Thesis Abstract

Antimicrobial activities of fruit extract from Capsicum annuum (chilli pepper) were examined against two organisms namely Staphylococcus aureus and Escherichia coli. These organisms are gram-positive and gram-negative bacteria respectively. The antimicrobial property was investigated using disc diffusion method (Sensitive test). The result of the extract prepared with cold water, hot water and ethanol with different concentrations of 50ug/ml, 25ug/ml, 12.5ug/ml, 6.25ug/ml and 3.125ug/ml were obtained as well as the minimum inhibition of 12.5mm, 6.25mm and 6.25mm respectively against Staphylococcus aureus while Escherichia coli has maximum inhibition concentration of 25mm, 12.5mm and 6.25mm using the same concentration as above. Both organisms were inhibited by the extract from chilli pepper.

Thesis Overview

1.0 INTRODUCTION

       Capsicum annuum (chilli pepper) is used as spice in cookery. They are sometimes dried, ground and used for their strong flavour and preservative effect. The two pungent compounds found in Capsicum species which are capsaicin and dihydrocapsaicin have antimicrobial effects.

      Fresh chilli peppers are very rich in vitamin C: 94mg which makes them very effective as immune system stimulants and healing agents especially for cellular damage. Many fork remedies recommended chilli pepper in wound cleaning preparations for gangrene and open sores and even as styptic, though more modern sources generally advise against using chilli on broken skin. Chillies diminish most of their vitamin C while drying thereby increasing the vitamin A content by 100 times. Vitamin A is a powerful anti-oxidant and anti-inflammatory agent. (Anguilar et al., 2010).

      Surprisingly, it has been shown that chillies do not aggravate or cause stomach ulcers. In fact they seem to have a preventative effect, as stomach ulcers are mostly caused by bacteria hence chilli’s antimicrobial actions kill such bacteria (Rogers, 2008).

      Chilli peppers can be very pungent and irritating. The degree of pungency can be adjusted by removing the seeds and white skin (placenta) which is where most of the capsaicin is concentrated.

      Chilli peppers are used for other health purposes like headaches, fever, colds, nasal catarrh, high blood pressure, stomach and digestive problems, sore throat etc.

      Extraction of the antimicrobial and antioxidant content of chilli pepper can be done by solvent extraction method being the simplest method. This method involves grinding the dried chilli pepper and mixing with an appropriate solvent which dissolves out the essential content of the pepper. Examples of such solvents include: ethanol, methanol, acetic acid and acetone (Duran et al., 2009).

1.1 Statement of Problem

Bacteria, Staphylococcus aureus and Escherichia coli have developed resistance to some antibacterial drug. This lead to the study on the antimicrobial activity of Chilli pepper to know whether it can be used as an alternative therapy for is faction caused by these organisms.

1.2     Objectives

–     To identify the antimicrobial properties of Capsicum annuum.

–     To determine the comparative study of Capsicum annuum.

1.3 Significance of the Study

      This work will help to unveil the potential use, application and extract from chili pepper to fight against spoilage and pathogenic microorganisms in food and body systems respectively.

1.4 Scope of Study

This project is based on antimicrobial activity of Staphylococcus aureus and Escherichia coli isolated from clinical sample (wound swab) collected from University of Nigeria Teaching Hospital Ituku Ozalla.  

1.5 Limitations of the Study

      This work is limited to the study on the antimicrobial properties of chili pepper. There were some difficulties in carrying out this research work which includes financial constrain, unavailability of laboratory equipment and time factor.