Effects of pulsed electric field processing on microbial survival, quality change and nutritional characteristics of blueberries

Abstract

a b s t r a c tWhole fresh blueberries were treated using a parallel pulsed electric field (PEF) treatment chamber and a sanitizer solution (60 ppm peracetic acid [PAA]) as PEF treatment medium with square wave bipolar pulses at 2 kV/cm electric field strength, 1ms pulse width, and 100 pulses per second for 2, 4, and 6 min. The effects of PEF on native microbiota and artificially-inoculated Escherichia coli K12 and Listeria innocua populations on blueberries were determined. Color, texture, anthocyanins and total phenolic compound concentrations were also evaluated. The combination of PEF and PAA was able to achieve up to 3 log reduction of E. coli and Listeria as well as 2 log/g reduction of native microbiota. PEF treatments did not cause any changes in color and appearance of the blueberries. The treatments did, however, cause the blueberries to soften in texture. Anthocyanins and phenolic compounds in blueberries increased by 10 and 25%, respectively, after PEF treatments. The results demonstrate the potential of PEF applications to enhance the safety and improve the quality and nutritional value of fruits and their derived products.Published by Elsevier Ltd.

Effects of pulsed electric fields pretreatment and drying method on drying characteristics and nutritive quality of blueberries

“…The calculated specific energy input per treatment was 2.5 kJ/kg. These PEF parameters were selected based on our previous trials considering the PEF process system power capacity (limit of 2 kW), electrical conductivity of blueberry samples, and system operation stability (Jin, Yu, & Gurtler, ; Yu, Jin, Fan, & Xu, ). Samples soaked in the salt solution for 4 min without PEF‐pretreatment served as controls.…”

Pulsed electric fields as an alternative to thermal processing for preservation of nutritive and physicochemical properties of beverages: A review

“…Similarly, it was reported that after PEF (2 kV/cm, 1 µs), blueberries had 10% more anthocyanins and 25% polyphenolic compounds (Yu et al, ). Demonstrating that PEF in blueberries could potentially improve the quality and nutritive value of fruits and their juices, in addition to enhancing food safety (Jin, Yu, & Gurtler, ). Another positive influence of PEF was reported with different berry fruit juice (strawberry) by improved antioxidant activities and anthocyanins content (Odriozola‐Serrano et al, ).…”

Enhancing phenolic content in carrots by pulsed electric fields during post-treatment time: Effects on cell viability and quality attributes

“…There are also studies in other whole products: potato (Galindo et al, 2009), apple (Soliva-Fortuny, Vendrell-Pacheco, Martín-Belloso, & Elez-Martínez, 2017), and tomato (Vallverdú-Queralt et al, 2013). However, the effect of PEF on both bioactive content and quality attributes were only studied in blueberry (Jin, Yu, & Gurtler, 2017) and tomato (González-Casado, Martín-Belloso, Elez-Martínez, & Soliva-Fortuny, 2018). As far as we know, there is no available information about the effect of PEF and post-treatment time on the phenolic content and on the quality attributes of whole carrots.…”