A study on Delicious and Granny Smith determined that the longer they are stored, the more susceptible to bruising they become. Packers notice that the fruit from certain rooms are more susceptible to bruising than others.
This can be traced back to the humidity within the room. Newer rooms are airtight and are run with a minimum number of defrost cycles to minimize moisture loss to prevent shrivel. Some methods of conditioning include increasing the number of defrost cycles, opening the doors and increasing the temperature, or placing the bins in a warm room before packing.
It is easy to remove a small amount of moisture, but difficult to ensure that all fruit in a bin are affected equally. There is no uniform method, and most packers use a number of techniques. Hyde, working with Red and Golden Delicious, found that the colder the apple, the higher the bruise susceptibility.
However, manipulating fruit moisture was more powerful than temperature. Firmness is not a good reflection of bruise susceptibility since over the course of five weeks in storage the fruit had lower firmness levels, but bruise susceptibility did not change.
After injury, the bruise will be larger if the fruit remains at a higher temperature—another reason to cool fruit rapidly after packing. Simple things like using pads to cushion drops, reducing elevation changes, and minimizing turns in the line can help reduce bruising. An instrumented pseudo-apple was developed that can precisely measure the impact forces on apples. The use of this device enabled Hyde to survey a number of Washington apple lines.
He found that, in general, damage was less when the equipment was full of fruit. The brush section can cause small bruises, and high brush speeds used for Red Delicious provided more impact than the low speeds for Goldens.
Transfer points can provide impact damage, and analysis of every drop is necessary. Definitions Bruise. This is a preview of subscription content, log in to check access. Ahmed, E.
Damaging stresses to fresh and irradiated citrus fruits. Journal of Food Science , 38 , — Google Scholar. Baritelle, A. Commodity conditioning to reduce impact bruising.
Postharvest Biology and Technology , 21 , — Blahovec, J. Bruise resistance coefficient and bruise sensitivity of apples and cherries. International Agrophysics , 13 , — Bollen, A.
Major factors causing variation in bruise susceptibility of apples Malus domestica grown in New Zealand. Brusewitz, G. Impact bruise resistance of peaches. Transactions of the American Society of Agricultural Engineers , 34 , — Chen, P.
Impact parameters related to bruise injury in apples. Donati, V. Bruise susceptibility of heat treated apples. Tips on choosing and storing fresh produce to get the most out of market season. When we go to the market, we look for the firmest and brightest colored produce we can find, tossing those with bruises and soft spots to the side. Yet after leaving the produce on the counter at home for a few days, the same dark spots develop and cause us to throw the otherwise good food away.
But why waste money by throwing out uneaten produce? Is it really spoiled and unsafe to eat? The fact of the matter is no— bruising does not indicate the produce is past its prime and has gone bad. This is why, for instance, sliced apples will remain white for a much longer time if they are first dipped in lemon juice. Coenders Parthenon Publishing Group, ; currently out of print but available in many libraries.
She fills in a few technical details "Discoloration of fruit results when an enzyme called polyphenoloxidase oxidizes the phenolic compounds that are found in the tissue of fruits.
The oxidation causes the phenolic compounds to condense into brown spots. While the tissue, or cell structure, remains intact, the enzyme and phenolic compounds are separated and so do not react with one another. It is the breaking down of the cell structure caused by the bruising that initiates the oxidation reaction and so triggers the onset of browning.
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