Bio-preservation of white brined cheese (Feta) by using probiotic bacteria immobilized in bacterial cellulose: Optimization by response surface method and characterization

Biopreservative technologies of food: an alternative to chemical preservation and recent developments

Despite centuries of developing strategies to prevent food-associated illnesses, food safety remains a significant concern, even with multiple technological advancements. Consumers increasingly seek less processed and naturally preserved food options. One promising approach is food biopreservation, which uses natural antimicrobials found in food with a long history of safe consumption and can help reduce the reliance on chemically synthesized food preservatives. The hurdle technology method that combines multiple antimicrobial strategies is often used to improve the effectiveness of food biopreservation. This review attempts to provide a research summary on the utilization of lactic acid bacteria, bacteriocins, endolysins, bacteriophages, and biopolymers helps in the improvement of the shelf-life of food and lower the risk of food-borne pathogens throughout the food supply chain. This review also aims to evaluate current technologies that successfully employ the aforementioned preservatives to address obstacles in food biopreservation.

Modification of pectin/starch-based beads with additives to improve Bacillus subtilis encapsulation for agricultural applications

The use of Bacillus as biofertilizer is a sustainable strategy to increase agricultural productivity, but it still requires the development of formulations to protect cells from stressful conditions. Ionotropic gelation using a pectin/starch matrix is a promising encapsulation strategy to achieve this goal. By incorporating additives such as montmorillonite (MMT), attapulgite (ATP), polyethylene glycol (PEG), and carboxymethyl cellulose (CMC), the properties of these encapsulated products could be further improved. In this study, we investigated the influence of these additives on the properties of pectin/starch-based beads for the encapsulation of Bacillus subtilis. FTIR analysis indicated pectin and Ca2+ ions interactions, while the XRD showed good dispersion of clays in the materials. SEM and X-ray microtomography revealed differences in the morphology of the beads due to the use of the additives. The viabilities at the encapsulation were higher than 1010 CFU g-1 for all formulations, with differences in the release profiles. In terms of cell protection, the pectin/starch, pectin/starch-MMT and pectin/starch-CMC formulations showed the highest cell viability after exposure to fungicide, while the pectin/starch-ATP beads showed the best performance after UV exposure. Moreover, all formulations maintained more than 109 CFU g-1 after six months of storage, which meets values required for microbial inoculants.

The study of nutritional value and microbiological characteristics of brine cheese with vegetable additive

This article investigated brine cheeses' nutritional value and safety by adding vegetable additives (dry powder of white cabbage and coriander). Brynza brine cheese was used as the basis for the recipe. By the chemical composition of the cheese with vegetable, additives has a significantly higher protein content (26.27 g/100g), while the fat content is lower (14.98 g/100g). There is a high content of amino acids and fatty acids (PUFA 6%, MUFA 24%). During prolonged storage of brine cheese, water activity aw decreases in control from 0.997 to 0.990, mass fraction of moisture increases from 60% to 62.5%, in the brine cheese with vegetable additives aw from 0.998 to 0.991, mass fraction of moisture from 61.1% to 63.7%.The use of vegetable additives in the formulation of cheeses does not affect the deterioration of microbiological parameters compared to the control sample. As a result of experimental studies, the shelf life of brine cheese with vegetable additives is 8-10 days.

Biodegradable edible film based on basil seed gum: the effect of gum and plasticizer concentrations.. [DOI: 10.21203/rs.3.rs-2626369/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

In this research, edible films produced from basil seed gum (BSG) with 3 different gum (0.5%, 1%, 1.5%) and plasticizer concentrations (1%, 3%, 5%) were developed, and the physical, thermal, barrier and microstructural properties of these films were measured. As a result of XRD, AFM, DSC, and FT-IR spectroscopy analyses, it was concluded that the mechanical and barrier properties and thermal stability of BSG-based films are quite good. The increase in gum and glycerol concentrations increased the crystallinity also strengthened the mechanical and barrier properties of the film. Also, films with low gum and high glycerol ratio have almost smooth surfaces and appropriate transparency for packaging applications. As the glycerol and BSG concentration increased, WVP values of the films increased. The complete dissolution of this film in the soil within 60 days, even at the highest gum concentration, showed that this material could be considered eco-friendly packaging. For this reason, it is thought that BSG-based films and coatings with suitable gum and plasticizer concentrations can be a potential packaging material for foods since they can be obtained at low cost, have a very good barrier, thermal and structural properties, and are edible and biodegradable.

Development and characterization of probiotic (co)encapsulates in biopolymeric matrices and evaluation of survival in a millet yogurt formulation

The formulation of probiotics-enriched products still remains a challenge for the food industry due to the loss of viability, mainly occurring upon consumption and during storage. To tackle this challenge, the current study investigated the potential of using sodium alginate and inulin (SIN) in combination with various encapsulating materials such as skim milk (SKIM), whey protein concentrate (WPC), soy protein concentrate (SPC), and flaxseed oil (FS) to increase the viability of Lactobacillus casei upon freeze-drying, under simulated gastrointestinal conditions, during 28 days of storage at 4°C, and in a formulation of millet yogurt. Microstructural properties of microcapsules and co-microcapsules by SEM, oxidative stability of flaxseed oil in co-microcapsules, and physicochemical and sensory analysis of the product were performed. The produced microcapsules (SIN-PRO-SKIM, SIN-PRO-WP, and SIN-PRO-SP) and co-microcapsules (SIN-PRO-FS-SKIM, SIN-PRO-FS-WP, and SIN-PRO-FS-SP) had a high encapsulation rate >90%. Moreover, encapsulated and co-encapsulated strains exhibited a high in vitro viability accounting for 9.24 log10 CFU/g (SIN-PRO-SKIM), 8.96 log10 CFU/g (SIN-PRO-WP), and 8.74 log10 CFU/g (SIN-PRO-SP) for encapsulated and 10.08 log10 CFU/g (SIN-PRO-FS-SKIM), 10.03 log10 CFU/g (SIN-PRO-FS-WP), and 10.14 log10 CFU/g (SIN-PRO-FS-SP) for co-encapsulated. Moreover, encapsulated and co-encapsulated cells showed higher survival upon storage than free cells. Also, the SEM analysis showed spherical particles of 77.92-230.13 µm in size. The physicochemical and sensory analysis revealed an interesting nutritional content in the millet yogurt. The results indicate that the SIN matrix has significant promise as probiotic encapsulating material as it may provide efficient cell protection while also providing considerable physicochemical and nutritional benefits in functional foods.

Strategies for the Development of Bioprotective Cultures in Food Preservation

Consumers worldwide are increasingly demanding food with fewer ingredients, preferably without chemical additives. The trend called "Clean Label" has stimulated the development and commercialization of new types of bioprotective bacterial cultures. These bacteria are not considered new, and several cultures have been available on the market. Additionally, new bioprotective bacteria are being identified to service the clean label trend, extend the shelf life, and, mainly, improve the food safety of food. In this context, the lactic acid bacteria (LAB) have been extensively prospected as a bioprotective culture, as they have a long history in food production and their antimicrobial activity against spoilage and pathogenic microorganisms is well established. However, to make LAB cultures available in the market is not that easy, the strains should be characterized phenotypically and genotypically, and studies of safety and technological application are necessary to validate their bioprotection performance. Thus, this review presents information on the bioprotection mechanisms developed by LAB in foods and describes the main strategies used to identify and characterize bioprotective LAB with potential application in the food industry.

The encapsulation strategy to improve the survival of probiotics for food application: From rough multicellular to single-cell surface engineering and microbial mediation

The application of probiotics is limited by the loss of survival due to food processing, storage, and gastrointestinal tract. Encapsulation is a key technology for overcoming these challenges. The review focuses on the latest progress in probiotic encapsulation since 2020, especially precision engineering on microbial surfaces and microbial-mediated role. Currently, the encapsulation materials include polysaccharides and proteins, followed by lipids, which is a traditional mainstream trend, while novel plant extracts and polyphenols are on the rise. Other natural materials and processing by-products are also involved. The encapsulation types are divided into rough multicellular encapsulation, precise single-cell encapsulation, and microbial-mediated encapsulation. Recent emerging techniques include cryomilling, 3D printing, spray-drying with a three-fluid coaxial nozzle, and microfluidic. Encapsulated probiotics applied in food is an upward trend in which "classic probiotic foods" (yogurt, cheese, butter, chocolate, etc.) are dominated, supplemented by "novel probiotic foods" (tea, peanut butter, and various dry-based foods). Future efforts mainly include the effect of novel encapsulation materials on probiotics in the gut, encapsulation strategy oriented by microbial enthusiasm and precise encapsulation, development of novel techniques that consider both cost and efficiency, and co-encapsulation of multiple strains. In conclusion, encapsulation provides a strong impetus for the food application of probiotics.

Application of innovative packaging technologies to manage fungi and mycotoxin contamination in agricultural products: Current status, challenges, and perspectives

The consumer demand for safe, "healthy," and premium foods, preferably with an extended shelf-life; demand for easy packaging; and choice for more sustainable food packaging have contributed to the development of novel packaging technologies. The application of adequate packaging materials has recently become a major post-harvest challenge concerning the control of fungi and mycotoxin. This review will describe the current antifungal packaging technology involved to prevent the contamination of fungi and mycotoxin, along with the characteristics and mechanism of action in food products. Antifungal packaging has incredible potential in the food packaging sector. The most suitable approach for the safe storage of agricultural produce for farmers is the hermetic packaging technology, which maintains quality while providing a good barrier against fungi and mycotoxin. Furthermore, active antifungal packaging is a viable method for incorporating antifungal agents against pathogenic fungi. Essential oils and organic acid have received more scientific attention due to their increased efficacy against mold growth. Polypeptides, chitosan, and natamycin incorporated in active packaging significantly reduced fungi. Even though nanotechnological advancements in antifungal packaging are promising, safety and regulation issues remain significant concerns.

The Role of Microencapsulation in Food Application

Modern microencapsulation techniques are employed to protect active molecules or substances such as vitamins, pigments, antimicrobials, and flavorings, among others, from the environment. Microencapsulation offers advantages such as facilitating handling and control of the release and solubilization of active substances, thus offering a great area for food science and processing development. For instance, the development of functional food products, fat reduction, sensory improvement, preservation, and other areas may involve the use of microcapsules in various food matrices such as meat products, dairy products, cereals, and fruits, as well as in their derivatives, with good results. The versatility of applications arises from the diversity of techniques and materials used in the process of microencapsulation. The objective of this review is to report the state of the art in the application and evaluation of microcapsules in various food matrices, as a one-microcapsule-core system may offer different results according to the medium in which it is used. The inclusion of microcapsules produces functional products that include probiotics and prebiotics, as well as antioxidants, fatty acids, and minerals. Our main finding was that the microencapsulation of polyphenolic extracts, bacteriocins, and other natural antimicrobials from various sources that inhibit microbial growth could be used for food preservation. Finally, in terms of sensory aspects, microcapsules that mimic fat can function as fat replacers, reducing the textural changes in the product as well as ensuring flavor stability.

Optimization of food-grade medium for co-production of bioactive substances by Lactobacillus acidophilus LA-5 for explaining pharmabiotic mechanisms of probiotic

This study aimed to optimize the co-production of conjugated linoleic acid (CLA), exopolysaccharides (EPSs) and bacteriocins (BACs) by Lactobacillus acidophilus LA-5 in dairy food-grade by-product. The factorial design revealed that the significant factors were temperature, time, and yeast extract. Then the response surface methodology was used for optimization. At the optimal conditions the viable cell number, CLA, EPSs, and inhibition activity were 2.62 ± 0.49 × 108 CFU/mL, 51.46 ± 1.50 μg/mL, 348.24 ± 5.61 mg/mL and 12.46 ± 0.80 mm, respectively. FTIR, GC, TLC, and SDS page analysis revealed the functional groups of pharmabiotics. The FTIR, GC, TLC, and SDS page analysis showed that both CLA isomers (c-9, t-11, and t-10, c-12) produced. The FTIR, GC, TLC, and SDS page analysis indicated that produced EPSs were composed of glucose, mannose, galactose, xylose, and fructose. FTIR, GC, TLC, and SDS page used to report BACs molecular weight, which showed two fractions by molecular mass 35 and 63 kDa. Previously the ability of different probiotic bacteria investigated and optimized the production of CLA, EPSs, and BACs, but, there was no report on the co-producing capacity of these bioactive metabolites by probiotics. The present work was investigated to optimize the co-production of pharmabiotic metabolites by L. acidophilus LA-5, in supplemented cheese whey as a cultivation medium.

Microencapsulation of Lactobacillus acidophilus LA-5 and Bifidobacterium animalis BB-12 in pectin and sodium alginate: A comparative study on viability, stability, and structure

The present study aimed at examining whether the microencapsulation of Lactobacillus acidophilus LA-5 and Bifidobacterium animalis BB-12 inside hydrogels could prolong their survival in freeze-drying conditions, stored at 4℃ and in the gastrointestinal medium. Microencapsulation was performed by emulsion with a syringe, while sodium alginate and high methoxyl pectin were used as a carrier material. A relatively high efficiency of encapsulation was obtained (>92%). Z-Average and pdI in samples were not significant (p < .05). In different treatments, changes in the number of bacteria after freeze-drying, 30 days of storage, and gastrointestinal conditions, compared to each other, were significant (p < .05). However, the survival rate after a reduction during storage was higher than 106 cfu/g, indicating the suitability of the microencapsulation process. The surface of microcapsules observed by a scanning electron microscope (SEM) confirmed the success of encapsulation. Finally, a lower decrease in the count of microencapsulated was observed in comparison to the free cells.

Evaluation of the bioprotectivity of Lactobacillus binary/ternary cultures in yogurt

The attempts toward addition of biocontrol agents in dairy products have gained popularity. Here, we worked on analysing the antifungal activity of binary and ternary combinations of three Lactic Acid Bacteria (LAB) against five spoilage yeasts in yogurt. The yogurt samples were characterized in terms of pH, acidity, WHC, textural parameters, viscosity, survivability and antifungal activity of LAB and sensorial properties during cold storage. The results showed that the inoculation of LAB in yogurt gave rise in significant reduction of pH throughout cold storage while titrable acidity and WHC decreased (p < .05). Inoculation of LAB resulted in significant increase in hardness and adhesiveness while springiness remained constant. On the other hand, apparent viscosity of all samples experienced a profound increase up to the 10th day of storage followed by a reduction trend for the rest of storage period. Analysis of inhibitory activity of LAB showed an efficient barrier against all five yeasts, in which the most activity was recorded for Lactobacillus reuteri followed by Lactobacillus acidophilus. On the other hand, the most resistance yeast was Kluyveromyces marxianus followed by Rhodotorula mucilaginosa. Sensorial analysis revealed that addition of LAB in yogurt brought about a profound improvement in textural quality of samples. Inoculation of LAB cultures in yogurt at 5% (v/v) not only could improve the physicochemical and sensorial properties of yogurt, but also could introduce a strategy toward substituting of chemical preservatives with biocontrol agents.

Postbiotics produced by lactic acid bacteria: The next frontier in food safety

There are many critical challenges in the use of primary and secondary cultures and their biological compounds in food commodities. An alternative is the application of postbiotics from the starter and protective lactic acid bacteria (LAB). The concept of postbiotics is relatively new and there is still not a recognized definition for this term. The word "postbiotics" is currently used to refer to bioactive compounds, which did not fit to the traditional definitions of probiotics, prebiotics, and paraprobiotics. Therefore, the postbiotics may be presently defined as bioactive soluble factors (products or metabolic byproducts), produced by some food-grade microorganisms during the growth and fermentation in complex microbiological culture (in this case named cell-free supernatant), food, or gut, which exert some benefits to the food or the consumer. Many LAB are considered probiotic and their postbiotic compounds present similar or additional health benefits to the consumer; however, this review aimed to address the most recent applications of the postbiotics with food safety purposes. The potential applications of postbiotics in food biopreservation, food packaging, and biofilm control were reviewed. The current uses of postbiotics in the reduction and biodegradation of some food safety-related chemical contaminants (e.g., biogenic amines) were considered. We also discussed the safety aspects, the obstacles, and future perspectives of using postbiotics in the food industry. This work will open up new insights for food applications of postbiotics prepared from LAB.