ABSTRACT
Wine is an alcoholic beverage made from grapes, generally vitis vinefera, fermented without the addition of sugars, acids, enzymes, water, or other nutrients. Yeast consumes the sugar in the grapes and converts it to ethanol and carbon dioxide. Some fresh fruits, such as grape, orange, banana, apple, watermelon, cucumber, pineapple etc. had been used for wine production. In this study, Ugiri (Irvingia gabonesis) and Roselle (Hibiscus Sabdariffa) were used for table wine production. Fresh Ugiri fruit were processed and sieved with Muslin cloth. Dried Roselle were washed, soaked in hot water and sieved with muslin cloth. The Ugiri and Roselle juice were mixed to obtain the must. The must was inoculated with the pure culture of strain of saccharomyces cerevisiae sourced from a stock culture isolated from fresh fermented palm wine. Sodium metabisulphite was also added into the must. The solution was allowed to ferment and during which some parameters such as pH, reducing sugar, specific gravity, titrable acidity and alcohol content determination were carefully carried out. The pH of wine ranged from 5.8 to 3.5, the specific gravity of the wine ranged from 0.63 to 0.40 kg/m3. Alcohol content of the fermented wine ranges from 0.33 to 0.74 kg/100ml and the reducing sugar of the fruit wine is from 0.67 to 0.38. The fermentation of Ugiri and Roswell must using Saccharomyces cerevisiae led to the successful production of wine.
TABLE OF CONTENTS
Title Page i
Certification ii
Approval iii
Dedication iv
Acknowledgment v
Abstract vi
Table of contents vii
INTRODUCTION
Aim of Study 4
Specific Objectives 4
LITERATURE REVIEW
Wines of African Origin 6
Classification 7
Uses of Wine 8
Roselle (Hibiscus Sabdariffa) 9
Origin 11
Rozelle Names 12
Taxonomy 13
Botanical Description 13
Bush Mango (Irigngia gabonesis) 14
Uses of Irvingia Species 15
Taxonomy and Local Names 17
Wine Production 21
Juice (‘Must’) Preparation 21
Fermentation 21
The Yeast Strain 22
Carbon Source 23
Alcohol 24
pH And Acids 24
Carbon Dioxide 24
Aging 25
Clarification 25
Packaging and Bottling 26
Quality Evaluation of Wine 26
Clarity/Appearance 27
Odor/Smell 27
Tastes 27
Color 28
MATERIALS AND METHODS
Collection of Sample 30
Isolation of Yeast 30
Characterization and Identification of Yeast 30
Inoculum Development 30
Must Fermentation 32
Parameters Evaluated 32
RESULTS
Discussion 36
Conclusion 37
References 38
LIST OF TABLES
Tables Title page
1 Local names for Irvingia wombolu 11
2 Local names for Irvingia gabonensi
3 Result of the Parameter Evaluated
INTRODUCTION
Wine is an alcoholic beverage typically made of fermented fruit juice (Okafor, 2007). Any fruit with good proportion of sugar may be used in producing wine and the resultant wine is normally named after the fruit. The type of wine to be produced dictates the fruit and strain of yeast to be involved (Amerine and Kunkee, 2005). Preservatives used in wine making include sulphur dioxide, potassium sorbate, sorbic acid and metabisulphides (Idris and Izuagbe, 1988). High concentration of these preservatives in wine, aside causing off odors, can induce lots of systemic disorderliness such as breathing problems in Asthmatic patients and gastrointestinal disturbances in allergic persons. The effects of bio accumulation of these chemicals could further compound these situations (Okafor, 2007). Reports on tropical fruit wines have been mainly on exotic species such as pineapple, cashew, banana, citrus, mango, pawpaw, apple, strawberries (Maldonado et al. 1975). Wine represents a safe and healthful beverage; it also provides calories and vitamins. During period when life was often strenuous, it offered relaxation and relief from pains. The yeasts are microorganisms that belong to the Fungi due to the lack of photosynthesis absence of motion structures, presence of rigid cellular wall and nucleus membrane; however, they differ from filamentous fungi by showing themselves, predominantly under unicellular form. The majority is classified as ascomycetous and show themselves as spherical, oval or cylindrical cells, with cellular division through budding (pelczar, 1980; Madigan et al., 2004). The distribution of yeasts in natural is done by insect vector and wind. The flowers and fruits are important habitats to their development due to the high concentration of simple sugars and low PH (Pelczar, 1980). Many authors have isolated yeasts with fermentative capacity from fruits, citric concentrates and other sugar substances (Trindade, et al., 2002). Due to their high fermentative capacity, the yeasts are essential in the production of alcoholic beverages. Among them, saccharomyces cerevisiae is universally employed in processes for the production of alcoholic beverages, especially wines. The term wine is only used for the fermentation of grapes, however, many other fruits can be used in the same process (Martins, 1998, Madigan et al., 2004, Dorneles et at., 2005), as well as other species of yeasts associated to these fruits (Trindade et al., 1999).
Carrying out preliminary investigation on the use of African bush mango in combination with Roselle for the production of wine.
Roselle (Hibiscus sabdariffa L.) belongs to the family Malvaceae, locally called “karkade”, is and important annual crop grown successfully in tropical and sub-tropical climates. The commercially important part of the plant is the fleshy calyx (sepals) surrounding the fruit (capsules). The whole plant can be used as beverage, or the dried calyces can be soaked in water to prepare a colorful cold drink, or may be boiled in water and taken as a hot drink. It also has some medicinal properties. The seeds contain 17.8–21% non-edible oil and 20% protein, and are sometimes used for animal feed. Roselle is a flexible plant with a number of uses. It is intercropped with crop staples such as sorghum and sesame, or planted along field margins. It requires little care. Its leaves, seeds, capsules and stems are used in traditional medicines.
In rural areas women are usually responsible for growing roselle. They add value to the crop by developing products for market Mclean and Wilson and Menzel reported that Hibiscus sabdariffa is a tetraploid (2n = 4x = 72), whose chromosomes are related to the diploid (2n = 2x = 36) Hibiscus cannabinus. The two botanical types of roselle are Hibiscus Sabdariffa var. sabdariffa, grown for its fleshy, shiny-red csabdariffsysts sabdariffa var. altissima grown for its phloem fiber. Despite its potential economic importance, karkadi has received little attention and there is a lack of information regarding its genetics, breeding and production, particularly under rain-fed conditions.
Ugiri (I. gabonensis) have a shelf life of less than 2 days if picked when ripe and not more than 10 days if harvested at the mature green stage due to high respiration rate, moisture loss and microbial attack (Joseph and Aworh 1991, 1992). Poor storage conditions and handling, as well as pest attack, diseases and deterioration contribute to high losses of saleable fruit. Initially, Joseph and Aworh (1991) tried to lengthen the shelf life of mature green bush mangoes by refrigerating them at 12-15ºC – a common method for delaying ripening. This resulted in chilling injuries such as pitting and black spots, which would reduce saleability considerably, making this an inviable option for storage. They then trialed several different post harvest storage methods including dipping, wrapping and waxing the fruit, to see which was the most effective (Joseph and Aworh 1992). They found that the longest shelf life resulted from briefly submerging the fruits in a hot sulphite dip (commonly used in the food industry) and then wrapping them in PVC film. Hot water or other hot chemical dips used in conjunction with waxing or packaging in wrapped boxes were also effective combinations for enhancing shelf life at 22-35ºC and 70-95% relative humidity, normal storage conditions in Africa.
Stored Irvingia seeds keep for up to a year (Ndoye et al. 1997), but are susceptible to pests. One major pest is the merchant grain beetle (Oryzaephilus mercator) which lays its eggs between the testa and cotyledons of the seed or in cracks in the cotyledons, so that when the larvae hatch they can consume the cotyledons (Dudu et al. 1998b). The testa could be fully removed to reduce the number of preferred oviposition sites, but this may allow other pests to attack. More careful handling of the seeds to prevent cracks will both help to prevent grain merchant beetle infestation and keep the value high, since damage reduces sale price. The beetle has a long life span as well as fast population growth, so it is essential that its presence is detected early to prevent huge losses. Dudu et al. (1998b) suggest that a diethyl ether extract of I. gabonensis could be used to attract the beetle, either to detect it or to attract it away from stored oilseeds, including Irvingia seeds themselves.
The various products of Irvingia kernels have differing length shelf lives. The sauce made from fresh kernels can be kept for 3 or 4 days, whilst ‘dika bread’ paste made from crushed, dried kernels can be stored for over a year (Ndoye et al. 1997). I. gabonensis fat, extracted from the kernels, has been stored for more than a decade with no adverse changes in it properties because it contains natural anti-oxidants that hinder oxidative decay (Okolo 1994).
Aim of Study
To preliminary investigate the use of roselle (hibiscus sabdariffa) and ugiri (irvingia gabonesis) in wine production.
Specific Objectives
The objective is to;
- Isolate yeas from palm wine
- Identify the yeast isolates
- Build up yeast inoculum
- Produce must from the combination of ugiri and roselle juice
- Produce table wine from the ugiri and roselle juice using the isolated yeast strain
