Gamma Irradiation of in-Shell and Blanched Peanuts Protects against Mycotoxic Fungi and Retains Their Nutraceutical Components during Long-Term Storage

Abstract

Peanut samples were irradiated (0.0, 5.2, 7.2 or 10.0 kGy), stored for a year (room temperature) and examined every three months. Mycotoxic fungi (MF) were detected in non-irradiated blanched peanuts. A dose of 5.2 kGy was found suitable to prevent MF growth in blanched samples. No MF was detected in in-shell peanuts, with or without irradiation. The colors of the control in-shell and blanched samples were, respectively, 44.72 and 60.21 (L *); 25.20 and 20.38 (Chroma); 53.05 and 86.46 (°Hue). The water activities (Aw) were 0.673 and 0.425. The corresponding fatty acids were 13.33% and 12.14% (C16:0), 44.94% and 44.92% (C18:1, ω9) and 37.10% and 37.63% (C18:2, ω6). The total phenolics (TP) were 4.62 and 2.52 mg GAE/g, with antioxidant activities (AA) of 16.97 and 10.36 μmol TEAC/g. Storage time negatively correlated with Aw (in-shell peanuts) or L *, linoleic acid, TP and AA (in-shell and blanched peanuts) but positively correlated with Aw (blanched peanuts), and with oleic acid (in-shell and blanched peanuts). Irradiation positively correlated with antioxidant activity (blanched peanuts). No correlation was found between irradiation and AA (in-shell samples) or fatty acids and TP (in-shell and blanched peanuts). Irradiation protected against MF and retained both the polyunsaturated fatty acids and polyphenols in the samples.

Use of a Potential Probiotic, Lactobacillus casei L4, in the Preparation of Fermented Coconut Water Beverage

“…Total phenolic contents were determined according to the Folin–Ciocalteu colorimetric method described by de Camargo et al (2012). A calibration curve was obtained using gallic acid (0–8.2 μg/mL) as the standard.…”

Phenolic Profile of Peanut By‐products: Antioxidant Potential and Inhibition of Alpha‐Glucosidase and Lipase Activities

“…The antioxidant and potential beneficial effects of different sources of proanthocyanidins against human LDL-cholesterol oxidation and proliferation of breast cancer cells has already been reported [12,25,32]. Contamination with mycotoxins remains a concern for different food products such as milk, wheat and peanuts [33][34][35]. However, it is very difficult to avoid this kind of contamination; furthermore, avoidance from consuming this kind of food products is not always possible.…”

“…The capacity of phenolic extracts in scavenging ABTS radical cation by donation of electrons followed the same trend as TPC. The antioxidant potential of whole and dry-blanched peanuts has already been reported [35]; however, only crude phenolics were evaluated and identification of phenolic compounds was not carried out. Furthermore, the antioxidant effect of crude phenolics of peanut skin in bulk oil has also been demonstrated [38].…”

Irradiation for Mold and Mycotoxin Control: A Review

“…Concerning dried fruits, the irradiation of peanuts was evaluated by de Camargo and others () who concluded that an irradiation level of 5.2 kGy was suitable to prevent the growth of aflatoxigenic fungi without significantly affecting their polyunsaturated fatty acid and polyphenol contents. This observation agreed with previous data from Chiou and others (), which proved that radiation levels of 2.5 and 5.0 kGy were effective in retarding the growth of A. parasiticus and in reducing the native mold population of peanuts, respectively.…”