Extraction of Lignin From Cocoa Pod Husk Theobroma Cacao)
Chapter One
Aims and objectives
The aim of the study is to extract lignin and to characterize the lignin extracted from the pod husk of cacao pod. Specific objectives are
- To quantify the amount of lignin content of cocao(Theobromacacoa) pod.
- To investigate the proximate content of cocoa pod with respect to it ash content, moisture content, carbon content and surface area.
- To characterize the lignin content of cocoa pod.
CHAPTER TWO
LITERATURE REVIEW
TAXONOMY OF COCOA (Theobroma cacao L.)
The taxonomy of cocoa plant belong to plant Kingdom Plantae, Order,Malvales, Family malvaceae, Genus,Theobroma and Species Theobroma Cacao.
Description of cocoa (Theobroma cacao)
The leaves of cocao are alternate, entire, unlobed, 10–40 cm (3.9–15.7 in) long and 5–20 cm (2.0–7.9 in) broad. The flowers are produced in clusters directly on the trunk and older branches; this is known as cauliflory. The flowers are small, 1–2 cm (0.39–0.79 in) diameter, with pink calyx. The floral formula is K5 C5 A(5°+5²) G(5)(Ronse & Louis P.2010). While many of the world’s flowers are pollinated by bees (Hymenoptera) or butterflies/moths (Lepidoptera), cacao flowers are pollinated by tiny flies called Forcipomyiamidges in the-subfamily Forcipomyiinae.
The fruit, called a cacao pod, is ovoid, 15–30 cm (5.9–11.8 inch) long and 8–10 cm (3.1–3.9 inch) wide, ripening yellow to orange, and weighs about 500 g when ripe. The pod contains 20 to 60 seeds, usually called “beans”, embedded in a white pulp. The seeds are the main ingredient of chocolate, while the pulp is used in some countries to prepare refreshing juice, smoothies, jelly, and nata( Figueira, Antonio, Janick, Jules, BeMiller & James,2014). The fermented pulp, until recently discarded in Ecuador, the Dominican Republic, and Peru, is now being distilled there into a popular alcoholic beverage sold in the United States( Bell & Katie,2015). Each seed contains a significant amount of fat (40–50%) as cocoa butter. Their most noted active constituent is theobromine, a compound similar to caffeine.
Distribution and Domestication of cocoa (Theobroma cacao)
Theobroma cacao is widely distributed from southeastern Mexico to the Amazon basin. There are two original hypotheses about its domestication
The first said that there were two foci for domestication, one in the Lacandon Jungle area of Mexico and another in lowland South America. More recent studies of patterns of DNA diversity, however, suggest that this is not the case. Motomayor et al,(2011) sampled 1241 trees and classified them into 10 distinct genetic clusters. This study also identified areas, for example around Iquitos in modern Peru, where representatives of several genetic clusters originated. This result suggests that this is where T. cacao was originally domesticated, probably for the pulp that surrounds the beans, which is eaten as a snack and fermented into a mildly alcoholic beverage(Clement,2010).Using the DNA sequences obtained by Motomayor et al(2011) and comparing them with data derived from climate models and the known conditions suitable for cacao, Thomas et al.,(2012) further refined the view of domestication, linking the area of greatest cacao genetic diversity to a bean-shaped area that encompasses the border between Brazil and Peru and the southern part of the Colombian-Brazilian border Thomas et al(2012).
CHAPTER THREE
MATERIAL AND METHODS
Apparatus and Equipment
The apparatus and equipment’s used are, beaker, weighing balance, soxhlet extractor, test tube,scanning electron microscopy(SEM) crucible ,stirrer, centrifuge(CF-30) filter paper, electric blender, oven, fourier transform infrared spectroscopy(FT-IR),Buchner funnel.
Reagents Used
H2SO4, NaOH, distill water,hydrogen peroxide, peroxyformic/ peroxyacetic acid, acetone, ethanol and n-hexane.
Collection of sample
The plant sample (cocoa pod) was bought from road side fruit sellers at Unizik temp site mini market.
Preparation Of Plant Sample
The cocoa pod( Theobroma cacao) was opened and the seed removed while the husk was air dried and grinded into powder form.
CHAPTER FOUR
RESULTS AND DISCUSSION
Proximate Analysis
Table 3.1 shows the result of the proximate analysis
CHAPTER FIVE
CONCLUSION AND RECOMMENDATION
Conclusion
Findings of the study shows that cocoa pod husk contain 8.5% moisture content and 4.12g ash content. The findings also showed that the husk of cocoa pod also have surface area of 176.6cm3/g and carbon content of 3.9g. this implies that the husk of cocoa pod contains some amount of dietary fibre which makes that plant good for human consumption.
The Characterization of the lignin shows that the husk of cocoa pod contain different functional group such as OH. Findings also showed that the lignin contains different wavelength and the rough structure of the lignin coupled with it’s chemical compound give the lignin the ability to serve as path for water conduction in the plant and at the same serve as strengthen the structure of the pod of cocoa(Theobroma cacao). The findings of the study agree to the finding of Hatfield and Fukushima 2005) who in his study observed and noted that lignin’s of cocoa pod contain free OH groups and acetic acid, followed by bromine replacement of α-carbon OH groups. The findings also agrees to the of leggli et al (2011) that the Ash content cocoa is an indication of mineral contents of foods and has been shown to be high in cocoa and it products.
Recommendation
Based on the findings of the study, it is recommended that more work should be done on the pod of cocoa to ascertain other component present in it.
Suggestion for Further Studies
Study should be carried out on cocoa bean seed to ascertain the chemical constituent of the bean seed of cocoa.
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