Vitamin E TPGS based palatable, oxidatively and physically stable emulsion of microalgae DHA oil for infants, children and food fortification

Pre-clinical and cellular safety assessment of oral administered DHA rich microalgae oil from Schizochytrium sp. (Strain ATCC-20889): acute, sub-chronic and genotoxicity

The lack of toxicity data for DHA-rich oil from Schizochytrium sp. (Strain ATCC-20889) leads to its exclusion from the Qualified Presumption of Safety list. Therefore, present study addresses toxicity evaluation of DHA-rich microalgae oil using ex-vivo (cytotoxicity assay) and in-vivo methods (acute (OECD 423 guidelines), sub-chronic (OECD 452 guidelines), and genotoxicity assay). The ex-vivo results showed >90% cell viability of Caco-2 cells after 48 h of treatment (200 µg/mL of DHA). Additionally, the in-vivo acute toxicity study found that microalgae oil was nontoxic and classified under category 5 molecule according to OECD 423 guidelines with a highest degree of safety at 2000 mg/kg b.w. The in-vivo sub-chronic study revealed no significant mortality and changes in feed intake, body weight, haematological, biochemical, neurological, and urine parameters after repeated 180-days administration of DHA-rich microalgae oil at 250 mg/kg, 500 mg/kg, and 1000 mg/kg. Moreover, histopathology evaluation, comet assay, chromosomal aberration, and micronuclei assay also confirmed the nontoxic behavior of DHA-rich oil. Thus, the results from the ex-vivo and in-vivo studies indicate that DHA-rich oil from Schizochytrium sp. (Strain ATCC-20889) is safe for use as a novel food, and can be included in infants, adults, pregnant women, and children formula.

Dual role of polyglycerol vitamin E succinate in emulsions: An efficient antioxidant emulsifier

α-Tocopherol, as an oil-soluble vitamin with strong antioxidant activity. It is the most naturally abundant and biologically active form of vitamin E in humans. In this study, a novel emulsifier (PG20-VES) was synthesized by attaching hydrophilic twenty-polyglycerol (PG20) to hydrophobic vitamin E succinate (VES). This emulsifier was shown to have a relatively low critical micelle concentration (CMC = 3.2 μg/mL). The antioxidant activities and emulsification properties of PG20-VES were compared with those of a widely used commercial emulsifier: D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS). PG20-VES exhibited a lower interfacial tension, stronger emulsifying capacity and similar antioxidant property to TPGS. An in vitro digestion study showed that lipid droplets coated by PG20-VES were digested under simulated small intestine conditions. This study showed that PG20-VES is an efficient antioxidant emulsifier, which may have applications in the formulation of bioactive delivery systems in the food, supplement, and pharmaceutical industries.

Recent advances in enhancing the production of long chain omega-3 fatty acids in microalgae

Omega-3 fatty acids have gained attention due to numerous health benefits. Eicosapentaenoic (EPA) and docosahexaenoic acid (DHA) are long chain omega-3 fatty acids produced from precursor ALA (α-linolenic acid) in humans but their rate of biosynthesis is low, therefore, these must be present in diet or should be taken as supplements. The commercial sources of omega-3 fatty acids are limited to vegetable oils and marine sources. The rising concern about vegan source, fish aquaculture conservation and heavy metal contamination in fish has led to the search for their alternative source. Microalgae have gained importance due to the production of high-value EPA and DHA and can thus serve as a sustainable and promising source of long chain omega-3 fatty acids. Although the bottleneck lies in the optimization for enhanced production that involves strategies viz. strain selection, optimization of cultivation conditions, media, metabolic and genetic engineering approaches; while co-cultivation, use of nanoparticles and strategic blending have emerged as innovative approaches that have made microalgae as potential candidates for EPA and DHA production. This review highlights the possible strategies for the enhancement of EPA and DHA production in microalgae. This will pave the way for their large-scale production for human health benefits.

Enhancing the oxidative stability of algal oil emulsions by adding sweet orange oil: Effect of essential oil concentration

The effects of sweet orange essential oil (SOEO) concentration (0-12.5% of oil phase) on the physical stability, oxidative stability, and interfacial composition of algal oil-in-water emulsions containing sodium caseinate-coated oil droplets was examined. SOEO addition had no influence on the microstructure and physical stability of the algal oil emulsions. The addition of SOEO enhanced the oxidation stability of algal oil emulsion. As an example, the values of algal oil emulsions with 0 and 10% SOEO were 198 and 100 mmol/kg algal oil after 16 days of accelerated oxidation, respectively. The absorbed protein level was higher in the algal oil emulsion containing 10% SOEO (70%) than in 0% SOEO (57%). This result suggested that the presence of SOEO enhanced the interfacial thickness, possibly by interacting with the casein molecules. A thicker protein layer may have helped to retard the oxidation of the omega-3 oils inside lipid droplets.