Studies on properties and utilization of granular size-classified starches of the sweetpotato low temperature gelatinizing starch

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K05892
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38050:Food sciences-related
• Research Institution: Kagoshima University
• Principal Investigator: Kitahara Kanefumi 鹿児島大学, 農水産獣医学域農学系, 教授 (30240922)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: サツマイモ澱粉 / 低温糊化澱粉 / 分級澱粉 / 分子構造 / 物理化学特性 / 澱粉利用 / 不均一性

Outline of Final Research Achievements

Starch fractions classified by granular size were prepared from the sweetpotato starch with low gelatinization temperature (LGT-SPST), and their physicochemical and utilization properties were studied. It was found that the starch of the small-granule fraction had lower maximum viscosity and gelatinization enthalpy, higher amylose content, and fewer extra-long chains and more short chains of amylopectin. The starch gel of medium-granule fraction exhibited a lower initial elastic modulus and a higher pre-break elastic modulus than those of the original starch, indicating that the chewiness and crispness of the gel were improved after classification. In addition, boiled udon-like noodles made with LGT-SPST had a unique chewy texture compared to noodles made with ordinary sweetpotato starch. In particular, the noodles made with the medium-granule starch were even more chewy than before classification and had more distinctive texture, suggesting that they would be high value-added noodles.

Free Research Field

農学

Academic Significance and Societal Importance of the Research Achievements

本研究では、サツマイモ低温糊化澱粉の粒径の不均一性に着目し、粒子サイズにより分級した澱粉の構造特性と利用特性を明らかにした。その結果、粒径と分子構造との間に関連性を明らかにする一方、約300倍の体積比となる粒子間に澱粉固有の構造特性が保持されていることも見出し、澱粉粒の成長過程に関する澱粉科学の基礎知見を得ることができた。また、食品産業利用においては、大粒子と小粒子が除かれた主画分の中粒子澱粉とすると、分級前より低温糊化澱粉の特有の物性が際立つことを明らかにし、高付加価値澱粉素材としての用途を提案することができた。