Pulsed Vacuum Osmotic Dehydration of Cherry Tomatoes: Impact on Physicochemical Properties and Probiotics Entrapment.

Osmotic dehydration (OD) and pulsed vacuum osmotic dehydration (PVOD) were employed to assess the various properties of partially-dehydrated tomatoes. Ascorbic acid and lycopene degradation and color and texture change were determined. The mastership incorporation of probiotics (Lactobacillus acidophilus TISTR 1338) into tomatoes was also investigated. OD mediums (20, 40 and 60 °Brix) consisted of a mixture of formulated tomato extract (FTE) and probiotic cell suspension. PVOD promoting mass transfer was clearly observed in a short-time process compared with OD. The physical and chemical properties of the tomatoes changed significantly after the dehydration processes, especially those of ascorbic acid content compared with lycopene. A more than 50 % loss of ascorbic acid was noted, starting at 10 g /100 g tomatoes of water loss. The hardness values significantly increased, while chroma values decreased. The cell entrapment on the tomatoes was in the range of 8 - 9 log CFU/g tomatoes. The highest entrapment of the probiotic bacteria was found in the long-time process (12 h) conducted with 20 °Brix FTE for the PVOD and OD processes, while entrapment was decreased by the short-time process (6 h). Using high solution concentration resulted in lower cell entrapment. However, cell entrapment could be increased by using the vacuum process. These results will provide a platform that encourages the inclusion of probiotics in high quality fresh-cut products and semi-moist products. These products can then be considered as alternative probiotic food choice for consumers. [ABSTRACT FROM AUTHOR]