Study of the effect of natural antioxidants in polyethylene: Performance of β-carotene (original) (raw)
Related papers
Natural antioxidants as stabilizers for polymers
Polymer Degradation and Stability
The additive packages routinely used today usually consist of a phenolic antioxidant and a phosphorus or sulfur containing secondary stabilizer. Several years ago some questions were raised about the health and environmental hazard of these additives and industry has not offered an alternatively solution yet. Nature produces a large number of antioxidants, which play a key role in radical reactions taking place in the human body. The substances containing these antioxidants are used in natural medicine for ages and they are applied in increasing quantities also in the food industry. The application of natural antioxidants for the protection of polymers is in its infancy, the information available is limited and often contradictory. This review paper summarizes published results, analyzes them and points out the advantages and drawbacks of the approach. Although a wide variety of compounds have been added to polymers to improve their stability, the most promising candidates are the carotenoids, the flavonoids, other natural phenols and phenolic polymers including lignin. Available results indicate that flavonoids are much more efficient stabilizers than the hindered phenols used in industrial practice. On the other hand, most of the natural antioxidants discolor the polymer and their solubility is limited. Nevertheless, natural antioxidants can be efficiently used in specific applications, but further research is needed to explore all their advantages and include them into additive packages used in practice.
Radical scavenging polyethylene films as antioxidant active packaging materials
Food Control, 2019
Most foods and beverages require the use of additives to avoid degradative reactions responsible for spoilage, yet consumers are demanding removal of such additives from product formulations. In the present work, fish protein hydrolysates (heretofore "peptides"), natural compounds with demonstrated antioxidant activity, were bound to polyethylene (PE) surface through a two-step conjugation. The films were activated by UV-ozone treatment, and polyethyleneimine (PEI) was used to tether the peptides. Surface characterization of control and modified films was performed using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), dye assays, contact angle and Trolox Equivalent Antioxidant Capacity (TEAC) after each functionalization step. Surface characterization confirmed the successful activation and functionalization of the PE through the incorporation of carboxylic acids and amines. The covalent attachment of the active peptides onto the PE surface was confirmed by the changes observed in dye assays results and introduction of characteristic absorbance bands in ATR-FTIR spectra. Surface wettability showed the increase of hydrophilicity after UV-ozone treatment, and amine and peptide conjugation. TEAC assay showed that the amount of peptide bounded was not enough to have radical scavenging capacity, however amine conjugated films showed ability to scavenge free radicals (~1.2 nmol Trolox/cm 2) and thus prevent oxidation reactions in foods. Such radical scavenging active packaging materials offer a potential alternative to the use of antioxidant additives in food and beverage formulations, addressing consumer demands for clean labels while mitigating food waste and loss due to spoilage.
Natural antioxidants for polypropylene stabilization
Polymer Degradation and Stability, 2011
A study on the efficiency of bio-based compounds as stabilizers for polypropylene (PP) is reported. A water extract from French maritime pine bark (Pycnogenol Ò ), a by-product containing polyphenols obtained from wine production, and a carotenoid-containing oleoresin from processing of tomatoes were used. Their stabilizing activity was compared with that of a commercial phenolic antioxidant. Thermogravimetric analysis and Oxidative Induction Time measurements performed on unaged samples, as well as infrared spectroscopy on samples aged at 70 C, provided evidence for the effectiveness of the natural stabilizers. Mechanical characterization was carried out on aged films and injection moulded samples. Experimental results indicated that particularly grape extract could provide long-term stabilization to PP under conditions of oxidative degradation. Therefore, it could be used as efficient and high value-added additive for polypropylene. Pycnogenol Ò also showed antioxidant activity, however the achievement of a more homogeneous dispersion in the polymer matrix could improve the mechanical performance of aged samples.
Journal of Agricultural and Food Chemistry, 2013
Two types of active antioxidant food packages with improved release properties, based on polypropylene (PP) as one of the most common polymers used in food-packaging applications, were developed. Incorporation of catechin and green tea as antioxidant provided PP with 6 times higher stabilization against thermal oxidation. Release of natural antioxidants (catechins, gallic acid, caffeine, and quercetin) into various food simulants from that nonpolar matrix were improved by blending poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) (PPG-PEG-PPG) as plasticizer into the polymer formulation. Increasing release levels between 10-and 40-fold into simulant A and between 6 and 20-fold into simulant D1 resulted from the incorporation of catechin and green tea as antioxidants and PPG-PEG-PPG as plasticizer into the film formulation. The efficiency of the antioxidants in the food simulants after the release process was also corroborated through antioxidant activity tests. Therefore, the developed PPG-PEG-PPG-modified polypropylene resulted in a potential system to be used in active packaging.
Recent Advances in the Carotenoids Added to Food Packaging Films: A Review
Foods, 2023
Food spoilage is one of the key concerns in the food industry. One approach is the improvement of the shelf life of the food by introducing active packaging, and another is intelligent packaging. Detecting packed food spoilage in real-time is key to stopping outbreaks caused by food-borne diseases. Using active materials in packaging can improve shelf life, while the nonharmful color indicator can be useful to trace the quality of the food through simple color detection. Recently, bio-derived active and intelligent packaging has gained a lot of interest from researchers and consumers. For this, the biopolymers and the bioactive natural ingredient are used as indicators to fabricate active packaging material and color-changing sensors that can improve the shelf life and detect the freshness of food in real-time, respectively. Among natural bioactive components, carotenoids are known for their good antimicrobial, antioxidant, and pH-responsive color-indicating properties. Carotenoids are rich in fruits and vegetables and fat-soluble pigments. Including carotenoids in the packaging system improves the film’s physical and functional performance. The recent progress on carotenoid pigment-based packaging (active and intelligent) is discussed in this review. The sources and biological activity of the carotenoids are briefly discussed, and then the fabrication and application of carotenoid-activated packaging film are reviewed. The carotenoids-based packaging film can enhance packaged food’s shelf life and indicate the freshness of meat and vegetables in real-time. Therefore, incorporating carotenoid-based pigment into the polymer matrix could be promising for developing novel packaging materials.
Oxidative degradation and stabilisation of polymers
International Materials Reviews, 2003
The aim of this review is to present a coherent terms primary and secondary antioxidants are also treatment of the fundamental aspects of the science that underpins current technological used sometimes even though the distinction is rather practices, and future advances, in the stabilisation arbitrary and does not relate to their mechanisms of of synthetic organic polymers. Aspects of polymer action. On the other hand, the rubber industry tends oxidation are introduced first before discussing the to use terms such as antidegradants, antifatigue agents role of antioxidants, with numerous examples, to and antiozonants, to refer similarly to chemical agents illustrate their basic mechanisms of action. The that act against the deleterious eVects of temperature, state of the art is discussed with particular stress and ozone, respectively. Although antioxidants emphasis on recent development and progress.
Chlorine dioxide resistance of different phenolic antioxidants in polyethylene
Polymer Degradation and Stability, 2015
A series of polyethylene tape samples containing 8 different phenolic antioxidants (concentration ¼ 0.1 ± 0.01 wt.%) were exposed to water containing 10 ppm chlorine dioxide buffered to pH ¼ 6.8 at 70 C for different periods of time. The degradation rate and depletion time of the antioxidants in the polyethylene were obtained by oxidation induction time measurements using DSC. The majority of the tape samples (6 out of 8) showed a simple behaviour: the rate of antioxidant loss decreased and the antioxidant depletion time increased in linear fashion with increasing initial molar concentration of phenolic groups in the polymer. The tape that contained Hostanox O3 had a high initial phenolic concentration but it exhibited a short antioxidant depletion time due to the limited solubility of this antioxidant in polyethylene. Tapes containing Irganox 1330 and Cyanox 1790 showed antioxidant depletion times that were almost twice that of the other antioxidants with the same initial molar concentration of phenolic groups.
Polymers, 2021
The new trend in food packaging films is to use biodegradable or bio-based polymers, such as poly(lactic acid), PLA with additives such as thymol, carvacrol, limonene or cinnamaldehyde coming from natural resources (i.e., thyme, oregano, citrus fruits and cinnamon) in order to extent foodstuff shelf-life and improve consumers’ safety. Single, triple and quadruple blends of these active compounds in PLA were prepared and studied using the solvent-casting technique. The successful incorporation of the active ingredients into the polymer matrix was verified by FTIR spectroscopy. XRD and DSC data revealed that the crystallinity of PLA was not significantly affected. However, the Tg of the polymer decreased, verifying the plasticization effect of all additives. Multicomponent mixtures resulted in more intense plasticization. Cinnamaldehyde was found to play a catalytic role in the thermal degradation of PLA shifting curves to slightly lower temperatures. Release of thymol or carvacrol fr...