The Use of Bitterleaf Vernonia Amygdalina Extract as a Means of Extending the ShelfLife of Locally Brewed Sorghum Beer

The Use of Bitterleaf (Vernonia Amygdalina) Extract as a Means of Extending the Shelf-Life of Locally Brewed Sorghum Beer

Project / Seminar Material
Reference ID: PS-304-TM

DEDICATION

This research material titled “The Use of Bitterleaf (Vernonia Amygdalina) Extract as a Means of Extending the Shelf-Life of Locally Brewed Sorghum Beer” is dedicated to God for his enabling grace, and to all computer enthusiasts who contributed to make life a pleasant experience during my research documentation.

ACKNOWLEDGEMENT

I extend my sincere gratitude to all those who contributed to the completion of this project. Special thanks to my Supervisor (Name of your Supervisor), the Head of Department (Name of your HOD), the Lecturers in the department of Brewing Science, Book Authors and Profound Scholars of existing or related project material on “The Use of Bitterleaf (Vernonia Amygdalina) Extract as a Means of Extending the Shelf-Life of Locally Brewed Sorghum Beer” for their invaluable guidance, support, and expertise throughout the journey.

I am also grateful to your study area (mention any funding organizations, if applicable) for their financial assistance. This research would not have been possible without the encouragement and assistance of some stakeholders (mention any mentors, teachers, or colleagues). Additionally, I would like to acknowledge the understanding and patience of my family and friends during this endeavor. Your unwavering support has been a constant source of motivation. Thank you all for being part of this meaningful endeavor.

ABSTRACT

Locally brewed beer (sorghum beer) is an indigenous alcohol average. It is produced mainly from sorghum grain (Sorghum vulgare) and the process of brewing involves malting, mashing, souring, fermentation and packaging. Locally brewed beer without hops has a short shelf-life. The aqueous extract of a tropical plant, bitter-leaf was used as the hop .Two type of drink were produced, one with hops and another without hops.

Chemical analyses were carried out on both drinks, which gave a significant (p=0.05) difference. Sorghum beer with hops has a total acidity of 0.562±0.03, fixed acidity of 0.203±0.001, Volatile acidity 0.360±0.02, PH 3.93, specific gravity 1.042±0.003, total dissolved solids 1.12×105ppm, total suspended solids 1.65×105ppm, ethanol content of 3.43±0.03 respectively. While sorghum beer without hops has a total acidity of 0.652 ±0.002, fixed acidity of 0.176±0.002, volatile acidity of 0.476±0.03, PH of 3.50 specific gravity of 1.021±0.003, total dissolved solid of 1.15×105ppm, total suspended solids of 1.5×105ppm and an ethanol content of 3.65±0.02.

The microbial count for sorghum beer with hop had no growth of E.coli, streptococcus and staphylococcus but aspergillus was present from the 4th day and heaviest on the 8th day. While the drink without hop had growth of staphylococcus and aspergillus which was seen from the 2nd day and heaviest on the 4th day but E.coli and streptococcus was absent. From the results, the drink with hops could keep for a longer period of time than the other drink without hops. Thus, the aqueous extract of Vernonia amygdalina could extend the shelf-life of locally brewed sorghum beer.

The Use of Bitterleaf (Vernonia Amygdalina) Extract as a Means of Extending the Shelf-Life of Locally Brewed Sorghum Beer

CHAPTER ONE

1.0 Introduction

The word beer derives from the Latin word bibere meaning to drink (Okafor, 2007). Beer is the world's oldest and most widely consumed alcoholic beverage and the third most popular drink overall after water and tea. Grossman (1995) defined beer as a general name given to beverages resulting from the germination of a malt or cereal grain. The process of brewing beer is called brewing. It is produced by the brewing and fermentation of starches mainly derived from cereal grains most commonly malted barley, although wheat, maize (corn), and rice are widely used (Gutcho, 1976). In Nigeria today, barley has been replaced by some locally grown cereals such as sorghum or guinea corn, millet and maize as the principal raw materials. The tropical beers (African local beers) are known by different names in different part of the world; burukutu, otika and pito in Nigeria, maujek among the Nandi's in Kenya, mowa in Malawi, kaffir beer in South Africa, merisa in Sudan, bouza in Ethiopia and pombe in some parts of East Africa (Okafor, 2007).

Burukutu is an indigenous alcoholic beverage. Burukutu, a popular alcoholic drink among indigenes of the middle belt region of Nigeria, is a local brew made from fermented sorghum and other protein enriched grains (Ekundayo, 1969). The age long drink, also known as BKT, serves as a source of alcohol for those who lack the financial means to patronize refined brew like beer and other foreign or imported drinks it is produced mainly from the grains of guinea corn (Sorghum vulgare and Sorghum bicolor). The process of production of burukutu involves malting, mashing, fermentation and maturation as described by Ekundayo (1969).The production process of these indigineous drinks involves fermentation at its initial production stage and comes out as an alcoholic drink. The microorganisms associated with fermentation include Saccharomyces cerevisiae, Saccharomyces chavelieria and Leuconostocmesteroides (Faparusi et al., 1973).

Sorghum is a large variable genus with many cultivars (Ettasoe, 1972). The method employed in brewing sorghum beer here involves, malting, mashing, wort boiling with hops, fermentation, (using brewer's yeast and bakers yeast) and packaging. The tropical sourced hop extracts used here is Vernonia amygdalina (Bitter leaf) which have been found to contain an anti bactericidal agent which is capable of extending the useful life of these indigenous beers (Okoh et al., 1999).

Chemical analysis on the prepared sorghum beer such as; ethanol content, PH value, specific gravity, fixed acidity, total acidity, total dissolved solids (TDS), total suspended solids(TSS) were analysed quantitatively, using different methods.

1.1 Aims and Objectives

The aim of the project is itemized into the following objectives;

a) To determine the shelf-life of locally brewed sorghum beer.

b) To check the effect of bitterleaf (Vernonia amygdalina) extract on the locally brewed sorghum beer.

c) To compare the results from the chemical analyses of locally brewed sorghum beer with bitterleaf extract and sorghum beer brewed without bitterleaf.

…

CHAPTER TWO

2.0 Literature Review

2.1 Introduction

This chapter focuses on the review of related literature. A literature review includes the current knowledge as well as theoretical and methodological contributions to a particular topic. It documents the state of the art with respect to the topic you are writing. It surveys the literature in the topic selected. In this research work the literature review includes the …

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