Fermentation of Gluten by Lactococcus lactis LLGKC18 Reduces its Antigenicity and Allergenicity

Inhibition of Biogenic Amines in Fermented Tilapia Surimi by Collaborative Fermentation of Latilactobacillus sakei and Pediococcus acidilactici

Fermentation is an effective method for ameliorating the gelation properties of freshwater fish surimi, but the formation of biogenic amines (BAs) during fermentation should also be controlled. In this study, the BAs in fermented tilapia surimi were inhibited by the collaborative fermentation of Latilactobacillus sakei and Pediococcus acidilactici, followed by the revelation of the BA inhibition mechanism. Most of the BAs, and the total BA, as well as their precusor free amino acids (FAAs), were significantly reduced, while the umami FAAs, including glutamic acid and aspartic acid, were significantly enhanced after cooperative fermentation with starters. The high-throughput sequencing found that the spoilage microorganisms such as Acinetobacter, Micrococcus, and Streptococcus as well as Pediococcus were significantly inhibited, while Latilactobacillus rapidly became the dominant genus after cooperative fermentation, suggesting the better environment adaptability of L. sakei than P. acidilactici. The group-dimension correlation analysis suggested that Lactiplantibacillus had the greatest influence on the decrease in BAss. The quick acidification of starters, especially L. sakei, could inhibit the growth and metabolism of spoilage microorganisms to reduce BAs. L. sakei and P. acidilactici can be developed as the special starters to control the BA production in the fermented tilapia surimi through collaborative fermentation.

Emerging Chemical, Biochemical, and Non-Thermal Physical Treatments in the Production of Hypoallergenic Plant Protein Ingredients

Allergies towards gluten and legumes (such as, soybean, peanut, and faba bean) are a global issue and, occasionally, can be fatal. At the same time, an increasing number of households are shifting to plant protein ingredients from these sources, which application and consumption are limited by said food allergies. Children, the elderly, and people with immune diseases are particularly at risk when consuming these plant proteins. Finding ways to reduce or eliminate the allergenicity of gluten, soybean, peanut, and faba bean is becoming crucial. While thermal and pH treatments are often not sufficient, chemical processes such as glycation, polyphenol conjugation, and polysaccharide complexation, as well as controlled biochemical approaches, such as fermentation and enzyme catalysis, are more successful. Non-thermal treatments such as microwave, high pressure, and ultrasonication can be used prior to further chemical and/or biochemical processing. This paper presents an up-to-date review of promising chemical, biochemical, and non-thermal physical treatments that can be used in the food industry to reduce or eliminate food allergenicity.

Predicting wheat gluten concentrations in potato starch using GPR and SVM models built by terahertz time-domain spectroscopy

The purpose of this study was for the first time to explore the feasibility of terahertz (THz) spectral imaging for the detection of gluten contents in food samples. Based on the obtained 80 THz spectrum data, Gaussian process regression (GPR) and support vector machine (SVM) models were established to predict wheat gluten concentrations in 40 potato starch mixture samples. The prediction performances of GPR and SVM obtained were R2 = 0.859 and RMSE = 0.070, and R2 = 0.715 and RMSE = 0.101 in the gluten concentration range of 1.3%-100%, respectively, showing that the linear SVM algorithm had better prediction performance. The results indicated that THz spectral imaging combined with GPR could be used to predict the gluten content in food samples. It is thus hoped that this research should provide a novel technique for gluten content detection to ensure gluten-free food samples.

The Differences in Protein Degradation and Sensitization Reduction of Mangoes between Juices and Pieces Fermentation

Given the allergic reaction caused by mangoes, nonthermal food technologies for allergenicity reduction are urgently desired. This study aimed to assess the impact of kombucha fermentation on the allergenicity of mangoes. The total proteins, soluble proteins, peptides, amino acid nitrogen, the SDS-PAGE profiles of the protein extracts, and immunoreactivity of the sediment and supernatant were measured in two fermentation systems (juices and pieces fermentation). Throughout the fermentation, the pH decreased from about 4.6 to about 3.6, and the dissolved oxygen reduced about 50% on average. However, the protein degradation and sensitization reduction of mangoes were different between the two fermentation systems. In juices fermentation, there was a drop in proteins and peptides but an increase in amino acids, due to the conversion of proteins and peptides into amino acids both in the supernatant and sediment. The allergenicity decreased both in the solid and liquid phases of juices fermentation. In pieces fermentation, proteins and peptides were decreased in the solid phase but increased in the liquid phase. This was due to the fact that proteins and peptides were partly transported into the culture liquid, resulting in a decrease of allergenicity in fruit pieces and an increase in culture liquid. The principal component analysis results showed that the fermentation type had significant effects on the protein degradation and sensitization reduction, while mango variety had no significant effect. These results demonstrate that kombucha fermentation can reduce the allergenicity of mangoes, and it is more effective in juices fermentation than in pieces fermentation. The present study provides a theoretical basis for developing hypoallergenic mango products.

Bacillus Strains Isolated from Korean Fermented Food Products with Antimicrobial Activity Against Staphylococci, an Alternative for Control of Antibiotic-Resistant Pathogens

Multidrug resistance in foodborne and clinical pathogens is a worldwide health problem. The urgent need for new alternatives to the existing antibiotics is emerging. Bacteriocin-like inhibitory substances can be considered part of the new generation of antimicrobials, which can be potentially applied in the food industry and health care practices. This study aimed to select Bacillus strains with antimicrobial activity against Staphylococcus spp. with future application in the formulation of pharmaceutical antimicrobial preparations. Putative antimicrobial agent-producing strains, previously isolated and preidentified as Bacillus spp. were profiled by repetitive element sequence-based polymerase chain reaction (rep-PCR) and 16s rRNA sequencing identified the strains as Bacillus tequilensis ST1962CD with 99.47% identity confidence and as Bacillus subtilis subsp. stercoris ST2056CD with 98.45% identity confidence. Both the selected Bacillus strains were evaluated via biomolecular and physiological approaches related to their safety and virulence, beneficial properties, enzyme production profile, and presence of corresponding genes for the production of antimicrobials and virulence. Both strains were confirmed to harbor srfa and sbo genes and be free of hemolysin binding component (B) and two lytic components (L1 and L2) [BL] and nonhemolytic enterotoxin-associated genes. Produced antimicrobial agents by strains ST1962CD and ST2056CD were partially purified through the combination of ammonium sulfate precipitation and hydrophobic-based chromatography on SepPakC18 and evaluated regarding their cytotoxicity. The dynamics of bacterial growth, pH change, accumulation of produced antimicrobials, and the mode of action were evaluated. Obtained results were pointing to the potential application of safe B. tequilensis ST1962CD and B. subtilis subsp. stercoris ST2056CD strains as functional beneficial microbial cultures that are putative producers of surfactin and/or subtilosin, as potent antimicrobials, for the treatment of some staphylococcal-associated infections. Expressed antimicrobials were shown to be not cytotoxic, and appropriate biotechnological approaches need to be developed for cost-effective production, isolation, and purification of expressed antimicrobials by studied strains.

Influence of Fermentation by Lactobacillus helveticus on the Immunoreactivity of Atlantic Cod Allergens

Fermentation techniques may induce alterations in fish allergen immunoreactivity. In this study, the influence of fermentation with three different strains of Lactobacillus helveticus (Lh187926, Lh191404, and Lh187926) on the immunoreactivity of Atlantic cod allergens was investigated via several methods. Gradually reduced protein composition and band intensity due to the fermentation by strain Lh191404 were found in SDS-PAGE analysis, and decreased immunoreactivity of fish allergens was confirmed by Western blotting and ELISA analysis due to the fermentation of strain Lh191404. Additionally, results from nLC-MS/MS and immunoinformatics tools analysis demonstrated that the protein polypeptide and allergen composition of Atlantic cod showed evident alterations after fermentation, with the epitopes of the main fish allergens being heavily exposed and destroyed. These results indicated that the fermentation of L. helveticus Lh191404 could destroy the structure and linear epitopes of the allergens from Atlantic cod and may have considerable potential in mitigating the allergenicity of fish.

Bioactive Peptides from Lupin (Lupinus angustifolius) Prevent the Early Stages of Atherosclerosis in Western Diet-Fed ApoE-/- Mice

We have previously reported the in vitro hypocholesterolemic, anti-inflammatory, and antioxidant effects of Alcalase-generated lupin protein hydrolysate (LPH). Given that lipoprotein deposition, oxidative stress, and inflammation are the main components of atherogenesis, we characterized the LPH composition, in silico identified LPH-peptides with activities related to atherosclerosis, and evaluated the in vivo LPH effects on atherosclerosis risk factors in a mouse model of atherosclerosis. After 15 min of Alcalase hydrolysis, peptides smaller than 8 kDa were obtained, and 259 peptides out of 278 peptides found showed biological activities related to atherosclerosis risk factors. Furthermore, LPH administration for 12 weeks reduced the plasma lipids, as well as the cardiovascular and atherogenic risk indexes. LPH also increased the total antioxidant capacity, decreased endothelial permeability, inflammatory response, and atherogenic markers. Therefore, this study describes for the first time that LPH prevents the early stages of atherosclerosis.

Fermentation of plant-based dairy alternatives by lactic acid bacteria

Ethical, environmental and health concerns around dairy products are driving a fast‐growing industry for plant‐based dairy alternatives, but undesirable flavours and textures in available products are limiting their uptake into the mainstream. The molecular processes initiated during fermentation by lactic acid bacteria in dairy products is well understood, such as proteolysis of caseins into peptides and amino acids, and the utilisation of carbohydrates to form lactic acid and exopolysaccharides. These processes are fundamental to developing the flavour and texture of fermented dairy products like cheese and yoghurt, yet how these processes work in plant‐based alternatives is poorly understood. With this knowledge, bespoke fermentative processes could be engineered for specific food qualities in plant‐based foods. This review will provide an overview of recent research that reveals how fermentation occurs in plant‐based milk, with a focus on how differences in plant proteins and carbohydrate structure affect how they undergo the fermentation process. The practical aspects of how this knowledge has been used to develop plant‐based cheeses and yoghurts is also discussed.

Selection of Bacteriocinogenic Bacillus spp. from Traditional Fermented Korean Food Products with Additional Beneficial Properties

Two Bacillus spp. isolated from kimchi, Bacillus tequilensis ST816CD and Bacillus subtilis ST830CD, were characterized for their antimicrobial properties and safety. The proteinaceous nature of their inhibitory metabolites was confirmed after exposure to proteolytic enzymes, resulting in partial loss of the antimicrobial effect. This indicated that different non-proteinaceous antimicrobial substances may also be produced by these strains. This hypothesis was later confirmed when genes associated with the production of surfactants were detected in their DNA. The expressed antimicrobial metabolites were not affected by treatment at different temperatures and pH levels, including exposure to selected chemicals. Their strong adherence to susceptible pathogens was not significantly affected by different temperatures, chemicals, or pH values. Both Bacillus strains showed inhibitory activity against clinical and food-associated pathogens, including Listeria monocytogenes ATCC 15313, and some Staphylococcus species. Several genes associated with the production of antimicrobial metabolites were detected, but key virulence and beneficial genes were not present in these strains. Even though only B. tequilensis ST816CD displayed γ-hemolysin production, both selected strains were found to produce gelatinase and biogenic amines, which are considered as either potential virulence- or health-related factors. Moreover, the strains were susceptible to a variety of antibiotics except for the penicillin G [1 IU/disc] resistance of B. tequilensis ST816CD. Both strains showed proteolytic activity. Additionally, both strains showed low hydrophobicity based on bacterial adherence measured by hydrocarbons (n-hexadecane).