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Carvacrol, &al and geraniol showed potent antibacterial activity against Salmonella typhimurium and its rifampicin-resistant (Rip) strain as determined in txyptic soy broth and by zone of inhibition on agar-based medium. Carvacrol had the most potent bactericidal activity, with minimum inhibitory and bactericidal concentrations (MIC and MBC) of 250 pg/mL for both tester strains. When tested at 0.5, 1.5 and 3.0% in 1%Tween 20 for bactericidal activity against RifR-S. typhimurium inoculated on fish cubes, carvacrol at 3.0% completely killed the inoculated bacteria, while geraniol killed most of the bacteria, and citral killed the least. Carvacrol and geraniol showed potent antibacterial activity at 1.5%. Bactericidal activity became more evident as storage of fish cubes at 4°C lengthened. The comparable inhibition of these strains of SaZmon@la and species of Gram-negative bacteria by carvacrol and geraniol support their application as potential antibacterial agents in food systems. CarvacrolCitral a (cis) Citral b (trans) Geraniol Fig. l-Structures of carvacrol, citral, and geraniol.

During peanut roasting, pyrazine compounds correlate highly with roasted flavor and aroma. Although roast color measurement is used to predict roasted flavor in peanuts, there are known variations between roast color and flavor development among genotypes. A method for measuring pyrazines using headspace solid-phase microextraction (SPME) was developed and 4 peanut genotypes were roasted and analyzed under a variety of time-temperature combinations. Peanut genotypes differed in roasted flavor and aroma, regardless of roast color. Florida MDR 98 formed the highest levels of pyrazines under the same roasting conditions, followed by Florunner, Georgia Greene, and SunOleic 97R, respectively. Of all pyrazines tested, 2,5-dimethylpyrazine was most highly correlated to roasted peanut flavor and aroma.

Single strength orange juice was treated with supercritical carbon dioxide (CO,) and the effect of process time, temperature and pressure on pectinesterase (PE) activity was determined. PE could be inactivated with supercritical CO2 below temperatures necessary for thermal inactivation. Higher pressure, temperature and longer treatment time resulted in more inactivation. Inactivation kinetics showed activation energy was significantly reduced at SC CO2 treatment at 31 MPa (97.4 KJ/mole), compared to identical treatments at atmospheric pressure (166.6 KJ/mole). D values ranged from 2673 min at atmospheric pressure and 40°C to 10 min at 31 MPa and 60°C. z value at atmospheric pressure was S-SC?, and at 31 MPa 5.2C'.

‘Florigraze’ rhizoma peanut (Arachis glabrata Benth.) is a perennial legume of high forage quality adapted to warm climates, but there has been no comprehensive evaluation of its responses to grazing management. In 1988 and 1989, the effects of grazing frequency and intensity on Florigraze persistence and herbage accumulation (HA) were evaluated on a loamy, siliceous, hyperthermic Grossarenic Paleudults soil. All 12 combinations of three levels of residual dry matter after grazing (RDM, 500, 1500, and 2500 kg ha‐') and four grazing cycle lengths (GC; 7, 21, 42, and 63 d between grazings, including a 0.5‐ to 2‐d grazing period) were replicated twice. Data were analyzed by fitting multiple regression equations starting with a second order polynomial model. In 1988, rhizoma peanut HA ranged from 6130 to 10 240 kg ha− and increased linearly as GC and RDM increased. There was a GC‐by‐RDM interaction for rhizoma peanut HA in 1989, whereby at low RDM, increasing GC increased HA, but GC had less effect as RDM increased. In 1989, rhizoma peanut HA of at least 8800 kg ha− was estimated to occur with GC of 42 d or longer when RDM was 1500 kg ha− or greater. Rhizoma peanut percentage in HA was greatest with high RDM and long GC, but values of 80% or greater in the second year were estimated for RDM as low as 1300 kg ha− when GC was 63 d, or with GC as low as 7 d when RDM was above 2300 kg ha−. Lowest values were obtained with low RDM and short GC. These data indicate that unlike most tropical legumes, rhizoma peanut is productive and persistent over a relatively wide range of grazing management practices.

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