Journal of Agricultural Science Vol. 2, No. 2, June 2010
requirements are properties such as viscosity, resistant to shear, low pH and high temperature. Accordingly, varieties of modified starches are used in food industry. Table 1 lists some of the modified starches that can be prepared from different sources to meet the marketing-related requirements. Today, modified food starch is a food additive and limits of its modification, use and labeling are clearly defined in the US Code of Federal Regulation (Sajilata & Singhal, 2004). The European Directive on food additives allows the following food starches in food products (Wikipedia, 2009). E1401 E1402 E1403 E1404 E1405 E1410 E1411 E1412 E1413 E1414 E1420 E1421 E1422 E1423 E1440 E1442 E1443 E1450 Acid-treated starch Alkaline-treated starch Bleached starch Oxidized starch Starches, enzyme-treated Monostarch phosphate Distarch glycerol Distarch phosphate esterified with sodium trimetaphosphate Phosphated distarch phosphate Acetylated distarch phosphate Starch acetate esterified with acetic anhydride Starch acetate esterified with vinyl acetate Acetylated distarch adipate Acetylated distarch glycerol Hydroxypropyl starch Hydroxypropyl distarch phosphate Hydroxypropyl distarch glycerol Starch sodium octenyl succinate
Modified starches consist of starch with low to very low level of substituent group. Enzymatic modification of starch is hydrolysis of some part of starch into a low molecular weight of starch called maltodextrin, or dextrin using amylolytic enzymes (Miyazaki et al., 2006). They are widely used for food and pharmaceutical industries. Physical modification involves pre-gelatinization, and heat-treatment of starch, etc (Miyazaki et al., 2006). Pre-gelatinized starches are pre-cooked starches that can be used as thickener in cold water (Wikipedia 2009). While the heat-treatment processes include heat–moisture and annealing treatments, both of which cause a physical modification of starch without any gelatinization, damage to granular integrity, or loss of birefringence. Chemical modification is the mainstream of the modified starch in the last century. Many developments of chemical modification of starches have been introduced in food, pharmaceutical and textile industries. Table 2 shows the classification of modified starches available currently. In order to investigate the uses of modified starches in selected food products, the findings has been divided in sub-groups according to their functional applications. Examples of the applications in selected food products will also be included as follows: 1.1 As Fat Replacer/Fat Mimetic As a food component, fat contributes to the flavor, appearance, texture, and shelf life of food products (Mun et al., 2009). Consumers nowadays are really concerns about the adverse health effect of overconsumption of certain types of lipids, this has resulted in some development of reduced-fat food to solve the issue. It is difficult to imitate traditional product quality when preparing reduced-fat foods. A combination of nonfat ingredients with different functional roles can be used to replace the quality attributes lost when fat is removed (Mun et al., 2009). Starch also can be modified by hydrolysis to form a fat replacer. Some well-known fat replacer from starch base is maltodextrin beside some other starch hydrolysis products. It is widely used for low-fat butter spread/margarine, low fat mayonnaise, low fat milk type products and low -fat ice cream (Sajilata & Singhal, 2004). www.ccsenet.org/jas 91
Journal of Agricultural Science Vol. 2, No. 2, June 2010 1.1.1 Low-fat yogurt
ISSN: 1916-9752 E-ISSN: 1916-9760
Some recent studies have been done in replacing fat with modified starch. Castilla et al., (2003), prepared three commercial fat replacers consisting of whey protein concentrate (WPC), microparticulated whey protein (MWP) and modified tapioca starch (MTS), along with the preparation of...