*3.4. Total Phenolic Content (TPC) and Total Anthocyanin Content (TAC) of Fresh and Dried Arils*

During storage of pomegranate fruit, a steady increase in both TPC (from 20.9 to 23.9 mg GAE/100 mL) and TAC (from 6.91 to 8.77 mg C3gE /100 mL) was observed (Table 3). Arendse et al. [6] reported a similar increase in TPC of pomegranate arils cv. 'Wonderful' stored at 5 ◦C, 7.5 ◦C and 10 ◦C for 5 months. Labbe et al. [45] also reported an increase in the total phenolic content of 'Chilean Chaca' pomegranate cultivar at 5 ◦C for 12 weeks.

**Table 3.** Changes in the phytochemical properties and antioxidant capacity of fresh pomegranate arils during 12 weeks of cold storage at 7 ± 0.3 ◦C, 92 ± 3% RH (w.b.).


RSA, radical scavenging activity; FRAP, ferric reducing antioxidant power; TPC, total phenolic content; TAC, total anthocyanin content; w.b. wet basis; Data presented as means ± SE in each column followed by different letters are significantly different (*p* < 0.05) according to Fisher's LSD.

Anthocyanin compounds exhibit the main characteristic red colour in pomegranate fruit [35]. Increase in anthocyanin concentration during storage could be related to the increase in biosynthesis and accumulation of anthocyanin, which is induced at lower temperatures in pomegranate fruit [46]. Results from this study agree with those reported by Arendse et al. [6], who attributed an increase in TAC in pomegranate 'Wonderful' to the continued accumulation of anthocyanins at lower temperatures during storage.

After 12 weeks of cold storage, TPC increased, albeit insignificantly, from 105.9 to 116.7 mg GAE/g DM in hot-air dried pomegranate arils, and from 135.6 to 142.7 mg GAE/g DM in freeze-dried arils. Drying methods contributed to the retention of TPC (*p* < 0.0001), as shown in Figure 3. The freeze-drying method retained approximately 18.2% more TPC than hot-air dried arils. This is in support of the study by Shishehgarha et al. [47], who reported that the freeze-drying method is a precision technology utilised to produce high-quality dried products. Additionally, the increased TPC in freeze-dried pomegranate arils could be attributed to mild fruit cell destruction during freezing and ice sublimation, which consequently enhances extraction of biochemical components [14].

The combined effect of drying method (*p* < 0.0001) and storage period (*p* < 0.003) influenced retention of TAC (Figure 4). This figure shows an increase throughout the 12-week storage period of approximately 13 and 5% in TAC of hot-air and freeze-dried pomegranate arils, respectively. A similar trend was observed in fresh arils during cold storage. However, the TAC of freeze-dried arils was higher compared to hot-air dried arils. This is in agreement with other authors who reported higher anthocyanin content in freeze-dried compared to hot-air dried blackberries [13] and blueberries [48]. The vacuum pressure combined with minimal temperature used during the freeze-drying process preserves bioactive compounds from oxidation [13,48].

**Figure 3.** Changes in the total phenolic content of pomegranate dried arils during 12 weeks of cold storage at 7 ± 0.3 ◦C, 92 ± 3% RH (w.b). HD, hot-air drying; FD, freeze-drying. D, drying methods; S, storage period (week). Different letters are significantly different (*p* < 0.05).

**Figure 4.** Changes in the total anthocyanin content of pomegranate dried arils during 12 weeks of cold storage at 7 ± 0.3 ◦C, 92 ± 3% RH (w.b). HD, hot-air drying; FD, freeze-drying. D, drying methods; S, storage period (week). Different letters are significantly different (*p* < 0.05).
