Microalgae antioxidant

Other applications — P-carotene is used in various pet foods as both a colorant and a precursor to vitamin A. It can be applied to an array of animal foods designed for dogs, cats, fish, and birds. The antioxidant and precursory vitamin A properties increase the appeal and application of P-carotene in pet foods. Additionally, P-carotene is an important carotenoid that may assist in improving the color of birds, fish, and crustaceans. Dunaliella salina can serve as a source of algal feed for fish and crustaceans. The microalgae provide carotenoids that are essential for flesh coloring, particularly of salmon and crustaceans. 

With the increasing interest in the food industry for natural sources of antioxidants for their beneficial effects on health, new potential sources have been screened among edible aromatic plants and microalgae. The cc-tocopherol content (a potent antioxidant) in parsley was reported to be 3.45mg/100g of fresh leaves obtained through supercritical fluid extraction (Diego et al., 2004). 

As an assay for antioxidant activity, we examined the inhibition of lipoxygenase activity and radical scavenging activity using the a, a-diphenyl-P-picrylhydrazyl (DPPH) decolorization test. Aqueous, ethanolic and methanolic extracts of microalgae were used in the assays. 

In the search of feasible new sources of natural antioxidants that can be used in the food industry, algae and microalgae have been suggested as possible raw materials. Both organisms are widely known and consumed in certain countries, and numerous health benefits have been associated to their u se. Different compounds with antibacterial, antiviral and antifiingical activity can be found in this type of organisms (30-32), along with compounds with antioxidant activity that, as has been already mentioned, is nowadays one of the most important fields of activity in food research. 

In a previous work, we studied the possibility of extracting antioxidants from microalgae Spirulina platensis using ASE with different solvents (33-34). Likewise, other authors have studied the carotenoids extraction from microalgae Haematococcus pluvialis and Dunaliella salina using ethanol as solvent and ASE (35). 

In conclusion, in this work we demonstrate the excellent capabilities of using ASE to extract compounds with antioxidant activity from natural sources as rosemary leaves and the microalga Spirulina platemis. ASE shows several advantages compared with traditional extraction processes such as 1) it is faster (IS min vs 2-24h in traditional extraction procedures) 2) it has less solvent volume consumption (13 ml vs 30>S00 mL/lOg) 3) it is more efficient (less dependant on matrix) and 4) it is automatic and allows sequential extraction of samples. The use of in-vitro assays and CE coupled to both, DAD and ESI-MS allows obtaining information about the biological and chemical properties of the ASE extracts. 

There are lots of research applications published regarding PLE and analysis of various compoimds in food and agricultural materials, for example pesticides in rapeseed (38), babyfood (39) and strawberries (40), lipids in com and oats (41) and in egg-containing foods (42), acrylamide in food samples (43), carotenoids in processed food (44), xanthones and flavanones in root bark (45), tocopherols in seeds and nuts (46), antioxidants in microalgae (47) and anthocyanins and total phenolics in dried red grape skin (48). More discussions... 

A. Bioactive peptides from microalgae B. Antioxidant activity of the peptides from 316... 

Arthrospira production is realized in China and India (Kato and Suzuki, 1971 Morris et ah, 2007). Therefore, new interest has been developed to search natural and safe bioactive peptides from natural sources. Furthermore, antioxidant peptides have been isolated from hydrolysates of various proteinaceous food materials and recently the possible roles of food-derived bioactive peptides in reducing the risk of diseases have been reported (Kim and Wijesekara, 2010). In addition, two peptides were identified from the enzyme hydrolysis of N. incerta. Table 25.2 shows some microalgae-derived peptides. 

Kang, K. H., Qian, Z. J., Ryu, B. M., and Kim, S. K. (2011). Characterization of growth and protein contents from microalgae Navicula incerta with the investigation of antioxidant activity of enzymatic hydrolysates. Food Sci. Biotechnol. 20,183-191. 

Natrah, F., F. Yusoff, M. Shariff, F. Abas, and N. Mariana. 2007. Screening of Malaysian Indigenous Microalgae for Antioxidant Properties and Nutritional Value. Journal of Applied Phycology 19 (6) 711-718. 

---