USDA Strawberry Recommendations

April 13, 2004

USDA Handbook 66 Handling Recommendations

Fresh strawberries are highly perishable and cannot be stored except briefly. For maximum life, perhaps of 5-7 days, fruit should be precooled immediately after harvest and placed at 0°C. The temperature of harvested strawberries in the field can get up to 30°, and higher when exposed to sun; and when fruits are allowed to remain at this temperature for 4 hours, marketability drops by at least 40 percent (634). Precooling of whole pallets by forced air is recommended because the desired temperature (1°) can be obtained with in 1 hour, whereas air cooling takes 9 hours (790). After a few days in storage, the fruit loses some of its fresh bright color, tends to shrivel, and deteriorates in flavor. Deterioration is arrested by low temperature; but after removal from storage, it proceeds more rapidly than in freshly picked strawberries (755). The major diseases causing storage losses in strawberries are gray mold rot, rhizopus rot, and leather rot. Prompt precooling to temperatures of 5° or below and holding at such temperatures in transit, storage, and during marketing will minimize such losses (367, 600, 634, 755, 894).


Refrigeration is sometimes supplemented with carbon dioxide gas from dry ice to modify the atmosphere during transit or storage. In air transport, pallets are covered with curtain coated fiberboard or heat-shrink polyethylene to retain the high level of carbon dioxide (366). High levels of carbon dioxide (10 to 30 percent) slow the respiration rate of the fruit and reduce the activity of decay-causing organisms, thus extending storage and market life (178, 352, 364, 983). Carbon dioxide atmospheres of 30 percent or greater can cause off-flavor. (365).


Low-oxygen atmospheres of 0.5 to 2 percent will also reduce respiration rate and decay, but the fruit develops off-flavor (178). Postharvest chemical and heat treatments can be useful in reducing decay during storage and handling (638, 870, 944, 1010). However, surface sheen can be lost when fruit are dipped in water or solutions.


Literature Cited


(634) Mitchell, F.G., E.C. Maxie, and A.S. Greathead. 1964. Handling strawberries for fresh market. Calif. Agr. Expt. Sta. Cir. 527, 16p.


(790) Ryall, A.L. and W.T. Pentzer. 1982. Handling, transportation, and storage of fruits and vegetables. Vol. 2. Fruits and tree nuts. 2d ed. 610 p. AVI Pub. Co, Westport, CT.


(755) Redit, W.H., and A.A. Hamer. 1959. Precooling and shipping Louisiana strawberries . U.S. Dept. Agr. Market. Res. Rpt. 358, 39 p.


(367) Harvey, J.M. and W.T. Pentzer. 1960. Market diseases of grapes and other small fruits. U.S. Dept. Agr., Agr. Handb. 189, 37p.


(600) Maxie, E.C., F.G. Mitchell, and A.S. Greathead. 1959. Studies on strawberry quality. Calif. Agr. 13(2):11, 16.


(894) Sommer, N.F., R.J. Fortlage, F.G. Mitchell, and E.C. Maxie. 1973. Reduction of postharvest loses of strawberry fruits from gray mold. Jour. Amer. Soc. Hort. Sci 98:285-288.


(366) Harvey, J.M. C.M. Harris, and F.M. Porter. 1971. Air transport of California strawberries: pallet covers to maintain modified atmosphere and reduce market loses. U.S. Dept. Agr. Market. Res. Rpt. 920, 37p.


(178) Couey, H., and J. Wells. 1970. Low-oxygen or high-carbon dioxide atmospheres to control postharvest decay of strawberries. Phytopathology 60:47-49.


(352) Harris, C.M. and J.M. Harvey. 1973. Quality and decay of California strawberries stored in CO2 enriched atmospheres. Plant Dis. Rptr. 57:44-46.


(364) Harvey J.M. 1982. CO2 atmosphere for truck shipment of strawberries. In D.G. Richardson and M. Meheriuk, eds., Proc. Symp. Controlled Atmos. for Storage and Transport of Perishable Agr. Commod. Oreg. State Univ., School of Agr., Symp. Ser. No.1, p. 359-365. Timber Press, Beaverton, OR.


(983) Van Doren, A., M.B. Hoffman, and R.M. Smock. 1941. Carbon dioxide treatment of strawberries and cherries in transit and storage. Proc. Amer. Soc. Hort. Sci. 38:231-238.


(365) Harvey, J.M., H.M. Couey, C.M. Harris and F.M. Porter. 1966. Air transport of California Strawberries. U.S. Dept. Agr. Market Res. Rpt. 751, 12p.


(638) Morris, J.R., and D.L. Cawthon. 1979. Postharvest quality of machine-harvested strawberries. Jour. Amer. Soc. Hort. Sci. 104:138-141.


(870) Smith, W.L., Jr., and J.T. Worthington. 1965. Reduction of postharvest decay of strawberries with chemical and heat treatments. Plant Dis. Rptr. 49:619-623.


(944) Thompson, B.D. 1958. Postharvest chemical treatments for the control of strawberry fruit rots. Proc. Amer. Soc. Hort. Sci. 71:224-230.


(1010) Watada, A.E. 1971. Postharvest physiology of strawberry fruits treated with sodium dehydroacetate. Jour. Amer. Soc. Hort. Sci. 96:177-179.