Freezing of green peppers assisted by combined electromagnetic fields: Effects on juice loss, moisture distribution, and microstructure after thawing

Abstract

AbstractThe combination of electric and magnetic field assisted freezing has potential as a new means of improving the freeze–thaw quality of green peppers. In this work, the quality of the freeze–thawed product was assessed in terms of thawing juice loss, moisture profile, ascorbic acid content, antioxidant activity, flavor, and microstructure. Juice loss was reduced by 16%–68%, freezing time was shortened by 15%–26%, and the nutrient retention rate was higher in the physical field‐assisted case compared to the no‐physical field case. Interestingly, the combined freezing of the two physical fields showed better freezing results compared to a single electric or magnetic field, with juice loss reduced to 3.04%, retention of 82% of calcium ions, retention of ascorbic acid increased by 6%–15%. In addition, the content of hexenal and methyl salicylate and other aromatic substances increased, showing a good flavor quality such as increased umami. The results suggest that combined electric and magnetic field assisted freezing is better in improving the quality of frozen products and may be a potential alternative to freezing and thawing of fruits and vegetables.Practical applicationThis research provides a simple and novel method for improving the speed and quality of frozen products. These steps combine electric and magnetic fields to explore, improve the quality of frozen products, but also provide a new idea for freezing research.