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Aims This work reports on one of the first attempts to use biofilm‐forming cyanobacteria for biomass and lipid production. Methods and Results Three isolates of filamentous cyanobacteria were obtained from biofilms at different Italian sites and characterized by a polyphasic approach, involving microscopic observations, ecology and genetic diversity (studying the 16S rRNA gene). The isolates were grown in batch systems and in a semi‐continuous flow incubator, specifically designed for biofilms development. Culture system affected biomass and lipid production, but did not influence the fatty acid profile. The composition of fatty acids was mainly palmitic acid (>50%) and less amounts of other saturated and monounsaturated fatty acids. Only two isolates contained two polyunsaturated fatty acids. Conclusions Data obtained from the flow‐lane incubator system would support a more economical and sustainable use of the benthic micro‐organisms for biomass production. The produced lipids contained fatty acids suitable for a high‐quality biodiesel production, showing high proportions of saturated and monounsaturated fatty acids. Significance and Impact of the Study Data seem promising when taking into account the savings in cost and time derived from easy procedures for biomass harvesting, especially when being able to obtain the co‐production of other valuable by‐products.

Whipped emulsions were prepared at pilot scale from fresh milk, whole egg, and other ingredients, for example, sugars and stabilizers (starch, polysaccharides). Egg content was varied: 4 recipes were studied differing in their egg to milk protein ratio (0, 0.25, 0.38, and 0.68). Protein and fat contents were kept constant by adjusting the recipes with skim-milk powder and fresh cream. Emulsions were prepared by high-pressure homogenization and whipped on a pilot plant. Particle-size distribution determined by laser-light scattering showed an extensive aggregation of fat globules in both mix and whipped emulsions, regardless of recipe. Amount of protein adsorbed at the oil-water interface and protein composition of adsorbed layer were determined after isolation of fat globules. Protein load is strongly increased by the presence of egg in formula. Values obtained for the whipped emulsions were dramatically lower than those obtained for the mix by a factor of 2 to 3. Sodium dodecyl sulfate-PAGE indicated a preferential adsorption of egg proteins over milk proteins at the oil-water interface, regardless of recipe. This phenomenon was more marked in aerated than in unaerated emulsions, showing evidence for desorption of some milk proteins during whipping. Egg proteins stabilize mainly the fat globule surface and ensure emulsion stability before whipping. Air bubble size distribution in whipped emulsions was measured after 15 d storage. When the egg to milk protein ratio is decreased to 0.25, large air cells appear in whipped emulsions during storage, indicating mousse destabilization. The present work allows linking the protein composition of adsorbed layers at the fat globule surface to mousse formula and mousse stability.

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Stabilisation of whipped dairy emulsion: substitution of gelatin by polysaccharide mixturesIn the area of foamed emulsions, one of the most important challenge is the replacement of gelatine, that plays an essential role in the formation and the stabilisation of foams, by some blends of polysaccharides. The aim of this experiment was to compare different combination of polysaccharides (xanthan, carrageenan, guar, pectin, alginate) in view to find the best compromise to manufacture stable foamed emulsions. We have showed that the different blends of hydrocolloids tested conducted to an increase of the size of the oil droplets, a decrease of emulsion viscosity and a decrease of air bubble size, as compared with a foamed emulsion prepared with gelatine. Some hydrocolloid blends permitted to obtain a suitable air incorporation rate (80%) but, whatever the blend, draining stability of foamed emulsions is not so satisfactory than that made with gelatine.