Low-Temperature Carrot Cooking Supported by Pulsed Electric Field—DMA and DETA Thermal Analysis

Abstract

The paper deals with carrot processing that combines the effect of the electric pulse loading with the lowtemperature heating. The pulse procedure was formed by one 10-ms long electric pulse (amplitude, 600 V/cm; basic frequency, 20 kHz) on the 160-ms long electric background less than 30 V/cm. The procedure was followed by the combined dynamic mechanical analysis (DMA) and dielectric thermal analysis (DETA) tests with the initial temperature of 30°C and final temperature of 90°C. Humidity in the test chamber was kept at 90 % during the whole heating test, with the heating rate of 1°C/min. During the whole test, both components of the complex modulus of elasticity (DMA) of the specimen as well as both components of the specimen's permittivity (DETA) were registered. A similar test was also performed with other specimens without the initial pulse procedure. Ratios of corresponding data (storage modulus, loss modulus, dielectric constant, and dielectric loss) are approximately constant up to the temperature of approximately 70°C where it starts to reduce substantially. The obtained results denote that can be processed using electric pulses reaching the similar state as during the tissue heating. Abbreviations A lower part of temperature scale (in our case cca 30-71°C) B higher part of the temperature range (in our case cca 71-90°C) B1 lower part of B (in our case approximately 71-80°C) B2 higher part of B (in our case approximately 80-90°C) CV (%) coefficient of variations DETA dielectric thermal analysis DL (−) or (%)dielectric loss (imaginary part of relative permittivity) DMA dynamic mechanical analysis DP (−) or (%) dielectric constant (real part of relative permittivity) E (V/cm) maximal intensity of the pulse electric field E 0 (V/cm) intensity of electric field-parameter of Eq.(2) IQR interquartile range Q3-Q1 K (cm/V) intensity of specimen impedance to pulse field (Eq. (2)) LM (Pa) or (%) loss modulus MV mean value Q1 first quartile Q2 second quartile R (−) ratio of Z x and Z i SM (Pa) or (%) storage modulus SE standard error SD standard deviation T (°C) temperature tg (−) symbol for loss tangent (in both DEA and DETA) X t (Ω) v a l u eo fZ x at infinite E

Kitchen cooking by electroporation

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Energy Efficiency in Meat Processing

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Effects of low temperature cooking methods and holding times on selected quality attributes of cooked pork longissimus dorsi

“…This could lead to overheating of the surfaces while waiting for the interior to reach the required temperature. In contrast, low temperature cooking can generally maintain high level of the nutritional values of the cooked products and is widely used in the food industry (Becker, Boulaaba, Pingen, Krischek, & Klein, ; Blahovec, Kourim, & Kindl, ).…”