Chemical Changes and Oxidative Stability of Peanuts as Affected by the Dry‐Blanching

Abstract

The oxidative changes of peanuts subjected to the dry‐blanching process were evaluated and compared with those of their in‐shell counterparts. In general, the fatty acid profile was not influenced. The content of α‐tocopherol decreased, but the remaining tocopherol homologs were unaffected. Nonanal, an oxidation product of oleic acid, increased. However, the contents of several volatile compounds with potential antioxidant properties were also increased. The higher oxidative stability of dry‐blanched peanuts was demonstrated by accelerated tests as evaluated by peroxide value, thiobarbituric acid reactive substances (TBARS) and the induction period of cold‐pressed oils and this was confirmed by the higher antioxidant properties of oils from such sample as evaluated by the DPPH radical scavenging activity. These results were further confirmed during long‐term storage of dry‐blanched and in‐shell peanuts. The decrease of tocopherols in peanuts due to dry‐blanching did not negatively influence their oxidative stability. In fact, dry‐blanched peanuts showed higher stability as compared with in‐shell peanuts; therefore, we suggest that loss of tocopherol might be less important than the generation of several volatile antioxidant compounds as well as possibly Maillard reaction products upon the dry‐blanching process. These results may be of practical interest to the peanut and peanut oil industries.

Extraction Technology Can Impose Influences on Peanut Oil Functional Quality: A Study to Investigate the Lipid Metabolism by Sprague–Dawley Rat Model

“…Further, these polyphenolic compounds acted as effective antioxidants, and protected tocopherols from degradation or oxidation upon high temperatures in the oil preparation process. There were no significant difference for γ‐tocopherol and δ‐tocopherol, and similar results were displayed in a previous research (De Camargo, De Alencar, & Shahidi, ).…”

Tocopherols and Tocotrienols in Common and Emerging Dietary Sources: Occurrence, Applications, and Health Benefits

“…In agreement with the above study, de Camargo et al [5] showed that gamma irradiation induced lipid oxidation in peanuts, and alpha-tocopherol was the most sensitive homologue extracted from the lipid fraction. In another study [102], alpha-tocopherol was also found to be the most sensitive to the blanching process conducted by the peanut industry. The above-mentioned studies [5,27,102] identified and quantified all four forms of tocopherol in their starting material, which is useful for comparative purposes.…”

“…In another study [102], alpha-tocopherol was also found to be the most sensitive to the blanching process conducted by the peanut industry. The above-mentioned studies [5,27,102] identified and quantified all four forms of tocopherol in their starting material, which is useful for comparative purposes. Tree nuts are also important sources of tocopherols [103]; gamma-irradiation decreased the content of alpha-tocopherol in walnuts by up to 87.4% when subjected to a dose of 8 kGy, and its concentration was under the detection limit in samples submitted to 10 kGy [104].…”

Date palm wood as a new source of phenolic antioxidants and in preparation of smoked salmon

“…The same fiber and minor modifications in the GC‐MS procedure described by de Camargo et al () were used. The DVB/CAR/PDMS divinylbenzene‐carboxen‐polydimethylsiloxane (Supelco, Bellefonte, PA, USA) fiber was preconditioned at 270°C for 1 hr following its exposure to the smoke for 10 min.…”

“…A capillary column (DB‐5MS 30 m × 0.25 mm ×0.25 μm, Agilent) was used. Method details are the same as those described by de Camargo et al (). The Chem Station software (Agilent) was used for data integration and prominent volatile phenolic compounds were tentatively identified with the Wiley 9th Edition/NIST 2008 MS library and Kovats index, according to literature data (Adams, ; Dallüge et al, ; Dötterl, Wolfe, & Jürgens, ; El‐Sayed, Heppelthwaite, Manning, Gibb, & Suckling, ; Högnadóttir & Rouseff, ).…”