Influences of pH and temperature on infrared spectroscopic features of brewed coffee

AbstractWe developed an infrared spectroscopic evaluation method of brewed coffee, whose quality and taste highly depend on the chemical contents, the interactions between the components, the pH value and the temperature, using a Fourier transform infrared (FT-IR) spectrometer equipped with an attenuated total reflection (ATR) accessory. The objective of this study is to understand the influences of the pH values and temperature on the spectral features of brewed coffee and the main components, since the component balances of the organic acids originating from coffee beans and being produced during processes such as roasting and extraction could closely relate to the brewed coffee characteristics. The absorption peak sifts of the ATR spectra of brewed coffee were observed as the influences of the pH and temperatures. Therefore, by analyzing the spectra of the coffee components under the various pH and temperature conditions based on the ionic dissociation equilibrium theory, the spectral behavior of the brewed coffee model due to the pH and temperature changes could mainly result from those of the organic acids as the main components. Consequently, the infrared spectral information analysis would be acceptable as a new method to evaluate a profile of brewed coffee for the quality evaluation relating to the taste and the non-intensive on-line monitoring of the coffee process

Effects of Assistance of High Frequency Dielectric and Infrared Heating on Vacuum Freeze Drying Characteristics of Food Model

[EN] By combining vacuum freeze drying combined with high-frequency dielectric and/or infrared heating, the drying time for frozen gels containing 1% agar with sucrose or sodium chloride was successfully shorten, and the drying time was influenced by the heating methods and by the additive component to the sample. Additionally, it was experimentally confirmed that the power consumption for freeze drying combined with electromagnetic wave heating could be reduced because of the shortened drying time. Consequently, this study could be a very important step for designing a vacuum freeze drying process optimally combining electromagnetic wave heating for each sample component.Hashimoto, A.; Suehara, K.; Kameoka, T.; Kawamura, K. (2018). Effects of Assistance of High Frequency Dielectric and Infrared Heating on Vacuum Freeze Drying Characteristics of Food Model. En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 795-802. https://doi.org/10.4995/IDS2018.2018.7461OCS79580

Development of a Simultaneous Quantification Method for Multiple Modes of Nitrogen in Leaf Models Using Near-Infrared Spectroscopic Measurement

By focusing our attention on nitrogen components in plants, which are important for cultivation management in data-driven agriculture, we developed a simple, rapid, non-chemical and simultaneous quantification method for proteinic and nitrate nitrogen in a leaf model based on near-infrared (NIR) spectroscopic information obtained using a compact Fourier Transform NIR (FT-NIR) spectrometer. The NIR spectra of wet leaf models impregnated with a protein–nitric acid mixed solution and a dry leaf model obtained by drying filter paper were acquired. For spectral acquisition, a compact MEMS (Micro Electro Mechanical Systems) FT-NIR spectrometer equipped with a diffuse reflectance probe accessory was used. Partial least square regression analysis was performed using the spectral information of the extracted absorption bands based on the determination coefficients between the spectral absorption intensities and the contents of the two-dimensional spectral analysis between NIR and mid-infrared spectral information. Proteinic nitrogen content in the dry leaf model was well predicted using the MEMS FT-NIR spectroscopic method. Additionally, nitrate nitrogen in the dry leaf model was also determined by the provided method, but the necessity of adding the data for a wider range of nitric acid concentrations was experimentally indicated for the prediction of nitrate nitrogen content in the wet leaf model. Consequently, these results experimentally suggest the possibility of the application of the compact MEMS FT-NIR for obtaining the bioinformation of crops at agricultural on-sites

Simultaneous Content Determination of Mono-, Di-, and Fructo-oligosaccharides in Citrus Fruit Juices Using an FTIR-PLS Method Based on Selected Absorption Bands

A quantification method was developed to determine the sugar components, either following addition or enzymatic treatment, in citrus fruit juices containing additional fructo-oligosaccharides using midinfrared spectroscopy. For the quantification, we compared the results obtained by applying the simultaneous equation method, which uses very little wavenumber information, and the partial least squares (PLS) regression method, which requires a lot of wavenumber information. In order to prevent overfitting in the PLS method, we concentrated on reducing the amount of spectral data used in the analysis. The corresponding FTIR-PLS method led to an accurate quantification of the sugar contents, even in enzymatically treated orange juices with complicated compositions. The spectral data used for model calibration were significantly reduced by focusing on the absorption and assignment information of the sugar components. The RMSEs of Glc, Fru, Suc, GF2, and GF3 in enzyme-treated orange juice before and after spectral data reduction were 0.50, 0.46, 0.61, 0.74, and 0.61 g/L and 0.51, 0.49, 0.73, 0.86, and 0.61 g/L, respectively. The developed method could be easily implemented for practical applications, using a simple measuring instrument since only absorption information at the limited absorption bands is required

赤外・近赤外分光法を援用したバイオマス由来の糖を用いる植物細胞培養系の糖代謝解析

application/pdf本研究は、3つのタイプの植物細胞を用いた培養系で、糖の種類が糖代謝速度に与える影響を評価することにある。赤外分光法により培地中の糖を同時計測(HPLCと同等の精度)して細胞の糖の取込み速度を算出できる手法を確立した。糖の取込み速度は糖の種類に大きく依存したが、細胞増殖を基準とした糖代謝には大きく影響しなかった。バイオマス由来の様々な糖と混合状態の糖を用いた際の細胞の挙動が把握できた。以上の成果は、バイオマス由来の糖を有効利用するための植物細胞利用(混合状態の糖化液を用いる際の培養特性の予測や糖成分をコントロールすることによる細胞増殖速度調整など)ならびに赤外分光法によるバイオプロセス計測制御法の進展に寄与すると考えられる。The objective of this work was to study the influence of sugar spices in the culture media on the kinetic sugar uptake phenomena for three types of plant cell cultivation. We developed the measurement method of sugar content in culture media suspended plant cells using the FT-IR/ATR method, and the sugar uptake rate of the suspension plant cells were calculated. The sugar uptake rate of the plant cell was different greatly on the kind of sugar, however, characteristic of sugar metabolism based on cell growth period was stable. Characteristic of metabolism of various sugars and sugar mixture (that is biomass degradation product) for three types of plant cells were obtained. These results will contribute to the development of a plant cell cultivation process planning and bioprocess monitoring by IR method to utilize the sugar derived from biomass materials.平成20~22年度科学研究費補助金(基盤研究(C))研究成果報告書2056072

可視･赤外分光計情報に基づいたワインの包括的品質評価手法の構築

application/pdf本研究はソムリエの感性を模倣したオプティカル･テイスティング（Optical Tasting）の概念を提唱することを目的としている。「味わいを確認する」ためのワイン（液相）を特徴付ける赤外分光情報解析法，「香りを感じる」ためのワインの蒸散成分（気相）の赤外吸収スペクトル計測・解析法，および，「外観をみる」ためのワイングラス中におけるワインの色彩情報のグラデーション解析法を確立した。さらに，それら解析手法を組み合わせることにより，ワインの総合的な特性を客観的かつ定量的に評価できる可能性が実験的に示された。This study aimed to develop the comprehensive quality evaluation method of wines based on the concept of “optical tasting” that imitates the sensibility of sommeliers by combing the multi-band optical sensing methods. By combining the infrared spectroscopic analysis on characterizing wine (liquid phase) for "confirming the taste", infrared absorption spectral measurement / analysis on the volatile components of wine (gas phase) for "feeling the aroma" and the analysis on the color parameters of the image of wine in the glass for "confirming the appearance", it was experimentally found that the comprehensive characteristics of wine could be objectively and quantitatively evaluated.2019年度～2021年度科学研究費補助金(基盤研究(C))研究成果報告書19K0631