Effects of combined pulsed electric field and blanching pretreatment on the physiochemical properties of French fries

Abstract

The aim of this work was to explore the effect of combining pulsed electric field (PEF) with blanching pretreatment on the physiochemical properties of French fries. The effects of PEF plus blanching pretreatment on the color parameters, texture, content and spatial distribution of moisture and oil, microstructure, colony count and acrylamide content of French fries were investigated. Results showed that the pretreated French fries were brighter (L value was 60.44) and golden yellow, with lower hardness (312.27 g), higher springiness (0.81) and higher chewiness (119.71). In addition, moisture and oil contents of the fries were reduced, with more uniform distributions. The cross-section microstructure of these French fries also showed near-complete gelatinization of starch particles, and the internal structure of fries was fluffy. Finally, French fries obtained by the combined pretreatment had an improved food safety profile, with a lower colony count (13 CFU/g) and acrylamide content (1533.75 ng/g). Industrial relevanceBlanching is a traditional thermal processing technology widely used in the field of fried potatoes. However, blanching has some disadvantages such as slow heat conduction, long processing time, substantial loss of soluble nutrients, and huge water wastage. PEF is an emerging technology in the 21st century that can maintain the original flavor, color, taste, and nutritional value of foods treated by it. The French fries obtained by combining PEF and blanching pretreatment were brighter and golden yellow, and were also softer, and more springy and chewy – an overall net improvement in aesthetic appeal and organoleptic profile. The above findings may provide useful information to guide effective strategies for the practical application of PEF combined with blanching in the preparation of fried potato foods.