Pulsed Electric Fields to Improve the Use of Non-Saccharomyces Starters in Red Wines.

Cristian Vaquero,Javier Raso,Antonio Morata,Ignacio Álvarez,Iris Loira,Carlota Delso

doi:10.3390/foods10071472

Abstract

New nonthermal technologies, including pulsed electric fields (PEF), open a new way to generate more natural foods while respecting their organoleptic qualities. PEF can reduce wild yeasts to improve the implantation of other yeasts and generate more desired metabolites. Two PEF treatments were applied; one with an intensity of 5 kV/cm was applied continuously to the must for further colour extraction, and a second treatment only to the must (without skins) after a 24-hour maceration of 17.5 kV/cm intensity, reducing its wild yeast load by up to 2 log CFU/mL, thus comparing the implantation and fermentation of inoculated non-Saccharomyces yeasts. In general, those treated with PEF preserved more total esters and formed more anthocyanins, including vitisin A, due to better implantation of the inoculated yeasts. It should be noted that the yeast Lachancea thermotolerans that had received PEF treatment produced four-fold more lactic acid (3.62 ± 0.84 g/L) than the control of the same yeast, and Hanseniaspora vineae with PEF produced almost three-fold more 2-phenylethyl acetate than the rest. On the other hand, 3-ethoxy-1-propanol was not observed at the end of the fermentation with a Torulaspora delbrueckii (Td) control but in the Td PEF, it was observed (3.17 ± 0.58 mg/L).

Highlights

Pulsed electric fields (PEF) are a nonthermal technique that causes electroporation of cell membranes by applying very short pulses of a high-intensity electric field
It should be noted that the yeast Lachancea thermotolerans that had received pulsed electric fields (PEF) treatment produced four-fold more lactic acid (3.62 ± 0.84 g/L) than the control of the same yeast, and Hanseniaspora vineae with PEF produced almost three-fold more 2-phenylethyl acetate than the rest
Effects of PEF on the Extraction of Grenache Must after 24 h of Maceration

Summary

Introduction

Pulsed electric fields (PEF) are a nonthermal technique that causes electroporation of cell membranes by applying very short pulses (μs) of a high-intensity electric field (kV/cm). The ability of PEF to inactivate vegetative cells of microorganisms, enhance mass transfer, and modify food structure may contribute to improving the competitiveness of the food industry by improving food quality, reducing energy inputs, and contributing to the bioeconomy strategy for sustainable growth [2]. Several studies have demonstrated that electroporation of red grape skin cells before the maceration-fermentation step reduces the duration of maceration and/or improves a wine’s colour and concentration of polyphenolic compounds without impairing its sensorial attributes [3,4,5]. PEF has been proposed as a technique to enhance wine quality by guaranteeing reproducible fermentations and reducing or replacing the use of SO2 for wine stabilisation due to the capability of PEF to inactivate microorganisms while preserving physicochemical and sensorial properties [3]

Objectives

Methods

Results

Discussion

Conclusion