Starch functional properties

Jackson, D. S. (2003a). Starch—Functional properties. In "Encyclopedia of Food Science, Food Technology and Nutrition—Revised Second Edition" (R. E. Wrolstad, ed.), pp. 5561-5567. John Wiley Sons, Inc., New York. 

Substances commonly found in starch granules are amylopectin, amylose, molecules intermediate between amylose and amylopectin, lipid (including phospholipids and free fatty acids), phosphate monoester and proteins/enzymes. The contents and the structures of amylopectin and amylose play major roles in the functional properties of starch. However, lipids, phospholipids and phosphate monoester groups have significant effects on starch functional properties, even though they are minor constituents. 

When starch is added to products as an ingredient, however, it is the functional properties of the starch that are usually important, not the calories. 

Due to the lack of a commercial supply, as well as their usually low molecular weight and poor solubility, xylans have found little industrial utility and interest in their modification has been rather low in comparison to commercially available polysaccharides such as cellulose or starch. With the aim of improving the functional properties of xylans and/or imparting new functionalities to them, various chemical modifications have been investigated during the past decade. Most of them were presented in recent reviews [3,399]. 

Matthey, F. P. and Hanna, M. A. (1997). Physical and functional properties of twin-screw extruded whey protein concentrate-corn starch blends. LWT Food Sci. Technol. 30,359-366. 

Pea starch granules are oval, sometimes fissured, with a diameter of 20-40 ym (13). Molecular and structural characteristics of the two main components of field pea starch—amylose and amylopectin—are important in determining functional properties (25,26). Smooth field pea starch concentrate contains 97.2% starch of which 30.3-37.8% is amylose (9,23,25-27), and wrinkled pea starch concentrate contains 94.8% starch, which is 64% amylose (26). The gelatinization temperature of smooth pea starch is between 64 to 69 C, and that of wrinkled pea starch is greater than 99 C to 115 C. Gelatinization temperature depends on maturity of field pea seed and amylose content (26,27). 

The efficiencies of protein (75-80%) and starch (88-93%) recoveries by the dry process were higher than the 73-79% recoveries by wet processing, and there were no losses of solids in the whey and wash water or need for effluent recovery. The starch fraction was similar to refined starch in most functional properties except for a low amylograph viscosity. 

The protein concentration in the field pea proteinate was only 87.7% due to the presence of significant quantities of ash, lipid and carbohydrate (Table I). Both refined starches were relatively pure, the protein levels being only 0.5%. The merits of producing protein and starch isolates as opposed to concentrates by the dry process would depend on their relative functional properties and the requirements of the end-user. 

Functional Properties. The pH s of the flours and products obtained by air classification varied between 6.5-6.7 (Table III), which was typical of legume flours (1.3). The proteinates were near oH 7 because of the neutralization orocedure after isoelectric orecioita-tion while the refined starch and fiber were still alkaline in pH despite several washings with distilled water. In a previous study, adjustment of the pH of lupine flour was shown to have a significant influence on functional properties (1) but pH was not adjusted in the present investigation. 

Pin milling alone improved one functional property, oil emulsification (Table III). The pin-milled flours, protein fractions and proteinates gave oil emulsification values of 70.0-79.0% compared to values of less than 18.0% for starch products. 

Kaur, L. (2004). Physico-chemical properties of potatoes in relation to thermal and functional properties of their starches. PhD dissertation, Guru Nanak Dev University, Amritsar. 

Physically modified potato starch is preferred in processed foods because of its improved functional properties over those of its native counterpart. Moreover, this modified strach can be safely used in different food products and other industrial applications. Different physical... 

Adebowale, K. O., Lawal, O. S. (2003). Functional properties and retrogradation behaviour of native and chemically modified starch of mucuna bean (Mucuna pruriens). J. Sci. Food Agric., 83, 1541-1546. 

Zheng, G. H., Han, H. L., Bhatty, R. S. (1999). Functional properties of cross-linked and hydroxypropylation waxy hull-less barley starches. Cereal Chem., 76,182-188. 

This relative molecular size difference between starch and the hydrolysis sugars gives maltodextrins and corn syrup solids their valuable functional properties for the flavor industry. 

This deficiency has been overcome by the development of "lipophilic" starches (18,19) starch hydrolyzates incorporating a covalently bound lipophilic species, 1-octenyl succinate. In this manner, a lipophilic polymer is produced which allows for excellent aqueous flavor emulsion stability, good water solubility (40% w/w), excellent retentions of the volatile flavoring material following drying and minimal "extractable" oil in the finished product (9), functional properties only exhibited by gum arabic prior to their development. 

Mutants of maize starch varieties have been extensively studied.12 85-100 Amylose, amylopectin, and intermediate material contents of various single and double mutants have been analyzed the results are shown in Table 6.2. Relationships between structures of the starch polymers and functional properties of these mutant starches have also been reported.12,85-100... 

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