The Role of Selected Lactic Acid Bacteria on Organic Acid Accumulation during Wet and Spray-Dried Fish-Based Silages. Contributions to the Winning Combination of Microbial Food Safety and Environmental Sustainability

Abstract

Organic acid contents of acidified and fermented fish silages made from gibel carp (Caracius gibelio) and klunzinger’s ponyfish (Equulites klunzingeri) fishes, and from fish processing residues or by-products, were determined and studied. The silages were undertaken in wet and spray-dried fish-based raw-materials for 3 weeks at room temperature (ca. 25 °C). Selected lactic acid bacteria (LAB) of Enterococcus gallinarum, Lactobacillus brevis, Lactobacillus plantarum, Pediococcus acidilactici, and Streptococcus spp. were employed to produce fermented fish-based silages, while acidified silage was prepared resorting to the addition of formic acid (3%, v/v). Lactic and propionic acids were the dominant produced organic acids, while succinic acid was formed at the smallest amounts in fermented silages. In the acidified silage, lactic and formic acids were produced in amounts higher than 800 and 1000 mg organic acid/100 g sample, respectively. Among the fermented fish-based silages, LAB strains unfolded considerable ability to presumptively produce propionic acid in gibel carp silage (>2370 mg organic acid/100 g sample). Spray-dried fermented silages displayed significantly higher organic acid content than wet silages. Propionic acid accumulation was found at the highest levels in gibel carp silage fermented with L. plantarum (6335.40 mg propionic acid/100 g sample). This research effort pointed out the good capability of various selected lactic acid bacteria strains to produce significant amounts of organic acids—especially lactic, acetic, and propionic acids—during the fermentation of fish-based silages. In terms of food safety and quality, such a production of relatively high amounts of organic acids in wet and spray-dried fish-based silages clearly indicated their suitableness to be used for animal feed.

Bioconversion of Milk Permeate with Selected Lactic Acid Bacteria Strains and Apple By-Products into Beverages with Antimicrobial Properties and Enriched with Galactooligosaccharides

“…LAB strains had a significant influence (p ≤ 0.05) on GOS synthesis in fermented MP-thus highlighting the importance of LAB fermentation of milk permeate-based by-products, due to the ability to metabolize lactose and the concomitant production of metabolites with antimicrobial and antioxidant properties, as well as to the fact of being beneficial microorganisms and their metabolites are classified as Generally Regarded as Safe (GRAS) and Qualified Presumption of Safety (QPS) [10]. The highest total content of GOS (26.80 mg GOS /100 mL sample ) was obtained in fermented MPLUHS29, while the lowest concentration (8.7 mg GOS /100 mL sample ) was noticed in fermented MPLUHS135.…”

“…In addition, LAB take a leading role in food fermentation as they not only improve sensory properties of foods, but also increase its biosafety [7]. Most of the LAB strains possess antimicrobial properties, because of various metabolic processes-for example lactose metabolism, bacteriocin and bacteriocin-like inhibitory substance (BLIS) production, organic acids (mainly lactic and acetic acids), polysaccharide biosynthesis, proteolytic enzymes, bacteriophage resistance, metal-ion and antibiotic resistance, and citrate uptake [8][9][10][11][12][13][14][15][16][17]. Incorporation of fermented foods is very important towards a healthy and balanced diet, since fermented foods offer numerous benefits to human health [18].…”

Monitoring and Optimization of Cupuaçu Seed Fermentation, Drying and Storage Processes

“…Instead of following composting, these by-products—rich in lignocellulose, polysaccharides and other carbohydrates compounds, among others—may be used to yield high-added value products such as bioethanol, biobutanol, biogas, biopolymers, and biofertilizers, among other possibilities. The microbial processing [anaerobic or solid-state fermentations (STF)] or pyrolysis to release fermentable sugars are promising solutions to further produce single cell proteins (SCP) and oils (SCO) [ 13 , 15 , 20 , 33 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 ]. Cupuaçu endocarp (placenta) could be used to produce vinegar (acetic acid) or as an ingredient in sweets.…”

“…Cupuaçu and similar autochthonous agro-products are well adapted to the local climate and soil conditions, are typically resilient against climate changes, and have outstanding nutritional and healthy attributes, while promoting a sustainable agriculture and preserving natural resources, plant genetic diversity, and heritage. Indeed, the local small farmers who use the best agronomical practices are seen as fundamental protectors of the environment and biodiversity [ 13 , 20 , 73 , 78 , 79 ], and they are vital to creating discontinuity agricultural stains to prevent forest fires. Such features meet the international and EU policies [ 80 , 81 , 82 , 83 ] and particularly, the 2030 United Nations (UN) agenda [ 84 ] for taking global actions toward the global sustainability development with the rational use of natural resources.…”

“…Simultaneously, food fermentation enables the growth and exponential multiplication of the competitive and desirable regular non-spore-forming Gram-positive rods and the catalase-negative Gram-positive cocci—for example, lactic acid bacteria (LAB)—such as lactobacilli, pediococci, lactococci, leuconostoc, micrococci, streptococci and group D-enterococci—, and the production by the latter of desirable bioactive, antimicrobial, and antioxidant metabolites, such as small peptides, exopolysaccharides (EPS), organic acids, ethanol, CO 2 , bacteriocins, etc. [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. These desirable microorganisms and resulting compounds from their metabolic activity are generally non-toxic and food-grade microorganisms, being classified as Generally Regarded as Safe (GRAS) and Qualified Presumption of Safety (QPS) [ 15 ].…”