Extraction, functionality, and applications of Chlorella pyrenoidosa protein/peptide

Impact of climate change on the toxicity of bisphenol A in Mytilus galloprovincialis and assessment of phycoremediation using Nannochloropsis salina via a multi-biomarker strategy and modeling

In the current study, the mussels Mytilus galloprovincialis, exposed to four varying temperatures (17, 20, 23, and 26 °C), were contaminated with 50 μg/L of bisphenol A both with and without Nannochloropsis salina. The toxicity evaluation is determined by quantifying various biomarkers related to oxidative stress, neurotoxicity, and cellular damage. The key findings indicate that the toxicity of bisphenol A is heightened by rising temperature. The impact of bisphenol A is most evident at 26 °C, leading to excessive production of reactive oxygen species, depletion of non-enzymatic antioxidants, and activation of antioxidant enzymes (catalase and glutathione-S-transferase). The rise in malondialdehyde levels confirms lipid peroxidation caused by bisphenol A and intensified by thermal stress. These findings have been supported by strong molecular interactions between bisphenol A and lectin mytilec apo-form and proximal thread matrix protein 1 from M. galloprovincialis following the computational modeling assay. The incorporation of N. salina as a food additive helped, firstly, to mitigate the stress effects and, secondly, resulted in a noticeable enhancement of oxidative balance and filtration ability, along with decreased lipid peroxidation.

Heatwave enhance the adaptability of Chlorella pyrenoidosa to zinc oxide nanoparticles: Regulation of interfacial interactions and metabolic mechanisms

Wide application of zinc oxide nanoparticles (ZnO NPs) and increasing frequency of heatwaves (HWs) have posed a great threat to freshwater ecosystems, while phytotoxicity of ZnO NPs mediated by HWs remains unclear. This study aims to link the physiological responses, bio-nano interactions, and metabolic mechanisms of Chlorella pyrenoidosa with ZnO NPs under heat stress. Results demonstrated a temperature-dependent growth inhibition against ZnO NPs, with a higher reduction of growth rate at 24 °C than 28 °C. Accompanied with lower reactive oxidative stress and cell damage at 28 °C, our results indicated that HW could enhance the adaptability of C. pyrenoidosa to ZnO NPs stress. Furthermore, HW induced the variation of algal surface properties, altered interfacial interactions in the bio-nano system, and decreased cellular Zn uptake. Metabolomics analysis supported the temperature-dependent influences of ZnO NPs on C. pyrenoidosa. The phytotoxicity of ZnO NPs was associated with the disturbance of amino acids, fatty acids, and energy metabolic processes, which were mitigated under HW condition, enhancing the responsiveness of algae to the adverse effects. These results emphasize the importance of taking the impacts of HWs into account when evaluating the environmental risks of ZnO NPs.

Microalgal proteins: Extraction, interfacial properties, bioactivities, and future perspectives - A review

The increasing global demand for protein, coupled with concerns over the environmental sustainability of animal-derived sources, has prompted the search for alternative protein sources. Microalgae have emerged as a promising solution due to their high productivity, protein content, and ability to grow in non-arable environments or photobioreactors. Their proteins, hydrolysates and peptides exhibit diverse bioactivities, including anti-obesity, anti-cancer, antioxidant, and anti-hypertensive effects, as well as functional properties such as emulsification, foaming and gelling. However, their practical utilization is hindered by challenges such as high production costs and environmental sensitivity, particularly in relation to pH, temperature, and light, which can affect their structural stability and functional performance. This review summarizes traditional and innovative extraction techniques, discusses the structure-function relationships of these microalgal components, and highlights their potential applications. Furthermore, it identifies key production and commercialization challenges, proposing strategies to enhance extraction efficiency and environmental stability during processing and storage, thereby facilitating broader industrial implementation.

Chlorella sp. as a promising protein source: insight to novel extraction techniques, nutritional and techno-functional attributes of derived proteins

Amidst the mounting environmental crises and ever-increasing global population, the quest for sustainable food production and resource utilization solutions has taken center stage. Microalgae, with Chlorella species at the forefront, present a promising avenue. They serve as a bountiful protein source and can be conveniently grown in waste streams, thereby tackling food security, environmental sustainability, and economic feasibility. This article embarks on a comprehensive journey through recent research on Chlorella by shedding light on its unique characteristics, its market value, cultivation techniques, and harvesting methods. It also delves into traditional and innovative extraction methods, underscoring the hurdles and breakthroughs in achieving high protein yields from the Chlorella biomass. Moreover, exploration of the protein's nutritional properties, bioactive peptides, and techno-functional attributes, enhance its potential for food applications. Further, this review also examines current market trends in consumer acceptance of this alternative protein and discusses strategies for reducing greenhouse gas emissions in their production. By providing invaluable insights into the current status and future prospects of Chlorella protein, it aspires to make a significant contribution to the ongoing dialogue on sustainable food production and resource management.

Methods of Protein Extraction from House Crickets (Acheta domesticus) for Food Purposes

Global population is projected to reach 9.1 billion by 2050, emphasizing the need for increased food production. Edible insects, such as house crickets (Acheta domesticus), emerged as promising due to higher nutritional value and efficient feed conversion rates compared to conventional protein sources. Incorporating insect powders into new food products can improve consumer acceptance but often leads to poor technological food processing functionality and/or undesirable organoleptic characteristics. Protein isolates have proven to be effective in enhancing this functionality and consumer acceptance, but existent protein extraction methods still lack improvements concerning the optimization of protein extraction rates. This study aimed to address this gap by developing and comparing the yield of three different protein extraction methods using sodium hydroxide, ascorbic acid or alcalase from house crickets (Acheta domesticus) for food applications. Protein extraction was performed on cricket powder with a mean protein content of 46.35 g/100 g, and the results were evaluated. The enzymatic method shows the highest protein extraction rate at 69.91% with a mean protein content of 60.19 g/100 g, while extraction with NaOH or ascorbic acid resulted in rates of 60.44 and 46.34%, respectively. Further studies on technological food processing functionality and sensorial evaluation of products developed with this protein extract are recommended.

Global Perspectives on Obesity and Being Overweight: A Bibliometric Analysis in Relation to Sustainable Development Goals

Obesity and being overweight are significant risk factors for diseases and disabilities, making it crucial to address malnutrition in all its forms to ensure health and well-being for all, as well as to achieve sustainable development. This study conducted a bibliometric analysis of research on obesity in relation to Sustainable Development Goals (SDGs) using data from the Web of Science database from 2015 to 2024 and the VOSviewer software. The findings revealed that while research on obesity and SDGs has grown slowly, SDG 3 (Good Health and Well-Being) is predominant in the literature. This study highlighted the fragmentation of research due to the complex, multifactorial nature of obesity, emphasizing the need for a more holistic approach. Furthermore, international collaborations were found to be vital for advancing research and formulating effective public policies. This analysis also identified gaps in the research related to several SDGs, including education (SDG 4), affordable and clean energy (SDG 7), and partnerships (SDG 17), suggesting the need for a broader, more holistic approach. Additionally, emerging research related to SDG 11 (Sustainable Cities and Communities) underscores the importance of urban environments in tackling obesity. In conclusion, future research should adopt an interdisciplinary approach to address these gaps and contribute to advancing the 2030 Agenda.

Phase inversion regulable bigels co-stabilized by Chlorella pyrenoidosa protein and beeswax: In-vitro digestion and food 3D printing

Algal proteins are an emerging source of functional foods. Herein, Chlorella pyrenoidosa protein (CPP)/xanthan gum-based hydrogels (HG) and beeswax-gelled oleogels (OG) are adopted to fabricate bigels. The phase inversion of bigels can be regulated by the ratio of OG and HG: As the OG increased, bigels turn from OG-in-HG (OG/HG) to a semicontinuous state and then HG-in-OG (HG/OG). In OG/HG bigels (OG ≤ 50 %), hydrophilic CPP acts as the emulsifier at the interface of OG and HG, while beeswax emulsifies the system in HG/OG bigels (OG = 80 %). A semicontinuous bigel appears during the transition between HG/OG and OG/HG. The increase of OG can enhance the viscoelasticity, hardness, adhesiveness, chewiness, and thermal stability. OG/HG bigels exhibit stronger thixotropic recovery and oil-holding capacity than HG/OG bigels. In the in-vitro digestion and food 3D printing, the high specific surface area and the highest thixotropic recovery caused by the emulsion structure of the OG/HG bigel (OG = 50 %) are conducive to the release of free fatty acids and molding of 3D-printed objects, respectively. This study provides a new approach to structure the gelled water-oil system with CPP and helps to develop edible algal proteins-based multiphase systems in food engineering or pharmacy.

From biomass to Energy: Investigating Chlorella pyrenoidosa's potential for fuel and carbon materials

This study investigated the bioenergy potential of Chlorella pyrenoidosa (CP) for use as fuel and carbon material through chemical and thermal characterization. The thermo-kinetic characteristics of Chlorella pyrenoidosa were assessed using isoconversional, linear regression, and non-linear regression approaches. The physicochemical analysis revealed high carbon (53.1 %), volatile (69.35 %), and low moisture (2.19 %), ash content (3.42 %). The results indicated that the non-linear model fitting method was the most accurate with the approximated activation energy (Eα) and pre-exponential Arrhenius constant (Ln A) were 124.92 ± 2.74 kJ/mol and 23.38 ± 4.63 min-1, respectively. Additionally, the inclusion of sodium bicarbonate resulted in a significant increase in BET surface area. FTIR analysis revealed several functional groups beneficial for carbon material, while XRD analysis showed a broad peak correlated with an amorphous structure. This study highlighted the potential of Chlorella pyrenoidosa biomass for various applications, including carbon material and renewable fuel.

Core-shell nanofibers based on microalgae proteins/alginate complexes for enhancing survivability of probiotics

In this study, a novel one-step coaxial electrospinning process is employed to fabricate shell-core structure fibers choosing Chlorella pyrenoidosa proteins (CP) as the core material. These nanofibers, serving as the wall material for probiotic encapsulation, aimed to enhance the stability and antioxidant activity of probiotics in food processing, storage, and gastrointestinal environments under sensitive conditions. Morphological analysis was used to explore the beads-on-a-string morphology and core-shell structure of the electrospun fibers. Probiotics were successfully encapsulated within the fibers (7.97 log CFU/g), exhibiting a well-oriented structure along the distributed fibers. Compared to free probiotics and uniaxial fibers loaded with probiotics, encapsulation within microalgae proteins/alginate core-shell structure nanofibers significantly enhanced the probiotic cells' tolerance to simulated gastrointestinal conditions (p < 0.05). Thermal analysis indicated that microalgae proteins/alginate core-shell structure nanofibers displayed superior thermal stability compared to uniaxial fibers. The introduction of CP resulted in a 50 % increase in the antioxidant capacity of probiotics-loaded microalgae proteins/alginate nanofibers compared to uniaxial alginate nanofibers, with minimal loss of viability (0.8 log CFU/g) after 28 days of storage at 4 °C. In summary, this dual-layer carrier holds immense potential in probiotic encapsulation and enhancing their resistance to harsh conditions.

Optimization of Protease Treatment Conditions for Chlorella pyrenoidosa Protein Extraction and Investigation of Its Potential as an Alternative Protein Source

This study aimed to determine enzymes that effectively extract Chlorella pyrenoidosa proteins and optimize the processing conditions using response surface methods. Furthermore, the potential of enzymatically hydrolyzed C. pyrenoidosa protein extract (CPE) as a substitute protein source was investigated. The enzymatic hydrolysis conditions for protein extraction were optimized using single-factor analysis and a response surface methodology-Box-Behnken design. The R2 value of the optimized model was 0.9270, indicating the reliability of the model, and the optimal conditions were as follows: a hydrolysis temperature of 45.56 °C, pH 9.1, and a hydrolysis time of 49.85 min. The amino acid composition of CPE was compared to that of C. pyrenoidosa powder (CP), which was found to have a higher content of essential amino acids (EAA). The electrophoretic profiles of CP and CPE confirmed that CPE has a low molecular weight. Furthermore, CPE showed higher antioxidant activity and phenol content than CP, with ABTS and DPPH radical scavenging abilities of 69.40 ± 1.61% and 19.27 ± 3.16%, respectively. CPE had high EAA content, antioxidant activity, and phenol content, indicating its potential as an alternative protein source. Overall, in this study, we developed an innovative, ecofriendly, and gentle enzymatic hydrolysis strategy for the extraction and refinement of Chlorella proteins.