Hot water dipping: Impact on postharvest quality, individual sugars, and bioactive compounds during storage of ‘Sonata’ strawberry

• Transpiration rate of strawberries was influenced by hot water treatment.
• Fruits dipped at 45 °C for 5 min had the highest sucrose content by the day 12.
• Antioxidant capacity was highest for strawberries hot water dipped at 45 °C.
• Hot water dips at 45 °C beyond 5 min is detrimental to the quality of strawberries.

Soluble sugars plays an important role in the ripening of strawberry fruit and whether hot water (HW) treatment has a significant impact on sugar content is yet unclear. This study investigated the impact of hot water treatment (35 and 45 °C) and dipping duration of 5 or 10 min on the physicochemical quality, individual sugars, antioxidant activity and visual quality of freshly harvested ‘Sonata’ strawberries stored in open packaging trays at 4 °C for 9 days and then transferred to 16 °C for 3 days. Hot water treatment and duration had significant impact on measured quality attributes of strawberries (p < 0.05). Hot water dip induced an initial sharp increase in transpiration rate (TR). Calculated TR for ‘Sonata’ strawberries ranged from 11.4 to 63.1 μg kg−1 s−1 across all treatments during storage. An initial decline in colour parameters chroma (61.3 ± 6.7) and hue angle (41.2 ± 5.4) was observed until day 6 and thereafter, they increased until the end of storage, across all treatments. A significant increase in total soluble solids and titratable acidity was observed. Concentration of sucrose declined sharply and significantly from 131.9 to 28.7 mmol L−1 during the storage period, followed by glucose and fructose. Percentage relative concentration decrease in sucrose, glucose and fructose was in the range of 60–78%, 10–20%, and 1–10%, respectively, at the end of storage. At the end of storage, antioxidant capacity was better retained in samples dipped at 45 °C for 5 and 10 min (14.3 and 14.5 μmol g−1 Trolox Equivalent, respectively). Overall, HW-treatment of 45 °C for 5 min had no detrimental effects and best maintained quality attributes of strawberries and prevented incidence of decay.