Influence of postharvest water loss on apple quality: The use of a sensory panel to verify destructive and non-destructive instrumental measurements of texture

• Published in: Postharvest biology and technology 2019-02, Vol.148, p.32-37
• Main Authors: Harker, F.R., Feng, J., Johnston, J.W., Gamble, J., Alavi, M., Hall, M., Chheang, S.L.
• Format: Article
• Language: English
• Subjects: Acoustic properties; Apples; Change detection; Containers; Cultivars; Dehydration; Destructive testing; Firmness; Food quality; Fruit quality; Fruits; Harvest; Mechanical properties; Sensors; Sensory evaluation; Storage; Texture; Trained panel; Water loss; Weight loss
• ISSN: 0925-5214; 1873-2356
• DOI: 10.1016/j.postharvbio.2018.10.008

•Sensory panellists tasted apples with different levels of postharvest water loss.•Texture was measured using puncture, acoustic impulse and tissue impact responses.•Acoustic impulse and tissue impact responses indicate a decline in firmness.•Sensory assessments and puncture tests indicated no change in texture.•Humans do not perceive changes in texture detected by some non-destructive tests. ‘Cripps Pink’/Pink Lady® and ‘Sciros’/Pacific Rose™ apples were stored at 0.5 °C in containers through which dry or humidified air was passed for up to 19 weeks. Sensory analysis by trained panellists was undertaken on apples that were removed from storage at a single point in time (15 or 19 weeks, respectively) so that cultivars and treatments could be directly compared. Weight loss during storage was 1.8 to 2.4 % for humidified air treatments and 5.0 to 5.7% for dry air treatments. The trained panel perceived differences between cultivars, but within cultivars there was no significant sensory difference between apples from higher and lower water loss treatments, except for juiciness which was lower for dehydrated apples. Measurements of puncture firmness were in accordance with the sensory results, suggesting that there was no effect of water loss on mechanical properties. However, non-destructive measurements (based on acoustic impulse and tissue impact responses) declined with water loss. These sensory-instrumental data along with monitoring during storage suggested that non-destructive measurements, particularly those based on acoustic impulse responses, are detecting changes in water status rather than mechanical properties of the fruit.