Published by Chris Hedges, Extension ITT Specialist, WSU TFREC
Disclaimer: this is a living document meant to give general guidance and to be adjusted as the industry gains more experience with packing this variety.
The current protocol was developed by an industry advisory group in consultation with packingline personnel, WSU, suppliers, the WA Tree Fruit Research Commission and PVM. This document is intended to provide general suggestions and will be updated when new information becomes available. If you have questions or suggestions please contact Chris Hedges, Postharvest ITT Specialist, WSU: john.hedges@wsu.edu.
General Comments
For a good wax coating cleaning and preparing the apple is essential. For best results don’t rush the line. Apply a consistent speed and avoid stoppage. The key is to have dry and clean fruit as it hits the wax brushes. Cosmic Crisp® fruit, especially from young trees, can be greasy. Last season (refers to 2019-20 packing season), packers struggled at times to provide an even/appealing wax coating. In addition, off-flavors were reported by consumers. Some of these sub-optimal eating experiences can be traced back to the handling on the packingline. As an industry, all efforts should be made to provide a consistent and enjoyable product to consumers. It is recommended to taste fruit before shipping.
Preparation of fruit before packing
- Fruit can be packed straight out of cold storage.
- If no heat in dumptank/short brush bed: consider storing fruit at 50°F for up to 1 week or keep fruit at room temperature over night.
- Run line at a manageable speed, no “stop go”, pushing fruit through the line too fast will cause poor wax also.
- Taste fruit: some lots are known to have off-flavor in the first 1-3 months of storage. If you encounter this situation, do not pack the fruit until the off-flavor dissipates after approx. 3 months of storage.
- Decay: remove all decay before fruit hits the line.
- Starch clearing: if you plan to pack fruit before January 1, 2022, make sure it conforms to starch clearance protocols, see 2021 Marketing and Quality Standards
- General thoughts: as a starting point, treat fruit like Red Delicious.
Dump tank
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Temperature: no optimum temperature established yet
- Scenario 1, non-greasy fruit: 60 – 70°F
- Scenario 2, greasy fruit: 90-100°F
Soap/Rinse
- The general idea is to use the maximum amount possible to create “snowball suds”. This will enable the wax to be emulsified (dissolved) within the soap suds and rinsed off that way. Otherwise, it is possible to have the wax brushes clog up. Give fruit time in the soap section, do not rush the process. Use a heavy blanket to hold down the fruit if your food safety plan allows for this.
- Before you use a new soap: check for sensitivity of fruit to lenticel breakdown (apply soap, leave fruit at room temperature, and observe for 2 weeks)
- Soap brushes: odd-even speeds (every other brush goes at the same speed, brushes next to each other run at different speeds, this creates a scrubbing action)
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- Ideal speed – Apples tumbling from one “pocket” pushing to the next. Look for rotation of fruit in “pocket” between brushes with NO bouncing over each other down the line. Slowest speeds should be used if LBD (lenticel breakdown) is a concern.
- When grease is extremely severe, try slowest speeds first. Increase brush speeds if skin temps are cold and grease is firm (not soft to touch).
- If only cold water is used during all stages of prep, fast speeds might help to “chip” away heavy grease (Red Delicious protocol).
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Type of soap: most soaps (alkaline, neutral, slightly acid) can be effective. Not every soap is the same. You need to experiment what works for your conditions. Apply all soap at maximum pump speed (1 gal./hr. pump).
- Examples: alkaline soap applied at a pH 9-12; dual application: slightly acid (pH 5.0) or neutral soap; acid soap alone can work also.
- Number of soap applications: Any single soap or dual application is better than none.
- Rinse: Make certain to rinse apples completely to fully remove any soap residue. A heated rinse water can help to remove the soap (90-100°F).
- Rinse brushes: constant speed to rotate the fruit and enable the soap to completely rinse off.
Drying section
- Make sure no soap carry over is happening, or fruit will not get dry before the wax.
- Use slowest speed possible after soap section.
- Drying brushes: odd-even speeds (every other brush goes at the same speed, brushes next to each other run at different speeds, this creates a buffing action and enables the fruit to tumble).
- If brushes are getting natural wax build up, the cleaning failed. Fruit was pushed through the soap section too fast. Beater bars: (angled iron bars underneath brush bed used to wick the moisture off the brushes). Move these bars 1/8 to max. ¼ inch into the brushes to wick the moisture off the brushes. Make sure the beater bars are engaged and working. Be aware, it wears those brushes out.
Waxing
ATTENTION: when fruit reaches that point it needs to be completely dry. Check fruit for remaining moisture in the stem bowl or calyx. Run at normal speeds determined by fruit online. Do not allow the brushes to dry, as this will lead to inferior waxing results (i.e. blotchiness, no wax, poor coverage). If the wax bed is drying out it may be hit with too much air from the dryers. Shield the section to slow down the warm air. Make sure wax brushes are not worn out, old brushes will not hold wax well. For best results during prolonged breaks (line break down, lunch), consider clearing the wax brushes. Apply wax before the line starts back up to get the brushes re-wetted.
Selection of wax: Each line is different. You need to test your waxes to determine which product gives you the best results in terms of shine, longevity, and taste of fruit. Work with your provider to select the best wax type to optimize the application results on your specific line. Ensure the fruit does not develop off flavor. Carnauba based wax typically works well on fruit that is not greasy but may have a difficult time covering over excessive natural wax without pullback, and splotches. Shellac based products can cause whitening**, and off flavor, while preventing bleed-through from the natural wax coat. **Discuss the propensity to whiten in some markets before use.
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