Nannochloropsis is well appreciated in aquaculture due to its nutritional value and the ability to produce valuable chemical compounds, such as pigments (zeaxanthin, astaxanthin. . .) and polyunsaturated fatty acids (EPA). Commercial exploitation needs high cell densities but the low growth rate and the small size of cells are practical difficulties. To increase biomass concentration the positive effect of several factors was evident: (i) pH:/8 control (with dilute Tris Á/HCl buffer); (ii) the continuous illumination (no evidence of photo-inhibition was observed); (iii) a quite large temperature range (259/5 8C); (iv) the presence of organic carbon source (with the danger of contamination); (v) the presence of urea as an additional nitrogen source (10 mM); (vi) a small air flow rate with large bubbles can be more efficient for CO 2 mass transfer (associated to reduced shearing). #

Valorization of food industry waste and plant residues represents an attractive path towards obtaining biodegradable materials and achieving “zero waste” goals. Here, melanin was isolated from watermelon (Citrullus lanatus) seeds and used as a modifier for whey protein concentrate and isolate films (WPC and WPI) at two concentrations (0.1% and 0.5%). The modification with melanin enhanced the ultraviolet (UV) blocking, water vapor barrier, swelling, and mechanical properties of the WPC/WPI films, in addition to affecting the apparent color. The modified WPC/WPI films also exhibited high antioxidant activity, but no cytotoxicity. Overall, the effects were melanin concentration-dependent. Thus, melanin from watermelon seeds can be used as a functional modifier to develop bioactive biopolymer films with good potential to be exploited in food packaging and biomedical applications.

Nannochloropsis, a green microalga, is source for commercially valuable compounds as extensively described and, in particular, is recognized as a good potential source of EPA (20:5v3), an important polyunsaturated fatty acid for human consumption for prevention of several diseases. Climate change might include variation in the UV levels, as one of the consequences derived from the antropogenic activity. This paper shows the response of Nannochloropsis cultures exposed for 7 days to UV-A added to PAR. Growth rates and photosynthetic activity were assessed to determine the impact of UV-A increased levels on the cell growth and basic metabolism activity. Xanthophyll pigments (zeaxanthin and violaxanthin), carotenoids (cantaxanthin and β-carotene) and PUFAs (miristic, palmitic, palmitoleic, araquidonic and eicosapentanoic acids) were measured for assessing the antioxidant response of the microalgae to added UV-A radiation to PAR. The results show that the modulated use of UV-A radiations can led to increased growth rates which are sustained in time by an increased light transduction activity. The expected antioxidant response to the incident UV-A radiation consisted of increases in zeaxanthin and β-carotene contents -synthesis of antioxidant carotenoids-and increases in the SFAs (saturated fatty acids) to PUFAs (polyunsaturated fatty acids) ratio. The results suggest that modulated UV-A radiation can be used as a tool to stimulate value molecules accumulation in microalgae through an enhanced both light transduction process and antioxidant response, while sustaining cell growth.

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