Differences in the physicochemical, digestion and microstructural characteristics of soy protein gel acidified with lactic acid bacteria, glucono-δ-lactone and organic acid

Exopolysaccharide (EPS) producing lactic acid bacteria (LAB) is considered to be an effective texture improver. The effect of LAB strains (different EPS production capacity) on physicochemical properties (texture profile, water distribution, rheological properties, and microstructure), protein conformation, and chemical forces of soybean protein gel was investigated. Correlations between EPS yield and gel properties were established. Large masses of EPS were isolated from L. casei fermentation gel (L. casei-G, 677.01 ± 19.82 mg/kg). Gel with the highest hardness (319.74 ± 9.98 g) and water holding capacity (WHC, 87.74 ± 2.00%) was also formed with L. casei. The conversion of β-sheet to α-helix, the increased hydrophobic interaction and ionic bond helped to form an ordered gel network. The yield was positively correlated with hardness, WHC, A22, viscoelasticity, and viscosity, but negatively correlated with A23 (p < 0.05). The macromolecular properties of EPS (especially the yield) and its incompatibility with proteins could be explained as the main reason for improving gel properties. In conclusion, the EPS producing LAB, especially L. casei used in our study, is the best ordinary coagulate replacement in soybean-based products.

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Treatment of Whole-Plant Corn Silage With Lactic Acid Bacteria and Organic Acid Enhances Quality by Elevating Acid Content, Reducing pH, and Inhibiting Undesirable Microorganisms

Frontiers in Microbiology ◽

10.3389/fmicb.2020.593088 ◽

2020 ◽

Vol 11 ◽

Author(s):

Fu-gui Jiang ◽

Hai-jian Cheng ◽

Dong Liu ◽

Chen Wei ◽

Wen-juan An ◽

...

Keyword(s):

Acetic Acid ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Organic Acids ◽

Organic Acid ◽

Acid Content ◽

Corn Silage ◽

Fresh Material ◽

Whole Plant ◽

Lactic Acid Content

We investigated the variation in microbial community and fermentation characteristics of whole-plant corn silage after treatment with lactic acid bacteria (LAB) and organic acids. The fresh corn forages were treated with a combination of L. acidophilus and L. plantarum (106 CFU/g fresh material) or a 7:1:2 ratio of formic acid, acetic acid, and propionic acid (6 mL/g fresh material) followed by 45 or 90 days of ensiling. Silages treated with LAB showed increased lactic acid content and decreased pH after 45 days. Although treatment with LAB or organic acids decreased the common and unique operational taxonomic units, indicating a reduction in microbial diversity, the relative abundance of Lactobacillus was elevated after 45 and 90 days compared with control, which was more distinct in the organic acid groups. Moreover, we found higher levels of acetic acid and increased abundance of Acetobacter in silages treated with organic acids whereas undesirable microorganisms such as Klebsiella, Paenibacillus, and Enterobacter were reduced. In summary, the quality of corn silages was improved by LAB or organic acid treatment in which LAB more effectively enhanced lactic acid content and reduced pH while organic acid inhibited the growth of undesirable microorganisms.

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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

Microorganisms ◽

10.3390/microorganisms8020172 ◽

2020 ◽

Vol 8 (2) ◽

pp. 172 ◽

Cited By ~ 6

Author(s):

Esmeray Kuley ◽

Gulsun Özyurt ◽

Ilyas Özogul ◽

Mustafa Boga ◽

Ismail Akyol ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Organic Acids ◽

Organic Acid ◽

Propionic Acid ◽

Gibel Carp ◽

Fermented Fish ◽

Acid Accumulation ◽

Dried Fish ◽

Spray Dried

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.

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Compression Molded Soy Protein Films with Exopolysaccharides Produced by Cider Lactic Acid Bacteria

Polymers ◽

10.3390/polym12092106 ◽

2020 ◽

Vol 12 (9) ◽

pp. 2106

Author(s):

Jone Uranga ◽

Mª Goretti Llamas ◽

Ziortza Agirrezabala ◽

María Teresa Dueñas ◽

Oier Etxebeste ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Soy Protein ◽

Fungal Spores ◽

Soy Protein Isolate ◽

Degradation Process ◽

Inhibitory Effect ◽

Protein Isolate ◽

Fungistatic Activity ◽

Vis Spectroscopy

Two exopolysaccharide (EPS)-producing lactic acid bacteria (LAB) strains, Liquorilactobacillus (L.) sp CUPV281 and Liquorilactobacillus (L.) mali CUPV271, were isolated from Spanish apple must. Each of the strains produced a dextran, with different branching degrees, to be incorporated into soy protein isolate (SPI) film-forming formulations. Films were prepared by compression molding, a more rapid processing method than solution casting and, thus, with a greater potential for scaling-up production. Thermal analysis showed that SPI and EPS start the degradation process at temperatures above 190 °C, confirming that the compression temperature selected (120 °C) was well below the corresponding degradation temperatures. Resulting films were transparent and homogeneous, as shown by UV-Vis spectroscopy and SEM, indicating the good compatibility between SPI and EPS. Furthermore, FTIR analysis showed that the interactions between SPI and EPS were physical interactions, probably by hydrogen bonding among the polar groups of SPI and EPS. Regarding antifungal/fungistatic activity, LAB strains used in this study showed an inhibitory effect on germination of fungal spores.

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Physicochemical, rheological and digestive characteristics of soy protein isolate gel induced by lactic acid bacteria

Journal of Food Engineering ◽

10.1016/j.jfoodeng.2020.110243 ◽

2021 ◽

Vol 292 ◽

pp. 110243

Author(s):

Xiaoyu Yang ◽

Chuxin Ke ◽

Liang Li

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Soy Protein ◽

Soy Protein Isolate ◽

Protein Isolate

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Lactic acid bacteria diversity in corn silage produced in Minas Gerais (Brazil)

Annals of Microbiology ◽

10.1007/s13213-019-01528-w ◽

2019 ◽

Vol 69 (13) ◽

pp. 1445-1459 ◽

Cited By ~ 3

Author(s):

Andréia de Oliveira dos Santos ◽

Carla Luiza da Silva Ávila ◽

Célia Soares ◽

Beatriz Ferreira Carvalho ◽

Rosane Freitas Schwan ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Organic Acid ◽

High Performance ◽

Random Amplified Polymorphic Dna ◽

Minas Gerais ◽

Corn Silage ◽

Organic Acid Production ◽

Rapd Pcr ◽

Band Profile

Abstract Purpose The diversity of lactic acid bacteria (LAB) in silages produced in warm climate countries is not well known. This study aimed to identify and characterise the metabolic and genotypic aspects of autochthonous LAB isolated from corn silage produced in the state of Minas Gerais, Brazil. Methods Eighty-eight LAB were isolated. To evaluate their performance at the strain level, all isolates were distinguished among strains using random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) and repetitive extragenic palindromic PCR (REP-PCR) techniques. The organic acid and ethanol production were determined by high-performance liquid chromatography (HPLC). Result The fingerprints obtained by RAPD-PCR with a M13 primer were more discriminatory than those obtained with the REP-PCR technique using a (GACA)4 primer. Moreover, 28 representative isolates were identified as Lactobacillus acidophilus, L. buchneri, L. casei, L. diolivorans, L. hilgardii, L. paracasei, L. parafarraginis, L. plantarum, L. rhamnosus, L. zeae and Pediococcus acidilactici. Different fingerprinting profiles between isolates within the same species were observed. However, some strains isolated from different silages showed the same band profile, thus suggesting the presence of clusters with high similar fingerprints in silages from various regions. Conclusion A variation in LAB diversity was observed in the silages of the evaluated regions, with L. rhamnosus and L. buchneri showing the highest distribution. Differences in organic acid production were observed among the strains belonging to the same species. This research contributes to a better understanding of the LAB community present in corn silage produced in warm climates. These strains will be studied as potential silage starters.

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