Progressive Crop Consultant May/June 2021

Internal bruise damage (% of samples in each category)
Cultivar Location 0 1 2 3 4 5
Draper Before 33.5 1 .5 21 .5 30.0 1 1 .0 2.5
After 22.5 7.5 26.5 30.0 1 1 .0 2.5
Legacy Before 47.0 1 .0 21 .5 20.5 1 3.0 2.0
After 23.5 1 .0 1 7.5 30.0 1 8.5 9.5
Table 3. Determination of internal bruise damage in machine-harvested Draper and Legacy
blueberry samples collected from packing line locations either before or after inspection
with an optical sorter. Samples were sliced through their equator and the bruised area was
assessed visually as the percentage of sliced area and converted to a value between 0 and 5
using a 5rating scale: 0= no bruise, 1= 1% to 5% bruised, 2= 6% to 10%, 3= 11% to 20%, 4=21%
to 50% and 5= greater than 50%.
Continued from Page 9
The analysis showed that at the site of
the bruise damage, the average fruit
firmness was 149 g/mm. However, at the
sites that were 90 and 180 degrees from
the impacted location, the firmness was
greater than 162 g/mm. This meant that
a lower firmness value was detected
when the damaged area was purposely
used to determine firmness, resulting
in a much higher r-value between fruit
firmness and internal bruise damage
values. Fruit that were firm at the time
of packing (e.g., >180 g/mm value using
a FirmTech II instrument) were found to
have internal bruise damage exceeding
15%. In the near future, our research
team will sort MH blueberries with
this imaging system to separate whole
unbruised and bruised blueberries and
conduct postharvest quality evaluation
for unbruised and bruised MH blueberries
to determine the shelf life of each
group with an eye toward exporting MH
blueberries to distant Asian markets. Of
course, taking this non-destructive imaging
system from the laboratory bench
to integrating it into commercial optical
sorting machines for IBD detection and
sorting is a challenge facing the machine
manufacturers.
Conclusions
More blueberries for fresh market are
being machine harvested.
Machine harvested blueberries have
more internal bruise damage.
On-going research is developing a better
understanding of what causes bruising
and working with harvest machine manufacturer
to reduce bruise damage.
New sensor technologies for blueberry
sorting could assist in reducing bruised
berries in fresh packs.
Our research has shown that to make
MH more profitable for blueberry growers,
the current OTR harvesters must
be modified to reduce impact damage
and ground loss. Cultivars with superior
machine harvestability are being
released by blueberry breeding programs,
and research must continue to develop
equipment capable of harvesting blueberries
with less bruise damage. The sorting
system on the packing line for MH
fruit must be improved with a greater
precision to eliminate fruit with severe
internal bruise damage. This would ensure
that the quality of MH blueberries
going into clamshells would be as good
as HH fruit. Blueberry growers in some
regions can then contemplate having
MH blueberries packed for export. Also,
proper training and pruning of blueberry
bushes to maintain a small crown can
increase MH efficiency. These changes
will help in making small, incremental
improvements in increasing pack-outs
and fresh quality of packed blueberries.
Finally, in order for MH blueberries to
have quality that is as good as HH fruit,
the blueberry industry needs to be willing
to make changes by growing superior
varieties, modifying how blueberry bushes
are grown and harvested, and improving
how the fruit is sorted. This will take
a concerted effort from growers, breeders,
horticulturists, engineers and supply
chain specialists. These changes could
lead to blueberry fields that look different
from what we see today, with radically
different ways of harvesting blueberries
and technological advancements for sorting
blueberries with the goal of improving
the quality of MH blueberries going
into clamshells.
In terms of harvesting and packing technology,
it is envisioned that U.S. blueberry
growers will be using robotic harvesting
systems in the field or in warehouses
with specialized automated or semi-automated
harvesting machines that will
avoid damaging berries, have better
selectivity to reduce green berries picked
and sort out over-ripe and diseased
berries in the field. In packing houses,
new non-destructive technologies are
needed that will be capable of analyzing
the blueberry fruit surface and below the
skin and sort fruit for quality (large size,
high sweetness, flavor, bloom, no bruise
damage and color). These advances will
facilitate market segmentation and high
prices as one U.S. and several European
blueberry distributors are doing already
with HH blueberries.
This research was supported in part by
the U.S. Department of Agriculture
agencies (Agricultural Research Service
(Project No. 8080-21000-028, National
Institute for Food and Agriculture
(Agreement No. : 2008-51180-19579 and
2014-51181-22471), Agricultural Marketing
Service (FY 18 Oregon Department
of Agriculture SCBG to WQY and
FY18 Washington SCBG to LWD), U.S.
Highbush Blueberry Council, Chilean
Blueberry Committee and Naturipe
Farms Blue Challenge.
Our gratitude goes to blueberry growers
and packers in Waldo, Fla.; Alma
and Homerville, Ga.; South Haven and
Grand Junction, Mich.; Kingsburg and
Stockton, Calif.; Hillsboro, Independence
and Roseburg, Ore.; and Burlington,
Prosser, Lynden and Sumas, Wash.,
and in Chile who provided much needed
in-kind support to the harvest project. A
special thanks goes to Oxbo International
Corporation which has collaborated
with the group since 2014.
Authors are employees of USDA-ARS (FT,
fumi.takeda@usda.gov) Oregon State
University (WQY, wei.yang@oregonstate.
edu), University of Georgia (CL, cyli@uga.
edu), Washington State University (LWV,
lisa.devetter@wsu.edu) and University of
Florida (SS, sasa@ufl.edu and JW, jgrw@
ufl.edu).
Mention of trade names or commercial products
in this publication is solely for the purpose
of providing specific information and does not
imply recommendation or endorsement by
the U.S. Department of Agriculture. USDA is an
equal opportunity provider and employer.
Comments about this article? We want
to hear from you. Feel free to email us at
article@jcsmarketinginc.com
10 Progressive Crop Consultant May / June 2021