Enzymatic hydrolysis of bacterial cellulose in the presence of a non-catalytic cerato-platanin protein

In this work, the effect of an expansin-like cerato-platanin (CP) protein as a pre-treatment for the enzymatic hydrolysis of bacterial cellulose (BC) is investigated. To this scope, cellulases from Trichoderma reesei are used as hydrolyzing agent using different enzyme/BC formulations. Turbidity experiments reveal that for the higher enzyme concentrations (formulations 0.5:1 and 1:1) the enzymatic hydrolysis of BC show similar hydrolysis kinetics and is not dependent of the CP. However, at higher BC concentrations (formulations 0.25:1 and 0.33:1), the hydrolysis of BC is hindered by the non-catalytic protein, as confirmed by the lower content of cellobiose and glucose in the presence of CP. Light scattering experiments show that the addition of CP led to an increase of the BC particle size from (445–630 nm) to (890–1.26 μm) for the formulation 1:1, which is also corroborated by atomic force microscopy and transmission electron microscopy analyses. These results suggest that CP did not positively affect the hydrolysis of BC, in contrast to what was previously observed for plant-derived cellulose. This work for the first time investigates the anomalous behavior of cerato platanin family members with regard to its loosening activity on the structure of bacterial cellulose

lpa1-5525: A New lpa1 Mutant Isolated in a Mutagenized Population by a Novel Non-Disrupting Screening Method

Phytic acid, or myo-inositol 1,2,3,4,5,6-hexakisphosphate, is the main storage form of phosphorus in plants. It is localized in seeds, deposited as mixed salts of mineral cations in protein storage vacuoles; during germination, it is hydrolyzed by phytases to make available P together with all the other cations needed for seed germination. When seeds are used as food or feed, phytic acid and the bound cations are poorly bioavailable for human and monogastric livestock due to their lack of phytase activity. Therefore, reducing the amount of phytic acid is one strategy in breeding programs aimed to improve the nutritional properties of major crops. In this work, we present data on the isolation of a new maize (Zea mays L.) low phytic acid 1 (lpa1) mutant allele obtained by transposon tagging mutagenesis with the Ac element. We describe the generation of the mutagenized population and the screening to isolate new lpa1 mutants. In particular, we developed a fast, cheap and non-disrupting screening method based on the different density of lpa1 seed compared to the wild type. This assay allowed the isolation of the lpa1-5525 mutant characterized by a new mutation in the lpa1 locus associated with a lower amount of phytic phosphorus in the seeds in comparison with the wild type

Influence of Two Innovative Packaging Materials on Quality Parameters and Aromatic Fingerprint of Extra-Virgin Olive Oils

The performance of two innovative packaging materials was investigated on two Sardinian extra-virgin olive oils (Nera di Gonnos and Bosana). In particular, a transparent plastic film loaded with a UV-blocker (packaging B) and a metallized material (packaging C) were compared each other and to brown-amber glass (packaging A). During accelerated shelf-life tests at 40 and 60 °C, the evolution of quality parameters (i.e., acidity, peroxide value, K270, and phenolic content) was monitored, together with the aromatic fingerprint evaluated by electronic nose. Packaging B resulted in the best-performing material in protecting oil from oxidation, due to its lower oxygen transmission rate (0.1 ± 0.02 cm3/m2 24 h) compared to packaging C (0.23 ± 0.04 cm3/m2 24 h). At the end of storage, phenolic reduction was on average 25% for packaging B and 58% for packaging C, and the aromatic fingerprint was better preserved in packaging B. In addition, other factors such as the sanitary status of the olives at harvesting and the storage temperature were demonstrated to have a significant role in the shelf life of packaged extra-virgin olive oil

Preparation and characterization of bioactive chitosan-based films incorporated with olive leaves extract for food packaging applications

Chitosan films with olive leaf extract (OLE) incorporated at different concentrations were characterized regarding their antimicrobial, antioxidant and some relevant physical properties (i.e., solubility, water vapor permeability, and tensile properties). Results indicate that the active films have substantial antimicrobial activity against Listeria monocytogenes and Campylobacter jejuni mostly extending the microorganisms lag phase. A lower level of inhibition was found in the case of Escherichia coli. However, the OLE seems not to improve the intrinsic antimicrobial properties of the chitosan itself, except for C. jejuni. These results were confirmed with in situ testing using chicken. The chitosan films with OLE exhibited antioxidant activity, increasing with the OLE concentration, from 0.04 to 0.15 g/L ascorbic acid equivalents, corresponding to films with 10%–30% OLE relative to the chitosan. Chitosan films loaded with OLE exhibited a higher solubility in food simulants and a reduced permeability against water vapor. Overall, the combination of OLE and chitosan allows to obtain a promising active bio-based packaging solution for addressing safety and quality issues.info:eu-repo/semantics/publishedVersio