Artificial Ripening. In commercial han¬
dling many fruits must be picked underripe.
It is important that the fruit be brought to
the right degree of ripeness at the proper
time. Low temperatures retard ripening and
high temperatures stimulate ripening. The
humidity of the surrounding air during
storage is an important factor affecting
quality. By regulation of temperature and
humidity, quality is maintained, and ripen¬
ing changes are controlled.
Exposure to ethylene gas has been found
to hasten ripening changes in certain fruits
and vegetables. Ethylene gas is especially
effective in speeding up color changes in the
skins of citrus fruits and tomatoes so that it
is most frequently used with these fruits. In
both cases the color is an important indica¬
tion of ripeness to the consumer. Early in
the season, green oranges may be ripe as
measured by the sugar-acid content, but
would be discriminated against by con¬
sumers because of the green color. Exposure
to ethylene gas hastens the appearance of
ripe coloring of fruits by destroying the
green chlorophyll. This allows the other
colors, orange, yellow, or red, to show when
they are present. During ethylene ripening,
starch may be changed to sugar and the
sweetness of some fruits is increased. There
is no increase of total carbohydrate. In some
fruits, such as persimmons, the tannins seem
to be oxidized and the flavor of the fruit is
generally improved by this treatment. These
changes occur even in extremely dilute con¬
centrations of the gas.
Studies show only normal changes in com¬
position and nutritive value when fruit is
ripened by this method. Tomatoes ripened
on the vine are better sources of vitamins
than those picked when immature. There
are no indications that ethylene gas has any
destructive effect upon any vitamins de¬
veloped before the fruit is picked. The com¬
mercial method of ripening tomatoes in
ethylene gas produces fruits as high in nutri¬
tive value as tomatoes picked green and
ripened at home in the sun. Ethylene ripen¬
ing is a quick method, inexpensive, and easy
to use.
Spoilage. After fruit is fully matured, rip¬
ening changes are retarded, continue slowly,
and the quality deteriorates. The sugars are
broken down as a result of the continuing
action of the enzymes present, with a loss of
both food value and flavor.
Under abnormal conditions spoilage may
take place before fruit is ripe. If the fruit
has not been properly sprayed, it may be in¬
fected with eggs from insects which develop
as worms in the fruit. If the tissues of the fruit
are injured by bruising, they break down,
and release enzymes that cause abnormal
changes. In either case, the normal processes
of ripening do not take place, undesirable
changes occur, and the fruit spoils. These
decay changes are brought about by enzymes.
But in these cases the fruit enzymes are sup¬
plemented by those produced and secreted
[48]
in the fruit by organisms growing there —
worms, bacteria, yeasts, and molds.
DIGESTIBILITY AND PLACE IN DIET
Fully ripened fruit is palatable and easily
digested when eaten raw. The digestibility
of unripe fruit and of fruits containing large
amounts of cellulose and starch is improved
by cooking.
When fruits are components of an ordi¬
nary mixed diet, they show a high percentage
of utilization. In diets composed largely of
fruit or of fruits and other vegetable foods,
the nutrients are less well absorbed.
Page 44
Presented as published in 1935. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
Artificial Ripening. In commercial han¬ dling many fruits must be picked underripe. It is important that the fruit be brought to the right degree of ripeness at the proper time. Low temperatures retard ripening and high temperatures stimulate ripening. The humidity of the surrounding air during storage is an important factor affecting quality. By regulation of temperature and humidity, quality is maintained, and ripen¬ ing changes are controlled.
Exposure to ethylene gas has been found to hasten ripening changes in certain fruits and vegetables. Ethylene gas is especially effective in speeding up color changes in the skins of citrus fruits and tomatoes so that it is most frequently used with these fruits. In both cases the color is an important indica¬ tion of ripeness to the consumer. Early in the season, green oranges may be ripe as measured by the sugar-acid content, but would be discriminated against by con¬ sumers because of the green color. Exposure to ethylene gas hastens the appearance of
ripe coloring of fruits by destroying the green chlorophyll. This allows the other colors, orange, yellow, or red, to show when they are present. During ethylene ripening, starch may be changed to sugar and the sweetness of some fruits is increased. There is no increase of total carbohydrate. In some fruits, such as persimmons, the tannins seem to be oxidized and the flavor of the fruit is generally improved by this treatment. These changes occur even in extremely dilute con¬ centrations of the gas.
Studies show only normal changes in com¬ position and nutritive value when fruit is ripened by this method. Tomatoes ripened on the vine are better sources of vitamins than those picked when immature. There are no indications that ethylene gas has any destructive effect upon any vitamins de¬ veloped before the fruit is picked. The com¬ mercial method of ripening tomatoes in ethylene gas produces fruits as high in nutri¬ tive value as tomatoes picked green and ripened at home in the sun. Ethylene ripen¬ ing is a quick method, inexpensive, and easy to use.
Spoilage. After fruit is fully matured, rip¬ ening changes are retarded, continue slowly, and the quality deteriorates. The sugars are broken down as a result of the continuing action of the enzymes present, with a loss of both food value and flavor.
Under abnormal conditions spoilage may take place before fruit is ripe. If the fruit has not been properly sprayed, it may be in¬ fected with eggs from insects which develop as worms in the fruit. If the tissues of the fruit are injured by bruising, they break down, and release enzymes that cause abnormal changes. In either case, the normal processes of ripening do not take place, undesirable changes occur, and the fruit spoils. These decay changes are brought about by enzymes. But in these cases the fruit enzymes are sup¬ plemented by those produced and secreted
[48]
in the fruit by organisms growing there — worms, bacteria, yeasts, and molds.
DIGESTIBILITY AND PLACE IN DIET
Fully ripened fruit is palatable and easily digested when eaten raw. The digestibility of unripe fruit and of fruits containing large amounts of cellulose and starch is improved by cooking.
When fruits are components of an ordi¬ nary mixed diet, they show a high percentage of utilization. In diets composed largely of fruit or of fruits and other vegetable foods, the nutrients are less well absorbed.