Green Bean Shelf Life Study

REQUEST:

Help customer with a green bean quality issue of browning ends on cut green beans by comparing to chemical solutions.

LAB ANALYSIS:

For this analysis the solutions were made as follows and chilled to 35° +/- 1°F to mimic hydrocooler temperatures as best as possible. The general directions for this test are as follows.

A. Prepare mixture as follows:

  1. 90 ppm activated KEEPER®
  2. 105 ppm activated KEEPER®
  3. 4 ppm sodium hypochlorite and 1.0% w/v calcium chloride
  4. 10 ppm sodium hypochlorite and 1.0% w/v calcium chloride

Beakers with above solutions were placed in a cold water bath and chilled until the temperature of the solutions reach 35°F. Whole green beans were then rinsed with potable water and excess water water removed. All beans were snapped into smaller pieces and 4 to 6 pieces were placed into each beaker containing the chilled dilutions listed above. These beans were allowed to remain in the beakers for 10 minutes.

For solutions 1 and 2 beans were drained and rinsed with a light potable water spray, placed in an appropriate dish and covered with labeled lid. Beans in solutions 3 and 4 were drained, placed in appropriate dishes and covered with labeled lid. All dishes were placed in a refrigerated environment for 48 hours. If no browning was observed they were removed from the refrigerator and allowed to warm to room temperature. All dishes continued to be monitored at regular intervals for browning on the broken ends.

CONCLUSIONS:

Solution 3 clearly shows browning on broken ends of beans. Solutions 1, 2, and 4 generally show broken ends with no browning or at least such minimal browning it is difficult to identify differences.

*Note that the sodium hypochlorite used in solutions 3 and 4 will react with organic components in the water, effectively using up free chlorine and requiring constant dosing to continue providing the required amount of free chlorine. As a result, total chlorine will have a tendency to climb.

The acidified sodium chlorite/chlorine dioxide in solutions 1 and 2 are relatively stable and non-reactive with organics in the water. This means concentrations remain more consistent and less dosing is required. There is also the added benefit of dosing only one product instead of two different products as with solutions 3 and 4.