The 2011 ASHS Annual Conference

Microbiological and physiological quality of fresh-cut lotus was evaluated after high pressure treatment with 400 MPa for 10 min, held in film packages filled with water and stored at 1, 5, and 10°C. The high pressure treatment reduced the counts of mesophilic aerobic bacteria, coliform groups, and lactic acid bacteria to non-detectable levels on fresh-cut lotus root. During storage, the bacterial counts remained below the limit of detection (2.4 log CFU/g) until day 4 at 10°C, day 6 at 5°C, and day 10 at 1°C. However, the treatment increased the rate of electrolyte leakage from tissue slices at all temperatures and induced brown discoloration with decease in L* values and increase in a* values of fresh-cut lotus root at 10°C. The brown discoloration of the fresh-cut lotus root was less at 5°C than at 10°C and the fresh-cuts did not develop browning during storage at 1°C. The high pressure treatment reduced phenyl alanine ammonia lyase (PAL) activity and respiration rate and did not affect texture of fresh-cut lotus root at all temperatures. These results indicate that high pressure at 400 MPa for 10 min would be useful as a physical sterilization of fresh-cut lotus root when stored in film packages filled with water at 1°C after treatment.