International Produce Training

The other day I received an interesting question concerning the net weight of a pint of strawberries.  After consulting with the Department of Weights and Measures I was able to give an educated response.  For those commodities designated by dry measurements, pints, bushels, etc. there is no net weight equivalent.

For example, you may receive strawberries, blueberries, or raspberries in clamshells marked 1/2 pint or 1 pint.  The clamshells are not required to weigh a specific weight.  The dry measurements are based on your old math equations, V=length x width x height.  Think of it this way.  You could have a full pint of potato chips and full pint of rocks……each is full, but the pint of rocks would weigh much more than the pint of potato chips.  The inspectors from the state departments of weights and measures would need to have a standard pint measuring device, such as a measuring cup.  2 cups is the equivalent of 1 pint.  Place the contents of the strawberries from the 1 pint clamshell or basket into the 2 cup measuring cup.  If the contents are equal or above the 2 cup line, the volume requirements have been met.  If the contents are below the 2 cup line, the pint of strawberries is in violation. 

Now remember, many if not most of the berry containers are now marked in net weight.  If this is the case, the net weight of the individual clamshell must be met.  Please see the post from February 23, 2009 for the procedures in determining net weight.

You may also find other products that sometimes are packed using volume or are packed by net weight.  For instance, cabbage and onions may be packed in sacks marked as 4/5 bushel by volume, or in sacks marked 50 lbs. Net Weight.  Let me know if you have any questions concerning net weight, or if you have encountered some other containers that make it difficult to determine its contents.

With the recent reports of freezing temperatures in Florida and in Texas you must be ready to keep your eyes open for citrus arriving with possible freezing injury.  It is impossible to detect externally, meaning you must be ready to cut some citrus to find any problems.

The first questions many people have are;  “What does freezing injury look like?” and “Where is found on the fruit?” and “How much do I have to cut?   Within the next few days or even weeks, citrus that has been subject to freezing temperatures may show 

1.   Segment walls have buckled at a cross section cut near the stem end;
2.   Watersoaked condition of the core;
3.   Mushy condition of segments or portions of segments;

After a few weeks the watersoaked portions will dry out, as the juice sacs collapse having been emptied of juice.

As an inspector you will want to familiarize yourself with some basic inspection procedures for looking for freezing injury in citrus.  Follow these steps:

As shown in the image above of this cara cara orange, you will make a preliminary cut on the orange , cutting enough of the rind at the stem end to just expose the flesh.

The next step is to cut a slice about 1/4 in width.  This segment is allowed to be totally dry or mushy from the freezing injury.  But if this entire segment is affected, and the mushy or dry condition extends into the remaining portion of fruit, the fruit is considered as being damage, a defect.  This defect is considered a quality defect and is scored against the 10% tolerance.

The most important question everyone asks is, how much do you have to cut?  As you can see the USDA has developed a cutting plan for their inspectors. 

The USDA recommends cutting a minimum of 10 fruit if freezing injury is suspected.   For example, if after cutting 10 oranges the inspector finds at least orange with a scoreable defect, from freezing injury, the inspector must cut all remaining fruit in that sample.  They must continue with this procedure for all their samples they inspect.

If you would like to deviate from this procedure I think it would be safe to cut 3-5 fruit per sample, and if a defect is found, cut 20 fruit in your sample.  Doing this for 3 samples would give you a good estimate of the percentage of citrus with freezing injury.

Although you may run into problems with frozen loads any time of year, due to issues with the reefers, this time of year adds the element of nature to compound the transit problems with produce.   There are specific products that are more susceptible  to freezing than others, and there are a few places you want to concentrate on looking when a trailer backs in and is ready to unload.

First off, products with higher sugar content usually have a lower freezing point.  For example, broccoli and celery will freeze at 31 degrees, while the freezing point of cherries and grapes is about 28 degrees Fahrenheit.  Finding the freezing injury on some commodities is relatively easy, such as identifying frozen lettuce, romaine, cucumbers.

Other commodities are more difficult to detect freezing injury, especially if it is slight.  Potatoes will breakdown when thawed out, will leak and will produce a strong odor, but in the frozen state they are very difficult to detect.  An inspector must take the point of their knife and insert it into the potato about 3/8 inch and twist the knife, hoping to hear a sharp snap.  If no snap is heard, the potato most likely is frozen.  Sweet peppers are also difficult to detect when freezing injury has affected them, as they will develop sunken pitted areas after they warm up.  But catching the problem up front is not easy.

There are a few places you can concentrate your search for possible frozen product: 

1. If you suspect a problem, as you may actually see frost inside the trailer floor or wall, the first pace you would want to look would be product in contact with the trailer floor.  Most shippers will stack their product on pallets or lay cardboard down on the floor for protection.  Whether the product is floor-stacked or not always zero in on the floor layer containers first.
2. The second place to check out would be any containers in contact with the sidewalls.  More specifically check the product that would be in contact with the walls.  Although the walls are insulated the extreme cold may penetrate the walls and affect the product.
3. And lastly you would want to inspect any of the cartons in contact with the metal rails along the sides of the trailer.  The metal will act as a conductor for the cold and will cause problems for some products in contact with the metal.

If you do find freezing injury always work you way up from the bottom or in from the sides of the trailer or rail car to determine how extensive the freezing injury may be.  If you need to call for a USDA inspection always let the inspector know you have found some freezing injury, point out the location of the problem, and you can even choose to request the inspection be restricted to freezing injury only.  They may otherwise miss the freezing injury as they take random samples throughout the load, not necessarily concentrating on the problem areas.

Have you noticed improvements with the quality of the product, such as less discoloration, less shriveling? 

Has anyone had any experience with storing oranges along with products that produce ethylene gas?  A reader has noticed that once they changed their storage of oranges, with other ethylene producing commodites, the oranges have showed an increase in decay.  Is there a corrolation between the two?  Your comments would be appreciated.

Does anyone have any good advice to offer, from experience, at what temperature bananas are subjected to chilling damage?

I have found some information, that relates temperature to the length of time of exposure, for irreversible chilling damage:

From your experience, do you agree with this chart?  Thanks, and I am looking forward to hearing from you.