Chlorella sorokiniana is a well-studied microalga with significant nutritional potential due to its health-promoting nutrients. C. sorokiniana is rich in proteins (~50%), lipids (~14%), vitamins, and other bioactive compounds, making it an attractive ingredient for the food industry. Other properties of C. sorokiniana, such as its foaming properties, have not been extensively investigated. The present work examines the foaming properties of C. sorokiniana biomass and of its fractions, namely the foaming properties of the whole-cell biomass, the disrupted-cell biomass, the water-soluble protein-rich extract, and the disrupted-cell biomass residue after oil extraction. The water/air interfacial tension, zeta potential, foaming capacity, foam stability, and foam morphology of C. sorokiniana biomass and its fractions were determined. Furthermore, the effect of the pH on the foaming properties of the water-soluble protein-rich extract was also investigated. The results show that the examined fractions decrease the water-air interfacial tension and form foams. The type of biomass fraction affects strongly the foam characteristics and foam stability. Furthermore, the stability and characteristics of the foam are significantly affected by pH. Overall, the water-soluble protein-rich extract at pH 7 presented the best foam stability, as the foam remained stable for more than 24 h and had a narrow bubble size distribution. The obtained results suggest that fractionated microalgae biomass could be used as an effective foaming agent in different commercial applications.

Background: The valorization of byproducts to obtain high nutritional value foods is of utmost importance for our planet where the population is booming. Among these products are oils rich in ω-3 fatty acids produced from fishery byproducts. Recently, mullet roe oil from roe byproducts was produced that was rich in the ω-3 fatty acids eicosatetraenoic acid (EPA) and docosahexaenoic acid (DHA). Oils are customarily characterized for their composition and degree of oxidation but little is known of their biological effects, especially the effect of the extraction method. Methods: The purpose of this study was to evaluate the effects of freshly extracted mullet roe oil from mullet roe byproducts and the effect of the extraction method on human red blood cells (hRBCs) and platelets. To this end, the hemocompatibility (cytotoxicity), oxidative effects, and erythrocyte membrane changes were examined after 1 and 24 h of incubation. Antiplatelet effects were also assessed in vitro. Results: The expeller press oil extraction method and alcalase-assisted extraction produced the most biocompatible oils, as shown by hemocompatibility measurements and the absence of erythrocyte membrane alterations. Solvent extracts and protease-assisted extraction oils resulted in the rupture of red blood cells at different examined dilutions, creating hemolysis. Conclusions: It seems that the proper functioning of oil–erythrocyte interactions cannot be explained solely by ROS. Further investigations combining chemical analysis with oil–cell interactions could be used as an input to design high nutritional value oils using green extraction technologies. All samples exhibited promising antiplatelet and antiblood clotting effects in vitro.

The demand of consumers for a healthier and functional diet necessitates amongst others, extending the shelf life of the natural probiotic kefir, reducing simultaneously packaging, transportation, and storage costs. Among the different drying methods, spray drying is widely used and industrially favorable to produce powdered products. The aim of the present work was to study the effect of the final fermentation pH and the pre-drying storage temperature (4 °C for 7 days) on the physicochemical properties, moisture content, pH, color, adsorption isotherms, and the microbiological characteristics of spray dried kefir. Kefir grains were used for the fermentation and the production of the samples. Viabilities of lactococci, lactobacilli, and yeasts were determined during a storage period of 45 days. Both final fermentation pH and low-temperature storage significantly affected the properties of the kefir powders and their respective reconstituted samples. According to the findings of the study, the desirable microbial populations of the reconstituted kefir powders are possible to accomplish by using an increased final fermentation pH at 5.2 and/or by applying low-temperature storage of the fermented milk, together with the kefir grains, at 4 °C for 7 days prior to drying. The yeast population was affected the least by the studied factors, and the use of kefir grains as starter culture favored the viability of lactococci and lactobacilli after spray drying and during storage up to 45 days.

The biological and nutritional value of kefir makes it imperative to widen its customer reach by extending its shelf life, enabling its storage and transport at ambient temperatures, and reducing its packaging cost requirements. A well-documented and widely used food processing method that can achieve the above-mentioned outcomes is spray drying through the formulation of kefir powder, with quality attributes that will closely resemble that of the original product. In the present work, a variety of drying carriers (trehalose, fructo-oligosaccharides, maltodextrin, gum arabic, and whey proteins) were studied with regard to their effect on the properties of powdered and reconstituted kefir samples. Particularly, the physicochemical characteristics (moisture content, pH, acidity, color), powder properties (bulk density, tapped density, water solubility index, insoluble matter), adsorption isotherms, particle size distribution, microbiological properties, and structural characteristics of the samples were evaluated. Gum arabic and maltodextrin produced kefir powder samples with the lowest moisture content. Spray drying affected a reduced acidity and, as a consequence, an increased pH in the reconstituted samples, especially without any carrier addition and with trehalose and fructo-oligosaccharides irrespective of their concentration. Desirable color attributes were achieved on the kefir powder samples with trehalose, fructo-oligosaccharides, and maltodextrin regardless of their concentration in the product. Fructo-oligosaccharides, added at 3%, gave the highest values of bulk density, while whey proteins, due to their nature, exhibited the lowest. All carriers tested improved the water solubility index when compared to the control sample. The sample with 10% whey proteins exhibited the lowest moisture adsorption compared to the control at the highest relative humidity environments employed for the test. In the absence of agglomeration, powder granule size and structural morphology were not affected by the carriers. The survival of lactococci in the powdered kefir samples, in comparison to the control product, was higher in the case where 4% trehalose or 5 to 10% whey proteins were added. On the contrary, yeast populations decreased significantly during drying and they were not affected by the presence of the different carriers. As shown by the findings of the present study, trehalose proved to be the most effective carrier, among the others used, for producing high-quality kefir powder products. However, further work is required with regard to the keeping quality of the product during long-term storage.

This paper studies the emulsification capacity of aqueous extracts from white beans and reports the relations between the composition and structure of the extracts’ macromolecular components and their exerted emulsification ability. The extracts comprise of three distinct populations: one of large (few MDa) polysaccharides, proteins (tens of kDa), and smaller molecular entities (oligopeptides and oligosaccharides, polyphenols, and salts, among other molecules); the proteins and the smaller molecules adsorb onto oil–water interfaces, providing some emulsification capacity at pH 3 and adequate emulsification at pH 7. Unabsorbed polysaccharides, such as starch, cause depletion flocculation. Pickering phenomena are involved in the stabilization mechanism. The findings are supported by SEC–MALLS/UV, confocal microscopy, zeta potential measurements, and FT–IR data. A discussion is made on the particular attributes of each population in emulsion stability, on their relevance to culinary practice, and in their potential as replacers of artificial emulsifiers.