Alleviation of chilling injury of custard apple (Annona squamosa L.) fruits

Abstract

Experiments were conducted to study the effect of modified atmosphere packaging (MAP) on alleviation of chilling injury in custard apple (Annona squamosa L.) fruits. Three different kinds of flexible films viz., low density polyethylene (LDPE), Cryovac Opti 300 and Cryovac PD-961 of 30×25 size were used for packing the fruits. Eight fruits were packed in each film bag and these packs were further packed in ventilated CFB boxes. The boxes were stored in “Walk-in” cold rooms maintained at 8, 12 and 15 oC (85- 90% RH) respectively. Each treatment was replicated thrice. At weekly intervals the fruits stored at different temperatures were taken out from film and allowed to ripen at room temperature (RT) to study their ripening behaviour. Experiments revealed that MAP of custard apple fruits with LDPE or Cryovac PD-961 film could alleviate the chilling injury to considerable extent, besides extending the storage life. Furthermore, MAP at lower temperature could maintain the quality of the fruits for a longer duration (two weeks) when compared to non-packed fruits at RT (four days). Fruits stored at 8 oC though maintained their quality up to three weeks of storage, but lacked desirable appearance due to development of chilling injury. At 12 oC, the fruits could be kept in unripe condition up to two weeks, when the fruits were packed either in LDPE or Cryovac PD-961 film. These fruits ripened normally without CI in three days when they were shifted to RT after unpacking. However, at 15 oC the MA packed fruits ripened within the pack by two weeks of storage life when compared to one week in non-packed fruits. Hence, it can be concluded that the storage life of custard apple fruits could be extended at 12 oC without any CI by packing the fruits in LDPE or Cryovac PD-961 film.