HARVEST MATURITY 
Maturity as defined by the United States Standards for Apples (85) means 
that the apples have reached the gtane of growth which will insure the proper 
completion of the ripening process. —/ Changes in the fruit after harvest are 
ripening changes, but such changes often occur on the tree and may accompany or 
follow the maturity changes. 
Haller and Magness (26) distinguished several stages of maturity in 
apples as follows: Immaturity--Apples picked immature will soften somewhat 
and may turn yellow when ripened, but the flesh is likely to be tough, the 
taste sour, the flavor lacking or undesirable, or the storage quality poor 
because of susceptibility to storage scald, bitter pit, or other disorders 
associated with immaturity. Early maturity--Apples picked at early maturity 
ripen with only fair dessert quality for the variety, but are reasonably free 
from disorders associated with immaturity during storage. The beginning of 
this maturity period is the earliest time at which picking can begin with 
satisfactory results. Optimum maturity--Apples picked at optimum maturity can 
be stored with a minimum of storage disorders and ripened with maximum dessert 
quality for the variety and conditions of growth. Late maturity--Apples picked 
at late maturity are still satisfactory for picking, but they will be somewhat 
flat in flavor and may show a slight tendency to become mealy and to develop 
disorders associated with overmaturity. Overmaturity--When allowed to remain 
on the tree until overmature, apples may ripen quickly to a mealy condition, 
may be flat in taste, or may be subject to internal breakdown or decay during 
storage. 
The following terms in the U. S. Standards for Apples (85) describe the 
varying degrees of firmness (or ripeness) of a mature apple: (Some ripening 
may occur while the fruit are still on the tree). 'Hard'’ means apples with a 
tenacious flesh and starchy flavor; ''firm'"’ means apples with a tenacious flesh 
but which are becoming crisp with a slightly starchy flavor, except the Deli- 
cious variety; "firm ripe'' means apples with crisp flesh except that the flesh 
of the apples of the Gano, Ben Davis, and Rome Beauty varieties may be slightly 
mealy; "ripe'' means apples with mealy flesh and soon to become soft for the 
variety; and "overripe'' means apples which are dead ripe, with flesh very mealy 
or soft, and past commercial utility. 
In defining maturity as the condition of mature fruit, Lott (43) said 
that maturity has no stages or degrees, 
Generally, the aspects of maturity take two forms, the physical and the 
chemical. These aspects have usually been investigated, with the prime objec- 
tive of determining when apples should be picked to have optimum storage and 
dessert qualities, 
In considering methods of determining maturity such tests as total 
soluble solids, total titratable acidity, starch content, firmness, juice 
volume, respiration, ground color, flesh color, days after full bloom, calendar 
date, ease of separation (abscission), size, and weight changes have been 
evaluated, Some of these tests have shown no promise in overall consideration 
but have been of value in specific locations where used and with certain vari- 
eties of apples. More promising tests have been implemented for more objecti- 
vity, such as firmness measurement, color, starch content, and respiration. 
1/  Underscored numbers in parentheses refer to Literature Cited, p. 15. 
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