Postharvest Hot Water-Dip Optimization for Accelerated Khalal to Tamar Transition of Aseel Dates
DOI:
https://doi.org/10.38211/joarps.2026.07.371Keywords:
Aseel date, accelerated ripening, hot water dip, Khalal, Tamar, postharvest processing, sensory qualityAbstract
High tannin astringency limits the commercial utility of Khalal-stage Aseel dates, while traditional sun-drying to the palatable Tamar stage is highly vulnerable to monsoon-induced spoilage. To overcome this climate-biochemical bottleneck, this study optimized postharvest hot-water-dip parameters as a rapid thermal curing strategy. This intervention successfully accelerated the Khalal-to-Tamar transition, mitigating weather risks while preserving superior physicochemical and organoleptic quality. Uniform Khalal fruits were subjected to two sequential hot-water-dip experiments: different temperatures (35, 70, 90 and 100°C for 5 min) and different dipping durations at 70°C (1, 3, 5, 7 and 9 min). Treated fruits were surface-dried and sun-cured for 2-3 days until a Tamar-like stage, followed by assessment of physical attributes, moisture, total soluble solids (TSS), pH, titratable acidity (TA), TSS:TA ratio, ripening percentage and sensory quality. Increasing temperature and dipping duration accelerated ripening and dehydration. At 5 min, ripening increased from 42.0% at 35°C to 92.0% at 100°C, while moisture decreased from 30.77% to 19.37% and TSS increased from 29.07 to 34.03 °Brix. However, the best sensory quality occurred at 70°C for 5 min, with the highest overall acceptability score (4.57) despite slightly lower ripening than at 100°C. HWD duration optimization at 70°C showed a similar pattern: 9 min produced the highest ripening (93.0%) but reduced overall acceptability (3.20), whereas 5 min gave high ripening (88.0%) with the highest overall acceptability (4.67). The findings indicate that 70°C for 5 min is the most balanced HWD condition for Aseel dates because it combines strong ripening induction, Tamar-like moisture reduction and superior sensory retention. The treatment offers a simple, low-cost postharvest option for reducing losses from premature Khalal harvesting in monsoon-affected date-growing regions.
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