96-8 |
Optimization of processing conditions and effects of commercial scale PEF processing on the microbiological, chemical, physical, and sensory properties of orange juice |
S. MIN1, Z. T. Jin, H. Yeom, S. K. Min, and Q. H. Zhang. (1) Food Science and Technology, The Ohio State University, 2015 Fyffe Road, Columbus, OH 43210 Pulsed electric field (PEF) is a nonthermal preservation method designed to produce microbiologically safe foods with fresh-like flavor and taste. Development of PEF processing system, optimization of PEF process conditions, and quality evaluation of PEF-treated products are needed for the industrial application of PEF processing. The objectives were to optimize PEF processing conditions for a commercial scale PEF system to obtain maximum microbial inactivation from orange juice and to investigate effects of PEF processing on the microbiological, chemical, physical, and sensory properties of orange juice after processing and during storage. The fresh squeezed orange juice was processed by a commercial scale PEF system (OSU-6), packed into 50mL-sterile bottles in a sanitary glove box, and stored at 4°C. The optimized PEF processing conditions were electric field strength of 40kV/cm, pulse duration time of 2.6ms, and total treatment time of 97ms. The flavor compounds, vitamin C, microbial stability, non-enzymatic browning index, pH, °Brix, and sensory quality of orange juice were determined before and after processing, and during storage. The PEF-treated samples were compared to those of the control (no treatment) and the heat-treated (90°C for 90sec) samples. Total aerobic microorganisms were inactivated by 5 logs after PEF treatment. Flavor compounds and vitamin C were retained more in the PEF-treated samples compared to the control and the heat-treated samples during storage. The non-enzymatic browning index of the PEF-treated samples was lower than that of either the control or the heat-treated samples (p<0.05). The sensory evaluation indicated that the PEF-treated samples had better texture and higher intensity of fresh flavor and overall acceptability than the heat-treated samples (p<0.05). The commercial scale PEF treatment was proved to be effective to preserve orange juice.
Session 96, Nonthermal Processing: Food safety and quality of nonthermal processed foods
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