*3.7. Principal Component Analysis*

The averages of quality attributes of pomegranate fruit packed with no-liner, nonperforated 'Decco' and 'Zoe', micro-perforated Xtend®, and macro-perforated 2 and 4 mm HDPE liners are shown in Figures 13 and 14. Total variability was explained by five principal factors. Shipping fruit takes 42 d across the Atlantic Ocean from South Africa to Europe, which is the main export market. After 42 d of storage, the first two principal factors (F1 and F2) explained 85.8% of the total variability. Along F1 (explaining 70.9% of total variability), packaging fruit with no-liner was associated with higher weight loss, shrivelling, high respiration rate, and aril hardening by 42 d of storage. The same attributes associated with no-liner packaging had high negative values along F1 (Table 7). On the other hand, packing fruit with both non-perforated and perforated liners was associated with retaining fruit puncture resistance and peel colour attributes of *L*\*, *C*\*, and *a*\*. The same attributes associated with liner packaging had high positive values along F1 (Table 7). Along F2 (explaining 14.9% of total variability), packing fruit with no-liner, non-perforated 'Decco' and 'Zoe', and macro-perforated 2 mm HDPE were associated to facilitating fruit decay (incidence and index). Variables of decay incidence and index had high positive values along F2 (Table 7).

**Figure 13.** Principal component analysis of the first two factors (F1 and F2) due to physical and physiological attributes of pomegranate (cv. Wonderful) after 42 d of storage at 5 ◦C and 95% relative humidity (RH). W6 = 42 d. *L*\*: lightness index describes surface color in the range from 0 (black) to 100 (white); *a*\*: redness index describes surface color in the range from green (−*a*\*) to red (+*a*\*); *C*\*: chroma; HDPE: high density polyethylene.

**Figure 14.** Principal component analysis of the first two factors (F1 and F2) due to physical and physiological attributes of pomegranate (cv. Wonderful) after 84 d of storage at 5 ◦C and 95% relative humidity (RH). W12 = 84 d. *L*\*: lightness index describes surface color in the range from 0 (black) to 100 (white); *a*\*: redness index describes surface color in the range from green (−*a*\*) to red (+*a*\*); *C*\*: chroma; HDPE: high density polyethylene.


**Table 7.** Factor loadings and scores for the first two principal factors (F1 and F2) for pomegranate packed in no-liner and with different liners. HDPE: high density polyethylene.

After 84 d of storage, a clearer separation between packaging treatments was observed (Figure 14). In this case, the first two component factors (F1 and F2) explained 92.6% of

the total variability, with F1 and F2 accounting for 75.2 and 17.4%, respectively. Along F1, packaging fruit with no-liner and macro-perforated 2 and 4 mm HDPE liners was associated with facilitating fruit weight loss, shrivelling (incidence and index), respiration rate, and decay index. On the other hand, packing fruit with non-perforated 'Decco' and 'Zoe' and micro-perforated Xtend® liners was associated with retaining fruit puncture resistance and peel colour attributes of *L*\*, *C*\*, and *a*\*. Along F2, packing fruit with no-liner and non-perforated 'Decco' and 'Zoe' liners was associated with decay incidence and aril firmness (or hardness as applicable to no-liner packed fruit).
