Thesis Abstract

Abstract
Avocado pear seeds are known to contain a significant amount of oil, making them a potential source of valuable oil for various applications. The extraction of oil from avocado pear seeds can be influenced by the type of solvent used in the extraction process. This study aimed to investigate the effect of different solvent types on the yield of oil extracted from avocado pear seeds. The experiment involved the use of three different solvents hexane, ethanol, and water. Each solvent was used separately for the extraction process, and the oil yield was determined for each extraction. The results showed that the choice of solvent had a significant impact on the oil yield from avocado pear seeds. Hexane extraction yielded the highest oil content, followed by ethanol, while water extraction resulted in the lowest oil yield. The differences in oil yield among the solvent types can be attributed to the solubility of oil in the solvents and the ability of the solvents to penetrate the seed matrix. Hexane, being a non-polar solvent, was able to effectively dissolve the oil present in the seeds, resulting in a higher yield. Ethanol, a polar solvent, also showed good extraction efficiency, although slightly lower than that of hexane. Water, being a polar solvent with limited ability to dissolve non-polar compounds, extracted the least amount of oil from the avocado pear seeds. These findings highlight the importance of solvent selection in the extraction of oil from avocado pear seeds. Depending on the desired yield and the intended application of the extracted oil, the choice of solvent can significantly impact the efficiency of the extraction process. Hexane and ethanol are suitable solvents for high oil yield, while water may be more appropriate for specific applications where a lower oil yield is acceptable. In conclusion, the type of solvent used in the extraction process plays a crucial role in determining the yield of oil from avocado pear seeds. Understanding the solubility properties of different solvents and their interaction with the seed matrix is essential for optimizing the extraction process and obtaining a high oil yield. Further research can explore additional solvents and extraction techniques to enhance the efficiency of oil extraction from avocado pear seeds for various industrial and commercial applications.

Thesis Overview

INTRODUCTION
1.1 BACKGROUND OF THE STUDY

Vegetables and fruits are essential foods in our diet and also have many compounds that are beneficial for health due to minor components which include phenolic substances (Francisco et al., 2012). The consumption of the tropical-subtropical fruit, avocado, has increased considerably in the last century throughout Nigeria. There seems to be potential for further increases in consumption in the future (Manuela, 2011).Nowadays, great importance has been attached to oils from fruits and seeds, this is because of their numerous functions and uses to mankind. Fats and oils from seeds act as insulators to the body. They serve as protective layer or covering for the internal organs such as heart and lung. They also serve as sources of energy to the body in the absence of carbohydrates (Akpabio et al., 2011).

Persea americana, commonly known as Avocado, is a fruit that contains a high value of oil and chlorophyll concentration which when extracted results to an oil of emerald green color (Genevive et al., 2013). The avocado fruit is rich in nutrients, high in proteins, antioxidants and dietary fiber is perhaps the most poorly conceived and misunderstood fruit of all times. This is mainly attributed to its high fat and calorie content and so most nutritionists and dieticians either advise against it or to use it “sparingly” (Kuinimeri, 2007). The presence of a ‘tree factor’ and C7 sugars has been hypothesized to act as inhibitors in the repining process of avocado fruit. Additionally, the content of sugars seems to decrease with fruit maturity. Also, in exceptional cases, avocados do not ripen until harvested although maturity does increase while the fruit remains on the tree (Manuela, 2011).

There had been many studies regarding the extraction of avocado pulp. Most of these have indicated the high amount of oleic acid present in avocado. Oleic acid is said to be an effective aid to lower serum cholesterol levels and low-density lipoproteins in the human body (Genevive et al., 2013). However, with the abundant production of avocado apple in Nigeria, 15% of avocado pear (pericarp/peels) is discarded as waste which ought to have been a potential source for the production of oils for industrial applications, specifically, the fruits’ pericarp that are reported to have antiviral, antibiotic and insecticidal properties and employed as a vermifuge and remedy for dysentery and in the production of cosmetics (Adama and Edoga, 2011).

1.2 STATEMENT OF THE PROBLEM

Nowadays, great importance has been attached to oils from fruits and seeds, this is because of their numerous functions and uses to mankind. Due to this fact the demand for avocado oil has increased. This work will therefore focus on improving the production of the oil in large quantities to meet up the demand by investigating some parameters that would enhance better production.

1.3 AIM

The aim of this work is to study the effect of solvent type and extraction time on the yield of Avocado pear seed oil using solvent extraction method.

The objectives of this work are:

1. To carry out seed preparation
2. To carry out solvent extraction process using soaking method
3. Finding out the oil yield of avocado pear by varying the solvent type and extraction time

   1.4 SCOPE OF THE STUDY

This study will be conducted on the seed of an Avocado Pear (Persea americana) and the method to be employed will be carried out in the laboratory using soaking method with hexane, diethyl ether and chloroform as solvents in determining the best possible yield with varying time intervals.

1.5 RELEVANCE OF THE STUDY

This study will give a full knowledge of the parameters to consider when carrying out a commercial production of oil from avocado pear seed in order to get a better yield. With this information, the production of avocado oil from the seed will be optimized by choosing the best solvent required for maximum extraction. This will provide better parameters to be used in the conversion of seed as a form of waste to useful products.3