Friday, March 7, 2008

Organic Versus Conventional Citrus

Dietary Help or Media Hype: Is Organic Produce Really Better?
Is Organic Citrus Fruit Worth The Extra “Squeeze?”

It’s winter in the U.S. Walk into a grocery store of any size, and your eyes are dazzled by color, as oranges, grapefruits, lemons, limes and other citrus varieties vie for your attention. Citrus deserves an honored place on any list of healthy foods. And I don’t know about you, but just a few minutes of squeezing fresh citrus to make my own juice is all the aromatherapy I need to get me through even the coldest, snowiest winter day. You’ll probably find some organic citrus in that grocery store, and these days it’s an easy matter to order it online. But is it worth the extra cost?

There are some compelling reasons to choose organic produce, such as the overuse of agrochemicals in conventional produce production, improved soil health in organic agriculture and concerns over pesticide residues. Those also apply to citrus production. So do some of the difficulties attendant upon organic cultivation, such as the “who do you trust?” game (are those organic navel oranges marketed by that corporate citrus giant really produced in accordance with organic regulations?), the fact that organic citrus may look less pretty than conventional counterparts and the issue of food miles—although the majority of all citrus consumed in the U.S. (except for limes) is at least grown domestically. The states that produce the most citrus within the U.S. are California, Florida, Texas, Arizona and Louisiana, so if you live in the Northeast, Midwest, or Northwest, a “locavore” diet (that is, eating only foods grown or produced locally) would necessitate that you skip this source of wintertime sunshine.

For this article, our goal was to taste organic citrus versus conventional citrus to see if a taste superiority could be detected that would make us want to choose the generally-more-expensive organic produce. Beyond choosing organic produce for its positive impact on the environment, some people might say that citrus is a category where organic doesn’t matter; that because the rind is peeled away, no pesticide is ingested. That isn’t true: citrus is zested for recipes, wedges are tossed into beverages.

First, a quick overview of the types of citrus used in this article.

The Fruits

Oranges are the most popular citrus fruit in the U.S., grown chiefly in California, Arizona and Florida. Some 90% of Florida’s orange crop goes into juice production—most Americans consume far more oranges as juice than as fresh fruit. While most people are familiar with Navel oranges and Valencias (the former are most commonly eaten out of hand, while the latter are famed for their juice), there are a number of other varieties available, including the Marrs, which is seen most often in Texas. Mandarins are an entire family of loose-skinned oranges (sometimes called “zipper skinned” for their effortless peeling quality) with segments that separate easily. This orange family includes Clementines, Dancys, Minneolas, tangerines and Satsumas.


Named for its fruit clusters, which are somewhat similar to that of grapes, grapefruit is the largest variety of domestic citrus (the pomelo, which it is believed was crossbred with the mandarin to create the grapefruit, is larger). Florida grows 70% of the world’s supply of grapefruit.

Consumers have been familiar with the “white” Marsh variety of grapefruit as the standard for years. However, pink and red grapefruit have become increasingly popular of late and are available under a host of different names, including Pink Marsh, Ruby Red, Ray Ruby, Rio Star, Star Ruby, Rio Red and Red Flame.

Although there’s a common belief that pink and red grapefruit are sweeter than white grapefruit, that’s not necessarily true. The microclimate where the grapefruit is grown has the greatest effect on a grapefruit’s sweetness or lack thereof, according to Tracy Kahn, a botanist with the University of California at Riverside. White grapefruits can be just as sweet as those with flesh of other colors.


Finally, there are lemons. Most lemons in the U.S. are grown in California or Arizona, although some newer varieties can tolerate Florida’s humidity and periodic cold spells.

Everyone knows the Eureka variety—the one you can find in any grocery store. But Meyer lemons have gained great favor, particularly with chefs and foodies, in recent years. Meyer lemons tend to be somewhat smaller, rounder and less hardy than Eurekas. They have smooth, thinner skins, and the juice contains far less acidity, which makes it much sweeter. Both aroma and juice have a slight floral note. Meyer lemons are probably the result of a natural cross between a lemon and an orange, probably a mandarin. Because they are more perishable than Eurekas, Meyer lemons may prove difficult to find at a typical supermarket; but try a specialty market. You can also order them online.

Now that we’ve reviewed the fruits, let’s look at what can happen to conventional and organic citrus fruits.

Citrus Beauty Treatments: Coloring, Waxing & More
What’s the difference between conventional and organic citrus? Let’s start in what we’ll call the “beauty department.” Apart from the use of agrochemicals used while the citrus is being grown, there are several standard postharvest procedures that bear some examination. Citrus is a nonclimacteric fruit, meaning that it does not go through any pronounced ripening changes once it has been picked (compare this to a pear or an avocado, both of which are climacteric fruits). This means that citrus must be picked when it is ripe. Ripeness is determined, at least within the state of Florida, by both juice content and the Brix Acid Ratio, a measure of how much sugar is in the fruit compared to the amount of acid.

Dye Jobs

Given the unpredictability of weather and various microclimates in citrus-growing regions, sometimes citrus is fully ripe before its natural “ripe” color (orange for oranges, yellow for lemons, etc.) is well-developed. In other words, there may still be green left on fruit that is fully mature. Occasionally, fully-ripe oranges will turn green, as well—and this is perfectly natural. But, consumers are comfortable using color as a test for ripeness. Because of this, many growers feel they must alter the appearance of their citrus. According to Earthbound Farms, growers in Florida can actually dye their citrus (usually oranges) to improve color, although coloring citrus in this manner is prohibited in both California and Arizona, and organic growers are not permitted to dye fruit at all.
Organic Meyer lemons from Lemon Ladies Orchard: no dye, gas or wax.


Growers can also give better color to citrus through “degreening,” a process sometimes called “gassing,” in which the citrus is exposed to ethylene gas under carefully controlled conditions. Ethylene is a gas emitted by fruit as it matures, and it causes coloration changes in the fruit’s peel. Gassing is an option for both conventional and organic growers. Although no harmful effects from ethylene have been documented when it is strictly controlled, there are people who dislike the idea of their produce having been exposed to it. Some organic growers scorn the practice, including Karen Morss of Lemon Ladies Orchard and Reena Luera of Sembra Citrus.


Waxing is another component of citrus processing. Veritable Vegetable, the country’s oldest distributor of certified organic produce, notes that a coat of wax is often applied to both conventional and organic lemons, limes, grapefruit, oranges and tangerines as a protective barrier against moisture loss and dehydration. It also gives the citrus a little more of a shine or attractive finish. Citrus actually produces a wax coating naturally, but, once it’s picked, citrus also undergoes a thorough cleaning, which can damage or destroy the wax covering. If citrus is to be shipped long distance, an insufficient wax coating might mean that the fruit reaches its destination in less than optimal condition, so additional wax is often applied.

Still, there are differences in the waxes applied to conventional and organic produce. Wax for conventional produce contains petroleum-derived ingredients, and it often has preservatives or fungicides in it. Wax is not digested by the human system, but it’s possible that chemicals in the wax may be absorbed by the body. Wax for organic produce, on the other hand, may not contain preservatives or fungicides, and it may not have petroleum-based ingredients. Beeswax, wood rosin and carnauba (extracted from palm leaves) are allowed, and they can be combined with vegetable oil, vegetable-based fatty acids, ethyl alcohol and water.


I had read online that conventional citrus fruit found in a supermarket is often several weeks away from the tree. Matt McLean, of Uncle Matt’s Organic, says that isn’t necessarily so. Like most citrus purveyors (organic or conventional), Uncle Matt’s picks to order. That is, a retailer will order a certain quantity of citrus, and only then is the fruit harvested, processed and shipped. The length of time it takes any piece of fruit to appear in a market “really depends on the retailer,” according to Mr. McLean, and how efficient it is about moving items in and out of its distribution warehouse(s). He adds that organic citrus has less of a time window than does conventional citrus. Because organic citrus is not treated preharvest or postharvest with fungicides, as is common practice for conventional citrus, the organic fruit is more subject to damage from mold exposure and temperature variations.

Once in a supermarket display, you’d think citrus would be content to behave itself and sit quietly until it’s purchased. But Mr. McLean knows that careful supervision is required, as it is for all produce. Ideally, a retailer will pick over any display of organic produce on a daily basis, to remove any items that are damaged, past their prime, or otherwise not up to par, a practice known as “turning.” While turning is done often in larger, natural food store chains, other retailers may turn less frequently. Turning is especially important for organic produce. If you’re going to pay extra for a grapefruit or potato because it’s organic, you want to walk into the organics section of your grocery store and see produce that looks perfectly fresh and vibrant.

Nutrients Matter
How about nutrition content? Citrus is, of course, a great source of vitamin C, and it has some fiber and potassium, as well. Red or pink grapefruit and tangerines have a good amount of vitamin A, while fresh oranges also contain some B vitamins. But does organic citrus have more nutrition bang for your buck? Some evidence suggests that organically-grown produce may have higher levels of vitamins, minerals and/or some antioxidants.

A slightly older study (2003) claims that statistically higher levels of secondary plant metabolites (phenols, which may be important in human health) were found in both organically- and sustainably-grown marionberries, strawberries and corn than in conventionally-grown counterparts.
A more recent inquiry (2006) measured vitamin C and levels of three antioxidants in both organic- and conventionally-grown tomatoes (two separate species) and bell peppers. The results? Higher levels of vitamin C and two antioxidants were found in one variety of tomato grown organically; in a second tomatoes species, only one antioxidant had higher levels in the organically-grown specimens. Bell peppers, also examined in this study, were not statistically different in quantities of these nutrients between agricultural methods.
Finally, Washington State University, in research supported by The Organic Center, measured levels of two forms of three antioxidants in organic and conventional citrus, apple and tomato juices, with varying results. I liked one aspect of this study in particular, in that the researchers measured both more and less bioavailable forms of the antioxidants (bioavailability is a measure of how well substances are absorbed into the system). Unfortunately, this study was carried out with rats, not people (see this blog entry from Uncle Matt’s). Uncle Matt’s also cites the QLIF project findings, discussed in last month’s article on organic produce, the results of a four-year U.K. study on conventional versus organic produce and dairy cows. One cautionary note: While the write-up states that antioxidant levels were 20% to 40% higher in organic wheat, tomatoes, potatoes, cabbage and lettuce, levels of some nutrients were found to be higher in conventionally-grown examples of certain types of produce. Full study results will not be published until this year.
In the November 30, 2007 edition of its blog, Uncle Matt’s quotes Alyson Mitchell, an associate professor of the Department of Food, Science and Technology at University of California at Davis. Professor Mitchell declares that nutrient levels for any fruit or vegetable can vary, depending upon ripeness when picked, storage conditions, age, and especially variety (a Valencia orange may have more or less vitamin C than a Navel orange, for instance). Any processing will also affect nutritional value. To sum up, there have been a number of studies indicating higher levels of some nutrients in some organic produce. But scientific, across-the-board evidence for higher nutrition levels in organic produce in general (and organic citrus in particular) simply does not exist right now. Of course, there are a good number of other reasons to choose organic foods whenever it’s possible (pro environment, anti pesticides, supporting family farms, etc.).y seeds in their Satsumas. I found no Satsumas locally, but most supermarket tangerines were juicy, albeit a little less sweet than the organics.

The Taste Tests
In Parts I and II of this article, you got to know the citrus fruits and how conventional (and sometimes organic) citrus can be “beautified” to look better. We also took a look at the current research on the nutritional value of conventional versus organic produce—which at this point is inconclusive.

Enough with the science already, you’re saying! How does organic citrus taste? I was in an unusually good position to find out with these taste tests.


I ordered organic citrus from several sources. Because not all of the citrus I received was sent simultaneously, there was a period of several weeks during which I purchased a few of whatever variety of conventional citrus I needed to compare against the organic counterparts. I shopped at different supermarkets and bought at least one of every type of citrus I was comparing from at least two grocers.

The Results

Navel Oranges. It’s expected that produce will be highly variable, and I found exactly that with conventional supermarket oranges. Some were very good, but a number of those I tried were insipid, not sweet, or dry. In addition, some of the supermarket Navel oranges were enormous—larger than I’d have liked, in fact. By contrast, the organic navel oranges were of a size I associate with being normal for this type of fruit, and all were very good to excellent. In particular, those from G and S Groves were outstanding—juicy, with a near-perfect balance of sweet and tart flavors.
Valencia Oranges. As with navel oranges, supermarket Valencias varied somewhat in quality, although I didn’t have any that were too bad. The organic Valencias from Diamond Organics were all very good. They contained a lot of juice, and the juice had good flavor.
Meyer Lemons. I could not test organic Meyer lemons against conventional Meyer lemons, because I was unable to find any Meyer lemons of any kind in local grocery stores. However, the organic Meyer lemons sent to me from Lemon Ladies Orchard were, as advertised, far less acidic than conventional supermarket lemons, with much sweeter juice and a beautiful aroma that was as welcome as a ray of sunshine on a cold winter day.
Mandarins (Satsumas, tangerines, etc.). I had never heard of sunburst tangerines before I received some from Uncle Matt’s Organic, but they were great! Sweet, a little tart, a great flavor and juicy. Likewise, the Satsumas from L’Hoste Citrus (shown in the photo at right) were a genuine treat. And, as advertised, I didn’t find many seeds in their Satsumas. I found no Satsumas locally, but most supermarket tangerines were juicy, albeit a little less sweet than the organics.

Grapefruit. Supermarket grapefruit were mostly of the Star Ruby or Ruby Red varieties. Their quality was inconsistent. Most were very good to excellent, but several lacked juiciness and/or sweetness. All organic grapefruits were excellent in quality, however; especially notable were the grapefruit from Sembra Citrus (Rio Red) and the almost-purple Red Flame variety from L’Hoste Citrus.

I was surprised by my results. Overall, I had a better experience with organic citrus than I did with conventional citrus, though I had not expected any substantial difference. Does that mean organic citrus tastes better than conventional citrus? It did in my case, but I can’t guarantee that will be true for anyone else. Matt McLean (of Uncle Matt’s) is understandably a strong promoter of organic citrus. When I related this story to him, he was very pleased but modestly added that it had probably just been a matter of luck. Factoring in weather conditions and handling practices, I suspect he’s right, as even an ideal piece of fruit can be damaged by either.

One positive aspect of organic citrus is not due to luck, however. If you look at most of the companies that supplied organic citrus for this article, you will find that the majority are run by the actual farmers who grow the citrus. They have smaller farms, usually family-run, and they work their tails off growing, packing and shipping organic citrus. Most are utterly devoted to what they do. That’s fortunate, because their businesses wouldn’t survive if their dedication was anything less than total. These are the types of companies I like to support, and the fact that they use organic (and, in some cases, biodynamic) agricultural methods makes it all just a little sweeter. I can recommend any of the companies listed below, and I hope you’ll try some organic citrus this season.

Sources & Acknowledgements
Sembra Citrus, available at


Karen Morss, Lemon Ladies Orchard
Aly Hein, Veritable Vegetable
Liz Bourret, Veritable Vegetable, “The Updated Wax Factor”
Dr. Louise Ferguson, Extension Specialist, Department of Plant Sciences, University of California at Davis
Mary Lu Arpaia, Extension Subtropical Horticulturist, University of California at Riverside
Background Statistics, Citrus: USDA Economic Research Service, 2005-2006 season,
Susan. L. Pollack, Senior Economist, USDA/ERS/Specialty Crops and Fiber Branch
P.B. Ramkrishnan, Program Director, Quality Certification Services, Gainesville, FL
Lemon Zest, by Lori Longbotham (Random House, Inc., 2002)
Matt McLean, Uncle Matt’s Organic, Inc.
The Man Who Ate Everything, Jeffrey Steingarten (Vintage Books: New York, 1997)

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