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The ability of sodium dodecyl sulfate (SDS) to plasticize edible films from whey protein isolate (WPI) was assessed. SDS was not able to plasticize WPI films on its own, but it was an effective coplasticizer in films containing either sorbitol or glycerol as the main plasticizer. In films that contained sorbitol, a mass ratio of SDS to WPI (R S:W) of 0.2 resulted in films that were more extensible and more soluble but with almost unchanged water vapor permeability (WVP). In films that contained glycerol, the same R S:W resulted in less extensible and soluble films with slightly higher WVP values. Values of R S:W > 0.3 resulted in antiplasticization, although there was a reduction in WVP. At R S:W > 1 films were so brittle that they could not be handled without breaking. The mechanical properties of WPI films that contained SDS were comparable to published values for other proteinaceous, edible films. Keywords: Plasticizer; Young's modulus; tensile strength; protein/surfactant interactions

Polyphenols extracted from extra virgin olive oil (EVOO) were tested for their ability to inhibit lipid oxidation of canned tuna. Hydroperoxide formation during oxidation was monitored by measurement of peroxide value and decomposition of hydroperoxides by static headspace gas chromatographic analysis of volatiles. In tuna oxidized at 40 and 100 degrees C, 400 ppm of the EVOO polyphenols was an effective antioxidant as compared with 100 ppm of a 1:1 mixture of the synthetic antioxidants butylated hydroxytoluene and butylated hydroxyanisole. However, at concentrations <100 ppm, the EVOO phenolic compounds promoted hydroperoxide formation and decomposition. The EVOO polyphenols were effective antioxidants when added to heated tuna muscle in the presence of either brine or refined olive oil. The oxidation rate in tuna muscle packed in brine was higher than that of tuna packed in refined olive oil. The EVOO polyphenols had higher antioxidant activity in the brine samples than in the refined olive oil. The higher antioxidant activity of EVOO polyphenols in tuna packed in brine may be explained by their greater affinity toward the more polar interface between water and the fish oil system.

This article focuses on the role of omega-3 fatty acids as precursors for lipid signaling molecules known as oxylipins. Although omega-3 fatty acids are beneficial in autoimmune disorders, inflammatory diseases and heart disease, they are generally underrepresented in the American diet. A literature review confirms that the consumption of omega-3 fatty acids — whether in food sources such as walnuts, flax seeds and fatty fish (including salmon and sardines), or in supplements — is associated with decreased morbidity and mortality. This growing body of evidence, including the results of a recent study of patients with kidney disease, highlights the need to measure omega-3 fatty acids and their oxylipin products as markers of metabolic health and biomarkers of disease. In addition, there is substantial evidence of the need to increase the omega-3 fatty acid content of American diets to optimize metabolic health.

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