Comparative study of physical methods for lipid oxidation measurement in oils

Abstract

For the determination of lipid oxidation in oils, electrical, optical, spectroscopic and extraction methods were investigated using rice bran oil and doubly‐fractionated palm olein as model systems. The oxidized polar components and dielectric constant of rice bran oil increased very similarly with those of double‐fractionated palm olein. In the case of rice bran oil, all of the test methods were shown to possess good statistical correlations. Polar components, dielectric constant, refractive index and polymer content showed relatively better correlations. It was shown that diene and triene content determined by spectroscopic methods was not suitable for more saturated oils such as palm olein.

Characterization of <i>Moringa oleifera</i> seed oil from drought and irrigated regions of Punjab, Pakistan

“…The specific extinctions at 232 nm (1.68-1.98) and 270 nm (0.75-1.02), which reveal the oxidative deterioration and purity of the oils (Yoon et al, 1985), were comparable to those of M.oleifera oil reported from Sindh . However, these values varied significantly from those of M.oleifera oil from India (Lalas and Tsaknis, 2002) and Kenya (Tsaknis et al, 1999) 1.73 meq/kg), which measures hydroperoxide products in the oils (McGinely, 1991) was significantly higher than those of M.oleifera oils from the Sindh province of Pakistan , but lower than those of M.oleifera oils from India (Lalas and Tsaknis, 2002) and Kenya (Tsaknis et al, 1999).…”

Effect of salinity on yield and quality of <i>Moringa oleifera</i> seed oil

“…Table 4 shows the results of some oxidation parameters of the extracted M. oleifera seed oils from the saline and non-saline areas of Pakistan. There were no significant (P ≥ 0.012) variations in the values of specific extinctions at 232 and 270 nm, which reveal the oxidative deterioration and purity of the oils (Yoon, 1985), PV and p-anisidine values, which measure hydroperoxides and aldehydic secondary oxidation products of oils and fats, respectively (McGinely, 1991), of M. oleifera oils from saline and non-saline areas. The conjugated diene (1.85, 1.82); conjugated triene (0.52, 0.49); PV (1.97, 2.11 meq kg -1 of oil) and Panisidine value (1.84, 1.81) of M. oleifera seed oil from saline and non-saline areas respectively were in good agreement with those reported in the literature (Anwar and Bhanger, 2003;Tsaknis, 1999).…”

Antioxidant activity of various plant extracts under ambient and accelerated storage of sunflower oil

“…However, the antioxidant activity of Lawsonia alba, as revealed by SFO treatments, was not agreeable with that of SBO treatments. The specific extinctions, in terms of conjugated dienes (CD) at 232nm and conjugated trienes (CT) at 268 nm are considered important parameters for the investigation of oxidative deterioration of the oils (Yoon, 1985) and thus a good indicator of the antioxidant effectiveness of the antioxidant extracts. Fig.…”

“…7a, 7b, respectively. The CT is also a good indicator of the degree of oxidative deterioration of the oils (Yoon et al, 1985) and thus a measurement of antioxidant activity of the extracts. The control showed higher CT among all the SBO treatments under both conditions of storage and thus indicated the highest degree of oxidation.…”