BIOCHEMICAL CHANGES IN ORANGE FRUIT JUICE DURING STORAGE, FRESH, FROZEN AND CANNED
1.1 BACKGROUND OF THE STUDY
Fruit and fruit juices are good sources of vitamins particularly vitamin C and minerals. They are recognized as contributing to the five portions per day of fruit and vegetables currently recommended, ( Hulme, 1971).
Some fruit juice has been made from fruit juice concentrate. This concentrate comes from fresh fruit, but the water content is reduced to make storage and transport easier. They use brix and acid ratios to ensure that it meets the internationally recognized standards. Fruit juice may be defined as the liquid expelled by pressure or other mechanical means from the edible portion of the fruit.
Orange belongs to citrus species which constitute the most important species of the Rutaceae family. Orange constitutes the bulk of the global citrus fruit production. As such it is the most popular and wide spread of the citrus fruit. The sweet orange does not occur in the wild. It is believed to have been first cultivated in south –eastern, chain, north eastern India or perhaps south eastern Asia (Formerly Indochina). After adopted as an edible fruit; it was so highly regarded that wealthy persons grew oranges in private conservatories called orangeries. Certainly by 1646 it was well known in Europe.
The demands for fruits are both in domestic and international market. However, these fruits could not be exploited to the full potentials for domestic markets and international trade. It continuous supply in domestic market and as source of foreign exchange earnings is limited due to storage, which enhance disease susceptibility. Many consumers consider orange juice the best source of vitamin C in their diets. Although several foods are richer in vitamin C citrus fruits, orange juice is the most popular, Whitney and Rolfes, (1999) reported that 225ml of orange juice contains approximately 125mg of vitamin C. United States National Academy of sciences, food and Nutrition Board, (1990) reported that the recommended daily allowance of vitamin C is 30 to 100mg / day for most people.
Juice undergoes change on storage due to chemical reactions between their constituents (Hulme, 1970). The loss of nutritional quality during the processing and storage of beverage has become an increasingly important problem with the introduction of nutrition labeling regulations.
There are many studies for determining the ascorbic acid content in fruit juice but only a few aims at determining the amounts of ascorbic acid last in fruit and fruit juices during storage. Therefore the aim of the study is to determine the changes in fruit juice under different storage conditions.
1.2 STATEMENT OF THE PROBLEM
The society suffer great losses as a result of the deterioration due to improper storage of fruit juice, therefore it became imperative to assess the effect of various storing methods on the biochemical changes of orange juices.
1.3 AIMS AND OBJECTIVES
To identify the biochemical changes of fruit and fruits juice during different storage conditions.
1.4 SIGNIFICANCE OF THE STUDY
This study will provide information on biochemical changes in orange juice stored under different conditions.
1.5 SCOPE OF THE STUDY
This study will involve extraction of orange juice, storage for a period of time, followed by the assessment of biochemical changes in fresh, frozen and canned orange juice.