Bruise Patterns of Fresh Market Apples Caused by Fruit-to-Fruit Impact

Abstract

Comprehensive understanding of bruise damage caused by apple-to-apple impacts is beneficial to design a low-impact fruit capturing mechanism for mass (shake-and-catch) harvesting, as well as to design other fruit handling devices. This study quantified the bruising severity in ‘Jazz’ apples induced by different levels of impact upon various fruit surface locations. Impact experiments were carried out to analyze bruising patterns in three zones in a fruit surface, i.e., middle/cheek-to-top/stem, middle-to-middle and middle-to-bottom/calyx. Moving fruit and stationary fruit were impacted using a pendulum-type test device, and an equivalent drop height of fruit was calculated to provide a more practical measure for designing a catching surface. In each impact zone, seven different levels of impacts were applied respectively at seven different locations on the fruit surface. Those locations were evenly distributed along the circumferential direction in each of the three zones, and moving fruit was replaced after each impact test. The United States Department of Agriculture (USDA) standard was then used to estimate percentages of fruit in the Extra Fancy Class 1 (no bruising), Extra Fancy (a bruising area diameter ≤ 12.7 mm) and Fresh Market (a bruising area diameter ≤ 19 mm) grades. Results showed that fruit bruising severity increased in a non-linear manner with increasing drop height. It was also found that there existed significant differences in fruit bruising severity between stationary and moving fruit under different fruit-to-fruit impact zones. The bottom zone showed the least bruising sensitivity, followed by the middle zone which was statistically similar to the same in the top zone. The results suggested that the free drop height need to be <3 cm to keep from fruit bruising caused by apple-to-apple impact at a negligible level for ‘Jazz’ apples.

Orchard management strategies to reduce bruises on apples in India: a review

“…For wood and concrete as target material, the minimal dropping height of apples, which caused bruises was only 1-1.3 cm (or converted into Newton meter: 0.02 N m), for cardboard 3-4 cm (0.06 N m) and for polyethylene foam 8-9 cm (0.14-0.15 N m). The minimal drop height of an apple against another apple to avoid bruising should be less than 3 cm for apples of the NZ cultivar 'Jazz' according to Fu et al (2020). These data show that the minimal dropping height, which causes bruising, is very low.…”

Early detection of slight bruises in apples by cost-efficient near-infrared imaging

“…There are two basic bruising techniques which are pendulum-based method and drop test that could be applied for various kinds of fruit [26]. The pendulum-based method involves hitting the apple with a pendulum arm [7], [9], [14], [24], [27], [28]. Therefore, the impact energy (i.e., the kinetic energy) could be adjusted by changing the releasing angle of the pendulum arm.…”

“…Early detection approaches were evaluated with apples immediately after being subjected to a bruising experiment [7], [10], and [23]. However, few studies focused on slight bruises with well-defined impact levels, partly due to no standard method currently available for assessing the severity of fruit bruising [24]. A controlled bruise was considered a slight bruise if it was difficult to recognize based on its texture and color [23].…”

Experimental analysis of specific energy with variable deformation volume under sphere oblique impact

“…The energy absorption/dissipation at impact interface between a sphere and a flat surface has been attached great importance in various applications, such as mechanical [1][2][3], agricultural [4,5], mineral [6][7][8], chemical [9], packaging [10,11] industries, etc. It has notable influences on the system stability, dynamic performance, frictional behavior, etc.…”