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Pastrana, Lorenzo

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  • Platform design for extraction and isolation of Bromelain: complex formation and precipitation with carrageenan
    Publication . Campos, Débora A.; Valetti, Nadia Woitovich; Oliveira, Ana; Pastrana-Castro, Lorenzo M.; Teixeira, José A.; Pintado, Maria Manuela; Picó, Guillermo
    The main objective of this work was to investigate for the first time the molecular mechanism of com-plex formation between bromelain (a positively charged enzyme) and carrageenan (a natural strongpolyelectrolyte, negatively charged) using spectroscopy techniques and thermodynamic approaches. TheBromelain-Carrageenan complex showed a maximal non-solubility at pH around 5.1. The solubility wasdependent on pH and ionic strength of the medium. To re-dissolve the formed complex, the pH waschanged and 500 mM of NaCl was added to the initial solution, proving the columbic mechanism forthe formation of non-soluble complex. The formation of the carrageenan-bromelain complex increasedin 8◦C the enzyme thermal stability, while its biological activity was not modified. The amount of totalenzyme recovered in solution after precipitation with around 0.08% w/v of carrageenan was 85–90%.
  • Integral valorization of pineapple (ananas comosus l.) by-products through a green chemistry approach towards added value ingredients
    Publication . Campos, Débora A.; Ribeiro, Tânia; Teixeira, José A.; Pastrana, Lorenzo; Pintado, Maria Manuela
    Industrial by-products are produced every day through fruit processing industries. Pineapple is not an exception; when processed, around 60% (w/w) of its weight are peels, stem, trimmings, and crown, the only used fruit part for human consumption. Due to high concerns of sustainability in the food system and negative high impact of human practice in the environment, a strategy has to be developed. Therefore, a green chemistry approach was applied to pineapple by-products to make an integrated valorization by the extraction of bioactive molecules. Two pineapple by-products (peels and stems) were studied, applying a green chemistry approach, which means the non-use of organic solvents or extreme methodologies. A subdivision of each by-product was done by the application of a juice machine. The peels and stems in the fresh state were ground separately, creating two fractions for each by-product—a juice and a wet pulp (press cake). The press cake was characterized, dried, and ground to create a fine powder flour. To the juice, a precipitation methodology with polysaccharides was applied, which allowed the bromelain separation (developing of an enzymatic fraction) from the fruit juice. The enzymatic extract was freeze-dried, and the juice was spray-dried, developing two more fine powders. Thus, three new ingredients were produced from each by-product, creating a total of six new ingredients. Overall, the enzymatic fractions represented around 0.26% (w/w) of pineapple weight. Pineapple stem juice represented 4.8% (w/w), and peel juice represented 17.3% (w/w). Pineapple stem flour represented 3.1% (w/w), and peel flour represented 11.4% (w/w) of the total pineapple weight. To valorize the by-products juices, a full characterization was performed of bioactive molecules and biological activities. When comparing the two juices, the peel juice showed lower content of total phenolic compounds, lower antioxidant capacity, and lower content of vitamin C. The different phenolic compounds were identified by HPLC analysis in the two pineapple by-products juices. However, the same compounds in both juices were quantified (chlorogenic, caffeic, and ferulic acids). On the other hand, the by-products flours had a high content of insoluble dietary fiber (IDF), mainly cellulose and hemicellulose. Therefore, the approach applied in this work opens the door to the production of green products, as a result of by-products valorization. This could be applied not only in the food industry but also in the nutraceutical and cosmetic industries.
  • Enzymatic production of xylooligosaccharides from Brazilian Syrah grape pomace flour: a green alternative to conventional methods for adding value to agricultural by-products
    Publication . Costa, Joana R.; Tonon, Renata V.; Gottschalk, Leda M. F.; Santiago, Manuela C. P. A.; Mellinger-Silva, Caroline; Pastrana, Lorenzo; Pintado, Maria M; Cabral, Lourdes M. C.
    BACKGROUND: The aim of this work was to determine the most favorable conditions for the production of xylooligosaccharides (XOS) from Brazilian Syrah grape pomace. Chemical processes were performed using a rotatable central composite design, where the concentration of sulfuric acid or concentration of sodium hydroxide and grape pomace flour: solvent mass ratio were the dependent variables. Enzymatic production was also evaluated using xylanase produced by Aspergillus niger 3T5B8 and Viscozyme® enzymatic commercial cocktail. RESULTS: Chemical extraction allowed to recover 21.8 to 74.6% and 5.2 to 96.3% of total XOS for acid and alkaline processes, respectively. Enzymatic production using xylanase extracted up to 88.68 ± 0.12% of total XOS and up to 84.09 ± 2.40% with Viscozyme®. CONCLUSION: The present study demonstrated different feasible methods to produce high added value molecules, the xylooligosaccharides, from Syrah grape pomace flour, valorizing this major by‐product. The use of enzymatic cocktails demonstrated to be an alternative to the conventional methods, allowing to obtain an eco‐friendly and sustainable grape pomace extract.