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Slightly acidic electrolyzed water (SAEW) has been recognized as an effective bactericidal agent with free chlorine, but its limitations include its instability and its great dependence on equipment. Newly developed circulating electrolyzed water (CEW) with a higher available chlorine concentration (ACC) could successfully overcome these limitations. In this study, SAEW (ACC of 20 mg/L), CEW1 (ACC of 200 mg/L), and CEW2 (ACC of 20 mg/L) were evaluated for changes in properties (pH, oxidization reduction potential [ORP], and ACC) during storage in open or closed glass bottles under light or dark conditions at room temperature (approximately 20 °C) and after washing pork and lettuce. Additionally, the washed pork and lettuce were evaluated for total viable counts, pH and general appearance. The results showed that CEW1 with a higher ACC has better stability than SAEW with a lower ACC for the storage and washing experiments, and CEW still remained stable after dilution with distilled water. The property indices of EW were greatly affected for the pork-washing experiments compared with the lettuce-washing experiments, probably due to the existence of alkaline and organic materials on the surface of pork. Furthermore, EWs were more effective for inactivating microbes in lettuce than in pork, while there was no significant difference in tissue pH and the general appearance of pork and lettuce. These findings indicated that CEW with a higher ACC shows potential for reducing foodborne pathogens on pork and lettuce without effects on their physicochemical characteristics, and it can be applied in a diluted form., (© 2016 Institute of Food Technologists®)

Application of ultrasound to extract a variety of biologically active compounds from plant materials has been widely investigated. However, there are few reports on the local effect of ultrasonic irradiation on the yields of these compounds. In the present article, the local effect of ultrasonic treatment on total phenolic content (TPC) and antioxidant activities (ATT) of extracts from citrus peels was investigated. To optimize the extraction process, a response surface methodology (RSM) was used to evaluate the effects of ultrasonic variables including ultrasonic power, ultrasonic time, and extraction temperature on extracts from penggan (Citrus reticulata) peel. The results showed that TPC and ATT increased on increasing ultrasonic time and temperature. The maximum of TPC and ATT by ultrasonic treatment was observed in near ultrasonic irradiation surface, in which ultrasonic power appeared to be positive effect. Furthermore, when the effect of the 3 independent variables was evaluated simultaneously using RSM, the optimal ultrasonic conditions for responses were determined as: 42 to 45 W, 23 to 25 min, 31 to 34 degrees C. The results presented here emphasized that application of ultrasound should be considered both the optimization of ultrasonic variables and available ultrasonic device.

Some dried citrus peels, more familiar as chenpi in China, have been widely used in traditional Chinese medicines from ancient times. This paper reports the efficiency of infusion cooking on extracting minerals and phenolic compounds (flavanone glycosides [FGs], polymethoxylated flavones [PMFs], and phenolic acids), and also antioxidant activity of hot water extract of citrus peels. Peels of 2 citrus varieties, namely, Satsuma mandarin (C. unshiu Marc.) and Ponkan (C. poonensis Hort. ex Tanaka), which belong to C. reticulata, were selected. As a result, hot water extraction was efficient in extracting phenolic acids and some minerals. As for citrus flavonoids, narirutin, nobiletin, and tangeretin were easier to extract than hesperidin. The result of antioxidant capacity assays indicated that for citrus peels, hot water extract had almost the same capacity as the methanol extract. We suggested that Ponkan was more suitable as the source of chenpi, since its hot water extract had much higher content of phenolic acids, FGs and PMFs, and higher antioxidant capacity than those of Satsuma mandarin. Generally, to raise the extraction temperature or to prolong the time could not yield higher content of phenolic compounds and stronger antioxidant capacity, though the content of minerals increased to some extent. Furthermore, a 2nd-time extraction seemed necessary since considerable minerals and phenolic compounds could be obtained by doing so. Finally, we suggested that 2 times extraction at 100 degrees C for 30 min was proper to extract the minerals and phenolic compounds in chenpi.