Estimation of "Denseness" of Tofu Microstructure by Simultaneous Triple-Wavelength Laser Light Scattering Measurement

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K20600
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0604:Agricultural economics and rural sociology, agricultural engineering, and related fields
• Research Institution: Niigata University
• Principal Investigator: Saito Yoshito 新潟大学, 自然科学系, 助教 (90964990)
• Project Period (FY): 2022-08-31 – 2024-03-31
• Keywords: 豆腐 / 光多重散乱 / 凝固 / 等価散乱係数 / 微細構造

Outline of Final Research Achievements

In this study, we investigated a laser scattering measurement method using simultaneous irradiation of three wavelengths to non-destructively evaluate the coagulation state of tofu. Measurements of near-infrared transmission spectra revealed that scattering increases as coagulation progresses, and scattering becomes more significant at shorter wavelengths. Furthermore, the results of the linearity evaluation of the constructed optical system showed that the 633 nm He-Ne laser was the most suitable.
A significant correlation was found between the reduced scattering coefficient at 633 nm and the viscosity of tofu, suggesting the possibility of non-destructively evaluating the coagulation state of tofu by measuring laser scattering light in the visible region. In the future, we plan to investigate noise removal and the use of near-infrared lasers to establish a high-precision light scattering measurement system.

Free Research Field

応用光学

Academic Significance and Societal Importance of the Research Achievements

世界的な非肉食圏の人口増加を背景として大豆製品の需要は増しており，それら加工品である豆腐の消費拡大も見込まれている。同時に，消費者の食のニーズも多様化が進む中，製造者には高品質な製品の安定生産が求められている。豆腐に見られる多孔質状の微細構造は豆乳に凝固剤が添加され「凝固」が起きる過程で形成されるが，凝固の制御は職人の“経験と勘”に依存しているケースが多く，多い場合には数百～数千kgの製造ロスに繋がる。
本研究は，豆腐以外の食品や，ひいては細胞培養培地の特性評価など，食品から生命科学に至る幅広い分野に応用可能であり，「微細構造の非破壊推定センサ」としての技術展開が期待できる。