📊 Full nutrition facts — per 100g
| Nutrient | Amount | % Daily value | Level |
|---|---|---|---|
| Calories | 94 kcal | 5% | |
| Carbohydrates | 23.6g | 8% | |
| Dietary fibre | 2.4g | 9% | |
| Sugars | 17.6g | — | |
| GI | ~54 — Low boundary | — | |
| Vitamin C | 19.2mg | 21% | |
| Vitamin B6 | 0.22mg | 13% | |
| Potassium | 382mg | 8% | |
| Magnesium | 18mg | 5% | |
| Thiamine B1 | 0.10mg | 7% | |
| Acetogenins | present — unique | — | |
| Tryptophan | present | — |
Based on Australian NRV. Source: FSANZ Australian Food Composition Database.
📈 Glycaemic index (GI)
💊 Key vitamins & minerals
✅ Health benefits
Custard apples contain annonaceous acetogenins — a class of polyketide compounds found almost exclusively in the Annona family (custard apple, soursop, pawpaw). Laboratory studies have found that specific acetogenins (particularly bullatacin and squamocin) are selectively cytotoxic to cancer cells at concentrations that do not harm normal cells, via inhibition of mitochondrial complex I (NADH ubiquinone oxidoreductase). While these are primarily cell-culture findings and the clinical significance for cancer prevention at dietary doses is not yet established, custard apple represents one of the few common foods with this unique class of compounds.
Custard apple contains tryptophan — the essential amino acid that is the precursor to serotonin (the key mood-regulating neurotransmitter) and melatonin (the sleep hormone). While tryptophan competes with other amino acids for brain entry, the combination of tryptophan with the carbohydrate content of custard apple (which increases the relative proportion of tryptophan reaching the brain) makes custard apple potentially supportive of mood and sleep. This has some biological plausibility for the traditional use of custard apple in various cultures for anxiety and sleep improvement.
A 100g serving of custard apple provides 21% of daily vitamin C and 13% of vitamin B6 — meaningful contributions at a moderate caloric cost. B6 is essential for immune function, neurotransmitter synthesis and homocysteine regulation. Combined with thiamine (B1 — neural energy metabolism) and the tryptophan content, custard apple provides a modest but genuine B vitamin contribution. The Vitamin C additionally enhances iron absorption from other foods in a meal.
Custard apple provides 382mg of potassium per 100g — the key electrolyte for blood pressure regulation via arterial relaxation and renal sodium excretion. Regular fruit consumption including potassium-rich tropical fruits is consistently associated with lower blood pressure and reduced cardiovascular disease risk in large population studies.
⚠️ Who should limit or avoid
The seeds of custard apple contain annonacin and other acetogenins in much higher concentrations than the flesh. Annonacin is a neurotoxin that accumulates in the brain and has been associated with an atypical form of Parkinson's disease (atypical parkinsonism) in populations consuming large quantities of Annona species (particularly soursop) in the French West Indies. Eating the flesh of custard apple in normal amounts is considered safe. Never consume the seeds, bark, leaves or unripe fruit in large quantities. Avoid drinking Annona leaf tea or consuming seed preparations.
Custard apple contains 17.6g of sugar per 100g — high for a fruit. Despite a GI of ~54, the caloric density and sugar content mean people with diabetes should limit serving sizes to half a fruit (approximately 75–100g flesh). The sweet, custard-like flesh makes it easy to overeat.
Custard apple is in the Annonaceae family. Some individuals with latex allergy may experience cross-reactivity. Introduce cautiously if you have known latex, banana, avocado or kiwi allergy (latex-fruit syndrome).
🛒 How to select & buy custard apple
A ripe custard apple yields gently and evenly to thumb pressure all over its surface — not just in soft patches. Rock-hard custard apples are unripe and need 3–5 days at room temperature to ripen. Completely soft or mushy areas indicate overripe sections with fermented flesh. The skin should be intact with no cracks or shrivelling. Colour varies by variety: some remain green when ripe, others develop yellow-green or brownish tones — rely on feel rather than colour.
Atemoya (Gefner variety): the most common in Australian supermarkets — a hybrid of cherimoya and sugar apple. Heart-shaped, pale green, smooth to slightly bumpy skin. Available March–September. Cherimoya: rounder, larger segments, cream-coloured flesh. Considered to have the best flavour. Sugar apple (A. squamosa): most tropical variety, knobbier surface, creamy segments that separate easily. All three are eaten the same way — halved, seeds removed, flesh scooped out.
Simply halve the fruit, scoop out the creamy white flesh with a spoon, and eat directly. Remove and discard all seeds — they are toxic and should never be swallowed. The flesh has a custard-like texture with the flavour of vanilla, pineapple and strawberry combined. Eat chilled for the best experience — refrigerate ripe fruit for 1–2 hours before eating. Works beautifully in smoothies, ice cream and desserts. The flesh browns quickly after exposure to air — serve immediately or squeeze lemon juice over it.
🧊 Storage tips & shelf life
Firm custard apples must be ripened at room temperature — never refrigerate unripe ones (cold prevents ripening and causes chilling injury). Check daily by gently pressing. When ripe all over (soft throughout), move to the refrigerator or eat immediately. Ripening time depends on initial firmness and room temperature.
Once fully ripe, custard apple can be refrigerated for 2–3 days to slow further deterioration. The cold temperature also firms the flesh slightly, making it easier to scoop and eat. Do not seal tightly — the fruit needs some air circulation. Eat chilled for the best flavour and texture experience.
Scoop ripe flesh, remove all seeds thoroughly, place in an airtight container with a squeeze of lemon juice to prevent browning, and freeze. Frozen custard apple flesh is excellent in smoothies and ice cream — the frozen texture is like a natural ice cream. Thaw partially in the fridge — do not microwave. Excellent for bulk-buying when in-season prices are lowest.
📖 About custard apple — complete guide
The custard apple encompasses several related species in the Annona genus (family Annonaceae): Annona squamosa (sugar apple, sweet sop), Annona cherimola (cherimoya), Annona reticulata (bullock's heart) and the commercially important hybrid Annona squamosa × cherimola (atemoya). All are native to the tropical Americas — South and Central America and the Caribbean — where they have been cultivated for at least 2,000–3,000 years. The Annonaceae family is one of the oldest flowering plant families, with a fossil record extending to the late Cretaceous period (approximately 65 million years ago). The Spanish and Portuguese spread Annona species globally during the 16th century, introducing them to Africa, Asia and the Pacific. Mark Twain, visiting Hawaii in 1866, described the cherimoya as 'the most delicious fruit known to men' — a quote that remains the most cited endorsement in custard apple marketing globally.
The pharmacological significance of acetogenins — the compounds that make custard apple and its Annonaceae relatives scientifically remarkable — is double-edged. On one hand, annonaceous acetogenins (particularly bullatacin and squamocin from Annona squamosa) have demonstrated potent, selective cytotoxicity against multiple cancer cell lines in laboratory studies, with mechanisms including mitochondrial complex I inhibition and induction of apoptosis. This has generated substantial research interest, with over 500 scientific papers on Annona acetogenins published. On the other hand, the same compounds — particularly annonacin in soursop (A. muricata) — have been associated with atypical parkinsonism in populations consuming large quantities of Annona products (particularly leaf teas and seeds) in the French West Indies. The practical implication: eating custard apple flesh in normal quantities is considered safe by food safety authorities globally. The seeds, leaves and bark contain much higher concentrations of acetogenins and should not be consumed.