Lipid Oxidation Kinetics of Pistachio Powder During Different Storage Conditions

Recent advances in understanding the interfacial activity of antioxidants in association colloids in bulk oil

The chemical stability of edible oils rich in polyunsaturated fatty acids (PUFAs) is a major challenge within the food and supplement industries, as lipid oxidation reduces oil quality and safety. Despite appearing homogeneous to the human eye, bulk oils are actually multiphase heterogeneous systems at the nanoscale level. Association colloids, such as reverse micelles, are spontaneously formed within bulk oils due to the self-assembly of amphiphilic molecules that are present, like phospholipids, free fatty acids, and/or surfactants. In bulk oil, lipid oxidation often occurs at the oil-water interface of these association colloids because this is where different reactants accumulate, such as PUFAs, hydroperoxides, transition metals, and antioxidants. Consequently, the efficiency of antioxidants in bulk oils is governed by their chemical reactivity, but also by their ability to be located close to the site of oxidation. This review describes the impact of minor constituents in bulk oils on the nature of the association colloids formed. And then the formation of mixed reverse micelles (LOOH, (co)surfactants, or antioxidations) during the peroxidation of bulk oils, as well as changes in their composition and structure over time are also discussed. The critical importance of selecting appropriate antioxidants and surfactants for the changes of interface and colloid, as well as the inhibition of lipid oxidation is emphasized. The knowledge presented in this review article may facilitate the design of bulk oil products with improved resistance to oxidation, thereby reducing food waste and improving food quality and safety.

Effect of packaging method, temperature and storage period on physicochemical and sensory properties of wild almond kernel

This research was performed to monitor the effect of different temperatures (4, 25 and 35 °C) and atmospheres (vacuum, CO₂ and normal air) on physicochemical and sensory properties of wild almond kernel during several weeks' storage. The color, moisture content and sensory analysis of the kernels, peroxide value (PV), 2-thiobarbiotic acid (TBA), conjugated dienes and trienes (CD, CT) and acid value (AV) of the oils were determined in defined time intervals. The results showed that the influence of temperature, time and type of atmosphere on the following parameters were significantly different. At all temperatures studied, AV, PV, TBA and CD/CT of oils from all samples increased with time which was less in the modified atmosphere packaging (MAP) compared with vacuum packaging (VP) and air atmosphere packaging (AAP). At the end of storage, the samples stored under AAP at 35 °C had the highest amount of PV (15.5 meq/kg), TBA (0.056 mg/kg) and CT (0.193 μmol/g), while the samples packaged under MAP at 4 °C had the lowest. Irrespective of packaging type, L* and b* values decreased during storage with a parallel increase of values a* resulting in gradual product darkening, especially in AAP. Sensory analysis also showed the decrease of overall acceptability during the storage among the three packaging systems. In conclusion, the use of MAP was the most effective method for protecting wild almond kernel from deteriorative reactions such as oxidation and hydrolysis.