Impact of Nannochloropsis sp. dosage form on the oxidative stability of n-3 LC-PUFA enriched tomato purees

Antioxidative capacity of microalgal carotenoids for stabilizing n-3LC-PUFA rich oil: Initial quantity is key

The health-beneficial long-chain omega-3 polyunsaturated fatty acids (n-3 LC-PUFA) are easily affected by the undesired process of lipid oxidation in fish oil, while being stable in the lipid extracts of photoautotrophic microalgae. The current research investigates the role of carotenoids by evaluating the oxidative stability of mixtures of fish oil with total lipid extracts of two different microalgae (Phaeodactylum and Isochrysis) throughout an accelerated storage experiment of 4 weeks at 37 °C. A clear separation between oxidatively stable and oxidatively unstable mixtures was observed for which the initial amount of carotenoids relative to the amount of n-3LC-PUFA was a good indicator. The lipid class composition, clearly differing between the two algae, was probably of minor influence. The antioxidative role of fucoxanthin, and diatoxanthin and β-carotene as minor carotenoids, was illustrated by their gradual degradation throughout storage. However, when their initial contents were too low, this role could not be exerted leading to thorough lipid oxidation.

Technological readiness of commercial microalgae species for foods

Microalgae have great potential as a future source to meet the increasing global demand for foods. Several microalgae are permitted as safety sources in different countries and regions, and processed as commercial products. However, edible safety, economic feasibility, and acceptable taste are the main challenges for microalgal application in the food industry. Overcome such challenges by developing technology accelerates transition of microalgae into sustainable and nutritious diets. In this review, edible safety of Spirulina, Chlamydomonas reinhardtii, Chlorella, Haematococcus pluvialis, Dunaliella salina, Schizochytrium and Nannochloropsis is introduced, and health benefits of microalgae-derived carotenoids, amino acids, and fatty acids are discussed. Technologies of adaptive laboratory evolution, kinetic model, bioreactor design and genetic engineering are proposed to improve the organoleptic traits and economic feasibility of microalgae. Then, current technologies of decoloration and de-fishy are summarized to provide options for processing. Novel technologies of extrusion cooking, delivery systems, and 3D bioprinting are suggested to improve food quality. The production costs, biomass values, and markets of microalgal products are analyzed to reveal the economic feasibility of microalgal production. Finally, challenges and future perspectives are proposed. Social acceptance is the major limitation of microalgae-derived foods, and further efforts are required toward the improvement of processing technology.

Iron from Co-Encapsulation of Defatted Nannochloropsis Oceanica with Inulin Is Highly Bioavailable and Does Not Impact Wheat Flour Shelf Life or Sensorial Attributes

Defatted green microalgae Nannochloropsis oceanica (DGM) is a rich source of bioavailable iron. However, its use in foods results in unacceptable color and taste development. Therefore, the purpose of this study was to investigate strategies to enhance the use of DGM in foods. DGM and inulin were encapsulated (EC) in an oil-in-water emulsion using high-pressure homogenization. To confirm iron bioavailability, C57BL/6 mice were fed an iron-deficient diet (ID) for 2 weeks. The mice were then fed one of the four diets: ID, ID + DGM (DGM), ID + EC (EC50 or EC100) for 4 weeks. To test the stability of DGM as an iron fortificant at two different fortification rates of 17.5 mg Fe/kg (50%) or 35 mg Fe/kg (100%), whole (DGM50/DGM100), encapsulated (EC50/EC100) and color-masked (CM50/CM100) DGM were added to wheat flour (WF) at two different temperatures: 20 °C and 45 °C and were examined for 30 days. Acceptability studies were conducted to determine sensory differences between rotis (Indian flat bread) prepared from WF/EC50/CM50/EC100. The mice consuming EC50/EC100 diets showed comparable iron status to DGM-fed mice, suggesting that encapsulation did not negatively impact iron bioavailability. Addition of EC to wheat flour resulted in the lowest Fe²⁺ oxidation and color change amongst treatments, when stored for 30 days. There were no differences in the overall liking and product acceptance of rotis amongst treatments at both day 0 and day 21 samples. Our results suggest that EC50 can be effectively used as an iron fortificant in WF to deliver highly bioavailable iron without experiencing any stability or sensory defects, at least until 30 days of storage.

Industry chain and challenges of microalgal food industry-a review

Currently, the whole world is facing hunger due to the increase in the global population and the rising level of food consumption. Unfortunately, the impact of environmental, climate, and political issues on agriculture has resulted in limited global food resources. Thus, it is important to develop new food sources that are environmentally friendly and not subject to climate or space limitations. Microalgae represent a potential source of nutrients and bioactive components for a wide range of high-value products. Advances in cultivation and genetic engineering techniques provide prospective approaches to widen their application for food. However, there are currently problems in the microalgae food industry in terms of assessing nutritional value, selecting processes for microalgae culture, obtaining suitable commercial strains of microalgae, etc. Additionally, the limitations of real data of market opportunities for microalgae make it difficult to assess their actual potential and to develop a better industrial chain. This review addresses the current status of the microalgae food industry, the process of commercializing microalgae food and breeding methods. Current research progress in addressing the limitations of microalgae industrialization and future prospects for developing microalgae food products are discussed.

Development of certified reference materials for four polyunsaturated fatty acid esters

Certified reference materials (CRMs) with high accuracy and traceability are essential tools for the validation of analytical methods and calibration of equipment. In this study, purity CRMs for four polyunsaturated fatty acids (PUFAs) esters, namely, cis-(4,7,10,13,16,19)- Docosahexaenoic acid methyl ester (DHA-ME), cis-4,7,10,13,16,19- Docosahexaenoic acid ethyl ester (DHA-EE), cis-(5,8,11,14,17)- Eicosapentaenoic acid methyl ester (EPA-ME) and cis-(5,8,11,14,17)- Eicosapentaenoic acid ethyl ester (EPA-EE), were first developed according to the ISO Guide. The CRMs' purity values were assigned based on the average of quantitative nuclear magnetic resonance and mass balance approaches. The certified value with expanded uncertainties (k = 2, 95% confidence interval) were determined to be (98.8 ± 0.4) %, (99.0 ± 0.3) %, (98.9 ± 0.4) % and (98.9 ± 0.4) % for DHA-ME, DHA-EE, EPA-ME and EPA-EE, respectively. The four PUFAs esters were homogeneous and stable for 12 months at -4 °C and 7 days at 50 °C.

A novel strategy to simultaneously enhance bioaccessible lipids and antioxidants in hetero/mixotrophic Chlorella vulgaris as functional ingredient

Microalgae are a promising source of polyunsaturated fatty acids as well as bioactive antioxidant compounds such as carotenoids, phenolics and tocopherols. However, the accumulation of these biomolecules is often promoted by conflicting growth conditions. In this study, a phased bioprocessing strategy was developed to simultaneously enhance the lipid and antioxidant amounts by tailoring nitrogen content in the cultivation medium and applying light stress. This approach increased the overall contents of total fatty acids, carotenoids, phenolics, and α-tocopherol in Chlorella vulgaris by 2.2-, 2.2-, 1.5-, and 2.1-fold, respectively. Additionally, the bioaccessibility of the lipids and bioactives from the obtained biomasses improved after pulsed electric field (5 μs, 20 kV cm^-1, 31.8 kJ kg^-1_sus) treatment (up to +12%) and high-pressure homogenization (100 MPa, 5-6 passes) (+41-76%). This work represents a step towards the generation of more efficient algae biorefineries, thus expanding the alternative resources available for essential nutrients.

Spirulina for the food and functional food industries

Humans are no strangers to the consumption of microalgae as already in the sixteenth century Spirulina was harvested from Lake Texcoco and consumed in markets in Tenochtitlan (today Mexico City). Nowadays, microalgae are being incorporated into many food formulations. Most of these use microalgae as a marketing strategy or as a colouring agent. However, Spirulina (and compounds derived thereof) show potential for being used as ingredients in the development of novel functional foods, which are one of the top trends in the food industry. Several human intervention studies demonstrated the potential of Spirulina for being used in the prevention or treatment of disorders related to metabolic syndrome. The aim of the current paper was to review current and potential applications of this microalga in the food and functional food industries. Health benefits associated with consuming Spirulina and/or some of the most important compounds derived from Spirulina were also discussed.