Decontamination of chokeberries (Aronia melanocarpa L.) by cold plasma treatment and its effects on biochemical composition and storage quality of their corresponding juices.

To improve the microbiological quality of chokeberries, corona discharge plasma jet (CDPJ) was employed as a decontaminating agent. The mean levels of aerobic bacteria and yeast and molds contaminants in chokeberries were 4.78 and 4.87 log CFU/g, respectively; the viable counts were decreased by 2.09 and 1.83 log units following CDPJ treatment for 3 min, respectively. A first-order kinetic model was well-suited for explaining the inactivations. The concentration of total polyphenols of chokeberries was unaffected (up to 3 min treatment), whereas DPPH radical scavenging activity was significantly decreased by CDPJ treatment (2 min and more). CDPJ treatment (all tested times) of chokeberries led to a significant decrease of monomeric anthocyanin content of their corresponding juices, whereas soluble solids content (Brix) and pH were unaffected. After storage at 4 °C for 72 h, juices obtained from CDPJ-treated berries possessed relatively low levels of contaminants with no significant alterations in pH and soluble solids content when compared with controls. In conclusion, CDPJ treatment for 2 min was optimal to improve the microbiological quality of the berries without negatively affecting biochemical qualities of their corresponding juices.

Effects of plasma treatment on the oxidative stability of vegetable oil containing antioxidants.

Plasma, the fourth stage of matter, is a partially or wholly ionized state of gas. Degree of lipid oxidation and effects of antioxidants were evaluated in bulk oils at plasma treatment. Significant changes in the conjugated dienoic acid were induced after 10 min of plasma treatment, which corresponded to treatment for 2.5 h at 100 °C and 48 h at 60 °C. Tocopherol stability in the stripped corn oil was significantly higher than that in medium-chain triacylglycerol after the plasma treatment. The antioxidant capacities of 10 µM of α-tocopherol and sesamol were higher than that of ß-carotene, and synergistic effects among α-tocopherol, sesamol, and ß-carotene were not observed. Added α-tocopherol and sesamol decreased CDA formation by 33 and 30% compared to control samples after plasma treatment. Moisture content in oils decreased significantly about 20% moisture after 6 min plasma treatment. Lipid oxidation could be an important issue in plasma-treated lipid-rich products.

Decontamination of collards (Brassica oleracea var. acephala L.) using electrolyzed water and corona discharge plasma jet.

Acidic electrolyzed water (AEW) was used for collards sanitization. In the AEW (pH of 3.6; 230 mg/L chlorine) generator, the rates of brine inflow and catholyte outflow were 2.73 and 442 mL/min, respectively. Following treatment of the collards with the AEW alone (5 min), the counts of aerobic bacterial contaminants were reduced by 1.91 log CFU/g, whereas 2.22 log CFU/g reduction was noted by the AEW soaking (5 min) followed by a corona discharge plasma jet treatment (1 min). In a similar manner, the counts of yeasts and mold contaminants were reduced (1.48 and 1.75 log CFU/g, respectively). The combination treatment exhibited an additive effect on the microbial inactivation. The combined treatment did not affect significantly the DPPH-radical scavenging activity and sensory properties (appearance, color and flavor) of the collards compared to negative controls. However, significant alterations in the levels of total phenolics and ascorbic acid were observed post-treatment.

Degradation of benzo[a]pyrene on glass slides and in food samples by low-pressure cold plasma.

Benzo[a]pyrene (BaP), a carcinogenic polycyclic aromatic hydrocarbon, is ubiquitous in nature, including smoked and grilled meats. BaP degradation has attracted attention due to its recalcitrant chemical nature. In this study, low-pressure cold plasma (LPCP) was used to degrade BaP on glass slides and in food materials. LPCP discharges were generated using different working gases (air, N2, O2), at chamber pressures (0.1-5.0 Torr), and with plasma powers (72-168 W). Optimal BaP degradation was observed upon treatment using LPCP generated with air as working gas (LPAP) at 1.0 Torr pressure and at 168 W power. Under this condition, initial BaP concentration on slides was reduced maximally by 82.7% in 30 min. The degradation kinetics of BaP were well fitted by a Weibull tail model compared with others. In food materials (roasted sesame and perilla seeds), the average levels of BaP degradation ranged between 40 and 46% following LPAP treatment for 30 min.

Saengshik, a formulated health food, prevents liver damage in CCl4-induced mice and increases antioxidant activity in elderly women.

Saengshik is a Korean noncooked food made with of more than 30 different whole gains, vegetables, fruits, mushrooms, and seaweeds. All of these ingredients are frozen and dried to minimize the loss of nutrients. Saengshik has become popular among health-conscious people in the Republic of Korea. The study aims to investigate antioxidant effects of Saengshik by in vivo and human experiments. In in vivo tests, mice were fed Saengshik for 4 weeks, and oxidative damage was induced by CCl(4). Then the effects of Saengshik on oxidative damage were examined. It was found that plasma lipid hydroperoxide and protein oxidative damages were significantly suppressed and antioxidants, glutathione, and thiol groups were increased. The activity of the antioxidant enzyme superoxide dismutase was increased, and the level of glutamate pyruvate transaminase was decreased. In a human study, elderly people were given Saengshik for 24 weeks, and changes in antioxidant defense of the body were examined. Antioxidant activities in plasma were enhanced, although the difference was not significant. Therefore, it is expected that Saengshik is effective at removing oxidants from body tissues, preventing oxidative damage, and eventually boosting the antioxidant capacity of the body.