CHAPTER I
INTRODUCTION
A. Background of the Study
Fruit juice comes from the tissues of fruits. It can be prepared by mechanically
squeezing the fruit but nowadays ready to drink fruit juices can be easily bought in any
stores worldwide.
The researchers thought that sunlight may affect the physical qualities of fruit juices
due to the heat of sunlight.
The J Medical Association (2002) in Thailand already did a study similar to this study
but what they did was broader and the fruit juices were not exposed to sunlight. The fresh
fruit juices were analyzed in terms of their pH, osmolality, electrolyte, carbohydrate and
data were compared to the previous study of commercial fruit juices. In this study the
natural fruit juices and commercial fruit juices were exposed to sunlight and were
analyzed in terms of their color, odor and pH only.
B. Statement of the Problem
Is there a significant change in the quality of commercial and natural fruit juices
in various containers after exposure to sunlight?
1) What are the characteristics of different juice samples before and after exposure to
sunlight in terms of:
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
Color

Odor

pH
2) Is there a significant difference in the characteristics of the juice samples before
and after exposure to sunlight for each type of container?
3) Is there an interaction between the type of container and time interval of exposure
to sunlight in natural and commercial fruit juices in terms of pH changed?
C. Hypothesis of the Study
1) There is no significant difference in the characteristics of different juice
samples before and after exposure to sunlight in terms of color, odor and pH.
2) There is no significant difference in the characteristics of the juice samples
before and after exposure to sunlight for each type of container.
3) There is no interaction between type of container and time interval of
exposure to sunlight in natural and in commercial fruit juices in terms of pH
change.
D. Objectives of the Study
This study aims to:
1) Determine the effect of sunlight on the quality of commercial and natural fruit
juices after exposure to sunlight in 1 hour, 2 hours and 5 hours.
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2) Determine if there is significant change in the pH level, color, and odor of
commercial and natural fruit juices after exposure to sunlight in 1 hour, 2 hours
and 5 hours.
3) Determine if there is an interaction between type of container and time interval of
exposure to sunlight in natural and in commercial juices in terms of pH change.
4) Determine if he different containers can affect the pH level, color and odor of
commercial and natural fruit juices exposed to sunlight in 1 hour, 2 hours and 5
hours.
E. Significance of the Study
This study was done to find an answer whether sunlight has an effect on fruit
juices exposed to sunlight. This study was done for the consumers, manufacturers,
and even sellers of commercial and natural fruit juices. Additional information gained
from this study will be helpful on consumer health education. Agencies that monitor
food quality can also profit from this study by establishing new rules and regulations
on how to sell and display fruit juices. Future researchers can set this study as a point
reference.
F. Scope and Delimitations of the Study
This study used commercial and natural fruit juices. Only 4 types of
container were used for both natural and commercial fruit juices namely plastic
and glass bottle for natural fruit juices and cup and pouch container for
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commercial fruit juices. The study was limited to only 1 flavor for natural fruit
juice namely coconut juice. For commercial fruit juices in cup container apple,
orange and mango were used. For commercial fruit juices in pouch container
apple, orange, pineapple and grapes were used. The exposure time is limited to 3
different durations during the span time of 9:30 am to 2:30pm. This study made 2
replications only.
G. Definition of Terms
Color
Color refers to the fruit juice’s physical
color determined before and after exposure
to sunlight.
Commercial Fruit Juice
Commercial
fruit
juice
refers
to
the
artificially produced fruit juices
Natural Fruit Juices
Natural fruit juice refers to the fresh coconut
juice.
Odor
Odor refers to the fruit juice’s scent
determined before and after exposure to
sunlight.
pH
pH is the level of acidity or basicity of a
substance that is determined in this study.
Quality
Quality refers to the physical qualities of
the fruit juice color, texture, and odor.
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Replication
Replication is the method used in research
to produce an exact copy of your original
samples.