EXTRACTION AND PHYSICO-CHEMICAL CHARACTERIZATION OF PORK OIL

Project Abstract

<p> </p><h2>ABSTRACT</h2><p>Pork oil was extracted through dry rendering from pork obtained from a local slaughter house in<br>Samaru, Zaria. The physicochemical properties (refractive index, saponification value, percent<br>free fatty acid content, iodine value, acid value, peroxide value, melting point, moisture content,<br>hydroxyl value, unsaponifiable matter and ash content) were assessed using standard procedures.<br>The result obtained compare favourably with recommended physicochemical properties of edible<br>oils, the fatty acid composition of the oil determine by Gas Chromatography-Mass spectrometry<br>(GC-MS) shows the major constituent to be oleic acid (46.49%), palmitic acid (28.19%) and<br>stearic acid (19.45%). The thermal degradation of the oil was studied using Fourier Transform<br>Infrared Spectroscopy (FTIR). These were carried out by heating oil at different temperatures)<br>for duration of one hour each. Spectra were recorded from a film of each oil sample between two<br>disks of NaCl. Changes in the value of the frequency of most of the bands of the spectra were<br>observed. The shifts of the frequency value of specific bands allowed for distinction between the<br>different stages of the oxidation process and to establish the degree of oxidation each oil sample.<br>The elemental analysis of the oil ash using Neutron Activation Analysis (NAA) shows the<br>presence of Al 2136 ± 175ppm, Ca 4005± 62ppm, Ti 155± 40ppm, V 1.9± 0.3ppm. Mn 87±<br>9ppm, Na 2022± I13ppm, K 1986 201ppm, As 0.15± 0.01ppm, Br 1.8± 0.1ppm, La 0.46±<br>0.05ppm, Tb 0.5± 0.1ppm, Sc 0.16± 0.02ppm, Cr 7± 2ppm, Fe 3762± 200ppm, Zn 227± 15ppm<br>and Ba 3611± 345ppm</p> <br><p></p>

Project Overview

<p><b>1.1 INTRODUCTION</b><br>The word oil has little specific meaning as it is applied to wide range of substances that are quite<br>different in chemical nature. They are derived mainly from two main source, plants and animals.<br>In Animals, they occur mainly in form of adipose tissue and as component of cells while in<br>plants they are mostly found in storage organ like seed (Deuel Jr., 1954).<br>Fats and fatty oil are water insoluble substances of plants and animal Origin which consist<br>mainly of glycerol esters of long chain fatty acids (Kirschenbauer, 1960). As a matter of fact,<br>there is no scientific differentiation between edible oils and fats and the two terms may be used<br>interchangeable. The common distinction between them is to consider solid product as fats and<br>liquid ones as oils. This difference is temperature dependent at high temperature all edible oils<br>and fats are liquid and at low temperature they appear to be solid. Even this latter statement is<br>only apparently true. As most natural fats while appearing solid at ambient temperature are<br>strictly blends of solid and liquid component (Hopkins, 1973). The products which form this<br>subject could equally well be referred to either as fatty oil or simply fats, irrespective of<br>consistency at ambient temperature.</p><p><br><b>1.2 CLASSIFICATION</b><br>The term oil has been applied in general usage to describe certain physical characteristics of<br>various substances rather than their chemical nature or composition. This common use has led to<br>confusion over the nature of oils and it is essential from the onset to understand their true<br>classification.<br>Oil and fats can be divided into groups according to both their origin and their chemical nature.<br>1.2.1 Fixed Oil and Fat<br>Animal fats derived from milk and body tissue of animals including marine animals.<br>1.2.2 Vegetable Oil and Fats<br>These are obtained from the fruits and seeds of a wide range of plants. These oils and fats are<br>esters of fatty acids (specifically glycerides) and are non-volatile.<br>1.2.3 Mineral Oil<br>These are distilled from petroleum and shale deposits this group of material include paraffin oil,<br>fuel oil and most lubricating oils.<br>1.2.4 Volatile Or Essential Oil<br>Oil of lemon, oil of clones and anamous oil these are obtained mainly from plant source.<br>Although, some are derived from animals. These oils are complex mixtures of aldehydes,<br>ketones, hydrocarbons alcohol, acid, and short chain esters. They are used for flavours,<br>perfumery and pharmaceutical purpose.<br>I.1.5 Crude Fat<br>These are completely untreated, as isolated from the oil bearing tissue. Crude oils are unpalatable<br>and hence inedible in this state.<br>1.4.6 Natural Fat<br>This may have been treated to remove the impurities which make them unpalatable but otherwise<br>have not been altered.<br>1.4.7 Modified Fat<br>These are fat or oil which has been changed by chemical treatment or physical separation to<br>produce a fat which is different from the original material.<br>1.4.8 Synthetic Fat<br>These are fats which have been chemically made from various source materials. Some have been<br>produced by oxidation of hydrocarbons to fatty acids which are then esterified with glycerol.<br>This process was operated on a large scale in Germany. However, not only was it costly, but the<br>fats produced contain unnatural fatty acids which were reported, to give rise to toxic effects<br>(Christie et al., 1972)<br>1.5 USES OF ANIMAL OIL<br>Animal Oils, like most vegetable oil and fat have found useful application in the industry and<br>commerce and as edible oil in several food preparations (Ekpeyong, 1989). Industrially, they are<br>used for example in foam, paint and surface coatings lubrications, adhesive plasticizers, textile<br>dyes, pharmaceutical and cosmetic formulation and many others (Terill and Ault, 1975; Burger,<br>1994).<br>1.6 JUSTIFICATION<br>Oils and fats are important parts of human diet and more than 90 percent of the world production<br>from vegetable, animal and marine source is used as food or as an ingredient in food products;<br>oils and fats is rich source of dietary energy and contains more than twice the caloric value of<br>equivalent amount of sugar. Their functional and textural characteristics contribute to the flavour<br>and palatability of natural and prepared foods. They contain certain fatty acids which play an<br>important role in nutrition and are also carriers of fats soluble vitamin (MMAF, 2005).<br>Many people in developing countries especially children under the age of five years suffer from<br>acute and chronic protein and energy deficiencies. At the current trend of population increase, it<br>is projected that, by the year 2020 there will be as many as 300 million chronically<br>undernourished people in the sub-Saharan Africa (Harsch, 1997). There is definitely a need for<br>food production to keep pace with the increase in world population. In order to achieve this<br>national development strategies in many agriculture-based tropical countries are now biased<br>toward increasing the diversity of consumable food productions in order to alleviate malnutrition<br>and stress on promotion and broadening of agricultural based industries to ensure that their<br>product are both whole some and safe.<br>The dietary role of edible oils and fats are highly recognised. The Food and Agriculture<br>Organization (FAO) and the World Health Organization (WHO) have recommended an average<br>daily intake of 55g fat per capita to complement the requirement for energy (Kabyemela et al.,<br>1992) and a 20-30% conversion rate for fat to energy to ensure good health (WHO, 1994).<br>Pork oil therefore, an edible oil obtained from any source is justifiably an area worthy of quality<br>research time.<br>1.7 AIM AND OBJECTIVE<br>The aim and objective of this research work include the following;<br>a. To extract oil from a pig carcass obtained from a local dealer by dry rendering.<br>b. To investigate some physiochemical properties of the extracted oil in (a) above.<br>c. To investigate the fatty acid composition of the extracted oil in (a) using Gas<br>chromatography-Mass spectrometry (GC-MS)<br>d. To investigate the thermal stability of the extracted oil using Fourier Transform Infrared<br>Spectrometry (FTIR). Identify shift and changes in the oil bands.<br>e. To determine trace elements available in the extracted oil ash using Neutron Activation<br>Analysis (NAA). <br></p>