Blueberry quality

Quality of blueberries is determined by several characteristics that give joy to the consumer. Important characteristics of quality are appearance, colour, texture and flavour. Appearance and colour are examples of external quality parameters. Texture and flavour are examples of internal quality. The quality characteristics are influenced by variety, pre-harvest factors, harvest practices and postharvest handling. Determination of fruit quality provides an important indication of the remaining storage potential and shelf-life.

Blueberries in consumer packaging at retail. Photo by hurricanehank/

Optimal quality of blueberries

Blueberry is a very popular crop that ideally rewards its consumer by a nice crunch, followed by an explosion of a sweet and characteristic flavour. Due to its popularity, year-round supply is highly desired and is realized by world-wide production of multiple cultivars. Each cultivar will show differences in flavour, firmness/texture and ripening speed. As such, a very important blueberry quality characteristic is firmness, which besides cultivar is also influenced by ripening and dehydration. Blueberries do not develop in flavour after harvest. Disorders in texture, such as mealiness and internal breakdown, increase with harvests later in the production seasons of individual cultivars, when an increasing percentage of blueberries is very ripe. Blueberries do not ripen uniformly on the bush. As such, picked blueberry batches show variation in ripeness and thus in quality.

Some minimum requirements for good-quality blueberries are that they should be clean, intact, firm, uniform blue colour, uniform bloom, free of any foreign smell and/or taste, i.e. the fruits must be sufficiently developed, carefully handled and display satisfactory ripeness.

Quality aspects of blueberries

  1. Appearance of blueberries is an important quality trait. Photo by Fotoluminate LLC/

    General appearance

    In general, blueberries should be dark blue with uniform bloom and without scarring or (fungal) decay. Different blueberry cultivars will differ somewhat in size, colour intensity bloom and flavour, but most of them will be sold as “blueberries” without specifying cultivar. In all cases, the consumer will demand fresh-looking and appealing blueberries. The fruit are more attractive without defects such as insect damage, punctures, bruises and especially (fungal) decay.
  2. Firmness can be measured with a penetrometer. Photo by WUR


    Firmness, crunchiness, mealiness and juiciness all contribute to the consumer's final judgement. One of the most obvious texture changes during ripening is loss of firmness, which for blueberry occurs mainly prior to harvest. During transportation and storage, blueberries lose texture due to senescence and dehydration. Blueberry firmness can be determined using firmness testers, although different firmness testers are differently influenced by ripeness, dehydration and senescence. This is especially important with prolonged storage, where dehydration-related loss of firmness becomes more dominant. Different cultivars and ripening stages vary strongly in the rates at which they lose texture due to senescence and dehydration. When overripe, dehydration can make blueberries more tough, whereas senescence may cause them to become ‘mealy’ and ‘less juicy’ or develop ‘internal breakdown’ with ‘mushy’ mouthfeel. In all these cases, blueberries will lose their ‘crunch’ and their ‘explosion of flavour’.
  3. Blueberries with clear bloom. Photo by WUR

    Skin colour

    Blueberries can range in colour from green to purple to deep dark blue, almost black. Unripe blueberries are green, less ripe blueberries are purple or light blue, fully ripe blueberries are dark blue and overripe blueberries are deep dark blue. Blueberry colour is strongly dependent on cultivar, ripeness at harvest and their bloom. Bloom is the white sheen on the blueberry caused by a layer of natural skin waxes that protect the berry from dehydration. Storage and handling will reduce the bloom.
  4. Tasting blueberries. Photo by serhii.suravikin/


    Flavour is an important characteristic of fruit quality as it is what makes consumers buy more of the fruit. Important attributes for blueberry flavour are sweetness, acidity, aroma and the ratio between sugars and acids. Blueberry flavour differs strongly based on cultivar and ripeness and can differ depending on origin.
  5. Blueberries to be discarded. Photo by WUR

    Disorders and diseases

    Good blueberries do not have any defects or diseases. Scarring, bruises and skin injuries reduce appearance, increase water loss and increase susceptibility to microbial decay. Disorders are not always visible from the outside, for instance in case of mealiness or internal breakdown. Tasting samples from fruit batches generally reveals these disorders. Blueberries are also prone to fungal infections, such as Botrytis.