Retention Of Bioactivity Research Articles

An efficient (nano) silica - In glucan particles protein encapsulation approach for improved thermal stability

Glucan particles (GPs) are hollow, porous microspheres derived from Saccharomyces cerevisiae (Baker's yeast). The hollow cavity of GPs allows for efficient encapsulation of different types of macromolecules and small molecules. The β-1,3-D-glucan outer shell provides for receptor-mediated uptake by phagocytic cells expressing β-glucan receptors and uptake of particles containing encapsulated proteins elicit protective innate and acquired immune responses against a wide range of pathogens. A limitation of the previously reported GP protein delivery technology is limited protection from thermal degradation. Here we present results of an efficient protein encapsulation approach using tetraethylorthosilicate (TEOS) to lock protein payloads in a thermostable silica cage formed in situ inside the hollow cavity of GPs. The methods for this improved, efficient GP protein ensilication approach were developed and optimized using bovine serum albumin (BSA) as model protein. The improved method involved controlling the rate of TEOS polymerization, such that the soluble TEOS-protein solution was able to be absorbed into the GP hollow cavity before the protein–silica cage polymerized and becomes too large to transverse across the GP wall. This improved method provided for >90% GP encapsulation efficiency, increased thermal stabilization of GP ensilicated BSA, and was shown to be applicable for encapsulation of proteins of different molecular weights and isoelectric points. To demonstrate the retention of bioactivity of this improved method of protein delivery, we evaluated the in vivo immunogenicity of two GP ensilicated vaccine formulations using (1) ovalbumin as a model antigen and (2) a protective antigenic protein from the fungal pathogen Cryptococcus neoformans. The results show that the GP ensilicated vaccines have a similar high immunogenicity as our current GP protein/hydrocolloid vaccines, as evidenced by robust antigen-specific IgG responses to the GP ensilicated OVA vaccine. Further, a GP ensilicated C. neoformans Cda2 vaccine protected vaccinated mice from a lethal pulmonary infection of C. neoformans.

Ce-MBGs Loaded with Gentamicin: Characterization and In Vitro Evaluation.

Mesoporous Bioactive Glasses (MBGs) are biomaterials widely used in tissue engineering, particularly for hard tissue regeneration. One of the most frequent postoperative complications following a biomaterial surgical implant is a bacterial infection, which usually requires treatment by the systemic administration of drugs (e.g., antibiotics). In order to develop biomaterials with antibiotic properties, we investigated cerium-doped MBGs (Ce-MBGs) as in situ-controlled drug delivery systems (DDSs) of gentamicin (Gen), a wide spectrum antibiotic commonly employed against bacteria responsible of postoperative infections. Here we report the optimization of Gen loading on MBGs and the evaluation of the antibacterial properties and of retention of bioactivity and antioxidant properties of the resulting materials. The Gen loading (up to 7%) was found to be independent from cerium content, and the optimized Gen-loaded Ce-MBGs retain significant bioactivity and antioxidant properties. The antibacterial efficacy was verified up to 10 days of controlled release. These properties make Gen-loaded Ce-MBGs interesting candidates for simultaneous hard tissue regeneration and in situ antibiotic release.

Scalable Production of Monodisperse Bioactive Spider Silk Nanowires.

Elongated protein-based micro- and nanostructures are of great interest for a wide range of biomedical applications, where they can serve as a backbone for surface functionalization and as vehicles for drug delivery. Current production methods for protein constructs lack precise control of either shape and dimensions or render structures fixed to substrates. This work demonstrates production of recombinant spider silk nanowires suspended in solution, starting with liquid bridge induced assembly (LBIA) on a substrate, followed by release using ultrasonication, and concentration by centrifugation. The significance of this method lies in that it provides i) reproducability (standard deviation of length <13% and of diameter <38%), ii) scalability of fabrication, iii) compatibility with autoclavation with retained shape and function, iv) retention of bioactivity, and v) easy functionalization both pre- and post-formation. This work demonstrates how altering the function and nanotopography of a surface by nanowire coating supports the attachment and growth of human mesenchymal stem cells (hMSCs). Cell compatibility is further studied through integration of nanowires during aggregate formation of hMSCs and the breast cancer cell line MCF7. The herein-presented industrial-compatible process enables silk nanowires for use as functionalizing agents in a variety of cell culture applications and medical research.

Design of encapsulation method for chlorogenic acid and caffeine in coffee waste by-product.

Coffee silver skin (CSS) is a thin covering over green coffee seeds inside coffee cherry. It is a good source of bioactive compounds like chlorogenic acid and caffeine. It is produced as a by-product of the roasting process. The goal of this study is to apply spray drying method to encapsulate 5-O-caffeoylquinic acid (chlorogenic acid) and caffeine extracted from CSS. The main-plots for optimisation were feed solid concentration (2.5, 5, 10°Bx), and the sub-plots of the whole-plot were carrier material type (maltodextrin, modified starch, arabic gum) and inlet air temperature (130, 160, 190°C). Responses included were drying yield, chlorogenic acid concentration, caffeine content, Carr index, and solubility values. Suitable conditions were spray drying inlet temperature of 190°C, extract concentration of 10°Bx, and wall material composition [modified starch/arabic gum (MS:AG)] 10.5:9.5. As the feeding CSS extract concentration increased, the amount of chlorogenic acid and caffeine in the final powder increased, while the powder's flow characteristics improved. The concentration stage might be used to produce free-flowing powdered particles with good bioactive retention for use in the food processing industry.

Ultrasound‐assisted extraction of bioactive compounds from giloy (Tinospora cordifolia) stem: Quantitative process optimization and bioactives analysis

AbstractGiloy (Tinospora cordifolia), a medicinal herb, contains several bioactives having immunomodulatory properties and various health benefits. In this study, giloy stem extract was derived using ultrasound process followed by screening of secondary metabolites and bioactives. Box–Behnken design coupled with RSM was employed for the optimization of yield, total phenolic content and antioxidant activity of GSE with respect to solvent‐to‐solid (SS) ratio, sonication time (ST), and ultrasound amplitude (UA). The UA, ST and their interaction effects had significantly influenced the green extract yield and quality. The optimum extractions conditions were found to be 30% (UA), 10:1 (SS ratio), and 30 min (ST). The optimum responses were obtained as follows: extract yield: 9.614 ± 0.015%, TPC: 100.04 ± 0.133 (mg GAE/100 g extract), and DPPH % inhibition: 78.8523 ± 0.399%. Screening of optimized extract through HR‐LCMS‐QTOF reported the presence of major polyphenols such as malic acid, catechin, and quercitrin with a match factor of 99.23%, 98.65%, and 90.58%, respectively.Practical applicationsGiloy (T. cordifolia) is a potential source of bioactive compounds with significant medicinal properties and chemical stability. Recent trends suggest paradigm shift toward research and development of active food from the herbal plant for special purposes such as supplements, functional food, nutraceuticals, or medicine. Thus, non‐thermal extraction and characterization of extract for screening along with higher retention of bioactive from herbal plants such as giloy and its utilization becomes a crucial part of any industry. In this regard, the present study on ultrasound extraction is the way ahead due to high bioactive retention and the cost implications of the process.

Optimization of storage conditions for lipid nanoparticle-formulated self-replicating RNA vaccines.

The recent clinical success of multiple mRNA-based SARS-CoV-2 vaccines has proven the potential of RNA formulated in lipid nanoparticles (LNPs) in humans, and products based on base-modified RNA, sequence-optimized RNA, and self-replicating RNAs formulated in LNPs are all in various stages of clinical development. However, much remains to be learned about critical parameters governing the manufacturing and use of LNP-RNA formulations. One important issue that has received limited attention in the literature to date is the identification of optimal storage conditions for LNP-RNA that preserve long-term activity of the formulations. Here, we analyzed the physical structure, in vivo expression characteristics, and functional activity of alphavirus-derived self-replicating RNA (repRNA)-loaded LNPs encoding HIV vaccine antigens following storage in varying temperatures, buffers, and in the presence or absence of cryoprotectants. We found that for lipid nanoparticles with compositions similar to clinically-used LNPs, storage in RNAse-free PBS containing 10% (w/v) sucrose at -20°C was able to maintain vaccine stability and in vivo potency at a level equivalent to freshly prepared vaccines following 30days of storage. LNPs loaded with repRNA could also be lyophilized with retention of bioactivity.

Horseradish Peroxidase Catalyzed Silk-Prefoldin Composite Hydrogel Networks.

Protein-based hydrogel biomaterials provide a platform for different biological applications, including the encapsulation and stabilization of different biomolecules. These hydrogel properties can be modulated by controlling the design parameters to match specific needs; thus, multicomponent hydrogels have distinct advantages over single-component hydrogels due to their enhanced versatility. Here, silk fibroin and γ-prefoldin chaperone protein based composite hydrogels were prepared and studied. Different ratios of the proteins were chosen, and the hydrogels were prepared by enzyme-assisted cross-linking. The secondary structure of the two proteins, dityrosine bond formation, and mechanical properties were assessed. The results obtained can be used as a platform for the rational design of composite thermostable hydrogel biomaterials to facilitate protection (due to hydrogel mechanics) and retention of bioactivity (e.g., of enzymes and other biomolecules) due to chaperone-like properties of γ-prefoldin.

Ultrasound processing of sweet lime juice: Effect of matrix pH on microbial inactivation, enzyme stability, and bioactive retention

AbstractThe effect of pH on microbial, enzyme inactivation, and bioactive retention in ultrasound (US) treated sweet lime (Citrus limetta) juice was studied. The pH of the juice varied at 3.5, 4.0, and 4.5, whereas the US duty cycle (DC) ranged between 75% and 95% (0.07–0.7 W/cm3), and the treatment time varied between 15 and 30 min. More than 5‐log reduction in Saccharomyces cerevisiae and Escherichia coli was achieved at DC 95% (25 min) while Listeria monocytogenes got inactivated at DC 85% (25 min). 95%–99% inactivation of peroxidase and pectin methylesterase was achieved at DC 95% (30 min), while 60% inactivation in polyphenol oxidase (PPO) was observed. The addition of ascorbic acid (1 g/L) as an EI resulted in the complete inactivation of PPO at DC 85% (25 min). A maximum color change (ΔE*) of 2.6 was noticed at the highest US treatment condition (DC 95%, 30 min). Eventually, pH showed a marginal effect (˂5%) on retaining vitamin C and bioactive compounds, but US treatment enhanced them. US treatment at DC 95% (30 min) produced microbially safe (˃5‐log cycle reduction) and enzymatically stable (99% enzyme inactivation) juice. To conclude, optimized US treatment increased total phenolic content (TPC), antioxidant capacity, and vitamin C in sweet lime juice by 16.7%, 10.7%, and 14.1%, respectively.Practical applicationsConsumer demand for superior quality sweet lime juice with minimal processing. This explores the opportunity of applying US technology as one of the nonthermal treatments for such a product. Furthermore, the treated juice should be microbially safe and enzymatically stable with better bioactive preservation. Typically, the pH of the fruit juice is one of the main influencing factors controlling microbiological spoilage. The current study explores the consequence of matrix pH and US conditions on the microbial inactivation, enzyme stability, and bioactive compounds of US‐treated sweet lime juice. The hypothesis is that the ultrasonic power required to achieve microbial safety at a lower pH of sweet lime juice should be lower. This will eventually help the industry choose an optimal harvesting condition to obtain the desired pH during processing.

Chitosan-cinnamon essential oil/sodium alginate-TiO2 bilayer films with enhanced bioactive retention property: Application for mango preservation

The bilayer anti-ultraviolet preservation films were developed successfully by incorporating the cinnamon essential oil (CEO) to chitosan (CH) as the bioactive layer, and incorporating the TiO2 to sodium alginate (SA) as the protective layer. The addition of CEO improved the antibacterial and antioxidant properties of the films. The addition of TiO2 enhanced the bioactive retention property of the films. Remarkably, CS-0.6 film had better water vapor permeability (WVP) and mechanical properties, but CS-1.2 film had better antioxidant and antibacterial properties. After 10 d of storage, the CS-0.6 group of mangoes maintained the highest firmness of 17.62 ± 0.85 N and the highest total phenol content of 254.40 ± 4.14 mg/100 g. It also had the lowest lipoxygenase activity of 5.00 ± 1.66 10−3 U/kg. The obtained research results revealed that the developed CH/SA based bilayer film incorporated with CEO and TiO2 could be used as a multifunctional packaging material to maintain the freshness of harvested mangoes.

Biomolecule-friendly conducting PEDOT interface for long-term bioelectronic devices

One of the main challenges in biosensing devices is the development of a biocompatible and stable long-term biosensing interface to efficiently convert biological information into detectable electrical signals. Herein, we propose a facile and universal strategy to fabricate protein-encapsulated poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) materials for signal transduction using the biopolymer chitosan as both the crosslinker of PEDOT:PSS and the bioprotectant of proteins. The solid electrostatic interaction between chitosan and PSS was verified using Fourier-transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), which makes PEDOT:PSS curable at room temperature, with good film formability and excellent aqueous stability. Electrochemical measurements revealed a low impedance for electron communication of the PEDOT:PSS/chitosan electrode through the solid-liquid interface. Notably, the bioactivity test using glucose oxidase (GOx) as a model protein encapsulated in PEDOT:PSS/chitosan demonstrated its exceptionally high bioactivity retention (94 % of their original catalytic activity), leading to a biosensor with high sensitivity and stability. Consequently, the developed glucose biosensor demonstrated a broad response range from 0.05 to 36.53 mM and a low limit of detection of 0.02 mM, with favorable long-term stability. To confirm its versatility, the proposed PEDOT:PSS/chitosan platform was successfully employed to detect lactate and epinephrine, which are the main components of biofluids. This work provides a straightforward and effective method for the fabrication of bio-device interfaces, demonstrating significant potential for applications in biosensors, biofuel cells, and other biosensing devices.

Stability and antioxidant activity of bioactive compounds in Cerrado fruit juices during storage

The development of beverages with differential characteristics is mandatory, due to changes in the food habits of the population. The production of ready-to-drink fruit juices presents an interesting process for the shelf life extension, integral utilization of the fruits and the development of new products. The introduction of Cerrado fruit in this segment increases the visibility of these native species that are still unexploited. This study aimed to evaluate the bioactive compound stability of juices (marolo, cagaita and mixed: marolo + cagaita) during the refrigerated storage. The content of the vitamin C, total phenolics and antioxidant activity (auto-oxidation of the β-carotene/linoleic acid system, ABTS •+ and DPPH• free scavenging radical) in the juices were determined during the storage. The use of marolo and cagaita in the development of ready-to-drink beverages was suitable. A reduction in the vitamin C, total phenolics and antioxidant activity (evaluated by three methodologies) was observed during the 90 days. Considerable bioactive retention was obtained, highlighting the importance of the Cerrado fruit juices production.

Encapsulation for efficient spray drying of fruit juices with bioactive retention

Encapsulation for efficient spray drying of fruit juices with bioactive retention

Application of Supercritical Fluid Extraction (SFE) of Tocopherols and Carotenoids (Hydrophobic Antioxidants) Compared to Non-SFE Methods

Natural antioxidants have renewed value for human health and the food industry. Green labeling is becoming an important attribute for consumers and is impacting food processing and formulations. Clean label is another attribute that ranked third after the “free-from” claims and “a good source” of nutrient claims. Clean label attributes also are ranked higher than local, seasonal, and organic. Techniques that are able to preserve the valuable characteristics of natural antioxidants, while eliminating even trace amounts of solvent residues from their extraction and processing, are important. Supercritical fluids (SCF) are an effective green technology that can be adopted for extraction of natural antioxidants. This review is focused on the application of supercritical carbon dioxide (SCCO2) for extracting hydrophobic antioxidant compounds with an emphasis on oilseed crops and carrots. The information provided about extraction parameters helps to guide optimization of the yield of tocopherols and carotenoids. Pressure is the most effective parameter for the extraction yield of tocopherol among the other parameters, such as temperature, time, and CO2 flow rate. For carotenoid extraction, both pressure and temperature have a large impact on extraction yield. Higher yields of antioxidants, greater purity of the extracts, and larger retention of bioactivity are the main advantages of supercritical fluid extraction (SFE) in comparison to other conventional techniques. The benefits of SCF technology may open new opportunities for extracting valuable, natural and effective antioxidant compounds from food processing co-streams for use as bioactive compounds.

Encapsulation of Catechin into β-Glucan Matrix Using Wet Milling and Ultrasonication as a Coupled Approach: Characterization and Bioactivity Retention

In this study, the nanoencapsulation of catechin into the β-glucan matrix from oats [O-Glu (C)] and barley [B-Glu (C)] was performed using the coupled approach of ultrasonication and wet milling. The nanoencapsulated catechin was characterised by particle size distribution, surface charge, SEM, and FTIR. The particle size was found to be 200 nm and 500 nm while zeta potential was found −27.13 and −24 mV for O-Glu (C) and B-Glu (C), respectively. The encapsulation efficiency of O-Glu (C) and B-Glu (C) was found to be 86.5% and 88.2%. FTIR and SEM revealed successful entrapment of catechin in β-glucan. The encapsulated capsules showed sustainable release during simulated gastrointestinal conditions. Moreover, both O-Glu (C) and B-Glu (C) showed that biological activity such as lipase inhibition activity and antioxidant assay were retained after in vitro digestion. It was concluded that O-Glu (C) and B-Glu (C) can be used as functional ingredients effectively in food as well as in the pharmaceutical field.

Comparative study of intermediate-wave and catalytic infrared drying on the kinetics and physicochemical properties of pineapple rings

This comprehensive study examined the effects of two infrared drying modes: intermediate-wave infrared drying (IWD) and catalytic infrared drying (CID), on drying kinetics and various quality parameters of pineapple rings at 60–80 °C. Hot-air drying (HAD) was the control drying operation. CID showed the highest drying rates and coefficients of moisture diffusivity (3.05 × 10−8 m2/s to 5.12 × 10−8 m2/s), resulting in drying times (1.88–3.15 h) that were about half that of HAD (3.57–7.25 h) and 10–34% less than that of IWD (2.08–4.75 h). Compared to IWD, CID exhibited minor color changes and a stronger flavor profile and enzyme inactivation potential. However, it resulted in a hardened product surface, thus reducing the rehydration ability. Overall, CID exhibited higher bioactive retention rates, especially at 60 °C (56–87%), followed by IWD at 70 °C (50–80%) and 80 °C (35–90%). Based on the results of this study, CID produces superior quality dried pineapples in a significantly shorter drying time, which is of potential industrial interest.

Phytosterol, Tocopherol and Carotenoid Retention during Commercial Processing of Brassica napus (Canola) Oil

Brassica napus (canola) seed is a rich source of phytosterols, tocopherols and carotenoids, which all have recognized health benefits, although these are reduced or lost during crude oil refinement. Many studies are now outdated, so new research to monitor bioactive retention through current processing techniques is warranted. In this work, canola seed, in-process seed, and oil samples were collected from the major stages of five commercial canola oil processes. Analysis of phytosterols, tocopherols and carotenoids indicated seed pre-treatment enhanced bioactive concentrations in the crude oil. Although the bleaching step in each process eliminated all carotenoids, high concentrations of phytosterols and tocopherols remained in the refined oil across all processes, with losses notably lower than those found in previous reports. Moreover, crude oil samples from a two-stage cold pressing process showed greatly enriched concentrations of tocopherols (+122%), sterols (+140%) and carotenoids (+217%). The results show that modern Australian canola oil processing retains high phytosterol and tocopherol concentrations and warrants further investigation into bioactive enrichment strategies. Given the growing interest in health-enhanced foods, this study provides opportunities for nutrition and health-enhanced oil products and the potential for adding value in the edible oil industry.

Combination treatment including irradiation improved the keeping quality of bitter melon (Momordica charantia L) with retention of functional bioactives while fulfilling phytosanitary requirement for export

Present work dealt with development of a combination process for prolonged extension of shelf life of whole as well as minimally processed bitter gourd samples. In this treatment, GRAS chemicals were used for extension of shelf life while radiation processing was optimized to use as a phytosanitary treatment. The whole process involved dipping the bitter gourd samples in sodium hypochlorite (200 ppm) at 52 °C for 10 min (as disinfectant treatment) followed by potassium metabisulphite at optimal concentration (0.5%) for 10 min at 26 ± 2 °C (as an antifungal treatment). Finally, the samples were exposed to low dose (1 kGy) gamma irradiation treatment as a phytosanitary measure. An extended shelf life of 30 days was obtained, while improving the microbiological quality and retaining the colour, textural and sensory qualities. Combination process significantly enhanced the total phenolic content in processed samples during the storage period as compared to unprocessed control. Antioxidant activities of processed samples in terms of FRAP and DPPH radical scavenging activity as well as the antimutagenic activity were also conserved in treated samples. Thus, the treatment developed enhanced the storage life of processed bitter gourd stored at 4 ± 2 °C while satisfying the phytosanitary requirement for export especially to the countries requiring longer voyage time.

Drying kinetics, chemical, and bioactive compounds of yellow sweet pepper as affected by processing conditions

The effect of processing (pre-treatments and drying temperatures) on yellow sweet pepper was evaluated in terms of drying kinetics, physico-chemical (non-enzymatic browning index and color), and bioactive (carotenoids, ascorbic acid, phenolics, flavonoids and antioxidant activity) components. Drying at 60°C results in a significant increase in drying rate (540 min) and decrease in the moisture (6.36%) of the final product. All the pre-treatments enhanced the drying kinetics relative to the control sample. The Page model was found to be the best appropriate model for explaining the slices drying behavior. Drying temperature at 60°C showed the highest retention of phenolics (706.59 mg/100 g), flavonoids (363.41 mg/100 g) and antioxidant activity (178.13 nmol/L). Sample treated with combined pre-treatment retained maximum bioactive compounds. These results were also clearly justified by Principal Component Analysis. This study revealed that combined pre-treatment at 60°C lowered the drying time, better bioactive retention and best preservation of color. Practical applications Yellow sweet peppers are abundant in bioactive compounds, which have nutritional and medicinal importance. However, sweet pepper is highly perishable and not easy to store for long time. Drying is most preferable and economical method to improve shelf life of peppers. This study showed that higher drying rate, lower drying time, combined pre-treatment resulted in the good product quality.

Partial depolymerization of capsular polysaccharides isolated from Streptococcus pneumoniae serotype 2 by various methods

Partial depolymerization of bacterial capsular polysaccharides (CPS) is an essential process carried out before its use as an antigenic preparation in a vaccine industry. Choice of CPS depolymerization methods depends on the process robustness, reproducibility, yield, retention of CPS bioactivity, etc. Partial depolymerization methods based on chemicals, enzymes, mechanical, thermal, etc. have been subject of many investigations before. Partial depolymerization of Streptococcus pneumoniae serotype 2 purified CPS was conducted by methods such as acid hydrolysis, microfluidization, ultrasonication, thermal and microwave. Partial depolymerization of the CPS was evaluated by size exclusion high performance liquid chromatography, whereas structural identity and conformity of CPS was ensured by 1H NMR spectroscopy. The antigenicity of CPS was assessed by bead based competitive inhibition assay. Microwave and thermal methods effectively depolymerized CPS and reduced the concentration of cell wall polysaccharide (CWPS) impurity, but both methods have a negative impact on the antigenicity of CPS. Whereas the trifluoroacetic acid treatment not only depolymerized the CPS but completely removed the CWPS while retaining the antigenicity of 92 ± 4% and this method is advantageous over other methods.

Encapsulation of phlorotannins from edible brown seaweed in chitosan: Effect of fortification on bioactivity and stability in functional foods

Phlorotannins are a family of proven therapeutic agents. However, low stability disturbs their full bioactivity expression in the human body. Hence, this study focused on preserving their vitality through encapsulation. Phlorotannins isolated from Sargassum ilicifolium were encapsulated in the chitosan-tripolyphosphate carrier. Their storage stability, processing stability, and bioactivity retention upon in vitro digestion were determined. Results revealed the highest total phlorotannin content (TPC) of 854.38 ± 48 mg Phloroglucinol Equivalence/g in the semi-purified ethyl acetate fraction while the NMR spectrum and the LCMS profile revealed the isolation of phlorotannins in it. Storage at –18℃ and 4℃ temperatures preserved thrice both the encapsulated and non-encapsulated phlorotannins than ambient conditions. Encapsulated compound reported 56.4% of TPC retention at 175 ℃ processing temperature. Fermented fraction of encapsulated form showed significantly higher (p < 0.05) antioxidant activities and TPC (0.23 ± 0.03 mg/mL) suggesting the potential for targeted delivery of phlorotannins to their absorption sites through encapsulation.