30B-33 |
Effect of slicing method on the respiration rate, ethylene evolution and microscopic structure of fresh cut collard (Brassica oleraceae var. acephala) and cabbage (Brassica oleraceae var. capitata) |
L. M. OLIVEIRA1, C. S. Teles2, M. A. Jaime1, M. A. G. Carnelossi2, C. I. G. L. Sarantópoulos1, and R. Puschmann2. (1) Packaging Technology Center - CETEA, Food Technology Institute - ITAL, Av. Brasil, 2880, Campinas/SP, 13073-001, Brazil, (2) Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Campus da UFV, Viçosa/MG, 36571-000, Brazil The fresh cut market in Brazil is dominated by small companies with reduced production of great variety of vegetables. In these companies the hand slice is much used. Slicing cuts through cells are critical. The mechanical damage may increase the vegetable metabolism and the microbial growth rate. The objective of this study was to evaluate the effect of manual and machine slicing on the respiration rate, ethylene production and cellular structure of collard leaves and cabbage. The vegetables were selected, washed, refrigerated, sliced, sanitized in 150ppm (10min/5ºC) and rinsed in 3ppm (10min/5ºC) chlorinated water and centrifuged. Manual slicing was carried out with commercial sharp blade knife and mechanical slicing was carried out using an industrial vegetable processing machine (Robot coupe) equipped with a sharp cutting disk. The respiration rate and ethylene production of the sliced vegetables were measured at 23ºC in intervals of 1 hour during 6 hours using gas chromatography. The transverse section of the products tissue was examined by scanning electron microscopy (SEM) using microscopy Zeiss (DSM 940A). The samples were covered with gold in a Bal Tec equipment (SCD 050)after dehydration at 40ºC. The collard mechanically sliced presented respiration rate (RR) 114% and gas ethylene evolution (EE) 150% higher than that one manually sliced. However the level of injuries of the tissues were lower using processing machine. The RR, EE and level of injuries of the cabbage sliced manually and mechanically were similar. The RR and EE of the collard didn't present correlation with the SEM analysis probably because the difference between the thickness of the slices produced by hand and machine. For collard the thickness of the slice was more critical than the slicing method. For the cabbage with the same thickness of strip the slicing method doesn't have influence on the RR and EE.
Session 30B, Fruit & Vegetable Products: Sensory, Product Development, Fresh-Cut, and Storage
|