Inactivation of naturally occurring microbiota in cucumber juice by pressure treatment.
The inactivation effects of high hydrostatic pressure (HHP) (350MPa/10min, 400MPa/4min and 500MPa/2min) with homogenization (20MPa/2min), nisin (100IU/mL) and decompression time (<3s and 7-8s) on naturally occurring microbiota in cucumber juice were investigated. Initial concentration of yeasts and molds (Y&M) was 5.6×10(3)-2.4×10(4)CFU/mL, and total plate count (TPC) was 1.0×10(5)-3.5×10(5)CFU/mL. Y&M were inactivated below the detection level (≤10CFU/mL) in all cases. The reduction of TPC in non-homogenized cucumber juice (NHCJ) was 2.5-3.0 log cycles, which was significantly higher than 1.0 log cycle in homogenized cucumber juice. The combination of nisin with HHP had a synergistic effect on the inactivation of TPC. The reduction of TPC in NHCJ with a decompression time of <3s was approximately 4.5 log cycles, which was significantly higher than a decompression time of 7-8s. Five non-linear models including the biphasic, Weibull, modified Gompertz, log-logistic and Baranyi models were fitted to TPC inactivation curves for the NHCJ at 300, 350 and 400MPa for 2-15min and 500MPa for 2-8min at a decompression time of <3s. The biphasic model provided the best fit for the data.
College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture, Beijing 100083, P.R. China.
Liang
L
Zhao
College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture, Beijing 100083, P.R. China.
Yongtao
Y
Wang
College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture, Beijing 100083, P.R. China.
Siyuan
S
Wang
College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture, Beijing 100083, P.R. China.
Hui
H
Li
College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture, Beijing 100083, P.R. China.
Wenshu
W
Huang
College of Food Science and Nutritional Engineering, China Agricultural University, National Engineering Research Center for Fruit & Vegetable Processing, Key Laboratory of Fruit & Vegetable Processing, Ministry of Agriculture, Beijing 100083, P.R. China. Electronic address: liaoxjun@hotmail.com.
Xiaojun
X
Liao
D000890:Anti-Infective Agents / Q000494:pharmacology; D001628:Beverages / Q000382:microbiology*; D015169:Colony Count, Microbial; D005516:Food Microbiology / Q000379:methods*; D005658:Fungi / Q000187:drug effects / Q000502:physiology*; D006874:Hydrostatic Pressure; D050296:Microbial Viability; D064307:Microbiota / Q000502:physiology*; D009561:Nisin / Q000494:pharmacology; D013995:Time; D015003:Yeasts / Q000502:physiology*
D000890:Anti-Infective Agents; D009561:Nisin; C102526:nisin A
Cucumber juice; Decompression time; High hydrostatic pressure; Homogenization; Modeling; Nisin