Natural rubber latex cushioning packaging to reduce vibration damage in guava during simulated transportation

A conventional foam net is commercially applied to protect or reduce mechanical damage of guava fruit during transportation. This study investigated the utilization of natural rubber latex foam net (NRL-FN) cushioning material to protect Guava fruit against vibration damage. NRL-FN is an eco-friendly cushioning material which was designed to enhance its biodegradability by adding bamboo leaf fiber (BLF). Different loadings of the BLF were added into the NRL-FN (0.0, 2.5 and 5.0 phr). Cushioning performance of the NRLFNs were compared with a commercial polyethylene foam net (EPE-FN) using a bare fruit as the control. The cushioning test investigated thickness, energy (E), cushion coefficient (C) and percentage transmissibility (PT) using Glom Sali guava under simulated vibration at acceleration (Grms) (8.826 m s-2), frequency (13.5 Hz), and vibration duration (40 min). Guava fruit was stored at 20 degrees C under 80% RH for 4 d to assess vibration bruising on guava peel by digital image analysis as bruise area (BA), gray scale, normalized fractal dimension difference (Delta FD/FD0), browning index (BI) and total color difference (TCD). Results showed that NRL-FN+BLF0.0 phr and NRL-FN+BLF2.5 phr (thickness of 3.2 mm) gave lower C and higher E values than that of NRL-NF+BLF5.0 phr (thickness of 3.1 mm) and EPE-FN (thickness of 5.4 mm), while NRL-FN+BL0.0 phr and EPE-FN had the lowest PT value. The NRL-FN+BLF0.0 phr, NRL-FN+BL2.5 phr and EPE produced the lowest BA (<2.5%) on guava peel followed by NRL-FN+BL0.0 phr (6-7%) and a bare fruit (control) (30-45%). No significant differences in Delta FD/FD0, BI and TCD were found among the four cushioning treatments. The NRL-FN with lower BLF composition provided greater cushioning performance against vibration bruising on guava peel with reduced thickness and lower C and PT values. Results demonstrated that NRL-FN possessed a potential for application in distribution packaging as a new cushioning material to protect against fruit mechanical vibration damages.