Product and Microbial Population Kinetics During Balsamic‐Styled Vinegar Production

Abstract

Balsamic‐styled vinegar is a nutraceutical product obtained from a two‐stage fermentation process of grape must. However, little is known about how fermentation conditions affect growth kinetics, bio‐product development, population dynamics and the final product quality. As a result, the current study investigated the effect of fermentation temperature and inoculation strategy on the fermentation dynamics of Balsamic‐styled vinegar production. A microbial consortium of non‐Saccharomyces yeasts (n = 13) and acetic acid bacteria (n = 5) was tested at various fermentation temperatures (22 °C, 28 °C and a fluctuating temperature regimen). Different inoculation strategies (co‐inoculation and sequential inoculation) were investigated, and population dynamics of the product selected due to a rapid fermentation period were confirmed using a 16S and 18S gene sequencing. A higher fermentation temperature (28 °C) and co‐inoculation strategy resulted in a shorter fermentation cycle, whilst the desired acetic acid concentration of 60 g/L was achieved within 38 days. 16S and 18S gene sequencing showed that 50.84% of Acetobacter species were abundant at the end of the fermentation cycle, while 40.18% bacteria were unculturable. The study provides a better understanding of how fermentation temperature and inoculation strategy affect the fermentation period, population dynamics and the growth kinetics of the microbial consortium during the production of Balsamic‐styled vinegar. Practical Application Lower quality South African wine grapes could be channelled to an alternative high‐priced product (Balsamic‐styled vinegar), with low technological input requirements. Thus, making it easier to incorporate a low capital start‐up business while empowering small business entrepreneurs and boosting the economy.

Effect of alcoholic and acetous fermentations on the phenolic acids of Kei‐apple (Dovyalis caffra L.) fruit

“…Kei‐apple fruit (approximately 5 kg) was handpicked and homogenized (Russel Hobbs domestic juicer, Russel Hobbs, Cape Town, South Africa) at the Nietvoorbij research farm near Stellenbosch (33.9331° S, 18.860° E), South Africa. The protocol followed was based on a published method 23,24 …”

“…Kei‐apple fruit has increased concentrations of l ‐malic acid, which causes it to be astringent. Kei‐apple juice was therefore inoculated with Schizosaccharomyces pombe (Sp) strain V2 because it has the ability to break down l ‐malic acid 24,25 . Schizosaccharomyces pombe strain V2 ( S. pombe strain V2 is deposited in the EMBL sequence database under the accession number HE963294, Polytechnic University of Madrid, Spain), 26 and the Saccharomyces cerevisiae (Sc) strain NT116 (commercial yeast, Anchor Oenology, Cape Town, South Africa) was propagated by inoculating a single colony into 10 mL yeast peptone dextrose broth (YPD) (Biolab, Merck, Cape Town, South Africa) and incubating at approx.…”

Aeration, Agitation and Cell Immobilization on Corncobs and Oak Wood Chips Effects on Balsamic-Styled Vinegar Production

“…The number of cells adsorbed on the CC and OWC for individual yeasts and bacteria were quantified using the dry cell weight method adapted from Stone et al [26] and Nguyen et al [27], with minor modifications. Prior to this, the yeast and bacterial cell concentration (Table 3) in liquid suspension were individually quantified following the procedure described in Hutchinson et al [28]. Furthermore, the yeast and bacteria were individually studied to assess the variations in cell adsorption capabilities.…”

“…NB: change in time ( t ) was expressed as dt for both equations. Furthermore, relative differences as employed in other studies [28,29] were calculated using Equations (3) and (4) in order to show the significance of the differences observed under the different conditions studied. All results were the average of three biological repeats accounting for standard deviations which were calculated using Microsoft Excel v2016.…”

Bioaugmentation by Pediococcus acidilactici AAF1-5 Improves the Bacterial Activity and Diversity of Cereal Vinegar Under Solid-State Fermentation

“…In TDMV fermentation, the raw materials are decomposed and metabolized into sugars, organic acids, amino acids, and multiple-flavor substances under the action of microorganisms (Hutchinson et al, 2019). Various types of microorganisms that derive from starter cultures or are naturally enriched from the environment, are involved.…”