Research articles
Research articles · 21. January 2020
This work reports on the production of sustainable, cost-efficient food packaging films from unpurified agarbased extracts obtained from Gelidium sesquipedale seaweed. Unlike the purified agars, that required the addition of a plasticizer, the presence of impurities such as other polysaccharides (mainly floridean starch) and proteins exerted a plasticization effect in the unpurified agars, forming flexible films with no added plasticizer. The formation of interpenetrating ...
Research articles · 21. January 2020
This work reports on the production and characterization of agar-based extracts from the seaweed Gelidium sesquipedale by means of simple protocols based on hot water and sonication treatments. The combination of sonication with the hot water treatment reduced 4-fold the extraction time without significantly affecting the extraction yield (ca. 10–12%) and the extracts' properties. Apart from agar, the extracts contained proteins, polyphenols and minerals, which conferred them high antioxidant...
Research articles · 21. January 2020
In this work, the effects of relative humidity (RH) pre-conditioning (53% vs. 85% RH) and incorporation of cellulose fillers (from Posidonia waste biomass) on the properties and retrogradation of melt compounded starch biocomposites were investigated. Pre-conditioning at 85% RH promoted starch gelatinization during processing, leading to more amorphous materials with reduced stiffness but better barrier properties. Furthermore, these films were less stable upon storage due to greater starch...
Research articles · 21. January 2020
Posidonia oceanica waste biomass has been valorised to produce extracts by means of different methodologies and their bioactive properties have been evaluated. Water-based extracts were produced using ultrasound-assisted and hot water methods and classified according to their ethanol-affnity (E1: ethanol soluble; E2: non-soluble). Moreover, a conventional protocol with organic solvents was applied, yielding E3 extracts. Compositional and structural characterization confirmed that while E1 and...
Research articles · 13. January 2020
Simplified extraction procedures (avoiding Soxhlet treatment and/or hemicellulose removal) were evaluated to valorize waste biomass from Posidonia oceanica leaves, obtaining cellulosic fractions and nanocrystals, which were subsequently used to produce films from their aqueous suspensions. Cellulose purification significantly improved mechanical and barrier properties of the films obtained from the fractions, while the extracted nanocrystals yielded films with remarkably improved properties,...
Research articles · 06. December 2018
This work reports on the valorization of residues from Posidonia oceanicaleaves for the purpose of obtaining lignocellulosic fractions of interest for the development of bio-based materials for food packaging. The lignocellulosic fractions were characterized, thereby confirming the purification of cellulose and showing increases in crystallinity and thermal stability after the consecutive extraction steps. Subsequently, pure lignocellulosic films were obtained and characterized and the pure...
Research articles · 06. December 2018
The objective of this work was to investigate whether the use of unpurified agar-based fractions extracted from the seaweed Gelidium as microencapsulation matrices has an impact on probiotic protection during storage. Therefore, unpurified and pure agar and agarose-based microcapsules were produced through emulsification/internal gelation for the protection of Bifidobacterium pseudocatenulatum CECT 7765. Initially, agarose-based formulations with other biopolymers were evaluated, given the...
Research articles · 20. November 2018
This study presents the valorization of the Gelidium sesquipedale seaweed for the development of bioactive aerogels with interest in food packaging applications. The raw seaweed was used to extract cellulose, highly crystalline (Xc∼70%) and high aspect ratio (∼40) nanocellulose and an agar-based extract, rich in polyphenols and with antioxidant capacity. Subsequently, pure PVA and hybrid aerogels containing cellulose and nanocellulose were produced by a physical cross-linking method. The...