The purpose of this study was to measure the vibration levels in commercial truck shipments in Thailand and observe the effects on packaged fruit. The study measured the vibration levels in two of the most commonly used truck types to ship packaged goods as a function of road condition and vehicle speed. The suspension type on the trailers studied was leaf-spring. The results of damage to packaged tangerine fruit as a function of location in the payload are also presented. The data presented in this study will assist product and package designers to reduce damage in transit. The results showed that vibration levels increased with speed and as a result of road condition. Analysis of variance indicated that three controlling factors, road surface, truck speed and truck type, significantly affected (p £ 0.05) peak PSD, PSD* (root mean square) over the frequency range 2-5 Hz, and fruit damage. As expected, based on previous work, an increase in truck speed resulted in an increase in vibration levels and damage to packaged fruit. The laterite road condition produced the highest vibration level for a given truck and travelling speed followed by concrete highway and asphalt road conditions. Fruit damage was found to be greatest in the uppermost container for every combination of road, truck type and travelling speed, which also corresponded to the highest vibration levels recorded. The results showed that a significant amount of damage can occur on unpaved roads (laterite), while the packages are transported from farms and harvesting areas to regional truck terminals. Damage on asphalt road conditions was minimal. This paper provides an updated history of measured and quantified levels of vibration for these specific trucks and road conditions.

Damage to fruits and vegetables continues to be a big challenge as global markets become a reality.Worldwide distribution of sensitive produce is faced with various levels of impacts from shipping and handling. Despite a variety of packaging options available today, bruising damage is commonplace for post-harvest apples throughout the supply chain. The major sources of bruising are compression, impact or vibration forces. Understanding where these forces occur can help reduce this type of mechanical damage to apples. The purpose of this study was to investigate the impact characteristics of foam net and corrugated board when applied as wrapping for individual apples. Two grades (count numbers 80 and 100) of "Fuji" cultivar apples imported to Thailand from China were studied. A simple ballistic pendulum test device was developed to measure bruise volume to impact energy relationship. A linear relationship for both types of apples was observed. Bruise volume occurrence probability and impact This is the pre-peer reviewed version of the following article: Jarimopas, B., Singh, S. P., Sayasoonthorn, S. and Singh, J. (2007), Comparison of package cushioning materials to protect post-harvest impact damage to apples. Packaging Technology and Science, 20: 315-324. doi: 10.1002/pts.760, which has been published in final form at http://onlinelibrary.wiley.com/doi/10.1002/pts.760/abstract energy relationship fitted by linear regression were created for cushioned and bare apples. Absorbed energy of various cushioning materials was also calculated under compressive forces.

No abstract

The purpose of this research was to determine the firmness of mango fruit at different stages of maturity. Immature, mature, and over mature fruit from two Thai mango cultivars (Nam Dokmai and Chok Anan) were subjected to two firmness measuring techniques: a slow compression technique using the Universal Testing Machine and a high-speed impact sensing technique using the low-mass impact tester. The firmness of a mango as determined by the compression test was expressed by the slope of the force-deformation graph, while firmness values derived from the impact test were defined by the ratio between maximum acceleration and the corresponding time (the firmness index). A very good correlation between the two indicators was obtained. Each firmness indicator of the two cultivars remained relatively unchanged from the immature through to the fully mature stage, although firmness rapidly decreased as the fruit ripened. The Chok Anan cultivar was firmer than the Nam Dokmai type throughout the development period. The impact method was able to determine mango firmness rapidly, accurately, and non-destructively.

No abstract