Using fractal image analysis for mechanical damage assessment in banana fruit

Bruise damage is one of the mechanical injury problems that could appear in fresh produce during the postharvest supply chain. Fresh horticultural produce like bananas are sensitive to inappropriate conditions during handling, transport, etc. A simulated handling experiment was conducted to assess bruising magnitude by digital image analysis on the quality of local bananas. In this study, banana fruits were impacted using a simulated impact test by dropping stainless-steel balls of 66, 98, and 110 g from a height of 0.4 m and stored for 48 h at 5, 13, and 22°C. Prior to and after the impact test and storage, banana fruits were evaluated for bruise measurements (bruise area (BA), bruise volume (BV), bruise susceptibility (BS)), color measurements (lightness (L*), yellowness (b*) and yellowness value (YV)), fractal dimension (FD) at the bruising region on peeled banana fruits, and bruise area measurements using image analysis. The fractal image analysis successfully evaluated the impact bruising intensity of banana fruits under different drop test condition (ball weights difference) and three temperature storage conditions. Bruising intensity acquired by image analysis increased as ball weight (impact damage) and storage temperature increased. The obtained results can provide the same data as manual bruise measurements did. The study recommended the use of digital image analysis which can help to detect the early formation of a bruise, therefore, reducing the mechanical damage resulting from inappropriate handling.