The Extraction of β-Carotene from Microalgae for Testing Their Health Benefits

Microalgae as a potential natural source for the green synthesis of nanoparticles

The increasing global population is driving the development of alternative sources of food and energy, as well as better or new alternatives for health and environmental care, which represent key challenges in the field of biotechnology. Microalgae represent a very important source material to produce several high-value-added bioproducts. Due to the rapid changes in the modern world, there is a need to build new materials for use, including those in the nanometer size, although these developments may be chronological but often do not occur at a time. In the last few years, a new frontier has opened up at the interface of biotechnology and nanotechnology. This new frontier could help microalgae-based nanomaterials to possess new functions and abilities. Processes for the green synthesis of nanomaterials are being investigated, and the availability of biological resources such as microalgae is continuously being examined. The present review provides a concise overview of the recent advances in the synthesis, characterization, and applications of nanoparticles formed using a wide range of microalgae-based biosynthesis processes. Highlighting their innovative and sustainable potential in current research, our study contributes towards the in-depth understanding and provides latest updates on the alternatives offered by microalgae in the synthesis of nanomaterials.

The effects of preformed vitamin A and provitamin A carotenoid supplementation on tadpoles of the poison frog Phyllobates vittatus

Understanding the nutritional requirements of captive animals is necessary for proper animal husbandry, however, the specific dietary requirements for many amphibian species commonly kept in captivity are unknown. Like most vertebrates, frogs cannot synthesize carotenoids and must therefore obtain these essential nutrients through diet. It is unclear if amphibians can cleave provitamin A carotenoids to form vitamin A metabolically within the body, so common practice is to supplement their captive diets with both preformed vitamin A and provitamin A carotenoids. We carried out a feeding experiment in tadpoles of Phyllobates vittatus, a commonly kept poison frog species, to test the effects of supplementing a fish flake diet with a provitamin A carotenoid (2.5 mg/g β-carotene) and vitamin A (0.033-0.066 µg/mL retinyl acetate), both individually and in combination. Contrary to our expectations, supplementation had either no effect or adverse effects on tadpole growth and survivorship. Tadpoles reared under supplemented diets with vitamin A showed higher mortality rates, coupled with symptoms of hypervitaminosis A. Survivors had a smaller body size and mass at metamorphosis. β-carotene supplementation alone had no detectable effect. The vitamin A and β-carotene levels in our supplemented diet have been shown to be harmless or benefit tadpoles of other species, yet our results indicate that adding these amounts to what is found in a generalist fish flake mix can have detrimental effects on P. vittatus tadpoles. More broadly, this study highlights the importance of creating husbandry guidelines based on the specific physiological needs of the species (or species groups) being kept in captivity, rather than general ones for all amphibians, as is often done.

Isomerization of carotenoids in photosynthesis and metabolic adaptation

In nature, carotenoids are present as trans- and cis-isomers. Various physical and chemical factors like light, heat, acids, catalytic agents, and photosensitizers can contribute to the isomerization of carotenoids. Living organisms in the process of evolution have developed different mechanisms of adaptation to light stress, which can also involve isomeric forms of carotenoids. Particularly, light stress conditions can enhance isomerization processes. The purpose of this work is to review the recent studies on cis/trans isomerization of carotenoids as well as the role of carotenoid isomers for the light capture, energy transfer, photoprotection in light-harvesting complexes, and reaction centers of the photosynthetic apparatus of plants and other photosynthetic organisms. The review also presents recent studies of carotenoid isomers for the biomedical aspects, showing cis- and trans-isomers differ in bioavailability, antioxidant activity and biological activity, which can be used for therapeutic and prophylactic purposes.

Potential Challenges of the Extraction of Carotenoids and Fatty Acids from Pequi (Caryocar brasiliense) Oil

Pequi is a natural source of bioactive compounds with wide versatility for fresh or processed fruit consumption, but it is still little explored economically. Functional foods are the subject of diverse scientific research since, in addition to being nourishing, they contain bioactive compounds capable of promoting several benefits to the human body. Pequi is a fruit species native to the Brazilian Cerrado, which is rich in oil and has components with a high nutritional value, such as unsaturated fatty acids (omega-3, omega-6, EPA, and DHA), antioxidants (carotenoids and phenolic compounds), and vitamins. Therefore, the present narrative review aims to compile and critically evaluate the methods used to extract oil from the pulp and almonds of pequi and describes the carotenoid separation from the oil because carotenoids are natural pigments of great interest in the pharmaceutical and food industries. It is emphasized that the main challenges linked to bioactive compound extraction are their susceptibility to degradation in the processing and storage stages of pequi and its derived products.

Emulsion-Based Delivery Systems to Enhance the Functionality of Bioactive Compounds: Towards the Use of Ingredients from Natural, Sustainable Sources

In recent years, the trend in the population towards consuming more natural and sustainable foods has increased significantly. This claim has led to the search for new sources of bioactive compounds and extraction methods that have less impact on the environment. Moreover, the formulation of systems to protect these compounds is also focusing on the use of ingredients of natural origin. This article reviews novel, natural alternative sources of bioactive compounds with a positive impact on sustainability. In addition, it also contains information on the most recent studies based on the use of natural (especially from plants) emulsifiers in the design of emulsion-based delivery systems to protect bioactive compounds. The properties of these natural-based emulsion-delivery systems, as well as their functionality, including in vitro and in vivo studies, are also discussed. This review provides relevant information on the latest advances in the development of emulsion delivery systems based on ingredients from sustainable natural sources.

Microalgae as a Nutraceutical Tool to Antagonize the Impairment of Redox Status Induced by SNPs: Implications on Insulin Resistance

Microalgae represent a growing innovative source of nutraceuticals such as carotenoids and phenolic compound which are naturally present within these single-celled organisms or can be induced in response to specific growth conditions. The presence of the unfavourable allelic variant in genes involved in the control of oxidative stress, due to one or more SNPs in gene encoding protein involved in the regulation of redox balance, can lead to pathological conditions such as insulin resistance, which, in turn, is directly involved in the pathogenesis of type 2 diabetes mellitus. In this review we provide an overview of the main SNPs in antioxidant genes involved in the promotion of insulin resistance with a focus on the potential role of microalgae-derived antioxidant molecules as novel nutritional tools to mitigate oxidative stress and improve insulin sensitivity.

Effect of the Emulsifier Used in Dunaliella salina-Based Nanoemulsions Formulation on the β-Carotene Absorption and Metabolism in Rats

SCOPE

Microalgae such as Dunaliella salina are a potential sustainable source of natural β-carotene due to their fast growth and high adaptability to environmental conditions. This work aims to evaluate the effect of the incorporation of β-carotene from this alga into different emulsifier-type nanoemulsions (soybean lecithin [SBL], whey protein isolate [WPI], sodium caseinate [SDC]) on its absorption, metabolization, and biodistribution in rats.

METHODS AND RESULTS

Nanoemulsions formulated with different emulsifiers at 8% concentration are obtained by five cycles of microfluidization at 130 mPa, then expose to an in vitro digestion or orally administer to rats. Feeding rats with nanoemulsions improves β-carotene uptake compared to control suspension, especially using SDC and WPI as emulsifiers. A greater presence of β-carotene and retinol in the intestine, plasma, and liver is observed, being the liver the tissue that shows the highest accumulation. This fact can be a consequence of the smaller droplets that protein-nanoemulsions present compared to that with SBL in the intestine of rats, which promote faster digestibility and higher β-carotene bioaccessibility (35%-50% more) according to the in vitro observations.

CONCLUSIONS

Nanoemulsions, especially those formulated with protein emulsifiers, are effective systems for increasing β-carotene absorption, as well as retinol concentration in different rat tissues.

Recent Advances in Marine Microalgae Production: Highlighting Human Health Products from Microalgae in View of the Coronavirus Pandemic (COVID-19)

Blue biotechnology can greatly help solve some of the most serious social problems due to its wide biodiversity, which includes marine environments. Microalgae are important resources for human needs as an alternative to terrestrial plants because of their rich biodiversity, rapid growth, and product contributions in many fields. The production scheme for microalgae biomass mainly consists of two processes: (I) the Build-Up process and (II) the Pull-Down process. The Build-Up process consists of (1) the super strain concept and (2) cultivation aspects. The Pull-Down process includes (1) harvesting and (2) drying algal biomass. In some cases, such as the manufacture of algal products, the (3) extraction of bioactive compounds is included. Microalgae have a wide range of commercial applications, such as in aquaculture, biofertilizer, bioenergy, pharmaceuticals, and functional foods, which have several industrial and academic applications around the world. The efficiency and success of biomedical products derived from microalgal biomass or its metabolites mainly depend on the technologies used in the cultivation, harvesting, drying, and extraction of microalgae bioactive molecules. The current review focuses on recent advanced technologies that enhance microalgae biomass within microalgae production schemes. Moreover, the current work highlights marine drugs and human health products derived from microalgae that can improve human immunity and reduce viral activities, especially COVID-19.

Biotechnological production of β-carotene using plant in vitro cultures

β-carotene is biologically active compound widely distributed in plants. The use of plant in vitro cultures and genetic engineering is a promising strategy for its sustainable production. β-carotene is an orange carotenoid often found in leaves as well as in fruits, flowers, and roots. A member of the tetraterpene family, this 40-carbon isoprenoid has a conjugated double-bond structure, which is responsible for some of its most remarkable properties. In plants, β-carotene functions as an antenna pigment and antioxidant, providing protection against photooxidative damage caused by strong UV-B light. In humans, β-carotene acts as a precursor of vitamin A, prevents skin damage by solar radiation, and protects against several types of cancer such as oral, colon and prostate. Due to its wide spectrum of applications, the global market for β-carotene is expanding, and the demand can no longer be met by extraction from plant raw materials. Considerable research has been dedicated to finding more efficient production alternatives based on biotechnological systems. This review provides a detailed overview of the strategies used to increase the production of β-carotene in plant in vitro cultures, with particular focus on culture conditions, precursor feeding and elicitation, and the application of metabolic engineering.

Effects of Tetraselmis chuii Microalgae Supplementation on Anthropometric, Hormonal and Hematological Parameters in Healthy Young Men: A Double-Blind Study

The aim of this study was to evaluate the effects of Tetraselmis chuii (TC) microalgae supplementation for sixty days on hematological, anthropometric and hormonal parameters in healthy young men. Forty-six men divided into a placebo group (PG; n = 16; 20.77 ± 2.7 years; 72.14 ± 7.18 kg; 1.76 ± 0.07 m), a group supplemented with 25 mg/day of TC (SG 25; n = 15; 20.40 ± 1.40 years; 71.28 ± 8.26 kg; 1.76 ± 0.05 m) and another group supplemented with 200 mg/day of TC (SG 200; n = 15; 20.83 ± 2.45 years; 72.30 ± 11.13 kg; 1.77 ± 0.08 m) participated in this double-blind study. PG ingested 200 mg/day of lactose powder. Participants underwent 4 assessments (baseline, month 1, month 2 and desadaptation) separated in time by an interval of thirty days. At SG 25 and SG 200, significant increases in percent muscle mass, erythropoietin, insulin-like growth factor 1, free testosterone, leukocytes, neutrophils and lymphocytes were observed (p < 0.05). Decreases in the levels of percent fat mass, platelets, hematocrit and mean corpuscular hemoglobin also occurred in these groups (p < 0.05). TC supplementation induced favorable changes on anthropometric, hematological and hormonal levels. In view of the data, it seems that the most effective dose was 25 mg/day of TC.