Fermentation Conditions Affect the Synthesis of Volatile Compounds, Dextran, and Organic Acids by Weissella confusa A16 in Faba Bean Protein Concentrate

Abstract

Fermentation with Weissella confusa A16 could improve the flavor of various plant-based sources. However, less is known about the influence of fermentation conditions on the profile of volatile compounds, dextran synthesis and acidity. The present work investigates the synthesis of potential flavor-active volatile compounds, dextran, acetic acid, and lactic acid, as well as the changes in viscosity, pH, and total titratable acidity, during fermentation of faba bean protein concentrate with W. confusa A16. A Response Surface Methodology was applied to study the effect of time, temperature, dough yield, and inoculum ratio on the aforementioned responses. Twenty-nine fermentations were carried out using a Central Composite Face design. A total of 39 volatile organic compounds were identified: 2 organic acids, 7 alcohols, 8 aldehydes, 2 alkanes, 12 esters, 3 ketones, 2 aromatic compounds, and 3 terpenes. Long fermentation time and high temperature caused the formation of ethanol and ethyl acetate and the reduction of hexanal, among other compounds linked to the beany flavor. Levels of dextran, acetic acid, and lactic acid increased with increasing temperature, time, and dough yield. Optimal points set for increased dextran and reduced acidity were found at low temperatures and high dough yield. Such conditions would result in hexanal, ethyl acetate and ethanol having a relative peak area of 35.9%, 7.4%, and 4.9%, respectively.

Role of tailored sourdough fermentation in the flavor of wholegrain-oat bread

“…n/a = not applicable. rLRI were obtained from Paradiso et al (2009) , Tuccillo et al (2022b) and “Flavornet and human odor space” ( http://www.flavornet.org/flavornet.html ) (accessed on October 3, 2023). The latter reports LRI of compounds chromatographically separated with the column OV17, having with similar polarities of the one used in the experiments and in the first two cited works (SPB-624).…”

“…VOCs were semi-quantified based on the relative area counts of the base peaks, which were manually integrated. Identification was conducted as reported in Tuccillo et al (2022b) and was based on the correspondence of MS spectra and Linear Retention Indexes with available library entries (Wiley 7 N, Wiley Registry of Mass Spectral Data, 7th Edition; “Flavornet and human odor space” from Acree and Arn (2004) accessed on October 3, 2023) and published literature ( Paradiso et al, 2009 ; Tuccillo et al, 2022b ). LRI were determined by calculating the retention times of the alkane series 7–30 (Sigma Aldrich, St. Louis, MO, USA) and hexane (Sigma-Aldrich, Schnelldorf, Germany).…”

Significance of Fermentation in Plant-Based Meat Analogs: A Critical Review of Nutrition, and Safety-Related Aspects

“…The beany flavor of plant materials can be successfully minimized or eliminated through the fermentation process. Researchers have demonstrated that soybean off-flavor characteristics, such as the beany flavor, decreased or disappeared after fermentation using different microorganisms, including Kluyveromyces marxianus, B. subtilis, and Weissella confuse [134,141,232]. It is believed that these microorganisms are capable of degrading lipoxygenases, which act on polyunsaturated fatty acids to produce off tastes such as beany notes.…”

The potentials and challenges of using fermentation to improve the sensory quality of plant-based meat analogs

“…Fermentation can be an effective method for reducing off-flavors in plant ingredients. Off-flavor notes (e.g., beany aroma) present in soybean decreased or disappeared after fermentation using Kluyveromyces marxianus ( Hu et al, 2019 ), B. amyloliquefaciens ( Cho et al, 2003 ; Jiang et al, 2019 ; Yang et al, 2019 ; Wang et al, 2021 ), and B. subtilis ( Sarkar and Tamang, 1995 ; Owens et al, 1997 ; Shrestha and Noomhorm, 2001 ; Shrestha et al, 2010 ) , Weissella confusa ( Tuccillo et al, 2022 ). These studies demonstrated how fermentation can be used to denature lipoxygenases [lipoxygenase catalyzes the oxidation of polyunsaturated fatty acids to form off flavors like beany notes, mainly aldehydes such as (E)-2-nonenal, hexanal, and (E, E)-2,4-nonadienal] or mask the off-notes present naturally in beans by producing desirable microbial volatiles ( Wang et al, 1997 ; Jiang et al, 2018 ).…”

“…For instance, certain bacteria can convert branched-chain amino acids (valine, leucine, isoleucine) or phenylalanine into volatiles like higher alcohols, aldehydes, and organic acids ( Barbieri et al, 1992 ; Montel et al, 1998 ). Faba bean protein concentrate was fermented by Weissella confusa and about 40 various volatile compounds were identified ( Tuccillo et al, 2022 ). The authors inoculated the protein concentrate with different initial inoculum ratios (10 5 –10 7 CFU/g) under solid-state fermentation with the presence of sucrose, and the volatiles was detected by headspace solid-phase microextraction gas-chromatography mass-spectrometry.…”