wheat flour : corn starch 5.3 10.0 120 14 – 200 70/30 5.0 13.4 120 14 – 300 70/30 5.5 11.1 120 14 – 150 50/50 5.4 16.4 120 14 – 250 50/50 5.7 25.8 120 14 – 350 50/50 6.2 20.3 120 14 – 200 30/70 Legumes beans HSF ^5 , (Ph. vulgaris L.) cv. : Corn flour 4.9 24.5 87 11 10 840 75/25 5.1 27.3 87 11 10 840 50/50 5.2 23.6 87 11 10 840 25/75 Chickpeas, (C. Arietinum) : rice flour 4.1 20.5 160 – 25 300 90/10 4.1 27.2 160 – 25 300 80/20 4.1 27.5 160 – 25 300 70/30 4.3 18.0 160 – 25 300 60/40 4.3 14.6 160 – 25 300 50/50 Soy bean : yam D. rotundata condyle 2.1 18.9 150 21 – 200 75/25 2.0 19.1 150 21 – 200 50/50 2.0 20.9 150 21 – 200 25/75 Model foods Corn starch : BSG ^4 6.3 20.5 120 12 25 200 90/10 6.6 18.0 120 13 25 200 90/10 6.8 18.3 120 14 25 200 90/10 6.8 15.9 120 15 25 200 90/10 7.1 15.8 120 16 25 200 90/10 7.3 13.8 120 17 25 200 90/10 6.1 16.7 120 14 – 150 80/20 5.4 22.6 120 14 – 250 80/20 5.4 15.6 120 14 – 150 70/30 5.3 21.4 120 14 – 250 70/30 5.1 25.3 120 14 – 350 70/30 Corn starch : cabbage red 4.3 58.3 120 12 25 200 90/10 5.0 47.8 120 13 25 200 90/10 4.9 61.7 120 14 25 200 90/10 4.3 32.5 120 15 25 200 90/10 5.0 43.0 120 16 25 200 90/10 5.4 14.5 120 17 25 200 90/10 Corn starch ^6 : whey protein concentrate 3.5 6.8 70 30 4 43 75/25 4.8 24.4 70 18 4 43 75/25 3.3 14.0 70 30 4 43 75/25 5.2 12.5 70 18 4 43 75/25 4.7 12.6 125 23 4 43 75/25 4.4 16.8 180 18 4 43 75/25 5.6 8.6 180 30 4 43 75/25 4.2 25.0 125 30 4 43 85/15 4.8 13.1 180 18 4 43 85/15 3.7 11.3 70 23 4 43 85/15 3.8 7.8 70 30 4 43 95/5 3.7 22.8 70 18 4 43 95/5 4.9 13.7 70 18 4 43 95/5 4.9 9.4 125 18 4 43 95/5 7.1 7.6 180 30 4 43 95/5 5.3 12.1 180 23 4 43 95/5 4.2 16.8 140 22 – 140 90/10 4.2 18.1 140 22 – 140 80/20 3.5 16.6 140 22 – 140 70/30 3.1 9.5 140 22 – 140 90/10 3.2 10.5 140 22 – 140 80/20 3.1 12.0 140 22 – 140 70/30 2.0 67.6 140 22 – 140 90/10 2.9 56.7 140 22 – 140 80/20 4.8 40.0 140 22 – 140 70/30 8.6 18.8 140 22 – 140 90/10 8.1 15.5 140 22 – 140 80/20 6.5 17.1 140 22 – 140 70/30 2.6 19.2 140 3 – 200 80/20 2.1 15.8 135 2 – 200 60/40 1.9 13.4 140 3 – 200 50/50 2.6 35.6 130 2 – 200 80/20 2.2 29.5 135 2 – 200 60/40 1.8 26.5 135 2 – 200 50/50 0.3 35.6 135 2 – 200 80/20 0.5 29.5 135 2 – 200 60/40 0.6 26.5 135 2 – 200 50/50 0.3 36.2 135 3 – 200 80/20 0.5 30.7 135 3 – 200 60/40 0.6 26.5 140 2 – 200 50/50 Corn starch : soy protein concentrate – 44.3 120 22 75 230 95/5 – 46.4 120 22 75 330 – – 46.8 120 22 75 230 90/10 – 48.5 120 22 75 330 – – 47.2 120 22 75 230 85/15 – 54.0 120 22 75 330 – – 48.9 120 22 75 230 80/20 – 58.7 120 22 75 330 – Potato starch : glycerol 2.3 70.9 150 32 14 110 88/12 1.6 76.0 150 21 14 110 88/12 1.2 75.6 150 9 14 110 88/12 4.6 2.0 150 29 14 110 84/16 4.9 26.4 150 24 14 110 84/16 2.8 48.2 150 17 14 110 84/16 1.8 70.5 150 11 14 110 84/16 1.9 72.4 150 5 14 110 84/16 1.1 79.0 150 – 14 110 84/16 3.6 9.3 150 27 14 110 82/18 5.8 6.1 150 21 14 110 82/18 3.6 38.5 150 15 14 110 82/18 3.5 43.8 150 9 14 110 82/18 2.5 56.6 150 – 14 110 82/18 2.9 15.3 150 22 14 110 80/20 4.2 8.4 150 19 14 110 80/20 3.9 19.8 150 16 14 110 80/20 6.6 14.1 150 13 14 110 80/20 5.6 17.5 150 9 14 110 80/20 7.7 11.9 150 6 14 110 80/20 6.4 19.2 150 3 14 110 80/20 2.1 61.5 150 – 14 110 80/20 Rice starch : soy protein isolate 5.3 – 170 23 4 42 75/25 4.4 – 150 23 4 42 75/25 4.0 – 150 28 4 42 75/25 3.6 – 170 28 4 42 75/25 4.3 – 170 28 4 42 75/25 4.7 – 150 23 4 42 75/25 4.2 – 150 28 4 42 75/25 4.6 – 170 23 4 42 75/25 3.7 – 160 25 4 42 50/50 3.5 – 160 25 4 42 50/50 3.2 – 160 25 4 42 50/50 3.2 – 160 25 4 42 50/50 3.3 – 180 25 4 42 50/50 6.0 – 160 25 4 42 50/50 3.2 – 140 25 4 42 50/50 2.2 – 160 25 4 42 50/50 3.0 – 160 25 4 42 50/50 3.3 – 160 30 4 42 50/50 3.4 – 160 25 4 42 50/50 3.4 – 160 20 4 42 50/50 2.3 – 150 28 4 42 25/75 2.3 – 170 23 4 42 25/75 4.0 – 150 23 4 42 25/75 4.4 – 170 28 4 42 25/75 2.4 – 150 23 4 42 25/75 4.4 – 150 28 4 42 25/75 4.1 – 170 23 4 42 25/75 2.3 – 170 28 4 42 25/75 Wheat starch : wheat germ oil 7.2 26.9 125 22 40 300 96/4 7.6 17.8 125 25 40 300 96/4 7.9 12.1 125 28 40 300 96/4 7.9 24.6 150 22 40 300 96/4 8.0 12.4 150 25 40 300 96/4 8.2 11.7 150 28 40 300 96/4 7.8 22.9 175 22 40 300 96/4 8.1 12.4 175 25 40 300 96/4 8.4 11.9 175 28 40 300 96/4 7.1 30.0 125 22 40 300 92/8 7.3 24.8 125 25 40 300 92/8 7.4 15.6 125 28 40 300 92/8 7.3 26.2 150 22 40 300 92/8 7.5 19.9 150 25 40 300 92/8 7.7 15.3 150 28 40 300 92/8 7.5 27.1 175 22 40 300 92/8 7.8 12.8 175 25 40 300 92/8 7.3 9.2 175 28 40 300 92/8 Vegetables Cassava roots : pigeon pea (C. cajan) 4.5 34.6 122 12 18 – 95/5 4.8 32.6 122 12 18 – 90/10 6.0 30.6 122 12 18 – 85/15 Potato : sweet whey solids 3.4 9.0 125 15 7 300 75/25 4.2 7.8 125 9 7 300 75/25 3.0 20.0 125 19 7 300 50/50 2.8 8.9 125 9 7 300 50/50 Potato : DDG ^1 5.3 – 160 15 – 100 90/10 6.0 – 160 22 – 100 90/10 5.6 – 210 15 – 100 90/10 6.0 – 210 22 – 100 90/10 5.8 – 250 15 – 100 90/10 6.0 – 250 22 – 100 90/10 5.2 – 160 15 – 100 80/20 5.7 – 160 22 – 100 80/20 5.6 – 210 15 – 100 80/20 5.9 – 210 22 – 100 80/20 5.6 – 250 15 – 100 80/20 5.9 – 250 22 – 100 80/20 4.5 – 160 15 – 100 60/40 5.5 – 160 22 – 100 60/40 4.7 – 210 15 – 100 60/40 4.8 – 210 22 – 100 60/40 4.7 – 250 15 – 100 60/40 4.8 – 250 22 – 100 60/40 Potato : whey protein concentrate 2.5 13.0 125 15 7 300 75/25 2.7 19.0 125 14 7 300 75/25 2.5 15.0 125 19 7 300 50/50 3.9 11.0 125 18 7 300 50/50 1 Dried Distillers Grains from corn & wheat; 2 High Protein Fraction; 3 Variety Seinita; 4 Brewer's spent grain; 5 High Starch Fraction; 6 Various levers of Amylose; 7 Various particle size; 8 Bengal, black, green gram; – Not reported. Table 4 The presentation format of data, the type of extruder and the effect of die temperature (DT), feed moisture content (FMC), and screw speed (SS) on WAI, WSI values WAI WSI Reference Presentation format of data Type of extruder DT FMC SS DT FMC SS Aguilera, J.M. et al. 1984[20] T ^1 SS ^3 – – – – – – Ahmed, Z.S. et al. 1999[14] T SS – – – – – – Allen, K.E. et al. 2007[1] G ^2 TS ^4 – – – – – – Amaya-Llano, S.L. et al. 2007[2] T SS E ^5 NE ^6 E NE Avin, D. et al. 1992[22] G SS E NE NE NE Badrie, N. et al. 1991[23] G SS E E E E E E Baik, B.-K. et al. 2004[24] T SS E NE – – – Balandran-Quintana, R.R. et al. 1998[19] G SS E E NE E NE NE Chauhan, G.S. et al. 1998[26] T SS NE E Chauhan, G.S. et al. 1985[27] T SS – – – – – – Choi, I., et al. 2008[28] T TS E Choudhury, G.S. et al. 1998[29] G TS – – – – – – Curic. D. et al. 2008[30] T TS E E E E E E Czarnecka, M. et al. 1998[31] G SS – – – – – – Czarnecki, Z. et al. 1993[32] T SS NE E De Mosqueda, M.B. et al.1986[33] T TS – – – – – – Desrumaux, A. et al. 1999[34] G TS – – – – – – Ding, Q.-B. et al.2006[35] G TS E E Elzbieta Gujska, E. et al. 1990[36] T SS E NE Gamlath Shirani, G. et al. 2009[37] G TS – Gamlath, S. 2008[38] T TS NE NE Gogoi, B.K. et al. 1996[39] T TS – – – – – – Gomez, M.H. et al. 1984[40] T SS – – – – – – Gomez, M.H. et al. 1983[41] T SS – – – – – – González-Soto, R.A. et al. 2007[42] T SS E NE E NE Guha, M. et al. 2003[43] T TS E E Gujral, H.S. et al. 2002[44] G SS – – – – – – Gujska, E. et al. 1991[45] T SS E E Gujska, E. et al. 1991[91] T SS – – – – – – Gutkoski, L.C. et al. 1999[46] T SS E E NE E Holguín-Acuña, A.L. et al. 2008[47] T SS – – – – – – Iwe, M.O. 1998[48] T NR – – – – – – Jaya Shankar, T. et al. 2005[49] T SS NE E NE Kim, C.H. et al. 1989[8] G SS E E Kirby, A.R. et al. 1998[50] G TS E E E E Kyung-Min, L. et al. 2006[51] G TS NE NE Lazou, A. et al. 2009[52] T TS E E E E Liceti, A.E. et al. 1995[53] T SS E E Lin, Y.-H. et al. 2003[54] T TS E E E E Lue, S. et al. 1994[55] T TS E E Mali, S. et al. 2001[56] T SS E E E E Mali, S. et al. 2001[57] T SS E E Martinez-Bustos, F. et al. 1996[15] T SS – – – – – – Martinez-Bustos, F. 1996[58] T SS – – – – – – Martínez-Bustos, F. et al. 1998[4] T SS E E E E Martίn-Cabrejas, M.A. et al. 1999[59] G SS – – – – – – Matthey F.P. et al. 1997[9] T TS – – – – – – Mesa, N.J.E. et al. 2009[5] T TS E E Mezreb, K. et al. 2003[12] G TS NE E Mezreb, K. et al. 2006[60] T TS – – – – – – Miladinov, V.D. et al. 2000[61] T SS – – – – – – Miladinov, V.D. et al. 2001[62] T SS E NE Milán-Carrillo, J. et al. 2000[16] T SS – – – – – – Milán-Carrillo, J. et al. 2002[63] T SS E E NE E E E Nabeshima, E.H. et al. 2001[64] T SS – – – – – – Ng, A. et al. 1999[92] T TS – – – – – – Onwulata, C.I. et al. 2006[66] T TS NE Onwulata, C.I. et al. 2001[67] T TS – – – – – – Onwulata, C.I. et al. 1998[68] T TS E E Onyango, C. et al. 2004[69] T SS NE NE NE NE Pelembe, L.A.M. et al. 2002[10] G TS – – – – – – Ramírez Ortiz, M.E. et al. 2008[70] T SS E E E E Rampersad, R. et al. 2003[17] T SS – – – – – – Reyes-Moreno, C. et al. 2003[72] T SS NE Rocha-Guzman, N.E. et al. 2008[73] G NR E E Rocha-Guzmán, N.E. et al. 2006[74] T SS NE Salay, E. et al. 1990[75] T NR NE NE Schmid, A.H. et al. 2005[76] T TS – – – – – – Sebio, L. et al. 2000[77] T SS E E E Seker, M. et al. 2005[11] T SS E NE Seker, M. et al. 2006[78] T SS – – – – – – Seker, M. et al. 2003[79] T SS – – – – – – Seker, M. et al. 2004[80] T SS NE NE Sharma, H.R. et al. 2004[81] T SS – – – – – – Shukla, C.Y. et al. 2005[82] G SS E E E E Singh, N. et al. 1998[83] T TS NE NE NE NE Sopade, P.A. et al. 1991[6] T TS – – – – – – Sriburi, P. et al. 2000[77] T TS – – – – – – Sriburi, P. et al. 1999[84] G TS – – – – – – Steel, C.J. et al. 1995[18] T SS – – – – – – Stojceska, V. et al. 2009[85] G TS E E Stojceska, V. et al. 2008[86] T SS NE NE Su, C.-W. 2007[87] T TS – – – – – – Su, C.-W. et al. 2007[88] T TS – – – – – – Vainionpää, J. 1991[89] T TS NE NE Van Der Burgt, M.C. 1996[90] T TS – – – – – – Yang, S.-H. et al. 2008[93] T SS – – – – – – 1 Table; 2 Graph; 3 Single screw; 4 Twin screw; 5 Effect; 6 Not Effect; – Not report.

RESULTS

Eighty-seven articles were retrieved from science journals during recent years that report experimental values for WAI and WSI from extruded products. The numbers of data which were collect from the above articles was about 1210 for WAI and 992 for WSI. The data mainly respect starchy or proteinaceous extruded food products and the values of WAI and WSI estimate according to Anderson et al.[13] The distribution of WAI and WSI values for all extruded products are presented in Figures 1 and 2, respectively. The WAI values are plotted versus die temperature, feed moisture content, feed rate and screw speed in Figures 3, 4, 5, and 6, respectively. Similar, the WSI values are plotted versus die temperature, feed moisture content, feed rate and screw speed in Figures 7, 8, 9, and 10, respectively. All the collected values of WAI, WSI and the related extrusion variables of grouping extruded materials are presented in Table 2. Similarly, Table 3 presents the values of WAI, WSI, and the related extrusion variables of grouping extruded blend materials. The effect of the three independent extrusion variables die temperature, feed moisture content ad screw speed, on the values of indices presents in Table 4. Obviously, there exist different opinions between workers about the effect of process variables on WAI and WSI. These means that is not fully understood the predominant mechanism of extrusion process yet.

Figure 1 The distribution of WAI values.

Figure 2 The distribution of WSI values.

Figure 3 WAI values for all products at various temperatures.

Figure 4 WAI values for all products at various feed moisture contents.

Figure 5 WAI values for all products at various feed rates.

Figure 6 WAI values for all products at various screw speeds.

Figure 7 WSI values for all products at various temperatures.

Figure 8 WSI values for all products at various feed moisture contents.

Figure 9 WSI values for all products at various feed rates.

Figure 10 WSI values for all products at various screw speeds.

A number of difficulties arise when trying to summarize published of WAI and WSI values. Firstly, different cultivars or hydrides of the same plants are used as raw materials. Secondly, processing conditions are not always well-defined and the variability of them has wide limits. Thirdly, the processing conditions are interrelated, making it difficult to relate the values of indices to any one single independent variable. Moreover, most raw materials in food processing are mostly of biological origin and their physical and compositional variations can be considerable.

CONCLUSION

Literature data of WAI and WSI values of food materials or blends were organized into a data base and presented. It is important to consider similar features in order to provide reproducible data and when comparing these values. Furthermore, the data can be used in research to validate structural models and to develop generic models to predict WAI and WSI values of food materials.