Whey protein-kefiran films as driver of probiotics to the gut

Sensitive delivery systems and novel encapsulation technologies for live biotherapeutic products and probiotics

Live biotherapeutic product (LBP), a type of biological product, holds promise for the prevention or treatment of metabolic disease and pathogenic infection. Probiotics are live microorganisms that improve the intestinal microbial balance and beneficially affect the health of the host when ingested in sufficient numbers. These biological products possess the advantages of inhibition of pathogens, degradation of toxins, and modulation of immunity. The application of LBP and probiotic delivery systems has attracted great interest to researchers. The initial used technologies for LBP and probiotic encapsulation are traditional capsules and microcapsules. However, the stability and targeted delivery capability require further improved. The specific sensitive materials can greatly improve the delivery efficiency of LBPs and probiotics. The specific sensitive delivery systems show advantages over traditional ones due to their better properties of biocompatibility, biodegradability, innocuousness, and stability. Moreover, some new technologies, including layer-by-layer encapsulation, polyelectrolyte complexation, and electrohydrodynamic technology, show great potential in LBP and probiotic delivery. In this review, novel delivery systems and new technologies of LBPs and probiotics were presented, and the challenges and prospects were explored in specific sensitive materials for LBP and probiotic delivery.

Sheep's Second Cheese Whey Edible Coatings with Oregano and Clary Sage Essential Oils Used as Sustainable Packaging Material in Cheese

Sheep's second cheese whey (SCW), the by-product resulting from whey cheese production, was used as a component of cheese coatings containing oregano (Origanum compactum) and clary sage (Salvia sclarea) essential oils (EOs). SCW powder was obtained by the ultrafiltration/diafiltration of SCW followed by reverse osmosis and freeze drying. The coatings were produced with a mixture of SCW and whey protein isolate (WPI) using glycerol as plasticizer. Model cheeses were produced with cow´s milk and those containing SCW:WPI coatings; those with and without EOs were compared to controls without coating and with a commercial coating containing natamycin. At the end of ripening (28 days), the cheeses containing EOs presented higher water activity (ca. 0.930) and moisture content, as well as lower titratable acidity. Concerning color parameters, significant differences were also observed between products and as a result of ripening time. However, the use of SCW:WPI coatings did not significantly influence the color parameters at the end of ripening. Regarding texture parameters, the cheeses containing SCW:WPI coatings presented significantly lower values for hardness, chewiness, and gumminess. Significant differences were also observed for all microbial groups evaluated either between products and as a result of ripening time. In all cases, lactobacilli and lactococci counts surpassed log 7-8 CFU/g, while the counts of yeasts and molds increased steadily from ca. log 3 to log 6 CFU/g. The lowest counts of yeasts and molds were observed in the samples containing natamycin, but nonsignificant differences between products were observed. In conclusion, SCW:WPI cheese coatings can successfully substitute commercial coatings with the advantage of being edible packaging materials manufactured with by-products.

Recent Highlights in Sustainable Bio-Based Edible Films and Coatings for Fruit and Vegetable Applications

The present review paper focuses on recent developments in edible films and coatings made of base compounds from biological sources, namely plants, animals, algae, and microorganisms. These sources include by-products, residues, and wastes from agro-food industries and sea products that contribute to sustainability concerns. Chitosan, derived from animal biological sources, such as crustacean exoskeletons, has been the most studied base compound over the past three years. Polysaccharides typically constitute no more than 3-5% of the film/coating base solution, with some exceptions, like Arabic gum. Proteins and lipids may be present in higher concentrations, such as zein and beeswax. This review also discusses the enrichment of these bio-based films and coatings with various functional and/or bioactive compounds to confer or enhance their functionalities, such as antimicrobial, antioxidant, and anti-enzymatic properties, as well as physical properties. Whenever possible, a comparative analysis among different formulations was performed. The results of the applications of these edible films and coatings to fruit and vegetable products are also described, including shelf life extension, inhibition of microbial growth, and prevention of oxidation. This review also explores novel types of packaging, such as active and intelligent packaging. The potential health benefits of edible films and coatings, as well as the biodegradability of films, are also discussed. Finally, this review addresses recent innovations in the edible films and coatings industry, including the use of nanotechnologies, aerogels, and probiotics, and provides future perspectives and the challenges that the sector is facing.

Preparation of Synbiotic Yogurt Sauce Containing Spirulina platensis Microalgae Extract and Its Effect on the Viability of Lactobacillus acidophilus

Background

Preparing a healthy and practical substitute for mayonnaise and reducing the complications caused by its consumption are two of the concerns of the producers of this product. Therefore, this study was conducted with the aim of evaluating the possibility of producing synbiotic yogurt sauce prepared with Spirulina platensis microalgae extract (SPAE) as a valuable and alternative product for mayonnaise.

Materials and Methods

After preparing yogurt from fresh cow's milk, synbiotic yogurt sauce was prepared according to the formulation, and the effect of SPAE at the rate of 0.5, 1, and 2% on the viability of the probiotic bacteria Lactobacillus acidophilus was evaluated, and chemical, rheological, and sensory tests were carried out in the storage period (35 days).

Results

The highest viability rate of L. acidophilus was related to the treatment containing 2% of SPAE with 1.31 log CFU/g reduction (from 9.02 log CFU/g on the first day to 7.71 log CFU/g on the final day) and 1% of SPAE with 2.98 log CFU/g reduction, respectively, which were significantly more effective than other treatments (P < 0.05), and it was found that the viability rate increases with the increase in the percentage of the prebiotic composition. There was also a significant difference between the treatments in the simulating conditions of the digestive system, and the viability of L. acidophilus in the treatment containing the prebiotic composition increased (P < 0.05). According to the results, during storage, in the presence of microalgae, acidity increased, and pH, viscosity, and sensory properties decreased compared to the control group. Upon analyzing the results, it was found that the addition of the prebiotic composition of SPAE, which is known as a functional product, led to a partial improvement in its properties. Therefore, the use of this alga, while benefiting from its medicinal and therapeutic properties, increases the viability rate of probiotic.

Effect of caseinate salt addition on the structural characteristics of kefiran systems

Sodium caseinates-kefiran systems were studied to explore whether any potential interactions between them might exist. The study was performed using low-deformation rheological techniques, which were dynamic and creep tests. The systems were prepared under various experimental conditions such as heating and acidification. Besides, the structure development of the systems in relation to time was also monitored using oscillatory shear rheometry. The results indicated that the structural characteristics of the systems were mainly affected by the state of the caseinates such as the formation of aggregates and to a lesser degree by the interactions of kefiran molecules with the caseinates. Freeze-thaw treatment produced cryogels with good thermal stability and fairly satisfactory mechanical properties. The morphology of the caseinate-kefiran systems was also investigated by means of confocal laser scanning microscopy.

Probiotics: mechanism of action, health benefits and their application in food industries

Probiotics, like lactic acid bacteria, are non-pathogenic microbes that exert health benefits to the host when administered in adequate quantity. Currently, research is being conducted on the molecular events and applications of probiotics. The suggested mechanisms by which probiotics exert their action include; competitive exclusion of pathogens for adhesion sites, improvement of the intestinal mucosal barrier, gut immunomodulation, and neurotransmitter synthesis. This review emphasizes the recent advances in the health benefits of probiotics and the emerging applications of probiotics in the food industry. Due to their capability to modulate gut microbiota and attenuate the immune system, probiotics could be used as an adjuvant in hypertension, hypercholesterolemia, cancer, and gastrointestinal diseases. Considering the functional properties, probiotics are being used in the dairy, beverage, and baking industries. After developing the latest techniques by researchers, probiotics can now survive within harsh processing conditions and withstand GI stresses quite effectively. Thus, the potential of probiotics can efficiently be utilized on a commercial scale in food processing industries.

Impact of adding prebiotics and probiotics on the characteristics of edible films and coatings- a review

Nowadays, conventional packaging materials made using non-renewable sources are being replaced by more sustainable alternatives such as natural biopolymers (proteins, polysaccharides, and lipids). Within edible packaging, one can differentiate between edible films or coatings. This packaging can be additivated with bioactive compounds to develop functional food packaging, capable of improving the consumer's state of health. Among the bioactive compounds that can be added are probiotics and prebiotics. This review novelty highlighted recent research on edible films and coatings additivated with probiotics and prebiotics, the interactions between them and the matrix and the changes in their physic, chemical and mechanical properties. When bioactive compounds are added, critical factors must be considered when selecting the most suitable production processes. Particularly, as probiotics are living microorganisms, they are more sensitive to certain factors, such as pH or temperature, while prebiotic compounds are less problematic. The interactions that occur inside the matrix can be divided into two main groups: covalent bonding (-NH₂, -NHR, -OH, -CO₂H, etc) and non-covalent interactions (van der Waals forces, hydrogen bonding, hydrophobic and electrostatic interactions). When probiotics and prebiotics are added, covalent and non-covalent interactions are modified. The physical and mechanical properties of films and coatings depend directly on the interactions that take place between the biopolymers that form their matrix. Greater knowledge about the influence of these compounds on the interactions that occur inside the matrix will allow better control of these properties and better understanding of the behaviour of edible packaging additivated with probiotics and prebiotics.

Novel nano-encapsulated probiotic agents: Encapsulate materials, delivery, and encapsulation systems

Gut microbes are closely associated with most human health. When ingested orally, probiotics can effectively regulate the composition and quantity of human intestinal microorganisms, which is beneficial to human health. However, probiotics will be affected by the harsh environment of the digestive tract during the in vivo transportation process, and ensuring the viability of probiotics is a great challenge. Probiotic encapsulating technology provides an effective solution to this problem. The introduction of extreme temperatures, large probiotic microcapsule sizes and the difficulty in controlling probiotic microcapsule particle sizes mean that traditional microcapsule encapsulation methods have some limitations. From traditional microcapsule technology to the bulk encapsulation of probiotics with nanofibers and nanoparticles to the recent ability to wear nano "armor" for a single probiotic through biofilm, biological membrane and nanocoating. Emerging probiotic nanoagents provides a new conceptual and development direction for the field of probiotic encapsulation. In this review, we presented the characteristics of encapsulated probiotic carrier materials and digestive tract transport systems, we focused on the encapsulation systems of probiotic nanoagents, we analyzed the shortcomings and advantages of the current agent encapsulation systems, and we stated the developmental direction and challenges for these agents for the future.

Lacticaseibacillus rhamnosus GG Survival and Quality Parameters in Kefir Produced from Kefir Grains and Natural Kefir Starter Culture

The study aimed to determine the effect of starter cultures (kefir grains and natural kefir starter culture without grains) on Lacticaseibacillus rhamnosus GG (LGG) survival and on the quality characteristics of kefir. To this end, the viability of probiotic L. rhamnosus GG strain and the rheological properties and quality parameters of kefir beverages were tested during storage over 21 days at 4 °C. The final LGG counts were 7.71 and 7.55 log cfu/mL in natural kefir starter culture and kefir grain, respectively. When prepared with probiotic bacteria, the syneresis values of kefir prepared using natural kefir starter culture was significantly lower (p < 0.05) than that of kefir made using grains. However, the viscosity indices, hysteresis loop, and dynamic moduli were similar between kefir made with natural kefir starter culture and other kefir formulations (p > 0.05). Moreover, all samples showed shear-thinning behavior. The flavor scores for kefir prepared using natural kefir starter culture were significantly higher than for the other samples (p < 0.05), but overall acceptability was similar at the 10-day assessment across both starters (with and without grain) after the addition of probiotic bacteria (p > 0.05). Overall, the results indicate that natural kefir starter culture could be a potential probiotic carrier.

Preparation of Edible Films with Lactobacillus plantarum and Lactobionic Acid Produced by Sweet Whey Fermentation

Cheese whey, one of the most abundant by-products of the dairy industry, causes economic losses and pollution problems. In this study, deproteinised sweet whey was fermented by Pseudomonas taetrolens LMG 2336 to produce a prebiotic compound (lactobionic acid, LBA). Endotoxins produced by these microorganisms were successfully removed using microfiltration techniques, allowing the fermented whey permeate to be used in the food industry. The fermented whey permeate was used to develop prebiotic edible films by adding two different concentrations of gelatine (0.45 and 0.9 g gelatine g−1 LBA; LBA45 and LBA90). Furthermore, Lactobacillus plantarum CECT 9567 was added as a probiotic microorganism (LP45 and LP90), creating films containing both a prebiotic and a probiotic. The mechanical properties, water solubility, light transmittance, colour, and microstructure of the films were fully characterised. Additionally, the LBA and probiotic concentration in LP45 and LP90 were monitored under storage conditions. The strength and water solubility of the films were affected by the presence of LBA, and though all these films were homogeneous, they were slightly opaque. In LP45 and LP90, the presence of LBA as a prebiotic improved the viability of L. plantarum during cold storage, compared to the control. Therefore, these films could be used in the food industry to coat different foodstuffs to obtain functional products.

Application of Whey Protein-Based Edible Films and Coatings in Food Industries: An Updated Overview

The recent surge in environmental awareness and consumer demand for stable, healthy, and safe foods has led the packaging and food sectors to focus on developing edible packaging materials to reduce waste. Edible films and coatings as a modern sustainable packaging solution offer significant potential to serve as a functional barrier between the food and environment ensuring food safety and quality. Whey protein is one of the most promising edible biopolymers in the food packaging industry that has recently gained much attention for its abundant nature, safety, and biodegradability and as an ecofriendly alternative of synthetic polymers. Whey protein isolate and whey protein concentrate are the two major forms of whey protein involved in the formation of edible films and coatings. An edible whey film is a dry, highly interacting polymer network with a three-dimensional gel-type structure. Films/coatings made from whey proteins are colorless, odorless, flexible, and transparent with outstanding mechanical and barrier properties compared with polysaccharide and other-protein polymers. They have high water vapor permeability, low tensile strength, and excellent oxygen permeability compared with other protein films. Whey protein-based films/coatings have been successfully demonstrated in certain foods as vehicles of active ingredients (antimicrobials, antioxidants, probiotics, etc.), without considerably altering the desired properties of packaging films that adds value for subsequent industrial applications. This review provides an overview of the recent advances on the formation and processing technologies of whey protein-based edible films/coatings, the incorporation of additives/active ingredients for improvement, their technological properties, and potential applications in food packaging.

Insights on the Critical Parameters Affecting the Probiotic Viability During Stabilization Process and Formulation Development

Probiotics have gained a lot of interest in recent years as an alternative as well as adjuvant therapy for several conditions owing to their health benefits. These live microorganisms have proven efficacy for treating gut disorders, inflammation, bacterial vaginosis, hepatic and depressive disorders, and many more. There are conventional as well as non-conventional formulations available for the delivery of probiotics with the latter having fewer regulatory guidelines. The conventional formulations include the pharmaceutical formulations specifically designed to deliver an efficacious number of viable microorganisms. Studies have indicated 10⁸-10⁹ CFU/g as an ideal dose of probiotics for achieving health benefits, and hence, all the formulations must at least contain the said number of viable bacteria to show a therapeutic effect. The most crucial feature of probiotic formulations is that the bacteria are prone to several environmental and processing factors which all together reduce the viability of the bacteria in the final formulation. These factors include processing parameters like temperature, humidity, pressure, and storage conditions. Thus, the present review primarily focuses on the critical process parameters affecting the probiotic viability during stabilization process and formulation development. Understanding these factors prior to processing helps in delivering probiotics in the required therapeutic numbers at the target site.

Functionalizing and bio-preserving processed food products via probiotic and synbiotic edible films and coatings

Edible films and coatings constitute an appealing concept of innovative, cost-effective, sustainable and eco-friendly packaging solution for food industry applications. Edible packaging needs to comply with several technological pre-requisites such as mechanical durability, low permeability to water vapor and gases, good optical properties, low susceptibility to chemical or microbiological alterations and neutral sensory profile. Over the past few years, functionalization of edible films and coatings via the inclusion of bioactive compounds (antioxidants, micronutrients, antimicrobials, natural coloring and pigmentation agents) and beneficial living microorganisms has received much attention. As for living microorganisms, probiotic bacterial cells, primarily belonging to the Lactobacilli or Bifidobacteria genera, have been exploited to impart bespoke health and biopreservation benefits to processed food. Given that the health benefit conferring and biopreservation potential of probiotics is dependent on several extrinsic and intrinsic parameters, the development of probiotic and synbiotic edible packaging concepts is a quite challenging task. In the present chapter, we aimed at a timely overview of the technological advances in the field of probiotic, symbiotic and synbiotic edible films and coatings. The individual or combined effects of intrinsic (matrix composition and physical state, pH, dissolved oxygen, water activity, presence of growth stimulants or inhibitors) and extrinsic (film forming method, food processing, storage time and conditions, exposure to gastrointestinal conditions) factors on maintaining the biological activity of probiotic cells were addressed. Moreover, the impact of living cells inclusion on the mechanical, physicochemical and barrier properties of the edible packaging material as well as on the shelf-life and quality of the coated or wrapped food products, were duly discussed.