International Produce Training

In many of these past posts I have referenced the defect “growth cracks” quite a few times.  There may be few of you that are not really clear on what a growth crack is, or how it is different from a scar.  To begin with, both scars and growth cracks are considered to be quality defects.  Which means these defects do not change or become worse, after they are picked or harvested.

The potato above has a growth crack.  The crack develops while the potato is in the ground, growing.  Due to heavy rains, or too much fertilizer, the potato has a sudden growth spurt, leaving a furrow or crack in the potato.  The potato continues to grow in the ground, and the growth crack heals over.  In addition to potatoes you will find growth cracks affecting tomatoes, carrots and celery, just to name a few.

Depending on the commodity, growth cracks will have different attributes.  If you have ever grown tomatoes yourself, after a heavy rain you will no doubt come across some tomatoes that have split at the stem end.  These splits are called growth cracks.

Scars, on the other hand, are not due to rapid growth.  Scars can be caused by many different things, insects, disease, or simply from a limb or leaf rubbing against the fruit or vegetable while growing.  Scars will range in color, in texture, and may or may not have depth associated with the injury.

So, when you come across scoring guidelines for scars or for growth cracks, they are specific defects.  It is important you are able to differentiate between the two defects, as they always have unique scoring guidelines.

Every now and then I disagree with a specific USDA sampling procedure, especially when it involves cutting (destroying) produce.  When it comes to eggplant, the USDA seems to go overboard with their cutting procedure instructions.  Their own inspection instructions state:

Sampling for Internal Defects

When inspecting eggplant for internal defects, randomly select and cut, a minimum of two fruit for packages containing 15 fruit or less, cut a minimum of four fruit for packages containing more than 15 fruit. If no defects are found it will not be necessary to continuing cutting.  However, if defect(s) are found cut the remainder of the sample.

I would agree with this procedure if you were finding internal discoloration on a regular basis, affecting your eggplant.  In my personal experience I have seen internal discoloration affecting eggplant every now and then.  For this reason, I suggest only to cut 1 to 3 eggplant during your entire inspection process, not 2 or 4 eggplant per sample.  I’d hate to see an inspector wasting their time and destroying 2 eggplant per sample, looking for a defect that is rarely found.  You will find most if not all USDA inspectors ignore this cutting procedure as well, as they use common sense in deciding whether to cut the specimens.  If they are finding internal discoloration they will cut more eggplant, if they do not find internal discoloration they will cut only a few eggplant throughout their inspection.

Internal discoloration may be found affecting the flesh resulting from a bruise, or it may be a physiological disease, exhibiting no external indication of internal discoloration.

As you can see in the image above, this type of discoloration is impossible to detect, without cutting.  If you find this discoloration you must also verify if the discoloration is turning into decay, becoming soft, or mushy.  If the discolored area is firm and dry, the USDA has developed a specific scoring guideline.  What may seem very lenient, the USDA allows an aggregate discolored area of 1 inch in diameter before it is scored as a defect against the U.S. No. 1 Grade.  If the discolored area is soft and mushy (decay), then it is considered a free from defect, meaning any amount is scored as decay.

In this eggplant, shown above, the discoloration is caused by the bruise, as the flesh was injured and became discolored.  Always check under the surface of bruised areas to determine the extent of the damage.  The same 1 inch scoring guideline is used for scoring discoloration caused by bruising.

Every now and then you may come across some problems with pineapples in a shipment.  Common defects are bruising and decay, which are easily identified.  Recently an inspector came across some pineapples that were showing a brown discoloration around the eyes.  It was correctly identified as gummosis.  He shared with me the following images.

As shown above, this defect can be found on the surface of pineapple, appearing as a brown to dark brown discolored spot.  The USDA Inspection Instructions state a definitive scoring definition.  Let’s take it one step at a time.  Based on the USDA, if the discolored spot(s) affect an aggregate area greater than 1/2 inch in diameter, it should be scored as damage.  Based on the scoring guideline, the discolored spot seen above does not appear to be larger than 1/2 inch in diameter, thus it would not be a defect.  But the USDA goes on to state, if the gum deposits slightly penetrate into the flesh, then regardless of the area, it is scored as damage (and as serious damage), a defect of the U.S. No.1 Grade.

As you can see, after cutting,  the gummy deposits do penetrate the flesh.  Remember, if the affected area alone is not exceeding 1/2 inch, you must cut into the pineapple to determine if the flesh is affected.  This pineapple is now scored as a defect.  In this case the defect is scored as serious damage.  Anytime the flesh is affected by a gummosis, it is scored as serious damage.

Your next question may be how many pineapples can be affected by gummosis, and still meet the U.S. No. 1 Grade.  The USDA classifies gummosis as a quality defect.  Insects, while the pineapples are growing, are the primary cause of this defect.  The discolored area will not become larger, or darker in color.  The affected area may be more susceptible to decay, but the gummosis itself will not become worse. The tolerances for pineapples allow for up to 8% quality defects, including 4% serious damage by quality defects.

In other words, if the affected discolored area of gummosis exceeded 1/2 inch, and the flesh was not affected, you would be allowed 8% of the pineapples to have this defect.  But if upon cutting, you found more than 4% of the pineapples with the flesh affected by gummosis then you would be out of grade.

To view the pineapple standard click here

Although you may come across some onions with a green color, caused by sunburn, the scoring guidelines will most likely prevent you from scoring sunburn as a defect.

We will discuss northern grown onions (onions grown in Idaho, Oregon Northern California, New York, etc) as the scoring guideline for Bermuda Granex Grao type onions is decidedly different.  Sunburn is a greenish discoloration of the outer scales caused by exposure to the sun.  There is no killing of the tissues, so you will not see sunken areas or sunken pitted areas associated with sunburn.

If you come across sunburn, the USDA has established a scoring guideline to follow:  Without removing the scales, if more than 33% of the surface of the onion has a medium green or darker color, then the onion is scored as a defect, sunburn.  Because the green color does not change, progress, or become more green , this defect is considered a quality defect.  But remember, you are not allowed to peel back the papery scales to look for sunburn, if you pick up an onion, and you see green color, then you would begin to determine if the color is dark enough green and is affecting at least 33% of the surface of the onion.

You may wondering what is “medium green” color?  The USDA has developed a visual aid, a color chip depicting what is meant by “medium green” color.

This color chip is to be used only to determine the green color of sunburn for northern grown onions. For BGG onions affected by sunburn, the USDA has developed an entirely different color chip to use.

Seems simple enough; if you find an onion with green color, and without peeling back the outer scales, if the green color is at least as dark or darker green than the color chip, and the affected area is more 33% of the surface of the onion, then the onion would be scored as a defect.

Although the U.S. Standard allows a total defect tolerance of only 5% for northern grown onions, sunburn has its own special tolerance.  If you find more than 33% of the onions being damaged by sunburn, then the lot would be out of grade.  In other words, you would have to find more than 33% of the onions with more than 1/3 of the surface affected by at least a medium green color to have the lot fail to grade U.S. No. 1 account of sunburn. 

I am sure you will find an occasional onion here or there that may be damaged by sunburn, but to find more than 33% of the onions with enough sunburn to be scored as damage is highly unlikely.

You will sometimes come across carrots that show definitive cracks running the length of the carrot.

Many inspectors confuse this defect with bruising or mechanical damage, or may think these are growth cracks.  But no, these are not caused by rough harvesting or due to sudden growth while in the ground.  This defect is called “air cracks” or “fresh cracks.”  The carrots are fine when shipped, but during transit or handling the bags during the unloading the process, the carrots actually burst, or pop open, resulting in cracks, when the carrots are moved around, more likely when they are cold and brittle.  The cracks are fresh, deep and narrow and affect from 1/2 inch to almost the entire length of the carrot.

Since this defect occurs after packing, it is considered a condition defect.  Once the crack develops, it will not become longer in size, nor will it become deeper.  Because the flesh is exposed it is more susceptible to decay but this is not very common.  It simply detracts from the appearance.  The USDA does have simple scoring guidelines; score as damage when the crack is more than 20% of the length of the carrot, or more than 1/8 inch wide, or if more than 1/4 inch deep.  For example, if this carrot was 7-1/2 inches long, the air crack would have to be longer than 1-1/2 inches to be scored as damage.  If the crack was less than 1-1/2 inches long, but the crack was more than 1/8 inch wide, then it still would be scored as a defect.

Air cracks can be scored as damage or as serious damage, and the US Grade Standards allow a total of 10% defects, including not more than 5% for serious damage.

With the recent cold weather you may have noticed some peeling and feathering affecting the outer leaves of romaine.  This defect is the by-product of romaine being affected by cold (below freezing temperatures) in the fields, while growing.  The water in the cell walls of the outer epidermis of the leaves freezes, and when ice crystals form, they puncture the cell walls, killing off the cells.  This leaves a peeling appearance.  When the outer epidermis peels, the exposed area becomes exposed to oxidation, which results in the yellow to brown discoloration frequently associated with peeling and feathering.

The USDA has a scoring guideline to follow; it states:  Score as damage when more than 2 leaves are materially affected and as serious damage when more than 4 leaves are materially affected by peeling and feathering.  You are not allowed to brush the area affected to determine the damage.  The question that arises is what is meant by “materially affected?”

If you can readily see the peeling and feathering and you find it affecting at least 3 leaves, then score the plant as damage.  If the peeling and feathering is affecting 5 or more leaves then score the plant as serious damage.  But if yellow to brown discoloration accompanies the peeling and feathering, then you would still need it to affect more than 2 leaves before scoring as damage, but you would need less of an area affected on each leaf, to be considered as materially affected.

Looking at the above image, the area affected is considered materially affected, so you would need to see this on at least 3 leaves to be scored as damage, or on at least 5 leaves to be scored as serious damage.

Every now and then, depending on the growing conditions you may see this defect on broccoli.  It is aptly named “hollow stem.”

Hollow stems could be caused by a boron deficiency, but not all hollow stems in broccoli are caused by boron deficiency.  Excessive nitrogen, or growing conditions favoring rapid growth could cause this defect.  That explains why some years you see lot after lot with hollow stems, but other years you may not see this defect at all.

Since it occurs while growing, this defect is considered a quality defect, meaning the hollow stem will not increase in size after harvest.  The area around the hollow area may become watersoaked, discolored, or may breakdown, as this area is more susceptible to infections.

The USDA provides a scoring guideline, but this guideline focuses on bunched broccoli and not the popular broccoli crowns.  The USDA states:  Score as damage, any hollow stem when the opening extends more than 3 inches up into the stem, or when the opening is more than slightly discolored or watersoaked.  But what do you do if you encounter hollow stems on broccoli crowns and the stem is much less than 3 inches in length?  You can never score hollow stems as a defect?

No, you would default to the generic scoring guideline, score as damage when the hollow stem materially affects the appearance.

As in the above image, cut into the stem and determine how far the hollow stem extends into the stem.  Score as damage when the hollow stem extends into the crown area.  The U.S. Grade Standards allow for 10% total defects. 

As I said earlier, this defect may be commonly found, depending on the growing conditions.  Some shippers are stipulating in their contracts they will not recognize this defect on inspection reports.  As an inspector, always check with your procurement staff and seek thier guidance on whether you should score this defect.

If you have inspected artichokes recently, you may have come across this defect.

  Yes, this is a defect.  You may have been told that these “frosted” artichokes actually may taste better.  Regardless, the appearance is still materially affected, thus these artichokes would be scored as a defect.  So what is it?  While the artichokes are growing, freezing temperatures (30 to 31°F) can cause the damage.

The cold temperatures freeze the artichokes, causing the moisture in the cells of the outer epidermis to crystallize.  When the crystals form they rupture the cell walls, damaging, or killing the cells.  The affect is the peeling and feathering you see in the above image.

The USDA realizes the freezing injury could occur while growing, or could occur in transit or storage, so they instruct their inspectors to refrain from calling the defect “field freezing.”  Instead the defect is described as “peeling and feathering.”  The damaged area will oxidize and become discolored in later stages.  The discoloration may range from a light brown to black color.  Because this defect progresses, it is to be classified as a condition defect.

Peeling a feathering may be scored as damage, if materially affecting the appearance, or as serious damage, if seriously affecting the appearance.  The artichoke shown in the top image would be scored as serious damage.  The U.S. Standards for artichokes do not include a restrictive tolerance for serious damage.  If you find damage or serious damage by peeling and feathering, the artichokes would be scored against the 10% tolerance, for total defects. 

Getting back to the assertion about tasting better, I have never seen any conclusive evidence supporting that claim, but I am welcome to hear any one’s opinion.

As the table grape season in Chile starts up, a defect to keep an eye out for is sulphur dioxide injury.  I wouldn’t say it is a common defect, but you will come across it every now and then.  When packed, the grapes are subjected to sulphur dioxide, to act as a fungicide, to control the presence of mold, mostly blue mold rot (pennicillium) and gray mold rot (botrytis).  The sulphur dioxide is applied as a gas or as a pad, placed in the individual grape cartons, during packing.

The following is taken from Peak Fresh USA: 

“Grape Guard Pads are designed to release an initial burst of sulphur dioxide and a slow release of additional sulphur dioxide over a period of eight to 12 weeks storage. The pads generate sulphur dioxide as a result of moisture take up and if moisture is excessive as a result of packing warm grapes or a break in refrigeration, then the amount of sulphur dioxide generated will be excessive and will taint the grape berries. By using PEAKfresh® carton liners and correct refrigeration, Grape Guard Pads will operate efficiently over extended storage periods.”

Unfortunately, sometimes damage to the berries does occur.

The above image is showing typical sulphur dioxide injury.  You can plainly see the bleaching out, at the capstems, from the SO2 injury.  It is easier to identify this defect on the darker color varieties of grapes, but even on Thomspson Seedless or Perlettes the bleaching is still evident.  The USDA scoring guideline states:

Injury that causes appreciable bleaching or loss of color of the berries of black or red grapes, and only slight bleaching but with the other effects apparent on white grapes shall be scored as “Sulphur Dioxide injury.”

Even though the defect is only affecting the color, the berries are scored as sulphur dioxide injury, against the total lot tolerance for defects, 12% (Do not score this defect against the color tolerance).

  This defect will progress (condition defect) and the affected area will be become soft and sometimes wrinkled.  In this stage, the defect would be scored as sulphur dioxide injury, but as serious damage, against the 4% tolerance for serious damage.

Have you opened a carton of limes and discovered a discoloration affecting the stylar end (opposite the stem end)?  You may have wondered if this is a type of decay, will it progress on the lime, will it spread to other limes?

What you have found is Stylar End Breakdown.  This is a fairly common defect found on limes, and one that may be a problem for you.  It is the most serious post harvest disorder affecting the lime industry.  Its cause is physiological, meaning stylar end breakdown is not caused by a pathogen or insect. 

Stylar End Breakdown is a physiological disease usually starting at the stylar end near the base of the nipple or tip and appears as a grayish tan, watersoaked spot. The affected area enlarges rapidly involving up to 1/3 or 1/2 of the fruit.

Occasionally the disease appears at the stem end as well as at the stylar end. The affected area remains firm but becomes darker with age and usually sinks below the level of healthy surface. There is often a partial collapse of the flesh and a watersoaking of the core tissue within the stylar end of the fruit. The affected rind is quickly invaded by bacteria or fungi, causing the fruit to deteriorate rapidly.

Stylar end breakdown is a condition defect, as the affected area will progress, become larger on the individual lime, and may eventually turn into decay.  Unaffected limes will not show symptoms of stylar end breakdown by being in contact with affected limes.  But unaffected limes may show symptoms of stylar end breakdown while in storage, but the source came from the growing conditions.

The scoring guidelines:  This is a free from defect, meaning if you see stylar end breakdown, even in a very early stage, the lime is to be scored as a defect, against the 5% tolerance for serious damage.  As the stylar end breakdown advances, secondary organisms invade the tissue and the tissue will be soft and mushy.  At this stage, the defect will now be scored as stylar end rot, and scored against the 3% tolerance for decay.