2005 Fiscal Year Final Research Report Summary
Modification of Food Starch by Control of Protein Structuring on Starch-Granule Surface
| Project/Area Number |
15580114
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Food science
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| Research Institution | Meiji University |
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Principal Investigator |
NAKAMURA Takashi Meiji University, School of Agriculture, Department of Agricultural Chemistry, Associate Professor, 農学部, 助教授 (30328968)
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| Project Period (FY) |
2003 – 2005
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| Keywords | starch / soybean protein / puroindoline / transglutaminase / microscopy / powder processing |
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| Research Abstract |
Starches from cereals, tubers and roots are widely used in the food industry as stabilizers or texture modifiers. To elucidate the relationship between starch types and starch pasting properties, we need to analyze in the starch-granules, which contain a little protein and lipid. The emphasis of this study is on the microstructure of starch-surface and its modification.
The surface-microstructure of starch-granules from different sources and the binding-ability of wheat-puroindoline to starch-granules were examined. The morphology of the starch granule, as shown by atomic force microscopy, exhibited a rougher surface structure, about 10nm scale in height. Puroindoline bound specifically to starch surface with a binding constant of about 10^8M^<-1>. The starch containing 100ppm puroindline obtained emulsifying ability. These results indicated that the starch granule surface proteins influence the rheological behavior in starchy food.
Moreover, a novel modifying process of food starch was
… More
developed. The modifying process had an enzymatic reaction. This process had three distinguishing characteristics, reacting on starch granule surface, with food ingredients and under the dry powdery state containing some water. All materials were used for food ingredients (base-starch : tapioca, substrate : soy-protein-isolate, and enzyme : transglutaminase). The enzyme reaction was progress under the dry powdery state, and then the soy-protein was insoluble on starch granule surface. This modification changed the gelatinization properties of starch. This modified starch had lower granular swelling, lower pasting viscosity, and higher pasting temperature. The modified starch was treated with proteases, and then the gelatinization properties revert to native them. When the base-starch changed from tapioca to waxy corn, the similar effects were obtained. These results show that this novel process method is the physical modification for an inhibited starch. This modifying process for food starch has no chemical usage and no environmental burden of wastewater, and therefore will be put to practical industry use. Less
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