In situ Creation of the Natural Phenolic Aromas of Beer: A Pulsed Electric Field Applied to Wort-Enriched Flax Seeds.

Evangelia A Tsapou,Vassilis Dourtoglou,Thalia Dourtoglou,Fotini Drosou,George Ntourtoglou,Panagiotis Tataridis,Stavros Lalas

doi:10.3389/fbioe.2020.583617

Evangelia A Tsapou, Vassilis Dourtoglou + Show 5 more

Open Access

https://doi.org/10.3389/fbioe.2020.583617

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Abstract

To fine tune the production of phenolic aromas in beer, a pulsed electric field (PEF) was applied to beer wort, which was enriched with flax seeds. The choice of flax seeds as a source of FA is based on its high content of ferulic precursors and their intrinsic nutritional value. PEF was applied to ground flax seeds, with and without beta glycosidase. Fermentation was carried out with Saccharomyces and non-Saccharomyces yeast strains. Moreover, 4-vinylguaiacol (4-VG), a flavor highly active derived from volatile phenol, was produced by decarboxylation of ferulic acid (FA), or its precursor and flavor-inactive (4-hydroxy-3-methoxycinnamic acid). All yeast strains could metabolize FA into 4-VG, using the pure compound in the synthetic medium or in flax seeds, with the best quantity produced by Saccharomyces cerevisiae as a precursor. The method yields 4-VG production efficiencies up to 120% (mgL−1). Experimental treatment conditions were conducted with E= 1 kV/cm, total time treatment 15 min (peak time ti = 1 μs, pause time tp = 1 ms, Total pulses 9003). Treatment efficacy is independent of the fermentation yeast.

Highlights

Flavoring with natural compounds is well-known in the food and beverage industry, driven by consistent consumer demand for more “natural” foods
Phenolic compounds are always present in the final product; they can be extracted from grains and hops during the process of Bioflavoring of Beer mashing or brewing
Three important conclusions are based on the findings: 1. Saccharomyces and non-Saccharomyces are strains with high exhibited ferulic acid (FA) decarboxylase activity

Summary

Introduction

Flavoring with natural compounds is well-known in the food and beverage industry, driven by consistent consumer demand for more “natural” foods. Industries can improve the techniques of extraction or isolation of aromatic compounds by frequently applying two or more technologies to isolate target molecules, thereby rendering the final aroma more attractive. The most difficult issue is to empower the typical aromatic character without changing the final product (from the commonly accepted taste and aroma). This is done by hydrolyzing enzymatically-bound aromatic compounds in polymeric precursors with glycolytic enzymes (i.e., in wine), by adding aromatic compound precursors or using physicochemical methods (e.g., distillation and enrichment of the beverage with the heads of distillates). Phenolic compounds are always present in the final product; they can be extracted from grains and hops during the process of Bioflavoring of Beer mashing or brewing. Some phenolic compounds have a small impact on beer, while others may cause some desirable or undesirable effects (Lentz, 2018)

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