Oranges

Oranges: freshness and ripeness guide

Navel oranges are non-climacteric: they do not ripen, sweeten, or grow juicier after picking, so the fruit in the bin is as good as it will ever be and choosing well is the entire task — the same whether you want it for tonight or for later in the week. Pick oranges that feel heavy for their size, which is the single best clue to juiciness because a light fruit has dried out inside, and that are firm with only the slightest give and wrapped in a fine-grained, fairly smooth skin; a thick, coarse, deeply pitted rind hides more white pith and yields less flesh. Do not judge ripeness by colour. Oranges are picked already mature, the bright orange of a winter navel is often the result of cool nights or a packing-house degreening step, and a ripe orange can carry a faint green tinge or regreen to a patchy yellow-green in warm storage without any loss of quality. Light surface russeting or scattered brown flecks are skin blemishes, not spoilage; pass instead on any orange with soft or sunken spots, a wrinkled or leathery rind, or fruit that feels light and spongy.

Because a navel does not improve on the counter, one is ready to eat the moment you buy it, and the only real decision is how long you need it to keep. For oranges you will eat in the next few days, a bowl at room temperature is fine and makes them a little easier to peel. To hold them through the week and beyond, refrigerate: loose in the crisper they keep one to two weeks, and in a bag or container that slows moisture loss they hold three to four weeks, far longer than at room temperature. Navels are best eaten reasonably promptly rather than stored for months — the flesh of this variety tends to turn bitter with long holding, a trait of navel oranges in particular — so buy what you will get through in a few weeks rather than stockpiling.

An orange is past its prime when the skin wrinkles and the fruit feels light, spongy, or hollow, all signs it has dried out within, or when you find soft sunken patches, weeping or stickiness, a fermented or sharply sour smell, or white, green, or blue mould; a mouldy orange should be thrown out rather than cut around, since the rot runs through the rind and the soft flesh beneath. One that has gone only slightly soft but still smells clean and citrusy is fine for juicing even when it is past peeling and eating out of hand. In an Edmonton winter, treat oranges as the cold-sensitive imported fruit they are: an orange left in a sub-zero vehicle will freeze and thaw into a dry, bitter, collapsed fruit, so carry them indoors promptly, and over long cold storage watch for the small sunken pits and brown staining of chilling injury, which shortens their life.

Sources:

• UC Davis Postharvest Research and Extension Center — Orange: recommendations for maintaining postharvest quality (non-climacteric behaviour, optimum storage temperature and humidity, chilling injury, and degreening). https://postharvest.ucdavis.edu/produce-facts-sheets/orange
• USDA Agricultural Marketing Service — United States Standards for Grades of Oranges, California and Arizona (maturity, colour, firmness, and skin-texture grading factors). https://www.ams.usda.gov/sites/default/files/media/Orange_(CA_and_AZ)_Standard%5B1%5D.pdf
• Sunkist Growers — Navel oranges: selection, seasonality, and storage. https://sunkist.com/variety/navel-oranges/