Fruit ripeness, seasonality, storage, safety, nutrition and practical signs of quality.
The lowest-calorie fresh fruits are generally those with the most water and very little fat. Reference values per 100 g include lemon ~29 calories, watermelon and lime 30, strawberries 32, cantaloupe 34, peach 39, pink/red grapefruit 42 and blackberries 43. Per-100-g figures compare energy density; realistic serving sizes still change how many calories you eat.
Among common fresh fruits, avocado is an outlier at only about 0.7 g total sugar per 100 g. Other low-sugar examples include lime (~1.7 g), lemon (~2.5 g), raspberries (4.4 g), blackberries (4.9 g), strawberries (4.9 g), watermelon (6.2 g) and pink/red grapefruit (6.9 g). Per-100-g rankings compare concentration; serving size and total nutrition still matter.
Localized brown patches inside an avocado often come from bruising, overripeness or internal tissue damage and do not automatically make the whole fruit unsafe. If the surrounding flesh looks normal, feels creamy rather than slimy and smells fresh, trim the damaged area. Mold, fermented or rancid odors and widespread breakdown are reasons to discard it.
A practical quality window for a cut avocado half is about 1-2 days in the refrigerator. Keep it at 40°F (4°C) or below and minimize air against the cut surface. Lemon or lime can slow browning; the pit only protects the area it physically covers and is not a substitute for tight packaging.
A ready-to-eat avocado should feel firm but yield slightly when you gently squeeze it in the palm of your hand. Avoid pressing with a fingertip or thumb, which can bruise the flesh. Hass usually darkens as it ripens, but other varieties remain green, so how it feels is more reliable than color alone.
Among common fresh fruits, guava provides about 2.6 g protein per 100 g, passion fruit about 2.2 g and avocado about 2.0 g. Those are high within the fruit category but low compared with beans, dairy, eggs, fish or meat, so fruit usually adds protein rather than serving as the main source.
Young jackfruit can mimic shredded-meat texture, but not its protein density: roughly 2–2.6 g/100 g versus about 20 g/100 g in raw 90/10 ground beef.
Among four common fresh berries, raspberries lead with about 6.5 g fiber per 100 g, followed by blackberries at 5.3 g. Blueberries and strawberries provide about 2.4 and 2.0 g respectively. A 150 g bowl of raspberries therefore approaches 9.8 g fiber.
Dried goji looks far more concentrated per 100 g largely because it contains very little water, while fresh blueberries are about 84% water. In realistic portions, 28 g dried goji provides about 98 calories, 3.6 g fiber and 12.8 g sugar; 150 g fresh blueberries provides about 86 calories, 3.6 g fiber and 14.9 g sugar.
Dragon fruit, or pitaya, is a relatively low-energy fresh fruit. One USDA reference provides about 57 calories, 3.1 g fiber and 9.8 g sugars per 100 g. A 200 g edible portion would therefore be roughly 114 calories, 6.2 g fiber and 19.6 g naturally occurring sugars.
Pomegranate arils provide about 83 calories, 4 g fiber and 13.7 g naturally occurring sugar per 100 g, along with about 236 mg potassium, 10 mg vitamin C and 38 mcg folate. Their polyphenols include anthocyanins and ellagitannins, while juice generally loses much of the fiber found in whole arils.
Blueberries and strawberries are both low-energy whole fruits, but they are not identical. Per 100 g, blueberries provide about 57 calories, 10 g sugar and 2.4 g fiber; strawberries provide 32 calories, 4.9 g sugar and 2 g fiber. Strawberries contain about six times as much vitamin C, while blueberries provide more vitamin K in USDA reference data.