Citrus Glossary
Key terms for understanding pomelos, citrus cultivation, nutrition, and the industry.
A
- Albedo
- The white, spongy inner layer of citrus peel, also called the pith or mesocarp. In pomelos, the albedo is exceptionally thick — often over an inch — and is sometimes candied or used in cooking.
B
- Brix
- A measurement of sugar content in fruit juice, expressed in degrees. Higher Brix values indicate sweeter fruit; pomelos typically measure between 9 and 13 degrees Brix depending on the variety.
C
- Citron
- One of the three ancestral citrus species (Citrus medica), along with pomelo and mandarin. Citrons have very thick rinds and are mainly valued for their peel rather than their juice.
- Citrus maxima
- The botanical name for the pomelo, reflecting its status as the largest citrus fruit. Previously classified as Citrus grandis, the name maxima is now the accepted scientific nomenclature. See also: What Is a Pomelo?
- Cultivar
- A plant variety that has been produced through selective breeding and is maintained through cultivation. Popular pomelo cultivars include Chandler, Tahitian, and Honey pomelo.
- CYP3A4
- A liver enzyme responsible for metabolizing many common medications. Pomelos contain furanocoumarins that inhibit CYP3A4, which can cause dangerously elevated drug levels in the body. See also: Pomelo Drug Interactions.
E
- Essential oils
- Volatile, aromatic compounds found in the oil glands of citrus peel. Pomelo essential oils contribute to the fruit's distinctive fragrance and have applications in aromatherapy, cleaning products, and cuisine.
- Exocarp
- The outermost layer of the fruit peel, also called the flavedo. In pomelos, the exocarp is the thin, colored skin that contains essential oil glands and can be zested for cooking.
F
- Flavedo
- The colored outer portion of the citrus peel, containing oil glands and pigments. The flavedo is where the zest comes from and is responsible for the pomelo's yellow-green exterior color.
- Flavonoids
- A class of plant compounds with antioxidant properties found abundantly in citrus. Pomelos are particularly rich in the flavonoids naringenin, hesperidin, and various polymethoxylated flavones. See also: Pomelo Health Benefits.
- Furanocoumarins
- Naturally occurring chemical compounds in certain citrus fruits, including pomelo and grapefruit, that inhibit drug-metabolizing enzymes. They are the reason pomelo can interact with many prescription medications. See also: Pomelo Drug Interactions.
G
- Graft / Grafting
- A horticultural technique where a cutting (scion) from one plant is joined to the rootstock of another. Most commercial pomelo trees are grafted to combine desirable fruit characteristics with robust root systems. See also: Growing Guides.
H
- Hesperidin
- A bioflavonoid found in citrus peels and membranes, including pomelo. Hesperidin has been studied for its potential anti-inflammatory and blood vessel-protective properties.
- Hybrid
- A plant produced by crossing two different species or varieties. Many popular citrus fruits — including grapefruit, oranges, and lemons — are hybrids that contain pomelo in their genetic ancestry.
J
- Juice vesicles
- The individual, elongated sac-like structures within each citrus segment that contain the juice. Pomelo vesicles are large and easily separated, giving the flesh its characteristic easy-to-pull-apart texture.
L
- Lycopene
- A red-pigmented carotenoid antioxidant found in pink and red pomelo varieties. Lycopene is associated with heart health benefits and gives red-fleshed pomelos their rosy color. See also: Pomelo Health Benefits.
M
- Mandarin
- One of the three ancestral citrus species (Citrus reticulata), along with pomelo and citron. Mandarins are small, sweet, and easy to peel, and have hybridized extensively with pomelo to produce oranges and other citrus.
- Membrane
- The thin, fibrous tissue that surrounds each individual segment of a citrus fruit. Pomelo membranes are notably thicker and tougher than those of other citrus and are typically removed before eating.
- Mesocarp
- The middle layer of the fruit wall, corresponding to the pith or albedo in citrus fruits. In pomelos, the mesocarp is exceptionally thick and spongy, providing natural cushioning for the fruit.
N
- Naringenin
- A flavonoid compound found in pomelo and other citrus fruits with antioxidant and anti-inflammatory properties. It is the aglycone (sugar-free) form of naringin. See also: Pomelo Health Benefits.
- Naringin
- A flavonoid glycoside that gives citrus fruits, particularly grapefruit and pomelo, their characteristic bitter taste. Pomelos generally have lower naringin levels than grapefruit, which is why they taste less bitter.
- Navel
- A secondary, undeveloped fruit embedded in the blossom end of some citrus, creating a navel-like formation. While most commonly associated with navel oranges, navel mutations can occur in various citrus including some pomelo varieties.
P
- Peel oil
- The essential oil extracted from the outermost layer of citrus peel by cold pressing or steam distillation. Pomelo peel oil has a fresh, bright aroma and is used in perfumery, food flavoring, and household products.
- Pericarp
- The entire wall of a fruit, consisting of three layers: exocarp (flavedo), mesocarp (albedo/pith), and endocarp. In pomelos, the pericarp is remarkably thick compared to other citrus species.
- Pith
- The white, spongy tissue between the outer rind and the fruit segments, also called albedo or mesocarp. Pomelo pith is the thickest of all citrus fruits and is traditionally used in Asian cooking. See also: Recipes.
- Pomelo
- The largest citrus fruit (Citrus maxima), native to Southeast Asia. One of the three original citrus species, pomelos are prized for their sweet, mild flavor and thick, easy-to-peel rind. See also: What Is a Pomelo?
- Pummelo
- An alternate spelling of pomelo, commonly used in horticultural and scientific literature. Both "pomelo" and "pummelo" are widely accepted; "pomelo" is more common in everyday usage.
R
- Rind
- The outer covering of a citrus fruit, encompassing both the colored flavedo and the white pith. Pomelo rind is exceptionally thick and can account for 25-50% of the fruit's total weight.
- Rootstock
- The lower part of a grafted tree that provides the root system. Pomelo trees are commonly grafted onto rootstocks like trifoliate orange or rough lemon, which provide disease resistance and climate adaptability. See also: Growing Guides.
- Rutaceae
- The botanical family to which all citrus fruits belong, commonly called the rue or citrus family. It includes over 150 genera, with Citrus being the most commercially important genus.
S
- Scion
- The upper part of a grafted tree — the cutting from a desired variety that is joined to the rootstock. In pomelo production, scions from proven cultivars are grafted to ensure consistent fruit quality. See also: Growing Guides.
- Sections / Segments
- The individual wedge-shaped divisions of a citrus fruit, separated by membranes. A pomelo typically has 11-18 segments, each enclosed in a thick, papery membrane that is removed before eating.
- Shaddock
- An older English name for the pomelo, derived from Captain Shaddock, a 17th-century English sea captain who reportedly brought pomelo seeds from Southeast Asia to the Caribbean. The name is still used in some regions. See also: What Is a Pomelo?
- Species
- The basic unit of biological classification. The pomelo species (Citrus maxima) is one of the three foundational citrus species, along with citron (C. medica) and mandarin (C. reticulata).
- Subtropical
- A climate zone between the tropics and temperate regions, characterized by warm summers and mild winters. Pomelos grow best in subtropical conditions with temperatures that rarely drop below freezing. See also: Growing Guides.
V
- Variety
- A subdivision of a species that differs in some characteristics from the typical form. Common pomelo varieties include Chandler (pink flesh), Tahitian (mild and sweet), and Honey pomelo (compact and very sweet).
- Vesicles
- The small, elongated juice-filled sacs inside each citrus segment. Pomelo vesicles are notably large and firm, making the flesh easy to separate into individual pieces by hand.
Z
- Zest
- The thin, outermost colored layer of citrus peel, removed by grating or peeling. Pomelo zest contains fragrant essential oils and can be used to add citrus flavor to baked goods, dressings, and marinades. See also: Recipes.
- Zygotic
- Produced from a fertilized seed, as opposed to nucellar (clonal) seedlings. Zygotic pomelo seedlings show genetic variation from the parent tree, which is why grafting is preferred for commercial cultivation.