Sara Lauzurica Gómez

Stabilization of β-Gal-3 ATCC 31382 on agarose gels: synthesis of β-(1→3) galactosides under sustainable conditions

β-Gal-3 ATCC 31382 (β-Gal-3) was immobilized by multipoint covalent attachment on an agarose support using different enzyme orientations on its surface. The derivatives that showed more activity and stability were the ones bound to a Lys rich region on a monofunctional glyoxyl-agarose (GA) support. Also, immobilization was performed using a Glu + Asp rich region on a heterofunctional amino-glyoxyl-agarose (AMGA) support. The immobilized enzyme was characterized in terms of optimal pH and thermal stability, and its catalytic efficiency was tested on the synthesis of β-(1→3) galactosyldisaccharides. Reactions were performed in the presence of green solvents ([Bmim][PF6] and 2HNND) with maximum conversion and maintained regioselectivity. Reusability assays under identical reaction conditions were also performed to find that GA immobilized enzyme retains about 90% of its activity after six batches with conversion yields above 75% when [Bmin][PF6] was used as reaction media. Furthermore, green solvent recovery and recycling are achieved retaining catalytic activity and increased productivity.

Meat and Meat Products Enriched with n-3 Fatty Acids

Meat is considered to be a good source of protein with high biological value as well as of micronutrients such as minerals (iron, zinc, selenium, …) and vitamins (B6, B12, A, D, …) with a high degree of bioavailability. These micronutrients are either not present in plant-derived food or have poor bioavailability. Consequently, consuming moderate amounts of lean meat as part of a balanced diet makes a valuable contribution to the intake of essential nutrients [1]. However, some constituents of meat, especially in red meat and meat products, have been proposed to be responsible for the development of cardiovascular disease and colon cancer. These elements include the fat content and the fatty acid composition. Meat and meat products are generally classified as “high-fat products”, although the various products available differ markedly in terms of their total fat content. Meat is generally considered to have a fat content in the range 1–20 %, depending on the retail cut and the amount of fat trimmed. Both the fat content and fatty acid composition of meat are influenced by factors such as species, breed, sex, age/weight and diet [2]. Figure 5.1 shows the fat content and fatty acid composition of some meats and meat products obtained from different species. The fat content is usually higher in processed meat products (5–40 %), where large amounts of fatty tissue are used.