3.2.4. Fruit Shrivelling

The effect of liner packaging on fruit shrivelling is summarised in Figure 10A,B. Fruit shrivelling results from moisture loss and subsequent loss in cell turgor pressure [47]. In pomegranates, shrivelling is expected after a 5% loss in fruit weight [38]. Fruit shrivelling was evident at 42 d of cold storage after 5.1% loss in weight for fruit packed with no-liner, with 86.1% incidences of shrivelling (Figure 10A). At 56 d of cold storage, shrivel incidence increased to 100% for fruit packed with no-liner. However, there was no incidences of fruit shrivelling observed for fruit packed with non-perforated 'Decco' and 'Zoe' liners throughout 84 d of storage. Slight shrivelling was observed especially at the crown area

for fruit packed with micro-perforated Xtend® and 2 mm macro-perforated HDPE liners after 84 d of storage, with a shrivel incidence of 83.3 and 85.7%, respectively. However, shrivelling started at 56 d for fruit packed with 4 mm macro-perforated HDPE liners with an incidence of 72.7%.

**Figure 10.** Percentage of total shrivelled fruit (shrivel incidence) (**A**) and shrivel index (incidence) (**B**) observed on pomegranate fruit stored for 84 d at 5 ◦C and 90% relative humidity (RH). HDPE: high density polyethylene.

The severity of fruit shrivelling (shrivel index) increased with storage time (Figure 10B). At 84 d of storage, fruit packed with no-liner were severely shrivelled with a shrivelling index of 4.3 (86.0%) compared to cases of extreme shrivelling with an index of 5 (100%). However, fruit packed with micro-perforated Xtend® and 2 mm macro-perforated HDPE liners were tracely shrivelled with shrivel index of 1.6 (31.1%) and 1.2 (24.3%), respectively. Fruit packed with 4 mm macro-perforated HDPE liners were slightly shrivelled, having a shrivel index of 2.1 (42.0%). The high shrivel incidence and index in fruit packed with

no-liner is attributed to excessive moisture loss during storage. Plastic liners, due to their barrier ability, maintain high relative humidity around the fruit, minimising moisture loss and subsequent shrivelling. Wiley et al. [41] did not observe shrivelling in kiwifruit packed in non-perforated and macro-perforated liners, but reported shrivelling for fruit packed with micro-perforated liners, after 119 d storage at 0 ◦C.
