250 FLORIDA STATE HORTICULTURAL SOCIETY, 1954

some varieties when mature. Attempts to

tabulate these whole fruit specific gravities

have given very erratic results, probably be

cause of the variations in size of the seed cav

ity. The low specific gravity is due to air be

tween the cells of the fruit. When the air

was removed by evacuation, the specific grav

ity was more than 1.0. Measuring the specific

gravity of a section of pulp was not satisfac

tory since the pulp expanded when cut.

Pressure testing, such as is used with

peaches and some other fruits showed very

little difference between freshly picked avo

cados whether mature or immature.

Conclusions

At present, no physical or chemical test can

be recommended as a measure of maturity for

Florida avocados. The best maturity stand

ard appears to be dates of picking which have

been correlated with palatability and appear

ance of the ripened fruit.

LITERATURE CITED

1. Bulletin 259, "Changes in Composition of Florida Avocados in Relation to Maturity," by Arthur L. Stahl, Agri. Exp. Sta., Gainesville.

2. Bulletin, Calif. Dept. of Agri., Vol. XXXVI No. 1

(1947), p. 20.

3. Mimeographed Report — "Tentative Method Cor the Determination of Oil in Avocados," State of Calif. Dept. of Agri. Bur. of Chem. and Bur. of Fruit and Vegetable Standardization, Sacramento. ..Nov. 18, 1948.

STUDIES ON THE WEST INDIAN CHERRY, MALPIGHIA PUNICIFOLIA L.; OBSERVATION AND

DATA ON A PROMISING SELECTION

of reducing and total sugars in the juice from

this cherry (6).

Description of the Genus Malpighia

The botanical literature on the genus Mal

pighia is rather limited. It has over 30 spe

cies in tropical and subtropical America and

was named in honor of Marcello Malpighi,

Italian botanist born in 1628 (1628-1693).

Apparently some confusion has arisen in the

description of two of the species namely, M.

punicifolia and M. glabra. Similarity of botan

ical characters exists between the M. punici

folia of Limnaeus and M. glabra of Mills-

paugh, this probably being the cause of ascrib

ing the two names to the same species.

A good botanical description of M. punici

folia, L. is given by Britton and Percy (7) and

is given here for purposes of clarification. Our

West Indian cherry selections correspond

closely to this description and thus we be

lieve our species to be M. punicifolia, L.

Malpighia punicifolia, L. Sp. PI. ed. 2, 609.

1762.

M. punicifolia lancifolia Ndz. Gen. Malp.

8. 1899.

M. punicifolia vulgaris Ndz. Gen. Malp.

8. 1899.

M. punicifolia obovata Ndz. Gen. Malp.

8. 1899.

A shrub or small tree. Leaves elliptic, ob

long, or obovate or narrowly oblanceolate, 2-7

F. Arostegui, C. F. Asenjo, Ana I. Muniz

and L. Alemany

Agricultural Experiment Station

and School of Medicine

University of Puerto Rico

Field work on the West Indian Cherry,

(Malpighia punicifolia L.) was started at the

Agricultural Experiment Station in 1947. At

the Main Station in Rio Piedras, two plantings

of four-hundred trees are under study since

then. During the years 1951, 1952 and 1953,

two-hundred-thirty-eight trees were planted

at the Isabela Substation on a Coto clay soil.

The West Indian Cherry or "Acerola," as it

is commonly called in Puerto Rico, has become

a potential economic crop because of the

studies made by Asenjo and co-workers in

1945 which led to the discovery of the high

ascorbic acid content of the juice of these

cherries (1, 4). Further work done by this

group in cherries harvested at the Agricultural

Experiment Station, has confirmed their orig

inal observations (2, 3).

Santini (5) has recently reported that be

sides ascorbic and dehydroascorbic acid, the

only other acid present in appreciable amounts

in the West Indian cherry is 1-malic acid, an

acid which is not biologically active. He also

has published a method for the determination

AROSTEGUI, ASENJO, MUNIZ, ALEMANY: MALPIGHIA 251

cm. long, 0.8-4 cm. broad, obtuse or rounded

and often emarginate at the apex, acute or

cuneate at the base, glabrous when mature,

the petioles 1.5-4 mm. long; cymes sessile or

short-peduncled, the branches usually pubes

cent; sepals ovate, 2.8-3 mm. long, pubescent;

petals pink or violet, the larger ones up to 9

mm. long; drupes globose, ovoid or subglo-

bose, 1-1.6 cm. in diameter, scarlet. (M. glabra

of Millspaugh, not of Limnaeus).

Occasionally spontaneous after cultivation

in Puerto Rico for its fruit. St. Croix; St.

Thomas;—St. Martin to Trinidad, Margarita

and Curacao, northern South America. Cereza

Colorada. West Indian Cherry. Chereese.

Vitamin C in the Ripe Cherries of

Selection B-17

Among the selections under study at our

Station, number B-17 seems to be a very prom

ising one when various factors are considered

such as yield of fruit per acre, fruit size, yield

of juice per fruit and vitamin-C content of

juice.

The yield of fruit per acre can be esti

mated from the available data to range from

3.6 to 5.4 tons of cherries harvested from four-

year-old trees. The average weight of fruit

ranges from 9 to 12 gm. and the average di

ameter of this particular selection is about 1.25

inches. (See figs. 1 and 2). In table 1 are

Table 1. Averago weight of one fruit, the yield of juice of one fruit. Grid the

Vitamin C content in the juice of ripe chorries of a West Indian Cherry

Selection.

t leverage wt.; fVitamin C tvitamin (,

Sample Iden-ft Date t of one *Yicld of juicp i(Ascorbic and t(Aseortic and tification ^harvested * fruit 1/ « per fruit 2/ fde hydro as oorb ic *de h yd roas corbie

* * * facid) per 100 :acid) in squeezed * i * nnl. of juice sjuice per fruit,

firs* t ial« t m^s. 5 inps*

119

119

120

120

121

121

122

122

123

223

124

124

127

127

128

128

130

130

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

B-17

:

I

t

I

1

}

«

$

I

I

t

%

t

I

t

t

June

Aug.

Juno

Aug.

Juno

Aug.

"ay Aug.

Juno

Aug.

Juno

Aug.

Juno

Aug.

May

Aup>

May ■

Au£>

3/541

8/641 3/64 •

8/fe4*

4/64 I 3/641

°3i4; 8/fe4« 3/fe4f

8/4>41 10/t4l

4/64 t 10/641

4/t4 1

7.8

11.6

9.1

8.9

8.7

9.5

10.8

9.8

7.2

9.1

7.0

10.1

8.3

12.1

8.1

11.8

9.8

11.4

t

t

%

%

1

%

I

%

t

;

t

1

c

1

t

5.3

7.6

6.2

6.2

6.0

6.2

7.4

6.2

4.6

6.1

4.0

7.1

5.6

8.9

5.4

8.8

6.8

8.1

I

i

1

f

i

t

1

i

t

%

%

s

t

$

9

i

i

t

1375

1950

1400

2125

1400

1950

1675

2125

1450

2200

1325

2250

1400

1900

1600

1350

1600

2200

f

f

%

%

t

t

1

1

I

%

t

1

%

i

1

c

t

%

72.9

148.2

86.8

131.8

84.0

120.9

123.9

125.6

66.7

134.2

53.0

159.8

78.4

169.1

86.4

162.8

108.8

176.4

1/Average of 10 fruits. 2/ Squeezed by hc*id in a piece of oloth.

252 FLORIDA STATE HORTICULTURAL SOCIETY, 1954

Fig. 1. Two fruits of Clone B-17

recorded the yields of juice obtained by

squeezing the fruits by hand in a piece of

cloth and the vitamin-C content per 100 ml. of

juice and of juice per fruit.

Table 1 presents data on fruits of nine trees

that belong to Selection B-17. The fruits were

r .•

brought to the laboratory in polyethylene bags

placed in a freezer as soon as they were har

vested. The analyses were performed within

the following 48 hours.

Ten fruits were taken at random from each

bag. Juice from 10 fruits was obtained as in

dicated above. The content of ascorbic and

dehydroascorbic acid was determined by the

method of Roe and Oesterlin (8) using 2,4-

dinitrophenylhadrazine reagent. Both ascorbic

and dehydroascorbic acids are known to have

equal vitamin-C activity.

The B-17 selection as can be judged from

the data in Table 1 is a high yielder of juice

as well as of vitamin C per juice per fruit.

The yield of juice was as high as 73% of the

weight of the fruit, while the vitamin C per

100 ml. of juice ranged between a minimum of

1325 and a maximum of 2250 mg. It is also

interesting to note the difference in vitamin-C

content of the cherries harvested in May and

those in June and August. This should be

further investigated as climatic conditions

might be responsible for the variations ob

served.

According to the recommended dietary al

lowances of the National Research Council the

daily vitamin C for an average man has been

set at 75 mg. per day. As can be seen in the

last column of table 1, a single cherry in the

/ T:'

j

Fig. 2. Ripe fruits of Clone B-17. Notice the shape and large size of these fruits.

AROSTEGUI, ASENJO, MUNIZ, ALEMANY: MALPIGHIA 253

large majority of the cases satisfies this recom

mended dietary allowance.

Economic Importance and Commercial

Possibilities of the West Indian

Cherry Juice

Due to its perishable nature and acid taste

we do not feel that the West Indian cherry

will be considered of much value as a fresh

fruit for the market. School children are fond

of the brightly red colored cherries and every

school in the Island should have in their yards

several trees planted. Several thousands have

already been distributed by our Station.

It is as a source of natural vitamin C that

the West Indian cherry has a promising eco

nomic future. As many pediatricians are of

the opinion that baby foods should not be en

riched with synthetic products, the use of

small amounts of this juice will permit en

richment with vitamin C without having to re

sort to the use of the synthetic vitamin.

Resumen

La acerola ha tornado importancia econo-mica en los ultimos anos desde el descubrimien-to hecho en la Escuela de Medicina Tropical de la Universidad de Puerto Rico del alto con tenido de &cido ascorbico (Vitamina C) en el jugo de esta fruta.

Los estudios hechos en la Seleccion B-17 demuestran que esta reiine requisitos adecuados en cuanto a tamaiio y diametro de la fruta y en cuanto al contenido de vitamina C.

El contenido de vitamina C en el jugo de diez y ocho muestras de frutas procedentes de nueve arboles de la Selccion B-17 (dos de cada arbol) fluctuo entre 1325 y 2250 miligramos por cada 100 ml. de jugo.

El contenido de vitamina C en el jugo por fruta de las diez y ocho muestras analizadas fluctuo entre 53 y 176 miligramos. A base de estos valores, el jugo de una acerola suplira la mayoria de las veces los requisitos diarios de vitamina C para un nino o un adulto.

El alto contenido de vitamina C en el jugo de la acerola ofrece posibilidades comerciales en Puerto Rico.

Summary

Six-hundred-thirty-eight trees of "acerola,"

the West Indian Cherry (Malpighia punici folia, L.) are under study at present.

The discovery made in 1945 of the high vitamin C content in the juice of this fruit

has led to regard the "acerola" as having po

tential economic importance since the juice

can be extracted without loss of its nutritional

value.

A selection of the fruit under study at pres

ent has proved to be a high yielder of juice as well as of vitamin C. The fruit has also a

large size.

The vitamin C content in the juice of eight

een fruit samples from nine trees of this selec

tion ranged from 1325 to 2250 milligrams of

vitamin C per 100 cubic centimeters of the

juice.

The vitamin C content in the juice of a

single fruit of the analyzed samples ranged from 53 to 176 milligrams. Based on these values, the juice of one fruit of this selection will supply in most cases, the minimum daily requirement of vitamin C for a child or an adult.

An apparent relationship between certain climatic factors and the vitamin C content has been observed. Differences between values of the vitamin C content of the fruit harvested at different dates during the year are so high that the cause of these variations should be further investigated.

LITERATURE CITED

1. Asenjo, C. F. and Freire de Guzman, S. R. The

2. Asenjo, C. F. and Moscoso, Carlos G. Ascorbic acid content and other characteristics of the West Indian cherry. Food Research 15: (2) 103-106. 1950.

w3i Asenjo, c- ?., Biological vitamin C activity of the Malpighia punicifolia L. pseudo cherry. Federation Proceedings 10: (1) 158, 1951.

4. Asenjo, C!. P. The story of the West Indian cherry (Malpighia punicifolia, L.) Bol. Col. de Quim-

5. Santini, R., Jr. Identification and determination of poly basic organic acids present in West Indian cherries (Malpighia punicifolia, L.) and in three vari eties of guava (Psidium guajava). J. Agric. Univ. P. R. 37: (3) 195-198, 1952.

6. Santini, R., Jr. Determination of reducing and total sugars in West rndiari cherry (Malpighia puni-cifoha, L.) juice. J. Agric. Univ. P. R. 37: (3) 199-205, 1952.

7. Britton, N. L. and Wilson, Percy. Scientific Sur vey of Porto Rico and the Virgin Islands. New York Academy of Sciences, Vol. 5: Part 1, 442-443, 1923.

8. .Roe, Joseph H. and Oesterling, M. J. The de termination of dehydroascorbic and ascorbic acid in plant tissues by the 2,4-dinitrophenylhydrazine method. J. Biol. Chem. 152: 511-517, 1944.

254 FLORIDA STATE HORTICULTURAL SOCIETY, 1954

"Harvesting West Indian Cherries in Puerto Rico" Hamilton Wright photograph

AROSTEGUI, ASENJO, MUNIZ, ALEMANY: MALPIGHIA 255

"Handful of West Indian Cherries"

FiV ..'-.3

Hamilton Wright photograph