Chromatographic fingerprint application possibilities in food authentication

The aim of the study was to compare the effectiveness of the use of low-peak chromatographic fingerprints for the differentiation of various food products. Three groups of unprocessed products (mushrooms, hazelnuts and tomatoes), food preparations (bread, dried herbs and tomato juice) and alcoholic beverages (vodka and two types of blended whiskey) were examined. A commercial electronic nose based on ultrafast gas chromatography (acquisition time 90 s) with a flame ionization detector was used for the research. Static headspace was used as a green procedure to extract volatile compounds without modifying the food matrix. Individual extraction conditions were used for each product group. Similarities and differences between profiles were analyzed by simple Principal Components Analysis. The similarity rating was determined using the Euclidean distances. Global model was built for recognition chromatographic fingerprints of food samples. The best recognition results were 100% and 89% for tomato juices, spices, separate champignon elements and hazelnuts. On the other hand, the worst recognition results were 56% and 77% for breads and strong alcoholic beverages.

One-Pot Synthesis of TiO2-rGO Photocatalysts for the Degradation of Groundwater Pollutants

A non-conventional approach to prepare titanium dioxide-reduced graphene oxide (TiO2-rGO) nanocomposites based on solar photoreduction is here presented. The standard hydro-solvothermal synthesis of the TiO2-rGO composites requires high temperatures and several steps, whereas the proposed one-pot preparation allows one to obtain the photocatalysts with a simple and green procedure, by exploiting the photocatalytic properties of titania activated by the solar irradiation. The TiO2-rGO catalysts were tested in the solar photodegradation of a widely adopted toxic herbicide (2,4-Dichlorophenoxyacetic acid, 2,4-D), obtaining the 97% of degradation after 3 h of irradiation. The as-prepared TiO2-rGO composites were more active compared to the same photocatalysts prepared through the conventional thermal route. The structural, optical, and textural properties of the composites, determined by Raman, Photoluminescence, Fourier Transform InfraRed (FTIR), UV-vis diffuse reflectance (DRS) spectroscopies, and N2 absorption-desorption measurements, showed as the solar irradiation favors the reduction of graphene oxide with higher efficiency compared to the thermal-driven synthesis. Furthermore, the possible toxicity of the as-synthesized composites was measured exposing nauplii of microcrustacean Artemia sp. to solutions containing TiO2-rGO. The good results in the 2,4-D degradation process and the easiness of the TiO2-rGO synthesis allow to consider the proposed approach a promising strategy to obtain performing photocatalysts.

GRAFTING METHOD OF FLUORINATED COMPOUNDS TO CELLULOSE AND CELLULOSE ACETATE: CHARACTERIZATION AND BIODEGRADATION STUDY

Cellulose (Cell) and cellulose acetate (CA) are attractive durable materials; they can acquire various properties through modification in order to obtain valuable industrial products. First, a series of novel fluorinated cellulose carbamate and fluorinated CA carbamate have been synthesized. The introduction of fluoro-groups onto cellulose and CA chain backbone was achieved by the one-pot grafting method using diisocyanate as a coupling agent, which can be considered as a green procedure. The compounds prepared were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), X-ray diffractometry (XRD), thermogravimetric analysis (TGA) and differential thermogravimetry (DTG) measurements. The results obtained from these analytical techniques confirm that modification occurs successfully. Second, the solubility behavior and biodegradation process of these new fluorinated materials have been studied. The results show that these new materials exhibit better solubility compared to cellulose, but this solubility decreases compared to that of CA. The phenomenon of biodegradation was studied using two methods, the rate of biodegradability was determined. The results of this part show that the biodegradation of fluorinated materials decreases compared to that of the starting materials. These novel materials are biodegradable, can substitute currently used industrial non-biodegradable products and be promising agents for several uses, such as bioplastics, drug carriers, etc. A sustainable development and an increased use of green chemistry principles are among the essential objectives of this work.

Green Procedure for Aerobic Oxidation of Benzylic Alcohols with Palladium Supported on Iota-Carrageenan in Ethanol

The search for selective heterogeneous catalysts for the aerobic oxidation of alcohols to ketones and aldehydes has drawn much attention in the last decade. To that end, different palladium-based catalysts have been proposed that use various organic and inorganic supports. In addition, supports that originate from a biological and renewable source that is also nontoxic and biodegradable were found to be superior. We heterogenized palladium chloride or acetate complexes with triphenylphosphine trisulfonate on iota-carrageenan xerogel by simple mixing of the complex and the polysaccharide in water. The resulting polysaccharide-catalyst mixture then underwent deep freeze and lyophilization, after which the catalyst was characterized by TEM, XPS and SEM-EDS and tested in aerobic oxidation. The new heterogeneous catalysts were successfully used for the first time in the aerobic oxidation of benzylic alcohols. Moreover, they were easily removed from the reaction mixture and recycled, yielding an increase in activity with each subsequent reuse. As determined by TEM and XPS, the reduction in palladium and the formation of nanoparticles during the reaction in ethanol yielded more active species and, therefore, higher conversion rates. A SEM-EDS analysis indicated that the palladium was thoroughly dispersed in the xerogel catalysts. Moreover, the xerogel catalyst was observed to undergo a structural change during the reaction. To conclude, the new heterogeneous catalyst was prepared by a simple and straightforward method that used a non-toxic, renewable and biodegradable support to yield an active, selective and recyclable heterogeneous system.

Microbial cellulose based films and composites for food packaging: a review

Currently, the production and application of non-biodegradable petroleum-based synthetic polymer (commonly known as plastic) are highly prevalent. As synthetic polymers as mostly non-biodegradable, they adversely affect the environment and result in the generation of excessive solid waste. The increasing awareness about the ill-effects of synthetic polymers among consumers has resulted in a demand for natural, disposable, biodegradable, reusable, or recyclable food packaging materials. Bio-based polymers and biopolymers have been one of the most favorable alternatives to be exploited and developed into eco-friendly food packaging materials. Certain microorganisms, such as Gluconoacetobacter xylinus, produce cellulose by a fully green procedure which is called bacterial cellulose. Bacterial cellulose demonstrates exceptional properties such as being a chemically pure material, highly flexible, high water absorbency, great tensile strength, highly crystalline nature, highly moldable, non-toxic nature, and biocompatible. However, there are some limitations such as lack of antibacterial properties, optical transparency, and stress-bearing capability which can be overcome by developing bacterial cellulose composites using hydrocolloids like proteins, starches, pectins, etc. The bacterial cellulose composites are employed to develop packaging films with properties such as high mechanical strength; antimicrobial, transparent, biodegradable, with air, water, and oil resistance properties, thus, making it an appropriate material for packaging.

Eco-friendly and Green Procedure for Iodination of Reactive Aromatics Using PEG 400-I2/HIO3 Combination

Background:: Iodination of organic substrate is an important reaction for synthesis of pharmacological active molecules. Methods:: In view of these concerns, we reported the convenient procedure for synthesis of iodo compounds using iodine and iodic acid in PEG-400.We have reported the eco-friendly procedure for preparation of aromatic iodo compounds using iodine and iodic acid in green reaction media as polyethylene glycol (PEG-400). Results:: The iodination of some aromatic compounds such as benzaldehydes, acetophenones, phenols, amines and heterocyclic compounds carried out using iodine, iodic acid and PEG-400. The synthesized substituted aromatic iodo compounds were confirmed based on spectral characterization and mixed melting points. Conclusion:: The method comprises several advantages such as simple reaction procedure, easy isolation, quantitative yields, and purity of iodo products.

High Hydrostatic Pressure Assisted by Celluclast® Releases Oligosaccharides from Apple By-Product

A novel and green procedure consisting of high hydrostatic pressure (HHP) aided by a commercial cellulase (Celluclast®) has been applied to valorise the apple by-product, a valuable source of dietary fibre but mainly composed by insoluble fibre. Optimal conditions for solubilisation of dietary fibre were first determined at atmospheric pressure as 2% (w/v) of substrate concentration and 20 Endo-Glucanase Units of cellulase. Monitoring of polysaccharides and oligosaccharides released from apple by-product was carried out by means of a newly validated HPLC method with refractive index detector. A synergistic effect was observed when the combined HHP plus cellulase treatment was used. Thus, the application of 200 MPa at 50 °C for 15 min enabled a significant increase in the release of water-soluble polysaccharides (1.8-fold) and oligosaccharides (3.8-fold), as well as a considerable decrease in the time required (up to 120-fold), compared to control at 0.1 MPa. Therefore, this technology could be a promising alternative approach to transform an industrial by-product into a novel rich-in-oligosaccharide food ingredient and a step forward into shaping the world of prebiotics.