Hot-fill Pasteurization of Cucumber Pickle Spears: An Alternative to Tunnel Pasteurization

For commercial production of acidified vegetable products, a tunnel pasteurizer is typically used for thermal processes. To help reduce energy costs and use of water, we developed a hot-fill method for pasteurization of cucumber pickle spears in 0.7 liter (24 oz) jars. The method required refilling jars three times with 70°C to 85°C brine. Initial cucumber spear temperatures up to 60°C were tested with insulated or uninsulated pickle jars. The data showed that for cucumber spears with an initial targeted temperature of 40°C or 60°C, a hot fill method could achieve or exceed a temperature of 73.9°C (165°F) for up to 13.9 min. These conditions exceed published 5-log reduction values (F160 of 5.6 min) for food pathogens and were sufficient to meet typical industry processing conditions of 10 or more min at 73.9°C, to destroy spoilage bacteria and inhibit cucumber softening enzymes. A simulation model was developed that may be useful for the optimization of brine temperatures and processing times. Although further development of processing equipment may be needed for inverting and refilling jars, the in-jar pasteurization process has potential application for cucumber spears and related products.