Effect of Microcontroller-Based Pulsed Magnetic Pretreatments on Some Quality of Frozen-Thawed Mango and Tomato

The current study applied a microcontroller pulsed magnetic field (PMF) device to pretreat mango and tomato prior to freezing and storage. The main goal is to investigate the effect of field intensities (9 T, 14 T, and 20 T) and treatment duration (5, 10, and 15 min) on some qualities including vitamin C content, total soluble solids (TSS), pH, drip loss, color change, and firmness of frozen-thawed mango and tomato under short-term frozen storage. The treated and untreated samples were frozen at − 18 °C and stored (at − 18 °C) for 2 weeks. Standards methods were employed to measure the quality parameters of the samples. The results showed that the PMF pretreatment device maintained vitamin C content and TSS of the frozen-thawed samples compared to untreated frozen-thawed ones. The device lowered the drip loss with no meaningful change in the pH. Moreover, photospectometry and texture meter confirmed that the color changes and firmness level of the samples treated at 20 T for 5 min were linked to unbroken cell structure in comparison to the untreated (control) samples. In conclusion, PMF device operated at 20 T and 5 min significantly preserved the vitamin C, TSS, color, and firmness and reduced the drip loss of frozen-thawed mango and tomato, enhancing their preservation.