Use of isothermal and nonisothermal chemiluminescence measurements for comparison of stabilizing efficiency of hydroxytyrosol (3,4‐dihydroxy‐phenylethanol), α‐tocopherol and irganox®1076 in polypropylene

Abstract

Hydroxytyrosol (3,4-dihydroxyphenylethanol) is a phenolic compound obtained during olive processing in oil manufacturing. It plays a role in enhancing the oxidative stability of olive oil with positive effects on human health. The raising interest towards the use of natural antioxidants as stabilizers in polymer formulations makes hydroxytyrosol a potential candidate to substitute synthetic antioxidants in polyolefin formulations. In this study, hydroxytyrosol was compared in antioxidant efficiency with two other compounds, one of them obtained from natural resources (a-tocopherol) and a synthetic commercial phenolic antioxidant (Irganox V R 1076). Chemiluminescence was used to as a tool to assess the increase in the polypropylene stability to thermo-oxidative degradation. A significant increase in the value of oxygen induction time with the initial concentration of natural antioxidants tested under isothermal conditions at 140, 150 and 160 C was observed. A comparison at the same concentration level (0.1 wt %) between the three antioxidants showed an order of stabilizing efficiency as: a-tocopherol > Irganox V R 1076 > hydroxytyrosol, but all them showed clearly their stabilization performance in polypropylene.

Cucumis metuliferus Fruit Extract Loaded Acetate Cellulose Coatings for Antioxidant Active Packaging

“…Moreover, it has an important effect on the reduction of deterioration reactions that begin at the food surface due to a more significant interaction with the surface of the packed food [ 11 , 14 , 15 ]. Additionally, there is a growing trend in the food packaging industry to replace synthetic additives with natural antioxidants in both petrochemical-based [ 16 , 17 , 18 , 19 ] and bio-based and biodegradable polymers [ 10 , 20 , 21 , 22 ], particularly with tocopherol, catechols, essential oils, and plant extracts [ 16 , 20 , 23 ].…”

Delivery Systems for Hydroxytyrosol Supplementation: State of the Art

“…A schematic representation of a possible active packaging system for HY-delivery is showed in Figure 7. The utilization of such systems proves that HY does not alter the morphological, optical, thermal and mechanical properties of the films [89,90]. In addition, HY-based films showed good performances by improving the shelf-life and health effects of the foodstuffs packaged.…”

“…These polymers were studied for active packaging applications by developing films loaded with natural ingredients, comprising the HY. Specifically, HY was incorporated in polypropylene, PCL and PVA films [88][89][90][91][92][93]. For this purpose, an aqueous solution of the selected polymer, dissolved by heating, was first prepared in distilled water to obtain the polymeric matrix; then, room temperature was reached under stirring.…”

Antioxidant and antibacterial effects of natural phenolic compounds on green composite materials

“…The aim with these tests was to ascertain the length of time that the biocomposite would resist before suffering oxidation. With the results obtained in the two DSC tests, we saw that α-tocopherol is an excellent antioxidant agent in a range of conditions and atmospheres, but acts particularly well in air atmospheres [15,23]. This effect can be explained by the fact that α-tocopherol has a high density of connected structures which are very efficient at 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 trapping free radical thus reducing the degradation of the biocomposite [15,18].…”