The effects of pulsed electric fields (PEF) on the inactivation of Salmonella Enteritidis inoculated into liquid whole egg (LWE) and on the physical properties and the shelf‐life of LWE were studied. PEF processing conditions were 1.2 mL/s flow rate, 200 pps frequency, 2.12 μs pulse duration, 25 kV/cm electric field strength, and 250 μs total treatment time. The PEF processing caused up to 1 log10 cfu/mL reduction in S. Enteritidis population in LWE. The PEF‐treated samples were subjected to heat at 55C for 3.5 min to inactivate the remaining bacteria without denaturing the LWE. The combination of PEF and heat treatments led to a 4.3 log10 cfu/mL reduction in S. Enteritidis population (P < 0.05) and caused no significant change in viscosity, electrical conductivity, color, pH, and Brix, relative to control samples (P > 0.05). The PEF+55C treated LWE samples presented significantly longer shelf‐life at 4C compared with the control and heat treated samples (P < 0.05).

Fumonisin B1 (FB1) was reacted with fructose in an attempt to detoxify this mycotoxin. Fischer 344/N rats were initiated with diethylnitrosamine (15 mg/kg body weight) and then fed 69.3 μmol FB1/kg diet or 69.3 μmol FB1 reacted with fructose (FB1−fructose)/kg diet for 4 weeks. In comparison with the rats fed basal diet or FB1−fructose, the FB1-fed rats had significantly increased plasma cholesterol (P < 0.01), plasma alanine aminotransferase activity (P < 0.05), and endogenous hepatic prostaglandin production (P < 0.05). Placental glutathione S-transferase-positive and γ-glutamyl transferase-positive altered hepatic foci occurred only in the FB1-fed rats. Liver-associated natural killer (NK) cell activity was significantly decreased in the FB1-fed rats and increased in the group fed FB1-fructose, as compared with the basal group (P < 0.03). Therefore, modifying FB1 with fructose seems to prevent FB1-induced hepatotoxicity and promotion of hepatocarcinogenesis while stimulating liver-associated NK cell activity in rats. Fumonisin B 1 (FB 1 ) was reacted with fructose in an attempt to detoxify this mycotoxin. Fischer 344/N rats were initiated with diethylnitrosamine (15 mg/kg body weight) and then fed 69.3 µmol FB 1 /kg diet or 69.3 µmol FB 1 reacted with fructose (FB 1 -fructose)/kg diet for 4 weeks. In comparison with the rats fed basal diet or FB 1 -fructose, the FB 1 -fed rats had significantly increased plasma cholesterol (P < 0.01), plasma alanine aminotransferase activity (P < 0.05), and endogenous hepatic prostaglandin production (P < 0.05). Placental glutathione S-transferase-positive and γ-glutamyl transferase-positive altered hepatic foci occurred only in the FB 1 -fed rats. Liver-associated natural killer (NK) cell activity was significantly decreased in the FB 1 -fed rats and increased in the group fed FB 1 -fructose, as compared with the basal group (P < 0.03). Therefore, modifying FB 1 with fructose seems to prevent FB 1 -induced hepatotoxicity and promotion of hepatocarcinogenesis while stimulating liver-associated NK cell activity in rats.

In this study, pulsed electric field (PEF) treatment of beer, effectiveness of PEF treatment on microbial inactivation, effects of PEF treatment on sensory properties, and detection of electrode material migration were explored. Beer samples were treated by PEF for the inactivation of natural flora and inoculated cultures of Saccaromyces uvarum, Rhodotorula rubra, Lactobacillus plantarum, Pediococcus damnosus, and Bacillus subtilis. Inactivation induced by the PEF treatment was 0.5, 4.1, 4.3, 4.7, 5.8, and 4.8 log 10 colonyforming units/mL in the above microorganisms, respectively (P < 0.05). There was a significant increase in the amount of Cr, Zn, Fe, and Mn ions in the beer samples after PEF treatment (P < 0.05) leading to a statistically significant degradation in flavor and mouth feel. Further studies are needed to optimize electrode materials and PEF treatment to minimize or eliminate this degradation.

This study investigated the role of intracellular and extracellular bacteria in the production ofparalytic shellfish toxins by dinoflagellated algal cells. Three strains of the toxic dinoflagellatespecies, Alexandrium tamarense, were purified by external bacteria using penicillin G (Pen.G) at levels of 500 and 1000 p.p.m. Levels of toxicity of the resulting purified dinoflagellatecultures were similar to those of the original strains contaminated with external bacteria,indicating that the external bacteria had no influence on toxicity. No bacterial colony formingunits (cfu) arose from disruption of algal cells derived from penicillin‐treated cultures, indicatingthat intracellular bacteria were not responsible for the toxicity of cultures.

14C-Fumonisin B(1) (FB(1)) was produced by Fusarium proliferatum M-5991 in modified Myro liquid medium and purified to >95% purity with a specific activity of 1.7 mCi/mmol. Nine male and nine female F344/N rats were each dosed by gavage with 0.69 micromol of (14)C-FB(1), (14)C-hydrolyzed FB(1), or (14)C-FB(1)-fructose/kg body weight. Urinary excretion of (14)C-FB(1) and (14)C-FB(1)-fructose was 0.5% and 4.4% of the total dose, respectively, and was similar between male and female rats. Urinary excretion of (14)C-hydrolyzed HFB(1) was significantly greater (P > 0.05) in female rats as compared with male rats (17.3% vs 12.8% of the total dose, respectively). There were no significant (P > 0.05) differences in biliary excretion of the three fumonisin compounds with a mean of 1. 4% of the dose excreted at 4 h after dosing. Lesser amounts continued to be excreted up to 9.25 h after dosing. Although biliary excretion of the (14)C-FB(1), (14)C-hydrolyzed FB(1), and (14)C-FB(1)-fructose was similar, increased urinary excretion of the (14)C-hydrolyzed FB(1) as compared to (14)C-FB(1) and (14)C-FB(1)-fructose indicated a greater absorption of the hydrolyzed form.

Pulsed electric field (PEF) exposes a fluid or semi-fluid product to short pulses of high-energy electricity, which can inactivate microorganisms. The efficacy of PEF treatment for pasteurisation of liquid eggs may be a function of processing temperature. In this study, effects of PEF, temperature, pH and PEF with mild heat (PEF + heat) on the inactivation of Salmonella typhimurium DT104 cells in liquid whole egg (LWE) were investigated. Cells of S. typhimurium were inoculated into LWE pH adjusted to 6.6, 7.2 or 8.2 at 15, 25, 30 and 40°C. The PEF field strength, pulse duration and total treatment time were 25 kV cm )1 , 2.1 ls and 250 ls respectively. Cells of S. typhimurium in LWE at pH 7.2 were reduced by 2.1 logs at 40°C and 1.8 logs at 30°C. The PEF inactivation of S. typhimurium cells at 15 or 25°C was pH dependent. Heat treatment at 55°C for 3.5 min or PEF treatment at 20°C resulted in c. 1-log reduction of S. typhimurium cells. Combination of PEF + 55°C achieved 3-log reduction of S. typhimurium cells and was comparable to the inactivation by the heat treatment at 60°C for 3.5 min. With further development, PEF + heat treatment may have an advantage over high-temperature treatment for pasteurisation of liquid eggs.

There is a pressing need to validate the shelf‐life extension of Pulsed Electric Field (PEF) treated foods. This study was designed to evaluate the shelf‐lives of cranberry juice and chocolate milk as a function of PEF and the interaction of PEF+heat treatments. Cranberry juice was exposed to PEF and PEF+heat (60C), and chocolate milk to PEF+heat (105 and 112C). Microbial analysis and color measurement were performed on untreated and treated cranberry juice and chocolate milk aseptically packaged and stored at 4, 22, and 37 C for 197 and 119 days, respectively. Microbial analysis of cranberry juices demonstrated that the shelf‐life of PEF and PEF+heat treated juices stored at 22 and 37 C increased significantly during 197 days (p<0.05). The shelf‐life of chocolate milk treated by PEF+105C and PEF+112C increased significantly at all storage temperatures (p<0.05). The PEF nor PEF+heat treatments did not result in any significant differences in color retention of either cranberry juice or chocolate milk (p>0.05). This study presented that PEF and PEF+heat treatments were very effective to increase shelf‐lives of cranberry juice and chocolate milk.

Fusarium proliferatum strain M5991 cultures were grown in shake flasks containing modified Myro (MM) medium (MgSO4 reduced to 0.5 g/L) plus 0, 0.25, 0.50, 0.75, 1.00, or 1.25% (v/v) hot-water and corn-hull-extract (CHE) for 69 days. After 4 days of incubation, shake flask liquid cultures with 0.75, 1.00, and 1.25% (v/v) CHE showed a reduction in pH from 6.0 to 2.6 and consumed sucrose at > 6.3 g/L/d. After 69 days of incubation, the same shake flask cultures produced over 7.8 g/L cell mass and over 990 mg/L fumonisin B1 (FB1). A minimum CHE level of 0.75% was recommended for enhanced FB1 production by F. proliferatum strain M5991. During three serial (10, 12, and 12 L) batch fermentations in MM medium + 1.00% (v/v) CHE (first batch only), F. proliferatum strain M5991 produced FB1 concentrations of 619, 659, and 375 mg/L after 35, 47, and 52 days of incubation, respectively. By analysis, a total yield of 20 g FB1 was obtained from three serial batch fermentations.