Electric and mechanical detection of changes in heated apple flesh. (November 2019)

• Record Type: Journal Article
• Authors: Watanabe, Takashi; Ando, Yasumasa; Nakamura, Nobutaka; Orikasa, Takahiro; Shiina, Takeo; Nagata, Masayasu
• Is Part Of: Journal of food engineering. Volume 261(2019)
• Page Start: 26
• Page End: 31
• Publication Date: 2019-11
• Subjects: Apples -- Heat processing -- Cole-cole plots -- Electrical impedance -- Mechanical property -- Juiciness; EIS Electrical impedance spectroscopy -- Mini Mass of a sample before heating (g) -- Mh Mass of a sample after heating (g) -- Vini Volume of a sample before heating (mm3) -- Vh Volume of a sample after heating (mm3) -- Z Electrical impedance of samples(Ω) -- R Real part of Z (Ω) -- Rtop R at the top coordinate on the circular arc in Cole-Cole plot (Ω) -- X Imaginary part of Z (Ω) -- Xtop X at the top coordinate on the circular arc in Cole-Cole plot (Ω) -- j imaginary unit -- LTO Length of a coordinate at the top of the circular arc of Cole-Cole plots from the origin (Ω) -- ER Ratio of electrolyte release in cellular fluids during compression tests to the total amount of electrolytes (−) -- ZC Electrical impedance of the water including a compressed sample (Ω) -- ZA Electrical impedance of the water including a compressed sample after heating at 105 °C for 4 min (Ω) -- Smax Maximum stress (MPa); Food industry and trade -- Periodicals; Food -- Analysis -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Analyse -- Périodiques; Aliments -- Recherche -- Périodiques; 664.005
• DOI: 10.1016/j.jfoodeng.2019.05.004
• Languages: English
• ISSNs: 0260-8774

Abstract

Abstract: The relationships between cell membrane damage by heating and textural parameters of apples were investigated. We determined changes in mass, volume, electrical impedance, mechanical properties, and juiciness of apple tissues after low-temperature steam heating at 40, 60, and 80 °C. The electrical indicator LTO was calculated from Cole-Cole plots using electrical impedance spectroscopy of apple tissues. Juiciness was estimated by measuring electrolyte release in cellular fluids during compression tests. At each temperature, the change in mass was very small compared to the sample volume. The LTO showed cell membrane damage of apples at 60 and 80 °C, which declined the mechanical properties, but increased juiciness. We showed that cell membrane damage affected the mechanical properties and juiciness of the heated apples. The LTO can be useful for estimation of changes in the mechanical properties and juiciness of apples during heat processing. Highlights: Properties of apples were measured following steam heating at 40, 60, or 80 °C. Changes in mass were small compared to those in volume at all temperatures. Cell membrane destruction began at 60 °C. Juiciness was increased by steam heating. A new theory was proposed for rapid assessment of the taste of processed fruits.