# Effect of Magnetic and Electrical Fields on Yield, Shelf Life and Quality of Fruits
## 2 Effect of Magnetic Fields and Electrical Fields on the Growth, Development, and Yield of Fruit
### Effect of Magnetic Fields and Electrical Fields on Fruit Quality
MFs penetrate deeper into cells and tissues; therefore, they can influence metabolic pathways at the cellular level [130]. On the other hand, [PERSON] et al. (2012) stated that a magnetic field, at low doses of 2.5 mT, did not influence the firmness of tomato fruit during storage at 16 \({}^{\circ}\)C [93]. However, treatment with AMF at 2.5 mT before the cutting of melo fruits influenced firmness, which was 54.9% higher in comparison with the control. These results showed that AMF retarded the softening of fruit tissue [124]. Other studies showed that the selected magnetic field of 100 uT at 50 Hz that was applied significantly influenced the quality parameters of fruits. Apple fruits treated with \begin{table}
\begin{tabular}{c c c c c} \hline
**Variety** & **Method** & **MF Parameter** & **Effect** & **References** \\ \hline \multirow{4}{*}{Mango fruits} & Fruit treatment & EF 1.5 kV/cm & \multicolumn{2}{c}{Decrease in antioxidative} & \\  & with titanium plate & of electric field for & \multicolumn{2}{c}{capacity of ripe fruit, no changes} & \\  & and needle & 45 min before storage & \multicolumn{2}{c}{in ascorbic acid, caroten,} & \\  & & and needle & 45 min before storage & \multicolumn{2}{c}{quercetin, total phenols soluble} & \\  & & & & solids, tittatable acidity, firmness & \\  & & & EF field of 6 kV/cm & \multicolumn{2}{c}{Decrease in malondialdehydedehyde} & \\  & & & for 30, 60, 90 or & \multicolumn{2}{c}{content and pectinesterase activity,} & \\  & (_Dispyros kaki_) & & between two plates & 120 min, 6 duplicates, before storage & \multicolumn{2}{c}{in orange in total phenols (but some increase in MDA} & \\  & & Fruit treatment & & after treatment) & \\  & & & & Increase in total content of & \\  & & between the two & \multicolumn{2}{c}{} & \\  & (_Dispyros kaki_) & & 9 days within storage & \multicolumn{2}{c}{} \\  & & Fruit treatment & & \\  & & with two-tier- & EF & \multicolumn{2}{c}{} \\  & (_Coccoloba vifera_) & parallel board & 7.5 kV/cm & \multicolumn{2}{c}{} \\  & before 9 days & \multicolumn{2}{c}{} & \\  & & storage & & \\  & & & & \\  & & EF intensity of 3.61, & \multicolumn{2}{c}{} \\  & & 4.56, and 5.13 kV/cm & \multicolumn{2}{c}{} \\  & & & for 60 min & \multicolumn{2}{c}{} \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & \\  & & & & \\  & & & & \\  & & & & \\  & & & \\  & & & & \\  & & & \\  & & & & \\  & & & \\  & & & & \\  & & & \\  & & & \\  & & & \\  & & & & \\ \end{tabular}
\end{table} 
Table 3: _Cont._an MF had 8 and 25% more fructose and glucose, respectively, when compared to the control. There was also a general tendency to improve the content of the total extract of strawberries from 6-9% depending on variety [122; 125; 131]. A similar tendency was noted by [PERSON] et al. (1968), who showed that tomato fruits treated with an MF of 6 mT had higher concentrations of glucose, beta caroten, and lycopene relative to control fruit [92]. However, [PERSON] et al. (2020) used magnetic field pre-treatment of 10 mT for PMF and 1.26 mT for AMF to improve the quality of frozen cherry fruit. The application of a magnetic field could reduce drip loss to some extent. Ice crystals formed homogeneously in the cells when a magnetic field was applied. Compared to the control group, this achieved a reduction in the average area of ice crystals of 67% and 78% with a PMF and AMF, respectively [123]. Many studies have proved that an electric field may also affect the quality of fruits. The mass loss at the end of storage for those samples treated with a HVEF at 4.56 kV\(\cdot\)cm\({}^{-1}\) was 1.36%, while it was 3.98% for the control [105]. Another study revealed the effect of ACEF in reducing water loss after nine days of storage of sea grapes [128]. [PERSON] et al. (2008) showed that firmness in tomato fruit treated with a \(-\)2 kV/cm electric field was 102.9% higher than that of control fruit on day 20 of storage [102].