Earticle

The growth responses of materials extracted from Juniperus virginiana leaves against Bifidobacterium bifidum, B. longum, Clostridium perfringens, Escherichia coli, Lactobacillus acidophilus, L. casei, and Streptococcus mutans were examined using impregnated paper disk agar diffusion. The biologically active constituent isolated from the J. virginiana extracts was characterized as -cedrene using various spectroscopic analyses including IR, EI-MS, and NMR. The responses varied according to the dose, chemicals, and bacterial strain tested. Methanol extracts of J. virginiana leaves exhibited a strong and moderate inhibitory activity against C. perfringens and E. coli at 5 mg/disk, respectively. However, in tests conducted with B. bifidum, B. longum, L. acidophilus, L. casei, and S. mutans, the methanol extracts showed no or weak inhibitory response. At 2 mg/disk, a-cedrene strongly inhibited the growth of C. perfringens and moderately inhibited the growth of E. coli and S. mutans, without any adverse effects on the growth of four lactic acid-bacteria. Of the commercially available compounds originating from J. virginiana leaves, cedrol and -pinene exhibited strong and moderate growth inhibition against C. perfringens, and -copaene revealed moderate growth inhibition against E. coli at 1 mg/disk. Furthermore, cedrol exhibited moderate and weak growth inhibition against S. mutans at 2 and 1 mg/disk, respectively. However, little or no activity was observed for camphene, (+)-2-carene, p-cymene, limonene, linalool, and a-phellandrene against B. bifidum, B. longum, C. perfringens, L. acidophilus, L. casei, and S. mutans at 2 mg/disk. The observed inhibitory activity of the J. virginiana leaf-extracted materials against C. perfringens, E. coli, and S. mutans may be an indication of at least one of the pharmacological actions of the J. virginiana leaf.

The myeolchi-jeot samples were divided into different groups with or without the supplementation with biogenic amines. Subsequently, the samples were placed in an oven at 80℃ for 1 hr to allow the chemical reaction to proceed, and then were analyzed for N-nitrosamine contents using GC-TEA. N-nitrosamine was not detected in any of the myeolchi-jeot samples which had been treated with/without sodium nitrite. On the other hand, the yield of N-nitrosopyrrolidine from 1,000 mg/kg of putrescine and spermidine in the myeolchi-jeot samples (treated with 5 mg/kg of sodium nitrite) was 0.002 and 0.014%, respectively. N-nitrosamine was not produced from any other biogenic amines like, histamine, tyramine, cadaverine and spermine. In addition, curing and heating were the factors which influenced the formation of N-nitrosamine during the nitrosation of biogenic polyamines. For the formation of N-nitrosamine in the food systems, treatment with sodium nitrite and heating at appropriate temperature along with the satisfied supplementation of biogenic polyamines are required.

Three flavonoid compounds - quercetin, luteolin, and kaempferol - were analyzed from two commercially available concentrated pomegranate extracts produced in Turkey and Italy, respectively. The samples were freeze-dried and hydrolyzed by 0.4 M hydrochloric acid in 50% ethanol at 80℃. HPLC (high-performance liquid chromatography) with DAD (diode array detection) at a wavelength of 260 nm was used for the detection of the three flavonoids. The detection limits of the three compounds were in hundreds of picograms and the signal-to-noise ratio ranged from 4 to 5: quercetin: >308 pg, s/n=4.0; luteolin: >262 pg, s/n=4.5; kaempferol: >688 pg, s/n=5.0. Quercetin, but not luteolin and kaempferol, was detected in the both pomegranate extracts. The concentrations of quercetin were 49.7 ug/g and 27.7 ug/g in the two pomegranate extracts made in Turkey and Italy, respectively.