Modified humidity clamshells to reduce moisture loss and extend storage life of small fruits

•A modified humidity (MH) clamshell was designed to maintain quality of small fruits.•To raise RH by 3.0–5.8% in clamshells leads to 2.6-fold reduced fruit weight loss.•Quality attributes susceptible to water deficit deteriorate quickly even in RH > 90%.•MH did not induce excessive decay apart from strawberries. Water loss is one of the major causes for the food loss and waste of small fruits, both in the retail market and at the consumer level. A modified humidity (MH) one-pound (˜454 g) clamshell was designed for small fruit packaging and was compared to a typical commercial (COM) clamshell for several small fruits held in cold (0–6 °C), refrigerated shelf (10 °C) and room (19–25 °C) temperatures, typical in the industry for shipment, storage and marketing. Water loss of litchis, sweet cherries, strawberries, blueberries, Chinese bayberries, apricots, loquats and cherry tomatoes packaged in the COM clamshells was 1.2–4.5-fold more than for MH clamshells. Quality attributes of the packaged fruits were generally better maintained in the MH clamshells, especially for those attributes susceptible to water deficit, such as shriveling, desiccation-induced browning and/or drying of pedicels in cherries, calyx of strawberries, pericarp of litchis, peel shriveling of cherry tomatoes and softening of blueberries and strawberries. The modification of the internal clamshell atmosphere was minor to moderate (mostly less than 1 kPa change, with a maximum change of 3.6 kPa which is still minor for O2, but is probably not so for CO2). MH clamshells could be problematic in some cases because it is more prone to condensation especially when raising temperature from cold storage to room temperature during marketing. Overall, the MH clamshells substantively reduced water loss, maintained fresh fruit quality and extended storage life of small fruits without excessively modifying the package atmosphere and inducing decay.