Abstract: In order to study the effect of low voltage electrostatic field (LVEF)-assisted freezing on the freezing characteristics of bamboo shoots, freezing curves, texture, drip loss, water migration, ice crystal morphology and microstructure were used as indicators to evaluate the effect of LVEF-assisted freezing (–35 ℃) and regular freezing (–35 ℃) on the quality characteristics of frozen bamboo shoots. The results showed that LVEF-assisted freezing improved the freezing efficiency, changed the shape and distribution of ice crystals, and reduced the degree of microstructural damage and thawing loss of bamboo shoots. The drip loss of bamboo shoot samples subjected to LVEF treatment at 10, 20, 30 and 40 cm away from the electrostatic field generating plate were 14.16%, 12.58%, 9.73% and 10.44%, respectively and were significantly lower than 21.01% for the control group (P < 0.05), and the hardness values were 461.19, 507.48, 496.65 and 455.31 g, respectively and were significantly higher than 350.70 g for the control group (P < 0.05). Low-field nuclear magnetic resonance (LF-NMR) spectroscopy indicated that the thawing loss of bamboo shoots was reduced under LVEF. Scanning electron microscope (SEM) observation showed that the bamboo shoot fibers were arranged neatly and the microstructure of bamboo shoots was well maintained. In summary, LVEF-assisted freezing can effectively improve the quality of bamboo shoots, which will provide guidance for utilizing LVEF in the frozen storage and cold chain transportation of fruits and vegetables.

Key words: low voltage electrostatic field; bamboo shoots; freezing method; quality control