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The processing of sprout vegetables in powder form has been known to extend the shelf-life by retaining nutritional values; however, sprout powder products were exposed to a variety of contaminants, such as microbial contaminants, during processing and storage. Therefore, the proper treatment for removing the contaminants in the powder was required...
Contexts in source publication
Context 1
... restitution coefficient 0.5 The original size of the chamber for mixing and heating sprout barely powder was 50 cm in height and 40 cm and 30 cm in the top and the bottom diameter, respectively. The chamber geometry used in the simulation was reduced to a scale of approximately one-twenty seventh of the original size, as shown in Figure 3. Two different colors (dark cyan and light yellow) particles were sequentially filled in the chamber geometry to observe the mixing patterns of particles, depending on the types of stirrer blades. ...
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... on the results obtained from the powder mixing simulation, the screw conveyor that could enhance heat transfer between the powder particles and the heating source with uniform mixing was fabricated to be applied to the vacuumsteam heating system. Figure 13 shows the inactivation rate of E. coli O157:H7 in sprout barley powder samples depending on the steam injection volume (0, 60 and 120 mL). The initial E. coli O157:H7 concentration of inoculated sprout barley powder was 5.38 log CFU/g. ...
Context 3
... coliform concentration of sprout barley powder was 4.33 log CFU/g. As shown in Figure 13a, E. coli O157:H7 in the powder samples thermally treated with/without steam injection were totally inactivated. By inoculating E. coli O157:H7 solution to the powder samples, the large amount of inoculum solution affected the increase in water activity and could improve heat transfer between the heating surface of chamber (inner chamber wall) and the powder sample (Figure 14). ...
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... order to investigate the coliform inactivation effect of the vacuum-steam combination heating system, the powder samples were treated with/without steam injection. The log reduction of coliform in the powder sample treated without steam was only 0.70 log CFU/g (Figure 13b). As vacuum heating progressed, the moisture content in the powder sample, which is the heat transfer medium, was rapidly evaporated. ...
Citations
... On average, these setups yielded a reduction of 5.09 log CFU/g for Salmonella and 7.34 log CFU/g for E. coli without significantly affecting the color and moisture content. A study by Huang et al. [9] yielded a 4.33 log reduction of E. coli 0157:H7 in sprout barley powder after 2 h of VSP on a larger sample of 5 kg with the addition of an agitator for mixing. The moisture content of the powder was significantly reduced due to the addition of vacuum, and direct steam caused a significant discoloration. ...
Eliminating microbes in low-moisture foods (LMFs) is challenging because this requires the preservation of their raw quality during pasteurization. Vacuum steam pasteurization (VSP) has been shown to be effective in reducing microbes while maintaining food quality. These studies were conducted at a laboratory scale where issues such as steam distribution, penetration, and condensation are not a concern, but in larger samples, these are of primary concern. Hence, this study repurposes a pilot-scale grain moisture conditioner (GMC) into a VSP system with the aim of replicating the lab-scale conditions in larger-scale applications. The modification entailed a series of design alterations, conducting a structural analysis of the conditioning chamber, creating a vacuum environment, ensuring uniform steam distribution, and designing and adding a preheater and a cooling system. Performance tests confirmed that the adapted system replicates the VSP’s lab-scale functionality. The results demonstrated that the VSP system can preheat to beyond 40 °C and achieve an absolute pressure of 11.7 kPa at 85 °C with a 344.7 Pa pressure increase per minute. Furthermore, steam distribution inside the chamber showed no significant variations, and rapid steam evacuation and chamber cooling could be performed simultaneously. The success of these modifications will be used in future experiments.
