Agriculture Reference
In-Depth Information
Table 2.1. Tropical and subtropical fruits: Tissue of origin and description.
Fruit
Tissue of Origin
Description
Avocado
Thick exocarp, fleshy mesocarp, and endocarp thin layer near the
outer covering of the seed
Cashew apple
Pedicel
Woody achene produced on fleshy receptacle
Fig
Peduncle
Multiple accessory hole with many achenes
Litchi
Aril
Mangosteen
Aril
Bark thick and strong with sweet flesh attached to the seed
Orange
Intralocular tissue
Modified berry with well-developed endocarp
Papaya
Superior ovary
Fleshy pericarp large central cavity
Pineapple
Peduncle
Multiple accessory
Strawberry
Receptacle
Aggregated accessory, large fleshy receptacle with many small
achenes external
Tomato
Intralocular placenta
Seeds embedded in juicy pulp
Watermelon
Inferior ovary
Modified berry carpel wall well developed, including some of the
receptacle tissue
Passion fruit
Thick pericarp, brittle
Source: Pantastico (1984); Wills (1999).
factors. Moreover, the differences in fruit types and diver-
sity of fruit tissues lead to very different ripening behavior
among fruits, and both the growing region and the environ-
mental conditions of each region significantly affect fruit
quality at the time of harvest and their postharvest response
to handling.
physico-chemical attributes, flavor, aroma, sensitivity to
microbial spoilage, chilling injury, and mechanical dam-
ages. In addition, geographical location, climate conditions,
cultural practices, and other factors can increase these dif-
ferences greatly.
Quality attributes
Quality attributes of fruits vary throughout development,
and while some fruits are primarily consumed ripened,
others are sold and used in an unripe state, such as some
fruits that are consumed as vegetables (cucumbers); fur-
thermore, some of them are consumed in both ripe and
unripe states (tomato, papaya, mango, and others).
The primary quality attributes of food products are color,
appearance, texture, flavor, and nutritional value (Garcia
and Barret, 2010). Those attributes change during process-
ing, to an extent which is dependent on the preparation
procedures and conditions. Fresh-cut fruits processes are
very light, with the aim to preserve fresh-like character-
istics of the whole fruits, while conventional processing
includes heat treatments for enzyme inactivation and mi-
crobial control, which causes significant changes in most
quality attributes of the fruit.
Among these quality attributes, color is very important
for consumer acceptance and preferences. It is used as ma-
turity stage indicator for many fruits to determine the har-
vest time, when to process, or when the fruit is ready to
eat, since in many cases, external and internal colors are
Fruit composition
Water is one of the major components of fresh fruits, rang-
ing from 85% to 95% in most of them. Their high level of
water is responsible for their high metabolic activity, which
makes fruits very perishable and negatively affects fruit
sensitivity to mechanical damages throughout postharvest
operations. Therefore, careful handling must be given to re-
duce damages and losses and minimize the quality changes
once the product is harvested.
Fruits are good sources of carbohydrates, proteins, and
energy as well as essential vitamins, minerals, and di-
etary fiber. They are rich in calcium, phosphorus, iron,
and magnesium, vitamin A (
-carotenes), vitamin B (thi-
amine, riboflavin, folic acid), and vitamin C (ascorbic acid)
(Salunkhe and Kadam, 1995).
β
Cultivar differences
For each fruit, typically there are several commercial cul-
tivars, which may include one or several native materials.
The quality attributes of the fruits from different cultivars
can vary significantly not only in appearance but also in
 
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