Antioxidant Protection of Bulk Fish Oils by Dispersed Sugars and Polyhydric Alcohols

Abstract

Selected sugars (fructose, sucrose, or raffinose) and polyhydric alcohols (sorbitol or mannitol) were equilibrated directly with bulk fish oil (10% by weight, excess) and exposed to fluorescent lighting (2550 Lx) for 24 h at 5 degrees C. Data for room temperature-equilibrated samples revealed that polyols functioned as antioxidants in fish oil. Increased times and temperatures of equilibration (to 90-110 degrees C, 1-2 mmHg, to 2 h) greatly enhanced the antioxidant activity of polyols in fish oil exposed to light. Under accelerated oxidation conditions (60 degrees C) in the dark, dispersed sorbitol in bulk fish oil greatly suppressed the peroxide value, primarily by chelating transition metals, while fructose showed a limited antioxidant activity. Sugars with a lower molecular weight and smaller numbers of equatorial OH groups exhibited a higher rate of permeation of sugars into fish oil triacylglycerols and hence rendered greater antioxidant activities. The treatment of bulk fish oils with polyols and then using the oils in the preparation of emulsions greatly reduced their antioxidant activities as compared to those observed for treated bulk oils. The introduction of polyols dissolved in propylene glycol into bulk fish oils at 90 degrees C (0.025% polyol, 0.25 h of equilibration) provided a similar antioxidant activity to that imparted by the introduction of polyols into the oil by equilibrating excess polyols (10% by weight) with them at 90-110 degrees C for 2 h. However, regardless of the method of the introduction of polyols to bulk fish oil, an elevated temperature (90 degrees C) exposure during fish oil treatment was required to induce a notable antioxidant activity.

The influence of drying methods on the stabilization of fish oil microcapsules: Comparison of spray granulation, spray drying, and freeze drying

“…This was the reason why propanal was chosen as an indicator of the oxidative stability of fish oil microcapsules. As a secondary oxidation product of omegaÀ3 fatty acids, propanal has been previously used by many others (Augustin et al, 2006;Faraji and Lindsay, 2005;Frankel, 1993;Frankel et al, 2002;Shen and Wijesundera, 2009). A capillary gas chromatograph (GC) fitted with an Optima delta-6 capillary column (0.35 lm  30 m  0.32 mm) and a flame ionization detector (FID) was used for propanal headspace analysis.…”

Physicochemical characterization and oxidative stability of fish oil encapsulated in an amorphous matrix containing trehalose

“…In several studies, propanal proved to a suitable marker for the evaluation of the oxidative status of Wsh oil (Faraji & Lindsay, 2005;Frankel, Satué-Gracia, Meyer, & German, 2002;Horiuchi, Umano, & Shibamoto, 1998;Shahidi, 1998). Therefore, propanal was analysed via static headspace gas chromatography with Xame ionization detection according to Frankel (1993) with modiWcations.…”

Mitigation role of erythritol and xylitol in the formation of 3-monochloropropane-1,2-diol and its esters in glycerol and shortbread model systems

“…In the case of polyols, their antioxidant properties have already been reported by Faraji et al [39], who revealed that polyols could function as antioxidants in fish oil. Hartog et al [40] demonstrated that in vitro erythritol was an excellent radical scavenger.…”