Essential‐Oil Analysis of Irradiated Spices by Using Comprehensive Two‐Dimensional Gas Chromatography

Abstract

Four different spices were packaged either under 100 % nitrogen or using ambient air, and then gamma‐irradiated at different doses. The essential oils of the original spices and of those irradiated were obtained by hydrodistillation. Changes to the essential‐oil compositions due to irradiation and effects of packaging were detected and compared by using comprehensive two‐dimensional gas chromatography (GC×GC). The use of GC×GC provided better separation and more reliable results. It enabled ready detection of some peaks that coeluted with other peaks in the first‐dimension column (1D). Differences in detected peaks were observed after irradiation of samples packaged under ambient air, with additional peak(s) noted. Two peaks appeared after irradiation of aerobically packaged rosemary, black pepper and thyme, and one peak increased in relative abundance in the samples. No changes in these three peaks were noted after irradiation of samples packaged under 100 % N2. These three essential‐oil components were identified by using GC×GC quadrupole time‐of‐flight mass spectrometry (Q‐TOFMS). The changes after irradiation were mainly due to packaging type, and no effect of the irradiation dose was observed in the study.

Modified atmosphere packaging and gamma-irradiation of some herbs and spices: Effects on antioxidant and antimicrobial properties

“…It was also reported that the application of MAP prior to irradiation of seasoned beef meatballs reduced lipid oxidation, degradations in color, and sensory properties during storage (Gunes, Ozturk, Yilmaz, & Ozcelik, ; Gunes, Yilmaz, & Ozturk, ). We found in our previous work that irradiation under a modified atmosphere (100% N 2 ) decreased some of the quality degradation in spices such as loss of essential oil content, alteration of the essential oil composition, and loss of color (Kirkin, Mitrevski, Gunes, & Marriott, , ).…”

Gamma radiation processing under modified atmosphere packaging effects on microbial quality and antioxidant activity of fresh leafy vegetables during storage

“…Aerobic Mesophilic total count [8], spore forming bacteria count [9], total yeast/mold count [10], coliforms count [11], Staphylococcus aureus [12,13] and Escherichia coli presence/absence [14] were evaluated in triplicate. Next, the appropriate plates containing 30-300 bacterial colonies and 15-150 fungal colonies, respectively were selected and counted [15]. The sample microbial contamination was calculated and reported in terms of cfu/g.…”