Effect of Compositional Factors against the Thermal Oxidative Deterioration of Novel Food Emulsions

Abstract

This work attempts to determine any relationship between certain endogenous parameters and the oxidative deterioration of protein-stabilized oil-in-water emulsions. The contribution of compositional factors (e.g., type and amount of emulsifier, fat phase, etc.) is further elucidated. Among 10% cottonseed o/w emulsions prepared by 1% emulsifier (Tween, sodium caseinate, or whey protein), lipid autoxidation (at 40°C) was much faster in the Tween emulsion than in the protein ones, with whey protein presenting a clear antioxidant effect. Increase in protein concentration (0.5-2% w/w) led to a decrease in droplet size but an increase in oxidative stability, in terms of conjugated diene hydroperoxides formation at 232 nm. The type of lipid phase significantly affected the rate of thermal oxidation at 60°C. In the most oxidatively vulnerable sunflower-oil-based emulsions, an increase in fat content (10-40%) resulted in a reduction of oxidative deterioration. By selecting a more concentrated emulsion (20% o/w, 2% emulsifier), in order to structurally approach real novel food products, any influence of the composition of the emulsifier (combination of Tween and sodium caseinate preparation) was subsequently tested. An increase in protein proportion in the emulsifier was found to inhibit proportionally the oxidative instability of the emulsions, as evaluated by the determination of both primary (conjugated diene and lipid hydroperoxides) and secondary [thiobarbituric acid-reactive substances (TBARS)] oxidation products.

Effect of Processing and Storage Parameters on the Oxidative Deterioration of Oil-in-Water Emulsions

“…Such an influence of emulsifier composition on oxidation has been recently reported and discussed by Kiokias et al 9 The results of this study indicated that the formation of primary oxidation products in emulsions is strongly temperature-dependent and the quantification of the reaction rate's reliance with temperature could help to monitor the oxidative alterations. On the other hand, the effect of pH is associated with the emulsifier used, and is more pronounced in Tween-stabilized emulsions.…”

“…A mixture of Tween/Na-CAS 1:1 was used and an emulsion with higher oil concentration was prepared, which is closer to the formulation of innovative real products. 9 From this point of view, this certain emulsion system was selected as appropriate to further examine any effect of pH. The water bath temperature was adjusted to 60°C to accelerate the oxidation experiment.…”

“…type and concentration of emulsifier and lipid phase) on the oxidative stability of food oil-in-water emulsions. 9 This paper focuses on the effect of various processing and storage parameters on the oxidative sensitivity of Tween-or sodium caseinate-stabilized emulsions. More specifically, the experimental work is investigating into the effect of storage temperature, pH, and homogenization pressure on emulsion oxidative deterioration, to propose strategies against the nutritional and quality deterioration of relevant products.…”

Developing a three component stabilizer system for producing astaxanthin nanodispersions

“…Richards, Golding, Wijesundera, and Lundin (2011) reported that the combination of SC with non-ionic small molecular emulsifiers showed greater inhibitory effect on lipid oxidation of o/w emulsions as compared to using it individually or in combination with ionic small molecular emulsifiers. Kiokias, Dimakou, Tsaprouni, and Oreopoulou (2006) could also improve the oxidative deterioration of linolenic acid in o/w emulsions by using a twocomponent stabilizer mixtures composed of polysorbates and globular proteins. In these systems, by increasing the proportion of polysorbates, protein displacement is simultaneously enhanced leading to the weakening of the thickness and functionality of the protein interfacial layer.…”

Luminol Chemiluminescence Profile of O/W Emulsions during Thermal Oxidation

“…2 Lipid oxidation in food results in off-flavors and toxic products due to the peroxidation of unsaturated fatty acids. 3,4 Therefore, evaluating of lipid oxidation in emulsions is important to control the quality and safety of food.…”