Maria Victoria Santos

Efficient cryopreservation is essential for maintaining the viability of Saccharomyces eubayanus, a cryotolerant wild yeast of industrial importance as the

Background Brewers' spent grain (BSG) is one of the most abundant by-products of the beer industry and causes serious environmental problems. Ferulic acid (FA) is an antioxidant with potential cosmeceutical applications. FA was extracted from BSG, developing a method of high extraction performance in order to be encapsulated in ultradeformable liposomes (Nanoferulic, NF). Aims To obtain a product with high added value such as FA, from a residue currently underused, using simple and economical chemical methods. To load FA into a nanosystem designed for the topical route, its encapsulation has the purpose to take profit from its photoprotective, anti-inflammatory, and antioxidant properties in the deep layers of the skin. Methods Ferulic acid was obtained from dried BSG using acid and basic treatments in series. NF was prepared by lipid film resuspension of a solution containing FA obtained from BSG. Size and Z-potential were determined. Cytotoxicity was assessed in vitro. Skin penetration was assessed by NF determination at different skin depths and by confocal microscopy. Results The yield of the extraction process was 0.43% on a dry basis. Encapsulation rendered liposomes of around 140 nm with 92% of encapsulation efficiency. No toxicity was observed in all the tested concentrations. Successful results were obtained from the regeneration studies. Conclusions It was possible to develop a nanosystem containing FA, generating a high-value commercial input for the pharmaceutical and cosmeceutical industry. The use of BSG generated in industrial scale would help to reduce the volume of highly polluting waste.

The aim of this work was to determine natural convective heat transfer rates in bottled liquid food pasteurized using different container orientations; conventional vertical, inverted vertical, and horizontal bottle positions. For this purpose, a computational fluid dynamic (CFD) model was applied to predict the temperature distribution, flow pattern, and quality changes in non‐Newtonian fluid foods for three orientations. The numerically predicted temperatures were successfully validated against experimental data and the model allowed to identify the critical point during the thermal process. Results showed that the fluid flow developed in a horizontal orientation provided a better mixing of liquid food and, hence, a more rapid heating of the slowest heating zone compared to a vertical position. Moreover, the horizontal orientation achieved a 47.2% reduction of processing time and quality losses decreased (45.5–46.4%) with respect to a vertical position. These results suggest that a horizontal position could be considered as an interesting alternative for food processors since processing times can be reduced improving the final quality of the product.Practical Applications: Pasteurization is a heat treatment process applied to a food product with the purpose of destroying disease‐producing microorganisms, inactivating spoilage‐causing enzymes, and reducing spoilage microorganisms. Overcooking causes detrimental effects in terms of the final product quality. Therefore, providing an adequate process with a desired sterility is one of the challenges to canning industry. In this work, we investigate how to improve, through container orientation modification, the natural convective heat transfer rates during pasteurization of fluid food. These results were obtained by the numerical simulation of the thermal process using CFD analysis which allowed to determine the temperature history and velocity field in the bottled liquid food. From the numerical results, the set of operating conditions that enhance the quality and the safety of the final product was determined, thus minimizing expensive and time‐consuming pilot test‐runs.