Peanut Safety Research Articles

Ensuring Peanut Safety by Harnessing Plant Defence

Ensuring Peanut Safety by Harnessing Plant Defence

Oven, Microwave, and Combination Roasting of Peanuts: Comparison of Inactivation of Salmonella Surrogate Enterococcus faecium, Color, Volatiles, Flavor, and Lipid Oxidation

Peanut safety and quality were evaluated for different roasting technologies. Shelled raw peanuts were roasted using an oven at 163 to 204 °C, microwave, or oven and microwave combinations. The lethal effect of these treatments was investigated on peanuts inoculated with the Salmonella surrogate, Enterococcus faecium and stored at room temperature for 1 h, 24 h, or 7 d before roasting. Roasted peanut color, odor activity values (OAVs), descriptive sensory panel analysis, free fatty acid, and peroxide values were determined. Color and OAVs were also analyzed on 2 commercial peanut butters. OAVs were calculated using volatile levels quantified with selected ion flow tube mass spectrometry and known odor thresholds. All treatments resulted in a minimum of 3 log reduction of inoculated bacterial population. Resistance to the process was not influenced by storage of inoculated peanuts prior to treatment. Roasting by different methods produced equivalent, commercially ideal L* color. Based on the OAVs, treatments had similar volatiles important to flavor compared to the commercial samples. Descriptive sensory analysis showed no significant difference between the roasting treatments for most of the sensory attributes. Lipid oxidation was not significantly different between the roasting methods, displaying no evidence that roasting time or temperature affected lipid oxidation, when ideal color was produced. These results suggest that oven, microwave, or combination roasting should be sufficient to mitigate the threat of Salmonella contamination and produce similar color, OAVs, sensory attributes, and lipid oxidation results.

Incorporated Vernolate and Other Weed Control Treatments for Peanut Production

Fifteen herbicidal treatments were evaluated for weed control effectiveness in peanut (Arachis hypogaeaL.) culture at three locations in the peanut production area of eastern North Carolina during 1964 and 1965. Delayed preemergence treatments of 4,6-dinitro-o-sec-butylphenol (DNBP) alone and in combination withO-(2,4-dichlorophenyl)O-methyl isopropylphosphoroamidothioate (DMPA) were superior to conventional herbicidal and non-herbicidal control methods as were single and multiple incorporated treatments ofS-propyl dipropylthiocarbamate (vernolate). A single postplant vernolate treatment incorporated 1 in deep provided weed control superior to that obtained for single preplant vernolate treatments incorporated 1 in or 3 in deep. Increased weed control and increased peanut safety were obtained from 2.5 lb/A of vernolate by incorporating treatments at 0, 7, and 14 days after planting rather than by using a single application. This multiple treatment was the optimum one evaluated and provided 53 days of control and required 10 hr/A of hoeing time.