Project Materials

CHEMICAL/MINERAL COMPOSITIONS OF WATER EXTRACTS OF Hibiscus sabdariffa

ABSTRACT

The chemical characteristics of the water extract of zobo (Hibiscus sabdariffa) drink were investigated using a sophisticated atomic absorption spectrophotometer. The zobo drink is popular in Nigeria, particularly in the north. The investigation revealed that the drink contains a high concentration of critical mineral nutrients required for healthy human growth and the proper maintenance of metabolic functions. When compared to other leaves, such as the popular vegetable leaf known as awa (Piper methysticum), zobo drink contains a high concentration of iron, a significant component of human haemoglobin.

Chapter one

INTRODUCTION

Epidemiological research and associated meta-analyses suggested strongly around the close of the twentieth century that long-term intake of plant-based diets provided some protection against chronic diseases, particularly cancer (Wallstromet al., 2000).

Because uncontrolled free radical production was thought to play a significant role in the aetiology of cancer (Guyton and Kensler 1993), these findings drew attention to the potential role of radical scavenging and radical suppressing nutrients and non-nutrients in explaining the apparent benefit of such diets (Weisburger, 1991).

The discovery that free radicals were also involved in the aetiology of many other chronic diseases (Kehrer, 1993; Stohs, 1995) drew attention to flavonoids and the foods and beverages rich in them.

An regrettable but unexpected side consequence of some research studies and papers was that many investigators misunderstood dietary phenols, polyphenols, and tannins (PPT) as encompassing just flavonoids, flavonols, and flavones.

Recent epidemiological research have shown the link between better health and long-term intake of plant-based diets (Hung et al., 2004; Jansen et al., 2004). However, whether this is because such diets minimise exposure to deleterious substances (example oxidised cholesterol, pyrolysis mutagens, salt, saturated fat, etc.)

or maximise intake of certain beneficial nutrients (example isothiocyanates and other sulfur-containing plant constituents, mono-unsaturated fatty acids, and poly-unsaturated fatty acids, PPT, polyacetylenes, selenium, terpenes, etc.), or some combination as advocated in the “Polymeal” concept, remains unknown. An in vitro investigation suggests that there could be a molecular foundation for real synergy between PPT and isothiocyanates.

In contrast, more recent research attempting to investigate the claimed link between the ingestion of flavonols and flavones, or other flavonoids, have yielded far less consistent results.

Some studies have suggested that flavonoids may protect against vascular illnesses (Hirvonen et al., 2001 and Mennen et al., 2004) or certain (but not all) malignancies (Knekt et al., 1997 and Sun et al., 2002).

Interestingly, an investigation into the relationship between the consumption of Hibiscus sabdariffa (zobo) and other cruciferous vegetables and the risk of breast cancer in premenopausal women is required to determine the beneficial effects of isothiocyanates and/or the phenolic components of the plants (such as dietary phenols including flavonoids) in the management of cancer growth and the initiation of various types of diabetes.

During the same time period, various studies have suggested a positive benefit associated with increased consumption of other types of dietary phenols.

For example, greater coffee consumption has been linked to a lower incidence of type II diabetes (van Dam et al., 2002; Saremi et al., 2003). Similarly, increased lignan consumption (or at least higher plasma concentrations of their metabolites) has been linked to a lower incidence of estrogen-related cancers

In some (Boccardo et al., 2004 and McCann et al., 2004) but not all studies (Kilkkinen et al., 2004 and Zeleniuch-Jacquotte et al., 2004), and a prospective study was equivocal.

1.1 Suggestions for Further Research

The flavonoids in Hibiscus sabdariffa water extract should be extracted for further experimental and clinical research in the treatment of specific diseases and disorders such as cancer and diabetes mellitus.

The mechanisms of flavonoid-protein interactions have been discovered; it is my recommendation that such mechanisms be applied to in-vivo metabolic and physiological processes in order to determine the exact mechanisms involved in cell ageing and disease development.

1.2 PURPOSE OF STUDY

The goal of this research is to identify the physicochemical (biochemical) and water constituents of Zobo derived from dried calyces of Hibiscus sabdariffa (Linn Roselle).

Using an atomic absorption spectrophotometer (AAS). When ingested, the zobo’s biochemical content has a negative impact on human health.