Strawberry

Nutrition

Nutritional value per 100 g (3.5 oz)
Energy	136 kJ (33 kcal)
Carbohydrates	7.68 g
Sugars	4.89 g
Dietary fiber	2 g
Fat	0.3 g
Protein	0.67 g
Vitamins	Quantity %DV†
Thiamine (B1)	2% 0.024 mg
Riboflavin (B2)	2% 0.022 mg
Niacin (B3)	3% 0.386 mg
Pantothenic acid (B5)	3% 0.125 mg
Vitamin B6	4% 0.047 mg
Folate (B9)	6% 24 μg
Choline	1% 5.7 mg
Vitamin C	71% 58.8 mg
Vitamin E	2% 0.29 mg
Vitamin K	2% 2.2 μg
Minerals	Quantity %DV†
Calcium	2% 16 mg
Iron	3% 0.41 mg
Magnesium	4% 13 mg
Manganese	18% 0.386 mg
Phosphorus	3% 24 mg
Potassium	3% 154 mg
Sodium	0% 1 mg
Zinc	1% 0.14 mg
Other constituents	Quantity
Water	90.95 g
Link to USDA Database entry
Units μg = micrograms • mg = milligrams IU = International units
†Percentages are roughly approximated using US recommendations for adults. Source: USDA FoodData Central

Raw strawberries are 91% water, 8% carbohydrates, 1% protein, and contain negligible fat (table). A 100 gram reference amount of strawberries supplies 33 kilocalories, is a rich source of vitamin C (71% of the Daily Value, DV), a good source of manganese (18% DV), and provides several other vitamins and dietary minerals in small amounts. Strawberries contain a modest amount of essential unsaturated fatty acids in the achene (seed) oil.[7]

Garden strawberries contain the dimeric ellagitannin agrimoniin which is an isomer of sanguiin H-6.[8][9] Other polyphenols present include flavonoids, such as anthocyanins, flavanols, flavonols and phenolic acids, such as hydroxybenzoic acid and hydroxycinnamic acid.[7] Strawberries contain fisetin and possess higher levels of this flavonoid than other fruits.[9][10] Although achenes comprise only about 1% of total fresh weight of a strawberry, they contribute 11% of the total polyphenol in the whole fruit; achene phytochemicals include ellagic acid, ellagic acid glycosides, and ellagitannins.[11]

Pelargonidin-3-glucoside is the major anthocyanin in strawberries and cyanidin-3-glucoside is found in smaller proportions. Although glucose seems to be the most common substituting sugar in strawberry anthocyanins, rutinose, arabinose, and rhamnose conjugates have been found in some strawberry cultivars.[7]

Purple minor pigments consisting of dimeric anthocyanins (flavanol-anthocyanin adducts : catechin(4α→8)pelargonidin 3-O-β-glucopyranoside, epicatechin(4α→8)pelargonidin 3-O-β-glucopyranoside, afzelechin(4α→8)pelargonidin 3-O-β-glucopyranoside and epiafzelechin(4α→8)pelargonidin 3-O-β-glucopyranoside) can also be found in strawberries.[12]

Furaneol is an important component of the fragrance of strawberries.

Sweetness, fragrance and complex flavor are favorable attributes.[13] In plant breeding and farming, emphasis is placed on sugars, acids, and volatile compounds, which improve the taste and fragrance of a ripe strawberry.[14] Although often sweet tasting, strawberries actually have relatively low sugar levels compared to other fruits. Esters, terpenes, and furans are the chemical compounds having the strongest relationships to strawberry flavor, sweetness and fragrance, with a total of 31 out of some 360 volatile compounds significantly correlated to favorable flavor and fragrance.[14][15][16] In breeding strawberries for the commercial market in the United States, the volatile compounds, methyl anthranilate and gamma-decalactone prominent in aromatic wild strawberries, are especially desired for their "sweet and fruity" aroma characteristics.[15][16]

Chemicals present in the fragrance of strawberries include:

As strawberry flavor and fragrance are characteristics that may appeal to consumers,[15][16][18] they are used widely in a variety of manufacturing, including foods, beverages, confections, perfumes and cosmetics.[19][20]

Modern strawberries are octoploid (8 sets of chromosomes).[21] The genome sequence of the garden strawberry was published in 2019.[22]

Some people experience an anaphylactoid reaction to eating strawberries.[23] The most common form of this reaction is oral allergy syndrome, but symptoms may also mimic hay fever or include dermatitis or hives, and, in severe cases, may cause breathing problems.[24] Proteomic studies indicate that the allergen may be tied to a protein for the red anthocyanin biosynthesis expressed in strawberry ripening, named Fra a1 (Fragaria allergen1).[25] Homologous proteins are found in birch pollen and apple, suggesting that people may develop cross-reactivity to all three species.

White-fruited strawberry cultivars, lacking Fra a1, may be an option for strawberry allergy sufferers. Since they lack a protein necessary for normal ripening by anthocyanin synthesis of red pigments, they do not turn the mature berries of other cultivars red.[25] They ripen but remain white, pale yellow or "golden", appearing like immature berries; this also has the advantage of making them less attractive to birds. A virtually allergen-free cultivar named 'Sofar' is available.[26][27]

Strawberries and cream

In addition to being consumed fresh, strawberries can be frozen or made into jam or preserves,[34] as well as dried and used in prepared foods, such as cereal bars.[35] Strawberries and strawberry flavorings are a popular addition to dairy products, such as strawberry milk, strawberry ice cream, strawberry milkshakes/smoothies and strawberry yogurts.

In the United Kingdom, "strawberries and cream" is a popular dessert consumed at the Wimbledon tennis tournament.[5] Strawberries and cream is also a staple snack in Mexico, usually available at ice cream parlors. In Sweden, strawberries are a traditional dessert served on Midsummer's Eve. Depending on area, strawberry pie, strawberry rhubarb pie, or strawberry shortcake are also common. In Greece, strawberries may be sprinkled with sugar and then dipped in Metaxa, a brandy, and served as a dessert. In Italy, strawberries are used for various desserts and as a common flavoring for gelato (gelato alla fragola).

Fresh strawberries are used as cocktail garnishes to add flavor and texture to a drink.

Polyphenol extracted from strawberries have been used in Kanazawa, Japan, to create melting-resistant popsicles.[36]

Top Strawberry producers
in 2021
Numbers in million tonnes
1.  China	3.38 (36.82%)
2.  United States	1.21 (13.18%)
3.  Turkey	0.67 (7.3%)
4.  Mexico	0.54 (5.88%)
5.  Egypt	0.47 (5.12%)
6.  Spain	0.36 (3.92%)
World total	9.18
Source: FAOSTAT[37]

In 2021, world production of strawberries was 9.2 million tonnes, led by China with 37% of the total and the United States and Turkey as other significant producers (table).

Due to the relatively fragile nature of the strawberry, approximately 35 percent of the $2.2 billion United States crop was spoiled in 2020. This led to an Idaho company planning to launch gene-edited strawberries in the near future in an effort to make them more durable. In the U.S. it costs growers around $35,000 per acre to plant and $35,000 per acre to harvest strawberries now, and more durable berries might reduce the rate of spoilage.[38]

For purposes of commercial production, plants are propagated from runners and, in general, distributed as either bare root plants or plugs. Cultivation follows one of two general models—annual plasticulture,[39] or a perennial system of matted rows or mounds.[40] Greenhouses produce a small amount of strawberries during the off season.[41]

The bulk of modern commercial production uses the plasticulture system. In this method, raised beds are formed each year, fumigated, and covered with plastic to prevent weed growth and erosion. Plants, usually obtained from northern nurseries, are planted through holes punched in this covering, and irrigation tubing is run underneath. Runners are removed from the plants as they appear, to encourage the plants to put most of their energy into fruit development. After harvesting, the plastic is removed and the plants are plowed into the ground.[39][42] Strawberry plants produce more and better fruit when they are young. After a year or two, they decline. Replacing them annually improves yields and enables denser planting.[39][42] However, this necessitates a longer growing season, for the plants to establish themselves. It also costs more to annually purchase plants, form new mounds, and cover them with (new) plastic.[42]

The other major method retains plants for multiple years. This is most common in colder climates. The plants are grown in rows or on mounds.[39][40] This method requires lower investment and lower maintenance, overall.[40] Yields are typically lower than in plasticulture.[40]

Another method uses a compost sock. Plants grown in compost socks have been shown to produce significantly more flavonoids, anthocyanins, fructose, glucose, sucrose, malic acid, and citric acid than fruit produced in the black plastic mulch or matted row systems.[43] Similar results in an earlier study conducted by USDA confirms how compost plays a role in the bioactive qualities of two strawberry cultivars.[44]

Strawberries may also be propagated by seed, though this is primarily a hobby activity, and is not widely practiced commercially. A few seed-propagated cultivars have been developed for home use, and research into growing from seed commercially is ongoing.[45] Seeds (achenes) are acquired either via commercial seed suppliers, or by collecting and saving them from the fruit.

Strawberries can also be grown indoors in strawberry pots.[46] Strawberries will not grow indoors in winter unless aided by a combination of blue and red LED lights.[47] In southern lands, such as Florida, winter is the natural growing season and harvesting begins in mid-November.[30]

The Kashubian strawberry (Truskawka kaszubska or Kaszëbskô malëna)[48] is the first Polish fruit to be given commercial protection under EU law. It is produced in Kartuzy, Kościerzyna and Bytów counties and in the municipalities of Przywidz, Wejherowo, Luzino, Szemud, Linia, Łęczyce and Cewice in Kashubia. Only the following varieties may be sold as kaszëbskô malëna: Senga Sengana, Elsanta, Honeoye that have been graded as Extra or Class I.

• 
  Strawberry field in North Rhine-Westphalia, Germany
• 
  A field using the plasticulture method

Most strawberry plants are now fed with artificial fertilizers, both before and after harvesting, and often before planting in plasticulture.[49]

To maintain top quality, berries are harvested at least every other day. The berries are picked with the caps still attached and with at least half an inch of stem left. Strawberries need to remain on the plant to fully ripen because they do not continue to ripen after being picked. Rotted and overripe berries are removed to minimize insect and disease problems. The berries do not get washed until just before consumption.[50]

Strawberries are usually picked and placed in shallow boxes in the field.

Soil test information and plant analysis results are used to determine fertility practices. Nitrogen fertilizer is needed at the beginning of every planting year. There are normally adequate levels of phosphorus and potash when fields have been fertilized for top yields. To provide more organic matter, a cover crop of wheat or rye is planted in the winter before planting the strawberries. Strawberries prefer a pH from 5.5 to 6.5, so lime is usually not applied.[51]

The harvesting and cleaning process has not changed substantially over time. The delicate strawberries are still harvested by hand.[52] Grading and packing often occurs in the field, rather than in a processing facility.[52] In large operations, strawberries are cleaned by means of water streams and shaking conveyor belts.

Organic gardener holding a large June-bearing strawberry

Strawberries are popular in home gardens, and numerous cultivars have been selected for consumption and for exhibition purposes.[53] The following cultivars have gained the Royal Horticultural Society's Award of Garden Merit:

Fresh strawberries being sold in plastic containers

In the United States in 2017, the collective commercial production of strawberries, blueberries, raspberries, and blackberries was a $6 billion industry dominated by the California growing and marketing company Driscoll's.[15] In 2017, strawberries alone were a $3.5 billion market of which 82% was for fresh fruit.[60]

To increase consumer demand in the 21st century, commercial producers of strawberries cultivated them mainly for favorable aroma characteristics similar to those of wild strawberries,[16] in addition to having large size, heart-shape, glossy red exterior, firmness, and slow ripening for long shelf-life favorable to ship by ground transportation from farms to stores nationwide for consumption within two weeks of harvest.[15] In US and Canadian grocery stores, fresh strawberries are typically sold in plastic clamshells, and are among the top fresh produce items in grocery revenues.[15] One marketing analysis identified strawberries and other berries as a source of "happiness" for consumers.[15]

Around 200 species of pests are known to attack strawberries both directly and indirectly.[61] These pests include slugs, moths, fruit flies, chafers, strawberry root weevils, strawberry thrips, strawberry sap beetles, strawberry crown moth, mites, aphids, and others.[61][62] The caterpillars of a number of species of Lepidoptera feed on strawberry plants. For example, the ghost moth is known to be a pest of the strawberry plant.

The strawberry aphid, Chaetosiphon fragaefolii, is a bug species found in the United States (Arizona), Argentina and Chile. It is a vector of the strawberry mild yellow-edge virus.

The amounts of pesticides required for industrial production of strawberries (300 pounds (140 kg) in California per acre) have led to the strawberry leading the list of EWG's "Dirty Dozen" of pesticide-contaminated produce.[63]

Strawberry plants can fall victim to a number of diseases, especially when subjected to stress.[64][65] The leaves may be infected by powdery mildew, leaf spot (caused by the fungus Sphaerella fragariae), leaf blight (caused by the fungus Phomopsis obscurans), and by a variety of slime molds.[64] The crown and roots may fall victim to red stele, verticillium wilt, black root rot, and nematodes.[64] The fruits are subject to damage from gray mold (Botrytis cinerea), rhizopus rot, and leather rot.[64] To prevent root-rotting, strawberries should be planted every four to five years in a new bed, at a different site.[66]

The NPR1 gene from Arabidopsis thaliana, AtNPR1, confers A. thaliana's broad-spectrum resistance when transexpressed in F. ananassa.[67] This resistance includes resistance to anthracnose, powdery mildew, and angular leaf spot.[67]

A 1997 study assessed many wound volatiles and found all effective against gray mold (B. cinerea).[68] Both Tribute and Chandler were tested and benefited from the treatments, although there are large differences between the substance x variety effects.[68] Strawberry metabolizes these volatiles, and does so more rapidly than either blackberry or grape.[68]

The plants can also develop disease from temperature extremes during winter.[64] Watering strawberry roots, and not the leaves, is preferred as moisture on leaves encourages fungal growth.[69] Strawberries may also often appear conjoined together or deformed due to poor pollination.[70]