Jack Fruit Introduction

 

. 2019 Jan 6;2019:4327183. doi: 10.1155/2019/4327183

Nutritional and Health Benefits of Jackfruit (Artocarpus heterophyllus Lam.): A Review

R A S N Ranasinghe ^1,✉, S D T Maduwanthi ¹, R A U J Marapana 

1. Introduction

Jackfruit is one of the commonly consumed foods in 

Sri Lanka from the ancient time. It is a nonseasonal fruit and had a major contribution to the food supply of the people and their livestock when there were short supplies of staple food grains [1, 2]. Therefore, it is referred to as poorman's food [3].

It is a monoecious tree and both male and female inflorescences are found on the same tree [4, 5]. The fertilization is by cross-pollination and the propagation is mostly through seeds. The complete fruit development process takes about three to seven months from the pollination, varying in different countries. [6].

1.1. Origin and Distribution

Jackfruit is considered to be originated in the rain forests of the Western Ghats in the Southwestern part of India, but some authors argue that Malaysia could be the possible centre of origin [7]. It is found in many parts of Asia, Africa, and South America [2, 6, 8, 9]. Jacktree grows in warm and moist regions [4, 10].

1.2. Jacktree and the Fruits

Jacktree is a medium-sized evergreen tree, and typically reaches 8-25 m in height [11]. The tree grows rapidly in early years, up to 1.5 m/year (5 ft/year) in height, slowing to about 0.5 m/year (20 in/year) as the tree reaches maturity [12]. It has a straight rough stem and a green or black bark which has a thickness of around 1.25cm, exuding milky latex [13].

The leaves are broad, elliptic, dark green in colour and alternate. They are often deeply lobed when juvenile on young shoots. Male heads are usually sessile or on short peduncles receptacles and sometimes born on the ultimate twing, while female heads are oblong ovoid receptacle [11–14].

Jackfruit has a relatively high productivity, about 25.71 t/ha [15]. The fruits are borne in the main and side branches of the tree [16]. A mature jacktree can yield from ten to two hundred fruits [17–21].

They are dicotyledonous compound fruits [22], which are oblong cylindrical in shape, and the length of the fruits ranges from 22 to 90 centimeters with the diameter 13-50 centimeters. The weight of individual fruits may vary between 2 and 20 kilo grams, and larger fruits of about 50 kilograms have been recorded [20, 23, 24].

Jackfruit has a green to yellow brown exterior rind that is composed of hexagonal, bluntly conical carpel apices that cover a thick, rubbery, and whitish to yellowish wall [11]. It is a multiple aggregate fruit which is formed by the fusion of multiple flowers in an inflorescence [16]. About 30% of the fruit weight is occupied by the flesh [8, 9, 20, 23, 24]. There are large number of bulbs inside the fruit, which have high nutritional value.

The fruit is made up of three main regions. They are

the fruit axis;

the persistent perianth;

the true fruit.

Due to the presence of laticiferous cells that produce latex, which helps to hold the fruits together, the axis and the core of the fruit are inedible.

The perianth is made up of three regions:

the bulb (the lower fleshy edible region);

the middle-fused region that forms the rind of the syncarp;

horny nonedible region commonly known as the spikes [11, 22].

The fruit colour changes from yellowish green to yellow due to the conversion of chlorophylls, anthocyanins, and carotenoids like pigments during ripening [25]. Depending on the variety, the colour of the bulb can be cream, white, light yellow, yellow, deep yellow, lemon yellow light saffron, saffron, deep saffron, or orange [8].

Jackfruit seeds are light brown, rounded, 2-3 cm in length by 1-1.5 cm in diameter [11]. They are surrounded by the flesh and enclosed in a white aril surrounding a thin brown spermoderm, which covers the fleshy white cotyledon. It has been found that these are rich in carbohydrates and proteins [16, 26].

Jackfruits in different maturity stages and jackfruit seeds are shown in the Figure 1.

Figure 1.zdifferent maturity stages and jackfruit seeds are shown in the Figure 1.

Figure 1.

(a) Jackfruit tree with the fruits of different sizes; (b) jackfruit tree with the fruits in different stages of fruiting; (c) the jackfruit with conical carpel apices; (d) raw jackfruit pieces used for curries; (e) the interior of a ripe jackfruit with the seed; (f) the ripe eatable flesh of jackfruit; and (g) the jackfruit seed (source: [6]).

There is a widespread belief that excessive consumption of jackfruit flakes can lead to certain digestive disorders. The utilization of jackfruit as a commercial crop is limited due to its wide variations in fruit quality and long seed dormancy [21].

The fruits must be utilized as early as possible when it reached the maturity as very sharp off flavours can be developed. Therefore, it is practiced to harvest the fruit when it is firm and in a semiripen condition before ripening on the tree and then store until becoming soft and fit for processing [25].