Aroma profile of pilot plant-scale produced fruit vinegar using a thermotolerant Acetobacter pasteurianus strain isolated from Moroccan cactus

Abstract

In this study, new thermotolerant Acetobacter pasteurianus CV01 strain recently isolated from local product of Morocco has been investigated for its ability to perform efficient acetous fermentation at a large-scale. Firstly, the thermotolerance basis bioconversion of CV01 strain was compared to other mesophilic and thermotolerant acetic acid bacteria. Subsequently, CV01 strain was assessed for its ability to produce and tolerate high amount of acetic acid at optimal and thermal stress conditions in lab-scale bioreactor. It was found that the studied strain exhibited thermotolerant properties compared to reference strains and could withstand the increase in temperature during acetous fermentation in fermenter. Furthermore, gas chromatography-mass spectrometry (GC-MS) was used on the samples prepared with solid phase microextraction (SPME) to determine the volatile compounds of the pilot plant produced apple vinegar based on developed start-up and semi-continuous fermentation protocol. The operation strategy in the 500-L pilot plant scale acetator allowed achieving 7.3% (w/v) of final acetic acid concentration recording high yield and acetification rate. The aroma profile of experimentally produced vinegar was found different from that of the commercial reference one. According to the literature, the results obtained show that major volatile compounds found in pilot-plant produced apple vinegar are related to good aromatic note descriptors which could have a positive impact on the organoleptic quality of industrial vinegar. Consequently, it can be concluded that CV01 Acetobacter strain is well suited for large-scale production of high quality fruit vinegar.

Comparative Study on Physico-chemical and Sensory Properties of Vinegar Produced from Apple Varieties

“…This may be due to the juice extraction method (fresh squeezing method) which was reported by Wang et al, (2020) as the best method compared to the two other methods (spiral juice method and broken juice method). Our results showed higher rates than those reported by Mounir et al (2018) with 0.68 l/kg as a yield rate. On one hand, this could be explained by the use of a stainless steel electric crusher for crushing fresh apples and then pressing them of using a manual press with steel grids and this process can affect the yield rate.…”

“…Three apple varieties (Starkrimson, Royal gala and Golden delicious) that were damaged by hail (Fig 1 ) were recovered during the season from September to November 2019 and transported immediately to LAPAPEZA laboratory (Batna 1 University) because they are very perishable due to their water and sugar content and must be processed very quickly (Mounir et al, 2018).…”

Inoculation with acetic acid bacteria improves the quality of natural green table olives

“…From more than 60 isolates, three microbial strains were selected to carry out experiments aimed at the preparation of natural table olives. These strains, namely : Lactobacillus plantarum S1, Saccharomyces cerevisiae LD01 and Acetobacter pasteurianus KU710511 (CV01) were identified using biochemical and molecular techniques and characterized in previous studies (Mounir et al, 2018;Mounir et al, 2016a;Mounir et al, 2016b;Mounir et al, 2016c) The determination of chloride, titratable acidity, pH, and counts of LAB, yeasts and AAB were carried out using the methods described in the Material and methods section. Then, samples were presented to tasters to evaluate their organoleptic quality.…”

“…It has also been reported that vinegar may be added to the brine solution to preserve the olives, adjust the pH, and impart a particular flavor (Colmagro, 2001). Thus, following our research, it seemed appropriate to consider three species of microorganisms: Lactobacillus plantarum S1, Saccharomyces cerevisiae LD01 and Acetobacter pasteurianus KU710511 CV01 isolated from Morocco (Mounir et al, 2016a;Mounir et al, 2016b;Mounir et al, 2016c;Mounir et al, 2018) The overall objective of our work was to develop a method for the preparation of natural table olives using locally selected microorganisms and without resorting to the usual techniques. This objective involves optimizing the synergy conditions between the selected microorganisms.…”

Production of Antioxidant Rich Tomato Vinegar: An Alternative to Coconut Vinegar in Culinary Production

“…Changes in Brix value (circle), acidity percentage (squares), sugar concentration (triangles), and ethanol content (crosses) in simultaneous tomato vinegar production using Baker's yeast and A. pasteurianus PP21 at 30°C (A), and 36°C (B) unfavorable nature of acetate overoxidation, the tomato vinegar production should be terminated by inactivating AAB as soon as the maximum acetic acid production level is reached. Moreover, Mounir et al [25] compared thermotolerance and bioconversion abilities between two thermotolerant reference AAB strains and two wild type thermotolerant and mesophilic strains at 30, 34, 38 and 41°C under agitation in GYEA/Mg 2+ medium. They observed that the wild type strains could perform considerable acetic acid production only at 30°C, and also no wild type mesophilic strains showed acetic acid production beyond 34°C.…”