Process conditions affect starch structure and its interactions with proteins in rice pasta
Alberto Barbiroli1, Francesco Bonomi, Maria Cristina Casiraghi
1Department of Food, Environmental, and Nutrition Sciences, University of Milan, Italy.
Carbohydrate Polymers
|February 13, 2013
Summary
Investigating rice pasta, this study reveals how raw materials and processing alter starch and protein structures, impacting cooking properties and glycaemic index. Parboiling rice flour enhances starch accessibility and modifies protein interactions for better pasta characteristics.
Area of Science:
- Food Science
- Materials Science
Background:
- Rice pasta production involves complex interactions between raw materials and processing conditions.
- Understanding structural changes in starch and proteins is crucial for optimizing rice pasta quality.
Purpose of the Study:
- To investigate the structural modifications of starch and proteins in rice pasta.
- To assess the impact of these changes on cooking behavior and glycaemic index.
- To determine the influence of raw materials (untreated vs. parboiled rice) and processing methods (extrusion vs. extrusion-cooking).
Main Methods:
- Enzymatic accessibility assays (alpha-amylase, pullulanase) to probe starch structure.
- Analysis of molecular properties of enzymatically released fragments.
- Protein solubility and cysteine thiol accessibility measurements to evaluate protein interactions.
- Preparation of rice pasta using different raw materials and extrusion techniques.
Main Results:
- Parboiling rice flour stiffened the protein network and increased starch accessibility for hydrolysis.
- Pasta-making induced significant starch structure modifications, particularly in the amylopectin fraction of untreated rice pasta.
- Interactions between starch and protein structural changes influenced the final product characteristics.
Conclusions:
- The interplay between starch and protein structural modifications is key to determining rice pasta's cooking behavior and glycaemic index.
- Parboiling and extrusion-cooking are critical factors influencing these structural changes.
- Tailoring raw materials and processing conditions can optimize rice pasta quality.
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