Comparing Antioxidant Effectiveness of Natural and Synthetic Free Radical Scavengers in Thermally‐Oxidized Lard using DPPH Method

Abstract

Antioxidant effectiveness of free radical scavengers (FRSs) of alpha-tocopherol, sesamol, butylated hydroxytoluene (BHT), and tert-butylhydroquinone (TBHQ) were evaluated in thermally-oxidized lard using methods of 2,2-diphenyl-1-picrylhydrazyl (DPPH), conjugated dienoic acid (CDA), and p-anisidine value (p-AV). Absorbance of DPPH with lard containing 2.5 micromol/g FRSs were low before oxidation while those with control lard was high due to the hydrogen atom donating ability of FRSs. During oxidation, DPPH absorbance with lard containing FRSs increased differently up to the certain point depending on the types of FRSs. DPPH absorbance of lard without FRSs started to decrease upon oxidation, which indicates that free radical scavenging compounds were generated from oxidized lipids. Results of CDA and p-AV showed that the highest antioxidant capacity was in the order of TBHQ = sesamol, BHT, and alpha-tocopherol. Antioxidant effectiveness of FRS should consider the hydrogen atom donating rates of FRS, the reactivity and stability of FRS at treatment temperature, and characteristics of radicals from FRSs, which may be predicted by the results of DPPH method.

Antioxidant and prooxidant activities of β-carotene in accelerated autoxidation and photosensitized model systems

“…Accelerated autoxidation of lard with β-carotene Headspace oxygen analysis has been used to determine the degree of oxidation in soybean oil and lard model systems (9,13,16). Effects of β-carotene on the depletion of headspace oxygen in lard oxidized at 60 o C for 60 h are shown in Fig.…”

“…The absorbance of DPPH is influenced by many factors including light, oxygen, pH, and types of solvents in addition to the free radical scavengers (FRSs) (11). Recently, new application areas of a modified DPPH assay have been introduced such as determining the degree of oxidation and the effectiveness of FRSs (12)(13)(14). The modified DPPH method uses isooctane as solvent instead of methanol to dissolve lipids.…”

“…Oxidized lipid can decrease the DPPH absorbance, which may be due to the formation of radical scavenging compounds from oxidized lipids (RSOLs) (14). Also, the antioxidant efficiency, which should consider hydrogen donating ability of FRSs and the stability of FRSs can be estimated through monitoring the changes of DPPH absorbance in oxidized lipids containing FRSs (13). Therefore, the modified DPPH method may provide important information on determining the antioxidant or prooxidant characteristics of β-carotene during accelerated autoxidation and photosensitization of lipids.…”

Effects of Roasting Conditions on the Physicochemical Properties and Volatile Distribution in Perilla Oils (Perilla frutescens var. japonica)

“…Absorbance of DPPH from PO210/30 had significantly lower than control PO0/0 ( P < 0.05), implying more DPPH radical scavenging compounds were present in PO210/30 than control PO0/0. DPPH method has been modified to determine the degree of oxidation of fats and oil and the antioxidant efficiency of free radical scavengers (Lee and others 2007a; Yeo and others 2010). Current results show that some compounds that are responsible for the decrease of DPPH absorbance were present in PO.…”

Investigation of the antioxidant activity of chitooligosaccharides on mice with high-fat diet

“…It was performed according to the method of Yeo with modifications (Yeo et al, 2010). Test samples, which were dissolved in methanol, were serially diluted into different concentrations (0.25, 0.5, 1.0, 2.5, and 5 mg/mL of COS) and taken in test tubes in triplicates.…”