Summary
Advanced structures of food proteins are maintained by many forces such as hydrophobic activities, electrostatic interaction, and disulphide bond interaction, which can affect their ...functional characteristics to a certain extent. Therefore, many approaches have been utilised to improve functional characteristics of food proteins. pH‐shift process refers to the method that food proteins are treated under extreme alkaline or acid conditions followed by adjusting pH to isoelectric point or neutral pH. Many studies have showed that pH‐shift process can significantly affect the functional characteristics of food proteins, for example emulsifying activities, forming property, solubility and water/oil adsorption ability. pH‐shift process has been utilised to recover protein isolates from many sources including fish, fish by‐products, meat processing products. Many researches have indicated that the functional and physicochemical characteristics of recovered protein isolates are significantly influenced by pH‐shift process. In this paper, the latest studies regarding the functional and physicochemical characteristics of proteins treated or recovered through pH‐shift process, and potential applications of obtained protein isolates in the production of the hydrolysates or used as a delivery system were reviewed.
Protein properties treated by pH‐shift process and its applications.
Calcium is one of the essential minerals that enhances various biological activities, including the regulation of blood pressure, the prevention of osteoporosis and colorectal adenomas. ...Calcium-enriched edible mushrooms can be considered as one of the important daily sources of calcium in foods. Calcium accumulation in edible mushrooms is an effective way to enhance its activities because the organic state of calcium metabolites in edible mushrooms can be formed from the original inorganic calcium. The main calcium sources for calcium-enriched edible mushrooms' cultivation are CaCO
, CaCl
or Ca(NO
)
. The growth and metabolic process of edible mushrooms are significantly influenced by calcium enrichment. Generally, Ca at low levels is good for the production of edible mushrooms, whereas the reverse phenomenon for the growth of edible mushrooms at high Ca contents is observed. In addition, metabolites, for example, phenolics, flavonoids, polysaccharides, enzymes, minerals, etc., are improved when edible mushrooms are enriched at a moderate level of calcium. This review summarized the literature regarding the influence of calcium enrichment on edible mushrooms' growth and major metabolites. Furthermore, the mechanisms of calcium enrichment in edible mushrooms were highlighted. Understanding calcium-enriched mechanisms in edible mushrooms would not only be beneficial to manipulate the cultivation of edible mushrooms having excellent biological activities and high levels of active Ca, but it would also contribute to the applications of calcium enrichment products in food industries.
Encapsulation and immobilization technology is important for the food processing and bioengineering industries. Chitosan is a natural polysaccharide prepared by the N - deacetylation of chitin. It ...has been widely used in food and bioengineering industries, including the encapsulation of active food ingredients, in enzyme immobilization, and as a carrier for controlled drug delivery, due to its significant biological and chemical properties such as biodegradability, biocompatibility, bioactivity, and polycationicity. In this work, chitosan nanoparticles and nanofibers used to encapsulate bioactive substances and immobilize enzymes were reviewed. Preparation of chitosan nanoparticles and nanofibers, including the work achieved in our group on chitosan nanoparticles for enzyme immobilization, were also introduced. Some problems encountered with nano - structured chitosan carriers for bioactive substance encapsulation and enzyme immobilization were discussed, together with the future prospects of such systems.
Bacterial contamination reduces the shelf-life of foods and presents serious risks to human health. Nanotechnology provides the opportunity for the development of new antibacterial agents. ...Nano-inorganic metal oxides have shown the potential to reduce bacterial contamination of foods. When the particle size of materials decreases from the micrometre to the nanometre range, nano-functional properties such as diffusivity, mechanical strength, chemical reactivity and biological properties are improved. Significantly, ZnO has been used in many applications with particular success. Many studies have shown that ZnO nanoparticles have enhanced antibacterial activity. This review discusses the main synthetic methods, antibacterial activity, antibacterial mechanisms and food applications of ZnO nanoparticles.
Summary
Owing to their considerable beneficial effects on human health, probiotics have been increasingly incorporated into food products. However, many findings have demonstrated that their survival ...and stability are very sensitive to processing and host gastrointestinal tract. To solve these problems, encapsulation techniques have been received considerable attention these days. So, in this review paper, methods for probiotics encapsulation, alginate‐based and protein‐based materials for probiotics encapsulation and application of encapsulated probiotics in food industry were discussed.
Carrageenan-locust bean gum coated milk microspheres were developed to encapsulate the probiotic Lactobacillus bulgaricus (L. bulgaricus) with the aim of enhancing the probiotic survival numbers ...during exposure to the adverse environmental conditions of the gastro-intestinal tract. The results indicated that milk microspheres with double layer structure could improve the stability of L. bulgaricus in simulated gastro-intestinal conditions. The viability of encapsulated L. bulgaricus did not change after 2 h incubation in simulated gastric fluid (SGF) pH 2.5. In SGF pH 2.0, the viability of encapsulated L. bulgaricus could be preserved more than 8 Log CFU/g after 2 h incubation. In 2 g/100 mL bile salt solution, encapsulated L. bulgaricus only suffered 1 Log CFU/g viability reduction after 1 h treatment, and 1.5 Log CFU/g viability reductions after 2 h treatment. Encapsulation could also improve the storage stability of encapsulated L. bulgaricus. The viability of encapsulated L. bulgaricus was kept constant after 1 month storage at 4 °C. Milk microspheres had high release rate for L. bulgaricus in simulated intestine fluid (SIF), which could be totally released in 45 min. This study presents a good encapsulation carrier which protects probiotic L. bulgaricus during exposure to adverse environment conditions.
•Lactobacillus bulgaricus was encapsulated in carrageenan-locust bean gum coated milk microspheres.•Encapsulated L. bulgaricus showed better survival rate compared with free cells.•Encapsulation of L. bulgaricus offers an effective delivery way to intestinal tract.
This study aimed to study the entrapment of Enterococcus faecalis HZNU S1 using a mixture of flaxseed protein isolate (FPI) and sodium alginate (SA) as an encapsulation agent. The characteristics of ...free and encapsulated cells during storage and under in vitro gastrointestinal conditions were investigated. The survival rate of encapsulated cells did not decline after 2 h exposure to pH 2.5 simulated gastric juice (SGJ), while viable free probiotics treated at the same conditions, were not found. After encapsulated probiotics were exposed to SGJ pH 2.0 for 2.0 h, the viability decreased from 10.01 to 8.01 Log CFU/g. After exposure to 1.0% and 2.0% bile salt solutions for 2 h, the viable amounts of encapsulated probiotics were still higher 8.0 Log CFU/g, whereas, viable free cells were not observed after treatment at the same conditions. Encapsulated probiotics were fully released from the microbeads in simulated intestinal juice (SIJ) in around 4 h. The viable numbers of encapsulated probiotics were only reduced 0.5 Log CFU/g after two weeks of storage (4 °C), and the viable amounts of encapsulated probiotics were reduced to 8.2 Log CFU/g at 25 °C after eight days of storage. However, the viable amounts of free cells were reduced from 10.01 to 8.8 Log CFU/mL (4 °C), and 4.0 Log CFU/mL (25 °C) during the investigated storage period, respectively. Encapsulated E. faecalis HZNU S1 showed enhanced resistance to environmental conditions, allowing the delivery of probiotics that could be used to increase foods added value.
Chronic postsurgical pain (CPSP) is a chronic pain state that is difficult to be treated clinically. A series of complicated changes have been produced from nociceptive stimulation to the occurrence ...and development of postsurgical pain. Many mechanisms remain unclear. In order to study the role of intercellular gap junctions in inducing inflammatory microenvironment at the beginning of nociceptor after operation, the model of skin/muscle incision and retraction (SMIR) was established. We observed the changes of the expression of exchange proteins directly activated by cAMP-1 (Epac1) and p120 catenin (p120), the quantities of macrophages and endothelial cells, vascular endothelial permeability, and mechanical withdrawal threshold (MWT). It was found that macrophages and endothelial cells were functionally coupled through Epac1-p120. Adhesive linkage disorder remodeled the chronic, inflammatory, and eutrophic microenvironment at the beginning of nociceptor after operation through macrophages, endothelial cells, and endothelial paracellular pathways. It might be an early event and a key step in peripheral sensitization of CPSP. The expression of p120 in muscle tissue around the incision might become a prognostic marker for the conversion of acute postsurgical pain into CPSP. Targeted intervention of Epac1-p120 might be a clinical strategy for inhibiting the conversion of acute postsurgical pain into CPSP.
Exopolysaccharides of Paenibacillus polymyxa: A review Huang, Xuan-Ya; Ye, Xin-Pei; Hu, Yan-Yu ...
International journal of biological macromolecules,
March 2024, 2024-Mar, 2024-03-00, 20240301, Volume:
261, Issue:
Pt 1
Journal Article
Peer reviewed
Paenibacillus polymyxa (P. polymyxa) is a member of the genus Paenibacillus, which is a rod-shaped, spore-forming gram-positive bacterium. P. polymyxa is a source of many metabolically active ...substances, including polypeptides, volatile organic compounds, phytohormone, hydrolytic enzymes, exopolysaccharide (EPS), etc. Due to the wide range of compounds that it produces, P. polymyxa has been extensively studied as a plant growth promoting bacterium which provides a direct benefit to plants through the improvement of N fixation from the atmosphere and enhancement of the solubilization of phosphorus and the uptake of iron in the soil, and phytohormones production. Among the metabolites from P. polymyxa, EPS exhibits many activities, for example, antioxidant, immunomodulating, anti-tumor and many others. EPS has various applications in food, agriculture, environmental protection. Particularly, in the field of sustainable agriculture, P. polymyxa EPS can be served as a biofilm to colonize microbes, and also can act as a nutrient sink on the roots of plants in the rhizosphere. Therefore, this paper would provide a comprehensive review of the advancements of diverse aspects of EPS from P. polymyxa, including the production, extraction, structure, biosynthesis, bioactivity and applications, etc. It would provide a direction for future research on P. polymyxa EPS.
PDF
