Rehydration of Osmotically Dehydrated Okazi (Gnetum Africanum) Leaves
ABSTRACT
In this study, rehydration of osmotically dehydrated Okazi leaves was studied Okazi leaves were osmotically dehydrated in 30 % sucrose, 40 % sucrose, 30 % sucrose + 10 % NaCl and 40 % sucrose + 10 % NaCl solutions. Effects of rehydration on dry matter loss and pH were evaluated. The results showed that increase in rehydration time increased the dry matter loss and pH of the rehydration solution. The sensory scores showed that there was no significant difference (P < 0. 05) in the general acceptability of the osmotically treated and untreated samples. The results showed that osmotic dehydration reduce the drying period while increase in rehydration time increase loss in dry matters.
CHAPTER ONE
INTRODUCTION
1.1 Background to the Study
Okazi Leaves (Gnetum africanum) are prone to injury when it is stored at low temperature and also due to its perishability in nature. Its shelf-life is low unlike every other vegetable leaf and cannot be sorted or kept for a long time. The modern storage facilities like the refrigerator, freezer etc has not adequately helped in the storage and preservation of Okazi leaves (Smith, 2004).
Moreover, its bulky nature also leads to its poor portability and also leads to its increase in its cost in some seasons of the year. Therefore, there is a need to device a means that can be used to process and preserve Okazi leaves which would increase its shelf-life, reduce post harvest losses and also reduce its cost of transportation and distribution and also make it suitable for to be properly packaged as food product.(Dutta, 2000).
“Okazi (Genetum aricanum) is one of the most popular grain leafy vegetable in Nigeria and is gaining equal popularity as a delicious food leaf in other African countries such as Cameroon, Gabon, Congo and Angola (Eyo and Abel, 2001). Gnetun africanum leaves are widely consumed in the sough eastern Nigeria due to its palatability and taste. It is now eaten as a vegetable soled when mixed with palm oil. The popularity known afang soup that is often listed in many continental restaurant menu is prepared from these leaves which sometimes is cooked with water leaves (Tanicum traiagulare) to give the soup a special savour.
(Gnetum africanum) (afang) grows as a wild evergreen climbing plant in the rainforest at Nigeria where is searched for and highly priced in the regional markets. It is recently been cultivated in south Eastern Nigerian homes as exotic plants. It belongs to the family Gnetacea and the order Gnetacea (Dutta, 2000). The seed at afang is oval in shape and small in size about 0.5 cm in diameter. They are greenish in colour when unripe and reddish when ripe.
Available literature reveals that both the leaf and the seed in particular have shown medicine efficiency in the treatment of enlarged spheen, sore throats, cohecluction of pains at child-birth, antidotes to some form of poison and snake bite. The seeds are specially used as fungicide for dressing fresh and septic wounds it also chewed raw in the management of excessive urination by infantile diabetic patients in traditional medical (Smith, 2004).
The mineral element content, amino and content and proximate composition of the leaves has been reported by (Eyo and Abel, 2001). Little or no information is unavailable on the chemical composition of the seeds of G: afrianum.
This study is designed to determine the chemical composition at the seed G. Africanum for public and dietary awareness of its nutritional states.
1.2 Justification of the study
This project is an attempt to compliment the alternative means of preserving fresh okazi leaf by hygienically rehydrating an already osmotically dehydration okazi leaf.
1.3 Objectives of the Study
The objective of this study are to
- dehydrate okazi leaves using osmotic method
- rehydrate the dehydrated okazi leaves
evaluate the rehydration and sensory quality of the product.
