Fresh Oranges

An orange lot is a quantity of fruit of a declared cultivar group, destined for one of two fates decided before harvest. Fresh-market fruit is picked with care, packed by size and count, and sold on the appearance of its rind. Processing fruit can be harvested faster and rougher, arrives at the plant in bulk, and is valued on juice yield and soluble-solids-to-acid ratio — nothing that happens to its skin matters, because the skin becomes a by-product.

Cultivar groups differ in ways the trade takes seriously: navel oranges are prized fresh but their juice develops bitterness on standing, while Valencia-type oranges are the classic juicing fruit with a longer hanging season. Blood oranges form a separate specialty stream. A buyer specifying "oranges" without specifying the group has not specified much.

Oranges hold on the tree well, which gives citrus growers a scheduling flexibility that most fresh-fruit growers lack: the fruit can be left hanging and picked to meet demand over an extended window. That flexibility has limits — fruit left too long loses acidity, can regreen in some climates, and becomes more prone to drop and to rind disorders.

Fresh-market fruit is clipped rather than pulled where the stem would otherwise tear the rind, because a torn button is an open door for decay. Harvest maturity is established by legal or contractual minimum standards based on juice content and the ratio of soluble solids to acid, and these standards are jurisdictional. Rind colour requirements, where they exist, are commercial and are met in some markets by degreening with ethylene — a colour treatment applied to a non-climacteric fruit, which does not ripen it.

Oranges are cooled after harvest and shipped refrigerated, but unlike apples they cannot simply be pushed to the lowest temperature available: citrus is moderately chilling-sensitive, and holding below its tolerance produces rind pitting and other chilling injuries that appear as the fruit warms. The tolerance varies with cultivar, growing region, and season, so citrus storage regimes are set with more care than the fruit's robustness suggests.

The rind is both the fruit's armour and its weak point. It resists handling far better than a berry or a stone fruit, giving oranges a comparatively long marketable life, but any wound in it invites the green and blue moulds that dominate citrus post-harvest decay. Fruit is therefore handled to avoid rind injury, and packhouses apply washing, waxing, and regulated fungicidal treatments whose permitted use differs by market.

Fresh-market grading works on the individual fruit: size and count, rind colour and smoothness, shape, firmness, and freedom from blemishes and decay. Processing fruit is assessed on entirely different terms — juice yield, soluble solids, acidity, and their ratio — measured on samples from the delivered bulk. The same orchard can supply both, with the packhouse cull becoming the juice plant's feedstock.

• Green and blue mould — the principal post-harvest decay, entering through rind wounds
• Rind pitting from chilling injury, appearing after transfer to warmer conditions
• Oleocellosis — rind oil spotting caused by handling turgid fruit
• Stem-end rind breakdown and button decay
• Regreening and uneven colour in some growing climates
• Granulation and drying of segments in fruit held too long

A very large share of the world orange crop is juiced rather than eaten whole, which makes orange juice the commodity's primary product rather than a sideline. Extraction leaves the peel, rag, and seeds behind in quantity, and this residue — citrus peel — is a genuine by-product with established feed and ingredient outlets rather than a disposal problem. The remaining fruit is sold fresh.

• Beverage — juice extraction, the largest single outlet for the crop
• Food — whole fresh fruit for eating
• Feed and industrial — peel and processing residues recovered as by-products