The Selection Of High Efficient Antibiological Agents And Suitable Drying Method For Chives

Chive(Allium schoenoprasum L.) is a perennial herbaceous plant belonging to Amaryllidaceae family. Chive is rich in vitamin C and A, carotene, minerals, etc. and has a long history being used as vegetable, culinary and medicine. The main export market of Chinese fresh chives and chive products are Japan, Korea, Russia, etc. Because of inadequate sterilization and the trade barriers, the problem of excessive micro-organisms in dried chive occurred frequently. In addition,90%of vegetables are dried by hot air in china, resulting in poor sensory quality. All these cause great problem in processing, quality control and export. This paper is mainly focused on the effective sterilization and dry way on chives in order to match the requirement of better quality and reducing microorganism for export.1. The effect of sterilization and quality on chives by sodium hypochlorite (SH), peracetic acid (PA), and chlorine dioxide (CD) by different concentration or for different contact duration was investigated. The results showed that the reduction of the total aerobic bacteria on chives by sodium hypochlorite was the lowest,<1.0lg cfu/g. PA and CD had nearly the same antibacterial effect on fresh-cut Chinese chives, reducted the total aerobic bacteria population approximately by1.68～2.22lg cfu/g,0.99～2.85lg cfu/g, respectively. As compared to control, all treatments reduced vitamin C, L value which related to chives’ color, but not considerable. The chives will be etiolation when CD concentration was over40ppm. The optimal conditions for PA and CD were100ppm PA for5min and40ppm CD for10min.2. All combined treatments of PA and CD reduced the microbes on chives greatly. Although all combined treatments reduced a*value, chlorophyll and Vc contents of Chinese chives to a certain degree, the quality of Chinese chives with different treatments was not significantly different. The optimal combined treatment congdition obtained by orthogonal test was40ppm CD+150ppm PA for8min.3. The efficacy of dehydration rate and quality on chives chives by hot-air drying and vacuum drying at different temperature was detected. The dehydration rate of chives enhanced with the increase of temperature which had siginifcant effect on the quality of chives by hot-air drying. The temperature over70℃caused poor sensory quality as indicated by browning and dark color, increasing a*value, decreasing Vc and rehydration ratio. Compared to the hot-air drying, vacuum drying temperature had little effect on chives’ sensory quality, and the difference of rehydration ratio at different temperature was not remarkable. At the same tine, the amount of total bacteria was reduced greatly after dehydration by using the two methods. Therefore, the vacuum drying was more suitable to chive drying and optimal condition was70℃for4h, the product moisture content would be below8%.