Visual Bruise Assessment and Analysis of Mechanical Impact Measurement in Southern Highbush Blueberries

Blueberries are prone to bruise damages and the majority of the fruit destined for the fresh market is hand-harvested. The industry needs to harvest fruit mechanically to reduce harvest cost and improve production efficiency while maintaining fresh market quality. In this study the bruise susceptibility of three firm-textured and one soft-textured highbush blueberry genotypes was related with the data recorded by the berry impact recording device (BIRD) by dropping both the fruit and the BIRD sensor onto two types of contacting surfaces (hard plastic and padding material). Bruise damages were evaluated by dropping the fruit from certain heights and assessing for tissue discoloration afterwards. The drop test confirmed that a soft-textured genotype (?Scintilla??) was more susceptible to bruising (76% bruise incidence at 120 cm drop height on hard plastic surface) than the firm-textured genotypes (?Farthing?? , ?Sweetcrisp?? and selection FL 05-528) (31-68% bruise incidence under the same drop condition). The selection was proven to be a promising machine harvestable genotype in terms of the resistance to bruising. The bruise incidences were related to the impact data recorded by the sensor. Using peak acceleration alone revealed a close relationship between BIRD sensor measurements and fruit bruising incidence when the sensor and fruit were dropped on hard plastic surfaces, but a close relationship between bruise incidence and sensor measurement was not established on the padded surface. Using both the peak acceleration and velocity change, we established bruising zones for each of the four highbush genotypes. This was useful in translating the impact data recorded by the BIRD sensor into bruising probability of a blueberry genotype. The sensor and the interpretation method relating fruit damage to BIRD data enable evaluation of various padding materials and machine designs in terms of the bruise damage they produce in the blueberry fruit. ? SourceASABE, American Society of Agricultural and Biological Engineers, elibrary; the Abstract is HEREApplied Engineering in Agriculture. 30(1): 29-37. (doi: 10.13031/aea.30.10224) @2014Authors:?? Pengcheng Yu, Changying Li, Fumiomi Takeda, Gerard KrewerKeywords:?? Instrumented sphere, Blueberry, Sensor, Accelerometer, Impact, Bruising probability. ?