Enhanced stability of C-phycocyanin colorant by extrusion encapsulation

Novel functional carriers based on Spirulina protein for the delivery of curcumin with improved stability and antioxidant efficiency

The potential of sustainably sourced Spirulina protein (SP), and SP nanoparticles (SPNP) obtained by heating gelation and ultrasound treatment as functional carriers for curcumin (Cur) was studied. The antioxidant activity, encapsulation performance, stability and digestive properties of the delivery system were analyzed. Compared with SP, SPNP exhibited higher hydrophobicity, and its antioxidant capacity was enhanced due to increased exposure of chromophores. The encapsulation performance of Cur-loaded complexes was influenced by the protein-Cur mass ratio, and the encapsulation efficiency of SPNP was significantly higher than that of SP (p < 0.05). Because of the better binding affinity, SPNP-Cur complexes showed improved thermal stability and UV protection effect. SP and SPNP all exhibited antioxidant synergism with Cur, and the antioxidant efficiency was closely related to pH, dissociating solvents, UV irradiation and digestion. The bioaccessibility of Cur was also greatly improved. It suggests that Spirulina protein may be an ideal carrier for delivering nutraceutical compounds.

New Green Biorefinery Strategies to Valorize Bioactive Fractions from Palmaria palmata

A biorefinery process was developed to isolate phycobiliproteins, sulfated polysaccharides, and phenolic compounds from Palmaria palmata. The extraction process was carried out in three stages using ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) integrated with different natural deep eutectic solvents (NaDESs). In general, PLE provided higher phycobiliprotein contents than UAE in the first step of the process. In fact, the hydrolysis product of the PLE-NaDES extracts achieved a higher antioxidant capacity than that of the UAE-NaDES extracts. Particularly, glycerol:glucose (2:1) with 50% water in combination with PLE was the most suitable NaDES to recover the highest phycobiliprotein, protein, and sulfated polysaccharide contents from Palmaria palmata in the first and second steps of the biorefinery process. Finally, a PLE-NaDES using choline chloride:glycerol (1:2) with 60% water as the NaDES was employed for the recovery of antioxidant and neuroprotective phenolic compounds from the residue of the second step, obtaining a higher total phenolic content than employing PLE with ethanol/water (70:30, v/v) as the extraction solvent. Moreover, a forced stability study revealed that the NaDESs provided a protective effect compared to the water extracts against the degradation of phycobiliproteins, preserving their color over time. This study contributes to the recovery of high-value components from an undervalued biomarine source through a sustainable biorefinery process.

Chromatographic purification of C-phycocyanin from Spirulina platensis: assessing antioxidant activity and stability

BACKGROUND

The efficient separation and purification of proteins like C-phycocyanin (C-PC) from Spirulina platensis are essential for their commercialization, yet they remain challenging. This study investigated three chromatographic methods for C-PC purification: weak anion exchange chromatography (DEAE), strong anion exchange chromatography (Q Sepharose), and hydrophobic interaction chromatography (HIC).

RESULTS

Weak anion exchange chromatography achieved a recovery of 36.80 mg unit (57.08%) with a purity of 3.23, outperforming Q Sepharose (yield: 23.21 mg unit means that 46.33%, purity: 2.76) and HIC (yield: 22.95 mg unit means that 17.57%, purity: 3.02). The purified C-PC consisted of α and β subunits with molecular masses of 16 kDa and 17 kDa, respectively. Further assessment revealed its antioxidant capacity through a 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. The stability of C-phycocyanin was tested at different pH levels and temperatures. Maximum stability was observed at pH 7, and pH 4 showed the lowest stability. Glutaraldehyde-treated C-PC (GC-PC) demonstrated gradual degradation up to 50 °C, retaining 73.25% after 30 min. Notably, GC-PC exhibited stability even at higher temperatures, with degradation rates of 57.32% at 70 °C and 50.96% at 80 °C.

CONCLUSION

Weak anion exchange chromatography proved superior for C-PC purification, offering higher yields and purity than Q Sepharose and HIC. The purified C-PC showed promising antioxidant capacity and stability, particularly GC-PC, which exhibited resistance to degradation, even at elevated temperatures. These findings underscore the potential of C-PC as a valuable compound for various applications, with DEAE chromatography being an efficient method for its production and commercialization. © 2024 Society of Chemical Industry.

Narrative Review of the Current and Future Perspectives of Phycobiliproteins' Applications in the Food Industry: From Natural Colors to Alternative Proteins

Vivid-colored phycobiliproteins (PBPs) have emerging potential as food colors and alternative proteins in the food industry. However, enhancing their application potential requires increasing stability, cost-effective purification processes, and consumer acceptance. This narrative review aimed to highlight information regarding the critical aspects of PBP research that is needed to improve their food industry potential, such as stability, food fortification, development of new PBP-based food products, and cost-effective production. The main results of the literature review show that polysaccharide and protein-based encapsulations significantly improve PBPs' stability. Additionally, while many studies have investigated the ability of PBPs to enhance the techno-functional properties, like viscosity, emulsifying and stabilizing activity, texture, rheology, etc., of widely used food products, highly concentrated PBP food products are still rare. Therefore, much effort should be invested in improving the stability, yield, and sensory characteristics of the PBP-fortified food due to the resulting unpleasant sensory characteristics. Considering that most studies focus on the C-phycocyanin from Spirulina, future studies should concentrate on less explored PBPs from red macroalgae due to their much higher production potential, a critical factor for positioning PBPs as alternative proteins.

Phycocyanin from microalgae: A comprehensive review covering microalgal culture, phycocyanin sources and stability

As food safety continues to gain prominence, phycocyanin (PC) is increasingly favored by consumers as a natural blue pigment, which is extracted from microalgae and serves the dual function of promoting health and providing coloration. Spirulina-derived PC demonstrates exceptional stability within temperature ranges below 45 °C and under pH conditions between 5.5 and 6.0. However, its application is limited in scenarios involving high-temperature processing due to its sensitivity to heat and light. This comprehensive review provides insights into the efficient production of PC from microalgae, covers the metabolic engineering of microalgae to increase PC yields and discusses various strategies for enhancing its stability in food applications. In addition to the most widely used Spirulina, some red algae and Thermosynechococcus can serve as good source of PC. The genetic and metabolic manipulation of microalgae strains has shown promise in increasing PC yield and improving its quality. Delivery systems including nanoparticles, hydrogels, emulsions, and microcapsules offer a promising solution to protect and extend the shelf life of PC in food products, ensuring its vibrant color and health-promoting properties are preserved. This review highlights the importance of metabolic engineering, multi-omics applications, and innovative delivery systems in unlocking the full potential of this natural blue pigment in the realm of food applications, provides a complete overview of the entire process from production to commercialization of PC, including the extraction and purification.

Enhancing phycocyanin yield from Spirulina sp. under salt stress using various extraction methods

Phycocyanin, a blue-coloured pigment, predominantly found and derived from Spirulina sp., has gained researchers' interest due to its vibrant hues and other attractive properties like antioxidant and anti-microbial. However, the lack of reliable and sustainable phycocyanin extraction strategies without compromising the quality has hindered the scaling up of its production processes for commercial purposes. Here in this study, phycocyanin was extracted from wet and dry biomass Spirulina sp., using three different physical cell disruption methods (ultrasonication, homogenization, and freeze-thaw cycles) combined with two different buffers (phosphate buffer and acetate buffer) and water (as control). The result showed that the freeze-thaw method combined with acetate buffer produced the highest yield (25.013 ± 2.572 mg/100 mg) with a purity ratio of 0.806 ± 0.079. Furthermore, when subjected to 30% w/v salt stress, 1.9 times higher phycocyanin yield with a purity ratio of 1.402 ± 0.609 was achieved using the previously optimized extraction method.

Investigation of the Potential of Selected Food-Derived Antioxidants to Bind and Stabilise the Bioactive Blue Protein C-Phycocyanin from Cyanobacteria Spirulina

Blue C-phycocyanin (C-PC), the major Spirulina protein with innumerable health-promoting benefits, is an attractive colourant and food supplement. A crucial obstacle to its more extensive use is its relatively low stability. This study aimed to screen various food-derived ligands for their ability to bind and stabilise C-PC, utilising spectroscopic techniques and molecular docking. Among twelve examined ligands, the protein fluorescence quenching revealed that only quercetin, coenzyme Q10 and resveratrol had a moderate affinity to C-PC (Ka of 2.2 to 3.7 × 105 M-1). Docking revealed these three ligands bind more strongly to the C-PC hexamer than the trimer, with the binding sites located at the interface of two (αβ)3 trimers. UV/VIS absorption spectroscopy demonstrated the changes in the C-PC absorption spectra in a complex with quercetin and resveratrol compared to the spectra of free protein and ligands. Selected ligands did not affect the secondary structure content, but they induced changes in the tertiary protein structure in the CD study. A fluorescence-based thermal stability assay demonstrated quercetin and coenzyme Q10 increased the C-PC melting point by nearly 5 °C. Our study identified food-derived ligands that interact with C-PC and improve its thermal stability, indicating their potential as stabilising agents for C-PC in the food industry.

Controlled Release of Phycocyanin in Simulated Gastrointestinal Conditions Using Alginate-Agavins-Polysaccharide Beads

C-phycocyanin (CPC) is an antioxidant protein that, when purified, is photosensitive and can be affected by environmental and gastrointestinal conditions. This can impact its biological activity, requiring an increase in the effective amount to achieve a therapeutic effect. Therefore, the aim of this study was to develop a microencapsulate of a complex matrix, as a strategy to protect and establish a matrix for the controlled release of CPC based on polysaccharides such as agavins (AGV) using ionic gelation. Four matrices were formulated: M1 (alginate: ALG), M2 (ALG and AGV), M3 (ALG, AGV, and κ-carrageenan: CGN), and M4 (ALG, AGV, CGN, and carboxymethylcellulose: CMC) with increasing concentrations of CPC. The retention and diffusion capacities of C-phycocyanin provided by each matrix were evaluated, as well as their stability under simulated gastrointestinal conditions. The results showed that the encapsulation efficiency of the matrix-type encapsulates with complex composites increased as more components were added to the mixtures. CMC increased the retention due to the hydrophobicity that it provides by being in the polysaccharide matrix; CGN enabled the controlled diffusive release; and AGV provided protection of the CPC beads under simulated gastrointestinal conditions. Therefore, matrix M4 exhibited an encapsulation efficiency for CPC of 98% and a bioaccessibility of 10.65 ± 0.65% after the passage of encapsulates through in vitro digestion.

Phycobiliproteins from algae: Current updates in sustainable production and applications in food and health

Phycobiliproteins are light-harvesting complexes found mainly in cyanobacteria and red algae, playing a key role in photosynthesis. They are extensively applied in food, cosmetics, and biomedical industry due to bright color, unique fluorescence characteristics and diverse physiological activities. They have received much attention in the past few decades because of their green and sustainable production, safe application, and functional diversity. This work aimed to provide a comprehensive summary of parameters affecting the whole bioprocess with a special focus on the extraction and purification, which directly determines the application of phycobiliproteins. Food grade phycobiliproteins are easy to prepare, whereas analytical grade phycobiliproteins are extremely complex and costly to produce. Most phycobiliproteins are denatured and inactivated at high temperatures, severely limiting their application. Inspired by recent advances, future perspectives are put forward, including (1) the mutagenesis and screening of algal strains for higher phycobiliprotein productivity, (2) the application of omics and genetic engineering for stronger phycobiliprotein stability, and (3) the utilization of synthetic biology and heterologous expression systems for easier phycobiliprotein isolation. This review will give a reference for exploring more phycobiliproteins for food and health application development.

Exploring the Benefits of Phycocyanin: From Spirulina Cultivation to Its Widespread Applications

Large-scale production of microalgae and their bioactive compounds has steadily increased in response to global demand for natural compounds. Spirulina, in particular, has been used due to its high nutritional value, especially its high protein content. Promising biological functions have been associated with Spirulina extracts, mainly related to its high value added blue pigment, phycocyanin. Phycocyanin is used in several industries such as food, cosmetics, and pharmaceuticals, which increases its market value. Due to the worldwide interest and the need to replace synthetic compounds with natural ones, efforts have been made to optimize large-scale production processes and maintain phycocyanin stability, which is a highly unstable protein. The aim of this review is to update the scientific knowledge on phycocyanin applications and to describe the reported production, extraction, and purification methods, including the main physical and chemical parameters that may affect the purity, recovery, and stability of phycocyanin. By implementing different techniques such as complete cell disruption, extraction at temperatures below 45 °C and a pH of 5.5-6.0, purification through ammonium sulfate, and filtration and chromatography, both the purity and stability of phycocyanin have been significantly improved. Moreover, the use of saccharides, crosslinkers, or natural polymers as preservatives has contributed to the increased market value of phycocyanin.

Assessment of the Anticancer Potentials of the Free and Metal-Organic Framework (UiO-66) - Delivered Phycocyanobilin

Phycocyanin (C-PC) is a constitutive chromoprotein of Arthrospira platensis, which exhibits promising efficacy against different types of cancer. In this study, we cleaved C-PC's chromophore phycocyanobilin (PCB) and demonstrated its ability as an anti-cancer drug for Colorectal cancer (CRC). PCB displayed an anti-cancer effect for CRC (HT-29) cells with IC50 of 108 µg/ml. Assessing the transcripts levels of some biomarkers revealed that the PCB caused an upregulation in the anti-metastatic gene NME1 level and downregulation of the COX-2 level. The flow cytometric results showed the effect of PCB on the arrest of the cell cycle's G1 phase. In addition, we successfully synthesized the UiO-66 (Zr-MOF). We incorporated the PCB into UiO-66 nanoparticles with a loading percentage of 46 %. Assessment of the cytotoxic effects of UiO-66@PCB showed a 2-fold improvement in the IC50 compared to the free PCB. In conclusion, we have shown that PCB displayed a promising potential as an anti-cancer agent. Yet, it is considered a safe and natural substance that can help to mitigate cancer spread and symptoms. In the meantime, UiO-66 can be used as a safe nano-delivery tool for PCB.

Biocolorants in food: Sources, extraction, applications and future prospects

Color of a food is one of the major factors influencing its acceptance by consumers. At presently synthetic dyes are the most commonly used food colorant in food industry by providing more esthetically appearance and as a means to quality control. However, the growing concern about health and environmental due to associated toxicity with synthetic food colorants has accelerated the global efforts to replace them with safer and healthy food colorants obtained from natural resources (plants, microorganisms, and animals). Further, many of these biocolorants not only provide myriad of colors to the food but also exert biological properties, thus they can be used as nutraceuticals in foods and beverages. In order to understand the importance of nature-derived pigments as food colorants, this review provides a thorough discussion on the natural origin of food colorants. Following this, different extraction methods for isolating biocolorants from plants and microbes were also discussed. Many of these biocolorants not only provide color, but also have many health promoting properties, for this reason their physicochemical and biological properties were also reviewed. Finally, current trends on the use of biocolorants in foods, and the challenges faced by the biocolorants in their effective utilization by food industry and possible solutions to these challenges were discussed.

Progress of Microencapsulated Phycocyanin in Food and Pharma Industries: A Review

Phycocyanin is a blue fluorescent protein with multi-bioactive functions. However, the multi-bioactivities and spectral stability of phycocyanin are susceptible to external environmental conditions, which limit its wide application. Here, the structure, properties, and biological activity of phycocyanin were discussed. This review highlights the significance of the microcapsules' wall materials which commonly protect phycocyanin from environmental interference and summarizes the current preparation principles and characteristics of microcapsules in food and pharma industries, including spray drying, electrospinning, electrospraying, liposome delivery, sharp-hole coagulation baths, and ion gelation. Moreover, the major technical challenge and corresponding countermeasures of phycocyanin microencapsulation are also appraised, providing insights for the broader application of phycocyanin.

Fabrication and characterization of phycocyanin-alginate-pregelatinized corn starch composite gel beads: Effects of carriers on kinetic stability of phycocyanin

Composite gel beads using calcium alginate and different concentrations of pregelatinized corn starch (PCS) were produced to encapsulate phycocyanin (PC). Rheological properties of different sodium alginate/PCS/PC mixtures, structural and morphological properties of beads, and kinetic stability of encapsulated PC (upon heating at various time-temperature combinations) were then assessed. Rheological properties of the mixtures exhibited shear thinning behaviors. Aquagram revealed that the PC-containing beads had more water structure with weak‑hydrogen bonds. Morphological images represented less subsidence in the structures of composite gel beads, unlike PCS-free beads. Kinetic study showed that degradation rate constant values of PC encapsulated in composite gel beads (1.08-3.45 × 10^-4, 3.38-4.43 × 10^-4, and 5.57-15.32 × 10^-4 s^-1) were lower than those in PCS-free alginate gel beads (4.45 × 10^-4, 9.20 × 10^-4, and 18.04 × 10^-4 s^-1) at 40, 50, and 60 °C, respectively. This study suggests that the composite gel beads can improve PC stability.

Preparation, Characterization, and Antioxidant Properties of Phycocyanin Complexes Based on Sodium Alginate and Lysozyme

In this study, phycocyanin-sodium alginate/lysozyme complex (PC-SLC) was prepared for the first time and characterized by UV spectroscopy, Fourier transform infrared spectroscopy (FT-IR), and circular dichroism spectroscopy (CD). The stability of PC-SLC under light, temperature, pH and simulated gastrointestinal fluid was investigated. The scavenging ability of the complexes against DPPH and ABTS radicals was determined. The results showed that the complex formed by the mass ratio of SA-LZM of 0.1 showed the highest PC encapsulation rate (89.9 ± 0.374%). The combination of SA and LZM changed the secondary conformation of PC. The PC-SLC complex shows an irregular spherical structure and the spheres are clustered together. Compared with phycocyanin (PC), its thermal stability was obviously improved, but it was still greatly influenced by light. It could exist stably in simulated gastric fluid (SGF) for 2 h and be slowly digested in simulated intestinal fluid (SIF), which helped to promote the absorption of nutrients in the intestinal tract. Meanwhile, the complex PC-SLC showed high scavenging ability for DPPH and ABTS radicals. It can be concluded that the complexes have good antioxidant activity. This study provides an idea for the construction of PC delivery system and makes it more widely used in food industry and other fields.

Uncovering the Use of Fucoxanthin and Phycobiliproteins into Solid Matrices to Increase Their Emission Quantum Yield and Photostability

In the search for a better and brighter future, the use of natural luminescent renewable materials as substitutes for synthetic ones in the energy field is of prime importance. The incorporation of natural pigments (e.g., xanthophylls and phycobiliproteins) is a fundamental step in a broad spectrum of applications that are presently marred by their limited stability. The incorporation of bio-based luminescent molecules into solid matrices allows the fabrication of thin films, which may dramatically increase the range of applications, including sustainable photovoltaic systems, such as luminescent solar concentrators or downshifting layers. In this work, we incorporated R-phycoerythrin (R-PE), C-phycocyanin (C-PC), and fucoxanthin (FX) into poly(vinyl alcohol) (PVA) and studied their optical properties. It was found that the emission and excitation spectra of the phycobiliproteins and FX were not modified by incorporation into the PVA matrix. Moreover, in the case of FX, the emission quantum yield (η) values also remained unaltered after incorporation, showing the suitability of the PVA as a host matrix. A preliminary photostability study was performed by exposing the solid samples to continuous AM1.5G solar radiation, which evidenced the potential of these materials for future photovoltaics.

Phycocyanin: A Natural Antioxidant to Combat Free Radicals

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Various research showed that antioxidants can effectively overcome the damage caused by free radicals to human health. Therefore, antioxidants are identified as one of the main directions in the development of health care and cosmetics products due to high demand in the market. This review mainly focuses on the phycocyanin, a type of natural antioxidant mainly found in cyanobacteria. This mini review summarizes the phycocyanin sources and numerous extraction methods of phycocyanin along with the analytical methods and determine its ability to suppress free radicals. Phycocyanin has been proven to play an important role in scavenging free radicals and enhancing the body’s antioxidant capacity. However, there is a lack of long-term randomized clinical trial results that can be used as evidence in showing the benefits of phycocyanin. The existing phycocyanin extraction methods using solvents, ultrasonic-assisted, freeze-thaw, etc. can extract high-quality phycocyanin efficiently and quickly. Scientists are also trying to incorporate advanced technologies, such as "Industry 4.0" to optimize and enhance the industrial production of phycocyanin. Lastly, this review also describes the difficulties faced during the phycocyanin production or extraction process and financial obstacles in order to achieve the popularization of phycocyanin.

Phycobiliproteins: Structural aspects, functional characteristics, and biotechnological perspectives

Phycobiliproteins (PBPs) are fluorescent proteins of various colors, including fuchsia, purple-blue and cyan, that allow the capture of light energy in auxiliary photosynthetic complexes called phycobilisomes (PBS). PBPs have several highly preserved structural and physicochemical characteristics. In the PBS context, PBPs function is capture luminous energy in the 450-650 nm range and delivers it to photosystems allowing photosynthesis take place. Besides the energy harvesting function, PBPs also have shown to have multiple biological activities, including antioxidant, antibacterial and antitumours, making them an interesting focus for different biotechnological applications in areas like biomedicine, bioenergy and scientific research. Nowadays, the main sources of PBPs are cyanobacteria and micro and macro algae from the phylum Rhodophyta. Due to the diverse biological activities of PBPs, they have attracted the attention of different industries, such as food, biomedical and cosmetics. This is why a large number of patents related to the production, extraction, purification of PBPs and their application as cosmetics, biopharmaceuticals or diagnostic applications have been generated, looking less ecological impact in the natural prairies of macroalgae and less culture time or higher productivity in cyanobacteria to satisfy the markets and applications that require high amounts of these molecules. In this review, we summarize the main structural characteristics of PBPs, their biosynthesys and biotechnological applications. We also address current trends and future perspectives of the PBPs market.

Preparation and Characterization of Mg-Doped Calcium Phosphate-Coated Phycocyanin Nanoparticles for Improving the Thermal Stability of Phycocyanin

Phycocyanin (PC) is a blue-colored, pigment-protein complex with unique fluorescence characteristics. However, heat leads to PC fading and fluorescence decay, hampering its widespread application. To improve the thermal stability of PC, we induced the in situ mineralization of calcium phosphate (CaP) on the PC surface to prepare PC@Mg-CaP. The nanoparticles were characterized using transmission electron microscopy, energy dispersive spectrometry, fourier transform infrared spectroscopy, and X-ray diffraction. The results showed that PC@Mg-CaP was spherical, and the nanoparticle size was less than 200 nm. The shell of PC@Mg-CaP was composed of amorphous calcium phosphate (ACP). The study suggested that CaP mineralization significantly improved the thermal stability of PC. After heating at 70 °C for 30 min, the relative concentration of PC@Mg-CaP with a Ca/P ratio = 2 was 5.31 times higher than that of PC. Furthermore, the Ca/P ratio was a critical factor for the thermal stability of PC@Mg-CaP. With decreasing Ca/P, the particle size and thermal stability of PC@Mg-CaP significantly increased. This work could provide a feasible approach for the application of PC and other thermal-sensitive biomolecules in functional foods requiring heat treatment.

Physicochemical degradation of phycocyanin and means to improve its stability: A short review

The cyanobacterium Arthrospira platensis, spirulina, is a source of pigments such as phycobiliprotein and phycocyanin. Phycocyanin is used in the food, cosmetics, and pharmaceutical industries because of its antioxidant, anti-inflammatory, and anticancer properties. The different steps involved in extraction and purification of this protein can alter the final properties. In this review, the stability of phycocyanin (pH, temperature, and light) is discussed, considering the physicochemical parameters of kinetic modeling. The optimal working pH range for phycocyanin is between 5.5 and 6.0 and it remains stable up to 45 °C; however, exposure to relatively high temperatures or acidic pH decreases its half-life and increases the degradation kinetic constant. Phycobiliproteins are sensitive to light; preservatives such as mono- and di-saccharides, citric acid, or sodium chloride appear to be effective stabilizing agents. Encapsulation within nano- or micro-structured materials such as nanofibers, microparticles, or nanoparticles, can also preserve or enhance its stability.

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Phycocyanin is in great demand for industrial application.

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Phycocyanin is sensitive to pH, temperature, and light.

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Optimal stability occurs between pH 5.5–6.0 and at temperatures <45 °C in the dark.

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The use of preservatives or its encapsulation with polymers enhances its stability.

Uncovering Research Trends of Phycobiliproteins Using Bibliometric Approach

Phycobiliproteins are gaining popularity as long-term, high-value natural products which can be alternatives to synthetic products. This study analyzed research trends of phycobiliproteins from 1909 to 2020 using a bibliometric approach based on the Scopus database. The current findings showed that phycobiliprotein is a burgeoning field in terms of publications outputs with "biochemistry, genetics, and molecular biology" as the most related and focused subject. The Journal of Applied Phycology was the most productive journal in publishing articles on phycobiliproteins. Although the United States of America (U.S.A.) contributed the most publications on phycobiliproteins, the Chinese Academy of Sciences (China) is the institution with the largest number of publications. The most productive author on phycobiliproteins was Glazer, Alexander N. (U.S.A.). The U.S.A. and Germany were at the forefront of international collaboration in this field. According to the keyword analysis, the most explored theme was the optimization of microalgae culture parameters and phycobiliproteins extraction methods. The bioactivity properties and extraction of phycobiliproteins were identified as future research priorities. Synechococcus and Arthrospira were the most cited genera. This study serves as an initial step in fortifying the phycobiliproteins market, which is expected to exponentially expand in the future. Moreover, further research and global collaboration are necessary to commercialize phycobiliproteins and increase the consumer acceptability of the pigments and their products.

Application of Encapsulation Technology in Edible Films: Carrier of Bioactive Compounds

Nutraceuticals, functional foods, immunity boosters, microcapsules, nanoemulsions, edible packaging, and safe food are the new progressive terms, adopted to describe the food industry. Also, the rising awareness among the consumers regarding these has created an opportunity for the food manufacturers and scientists worldwide to use food as a delivery vehicle. Packaging performs a very imminent role in the food supply chain as well as it is a consequential part of the process of food manufacturing. Edible packaging is a swiftly emerging art of science in which edible biopolymers like lipids, polysaccharides, proteins, resins, etc. and other consumable constituents extracted from various non-conventional sources like microorganisms are used alone or imbibed together. These edible packaging are indispensable and are meant to be consumed with the food. This shift in paradigm from traditional food packaging to edible, environment friendly, delivery vehicles for bioactive compounds have opened new avenues for the packaging industry. Bioactive compounds imbibed in food systems are gradually degenerated, or may change their properties due to internal or external factors like oxidation reactions, or they may react with each other thus reducing their bioavailability and ultimately may result in unacceptable color or flavor. A combination of novel edible food-packaging material and innovative technologies can serve as an excellent medium to control the bioavailability of these compounds in food matrices. One promising technology for overcoming the aforesaid problems is encapsulation. It can be used as a method for entrapment of desirable flavors, probiotics, or other additives in order to apprehend the impediments of the conventional edible packaging. This review explains the concept of encapsulation by exploring various encapsulating materials and their potential role in augmenting the performance of edible coatings/films. The techniques, characteristics, applications, scope, and thrust areas for research in encapsulation are discussed in detail with focus on development of sustainable edible packaging.

Spirulina sp. LEB 18-extracted phycocyanin: Effects on liposomes' physicochemical parameters and correlation with antiradical/antioxidant properties

This study describes the physicochemical properties of soybean asolectin (ASO) liposomes loaded with phycocyanin (Phy) extracted from Spirulina sp. LEB 18. The effects of Phy in the liposomes' properties were investigated by Fourier transform infrared spectroscopy (FTIR), ¹H and ³¹P nuclear magnetic resonance (NMR), zeta (ζ)-potential, dynamic light scattering (DLS) and ultraviolet-visible (UV-vis) techniques. Phy restricted the motion of ASO polar and interface groups and disrupted the package arrangement of the lipid hydrophobic regions, as a likely effect of dipolar and π interactions related to its amino acid residues and pyrrole portions. These interactions were correlated to antiradical/antioxidant Phy responses obtained by 2,2-diphenyl-1-picrylhidrazil (DPPH) assay, thiobarbituric acid reactive substances (TBARS) and ferric reducing antioxidant power (FRAP) methods, and discussed to bring new chemical perspectives about Phy-loaded liposomes-related nutraceutical applications in inflammatory and viral infection processes.

A novel method for double encapsulation of C-phycocyanin using aqueous two phase systems for extension of shelf life

Spirulina platensis is having high nutritive value due to pigments such as chlorophyll-a, phycobiliproteins (especially phycocyanins) and carotenoids. In our present work, C-phycocyanin (C-PC) was extracted from dry biomass of Spirulina platensis. C-PC being heat sensitive, reiterates the need for additional protection during drying (micro encapsulation). Accordingly, a novel method employing aqueous two phase systems (ATPSs) as carrier materials to achieve double encapsulation was studied for the first time. PEG 4000/Potassium phosphate and PEG 6000/Dextran were used at already standardized tie line length, at different volume ratios (by varying the total phase composition). ATPS at each volume ratio acted as different carrier materials offering varied degree of heat protection during double encapsulation while maltodextrin, being the conventional carrier material, was used for comparison. The best results of spray dried powders using PEG (4% w/w)/Potassium phosphate salt (18%, w/w) and PEG (6%)/Dextran (10%, w/w) phase systems as carrier materials were compared with conventional encapsulation (MDX as a carrier material) and freeze dying as control. PEG/Dextran as a carrier material with volume ratio of 0.25 resulted in the highest retention of blue colour (b*value), purity (0.43) as well as yield (Y_EP) of 94.99% w/w of C-PC, which could be stored for 6 months without much reduction from initial powder characteristics. From the overall results, it can be concluded that ATPS can be used as an effective carrier material for double encapsulation of biomolecules such as C-PC with additional benefit of enhancing the purity.

Phycobiliproteins from extreme environments and their potential applications

The light-harvesting phycobilisome complex is an important component of photosynthesis in cyanobacteria and red algae. Phycobilisomes are composed of phycobiliproteins, including the blue phycobiliprotein phycocyanin, that are considered high-value products with applications in several industries. Remarkably, several cyanobacteria and red algal species retain the capacity to harvest light and photosynthesise under highly selective environments such as hot springs, and flourish in extremes of pH and elevated temperatures. These thermophilic organisms produce thermostable phycobiliproteins, which have superior qualities much needed for wider adoption of these natural pigment-proteins in the food, textile, and other industries. Here we review the available literature on the thermostability of phycobilisome components from thermophilic species and discuss how a better appreciation of phycobiliproteins from extreme environments will benefit our fundamental understanding of photosynthetic adaptation and could provide a sustainable resource for several industrial processes.