Electrical Properties of Garut Citrus Fruits at Low Alternating Current Signal and its Correlation with Physicochemical Properties During Maturation

Abstract

In this research, local citrus fruits, namely Garut citrus, were analyzed for electrical properties related to physicochemical properties. Electrical measurement on fruit was done by using low alternating current with a frequency varying from 50 Hz to 1 MHz. The fruits are placed between two plate electrodes and treated as dielectric material. Electrical parameters per unit of weight were used in this study to compensate variations in weight. Electrical impedance, resistance, and reactance per weight of citrus fruits will decrease if the frequency is increased. Electrical circuit models have been constructed to describe the internal conditions of citrus fruits. To indicate the fruit maturity, the physicochemical properties were used, i.e., firmness, total soluble solids, pH, and hydrogen ion concentration. The value of resistance, impedance, and reactance per weight declined during citrus fruits maturation. The correlations between electrical and physicochemical properties are investigated too. The highest consistency of correlations happens at a frequency of 1 MHz. Based on the model of an electrical circuit, the highest value of electrical resistance is outer shell and the lowest is seed. And then, the highest value of electrical capacitance is albedo and the lowest is segment. Resistance values of the parts of citrus fruits, i.e., seed, segment, segment wall, and outer shell, were decreased during maturation. While capacitance value of segment, albedo, and flavedo were increased.

Electrical Properties of Indian Banana Cultivars during Ripening

“…From the table it was observed that Karpuravalli had higher coefficients of determination (R 2 ) 0.98 at 700 kHz followed by Robusta (0.96) at 500 kHz and Poovan (0.89) at 500 kHz respectively. These results agree with the impedance observed for Berangan variety banana [5]and Garut citrus [7].…”

Dielectric properties of guava, mamey sapote, prickly pears, and Nopal in the microwave range

“…Nevertheless, diverse reports have demonstrated that measuring an isotropic homogeneous fruit-paste resulted in useful data for further applications. [9][10][11][12][13] Physicochemical analysis in samples pH was determined with a digital pHmeter (Model pH120, Conductronic, Mexico City), previously calibrated with buffer 7.0 and 4.0. pH was measured by direct immersion of the electrode in the paste of every sample. [11] Total soluble solids (TSS) were determined in the paste of every sample with a digital refractometer (Model HI 96801, Hanna Instruments, Romania), previously calibrated with distilled water at 20ºC.…”

“…In order to develop microwave heating methods, the dielectric properties (DPs) of the foods should be obtained. Dielectric properties of diverse fruits and their nectars have been reported in the literature, such as apple, cherry, grape fruit, and orange; [9] avocado, cherimoya, longan, passion fruit, persimmon and white sapote; [10] mango; [11] tomatoes, [12] garut citrus fruits, [13] apple, apricot, peach, and pear nectars [14] Nevertheless,, to the best of our knowledge, DPs of guava, mamey sapote, cactus pears, and nopal have not been studied Dielectric properties are described by the complex permittivity (ε) of a given material, expressed as [15] ε ¼ ε 0 À jε 00 (1) where the real part ε' is the dielectric constant, ε" is the dielectric loss factor, and j = √-1. ε' is related to the capacity of the material to store electrical energy, while ε" is related the absorption mechanisms of energy dissipation and usually, it is significantly smaller than ε'.…”

“…where d p is the penetration depth (m), c is the speed of the light in free space (3 x 10 8 m/s), and f is the frequency (Hz). Since the dielectric properties of foods are affected by frequency, temperature, and ripening, [9][10][11][12][13]16,17] in this work, we studied the dielectric properties of the aforementioned fruits in the microwave range from 500 MHz to 20 GHz, at different temperatures (20,40, and 60ºC), and different ripening stages…”

Electrical impedance of Shiraz berries correlates with decreasing cell vitality during ripening

“…, Juansah et al. ) and in response to postharvest treatments or damage (Harker et al. , Jackson and Harker , Rehman et al.…”