Polylactic acid as a promising sustainable plastic packaging for edible oils

The influence of renewable packaging materials on the oxidative stability of sunflower oil was investigated to evaluate whether they could be used as alternatives to conventional plastics. Two renewable bottle materials, polylactic acid (PLA) and bio-polyethylene (Green-PE) were compared to conventional plastics consisting of virgin and recycled polyethylene terephthalate (PET, r-PET) and regular polyethylene (PE), in a storage study over a period of 56 days. The results showed that the progress of lipid oxidation in PLA was similar to PET and r-PET until day 28, while it was significantly increased in PE and Green-PE. Benzene was detected as the only migration compound in the oil stored in PET and r-PET, with concentrations of 0.153 ± 0.027 µg/g and 0.187 ± 0.024 µg/g after 56 days of storage. The study concluded that PLA could be used as an alternative packaging material for edible oils to replace PET.This work was kindly funded by the Austrian Science Fund (FWF): P 34512. J. Alberdi-Cedeño thanks the EJ-GV for a postdoctoral grant (POS_2020_1_0040). The authors want to thank Sandra Auernigg-Haselmaier for the technical assistance with the LC-MS and the NMR core facility of the Division of Pharmaceutical Chemistry at the University of Vienna for providing access to the NMR instruments

Interlaboratory study on lipid oxidation during accelerated storage trials with rapeseed and sunflower oil analyzed by conjugated dienes as primary oxidation products

11 Páginas.-- 5 Figuras.-- 2 Tablas.-- Material suplementarioAccelerated storage tests are frequently used to assess the oxidative stability of foods and related systems due to its reproducibility. Various methods and experimental conditions are used to measure lipid oxidation. Differences between laboratories make it necessary to determine the repeatability and reproducibility of oxidation tests performed under the same conditions. The objective of the present interlaboratory study was to evaluate the outcome of a storage test for two different bulk oils, sunflower oil (SFO) and rapeseed oil (RSO), during a period of 9 weeks at 20°C, 30°C, 40°C, and 60°C. Sixteen laboratories were provided with bottled oils and conducted the storage tests according to a detailed protocol. Lipid oxidation was monitored by the formation of conjugated dienes (CD) and the activation energy (Ea) was determined for comparative purposes and statistically evaluated. An increase in CD formation was observed for both oils when the storage temperature was increased in all laboratories. The Ea,1 ranged from 47.9 to 73.3 kJ mol−1 in RSO and from 27.8 to 62.6 kJ mol−1 in SFO, with average values of 58.2 and 46.8 kJ mol−1, respectively. The reproducibility coefficients were 10.9% and 18.2% for RSO and SFO, respectively. Practical applications: In order to compare results on oxidative stability of foods derived from different studies, the reproducibility of storage tests and methods employed to evaluate the oxidation level should be considered. This study provides fundamental data on the reproducibility of lipid oxidation under accelerated storage conditions and defines important parameters to be considered for the conduction of experiments.Open access funding enabled and organized by Projekt DEAL. We thank Brökelmann + Co – Oelmühle GmbH + Co for the donation of the vegetable oils. The authors gratefully acknowledge Lina Stuthmann from the Food Technology Division, Kiel University and Inge Holmberg from the National Food Institute, Technical University of Denmark for their skillful help.Peer reviewe

Enrichment of Sunflower Oil with gamma-Tocopherol. Study by H-1 NMR of Its Effect Under Accelerated Storage Conditions

The effect of the enrichment of sunflower oil with gamma-tocopherol on the evolution of its oxidation is the subject of this study. Sunflower oil and samples of this oil enriched with different gamma-tocopherol concentrations are submitted to accelerated storage conditions and their evolution, until total polymerization is monitored by H-1 NMR spectroscopy. The concentrations of linoleic acyl groups, of primary and of a great number of secondary oxidation compounds are determined throughout the process. These concentrations, and the times at which the main changes in them occur are analyzed to elucidate if they are valid markers of the global effect of gamma-tocopherol enrichment. It is proved for the first time that certain comparisons between concentrations of some of the compounds formed in oxidation can lead to erroneous conclusions about the effect of this enrichment. It is shown that, during a first short period of time under accelerated storage conditions, the higher the concentration of gamma-tocopherol the faster the degradation of linoleic acyl groups and the higher the concentration of hydroperoxides; after this first period this relationship is more complex. Generally, the higher the gamma-tocopherol concentration the slower the degradation of the oil, except in the first period.Practical Applications: This study provides very valuable information about the effect caused by enrichment with gamma-tocopherol on sunflower oil oxidative stability and oxidation across a very broad range of concentrations. In addition, the amount of information obtained can be of great importance from several points of view because the oxidation process has been monitored globally. This may be of interest not only to researchers involved in the analysis of oxidation mechanisms but also to those in the field of technology and edible oil legislation, and even to those worried about edible oil safety and its effect on nutrition and health. Another important feature of this study, from the practical point of view, is the methodology used because it does not involve the chemical modification of the sample and the same H-1 NMR spectrum is able to provide information about all the above-mentioned aspects. Sunflower oil enriched with different levels of gamma-tocopherol. Concentrations of primary and secondary oxidation compounds after 4 and 9 days, respectively, under accelerated storage conditions.This work has been supported by the Spanish Ministry of Economy and Competitiveness (MINECO AGL 2015-65450-R), the Basque Government (EJ-GV, IT-916-16), and the Agriculture Department of the Basque Government (PA19/02)