Culinary Spices in Food and Medicine: An Overview of Syzygium aromaticum (L.) Merr. and L. M. Perry [Myrtaceae]

Spices-dried aromatic parts of plants (leaves, seeds, bark, roots, rhizomes, buds, etc) used to enhance flavour, taste and colour (sensory quality) of foods, are increasingly finding other useful roles in healthcare beyond their primary use as culinary organoleptic enhancers. Several spices are currently being investigated for their potential health benefits, because of the failing efficacy, toxicity and high cost associated with conventional drugs. One such spice: Syzygium aromaticum (L.) Merr. and L.M.Perry [Myrtaceae] (Clove), has a multi-dimensional role in diet, medicine, functional foods and nutraceuticals, agriculture, among other industries. Peer-reviewed articles, mostly from PubMed and Google Scholar, were consulted for the purpose of this review. The nutritional and phytochemical contents, selected biological activities as well as some functional foods and beverages of clove and their uses for human health are presented. Although these observations are largely empirical, the efficacious attributes have led to their pharmacological applications in the indigenous system of medicine all over the world and bridge between food, diet and medicine. Considering the GRAS status of clove, more studies on bioavailability, accumulation, toxicity, dosage and efficacy of clove as a spice drug or functional foods in biological systems especially in humans are required. Meanwhile, clove and its products can be used as co-adjuvants in the prevention, treatment and management of chronic diseases. Further, many applications of clove in food, health, cosmetics, pharmaceutics, nanoparticles and agricultural industries are still open for investigations.

Fractionation of Sugarcane Extracts and Determination of Phenolic Compounds and their Antioxidant Activity

Crude ethanolic extracts of four cultivars of sugarcane (Saccharum officinarum L.) were firstly prepared and then fractionated using silica gel column chromatography before the determination of their oxidative substances. The fractionated extracts were then tested for antioxidant activity by various assays. Finally, high-performance liquid chromatography (HPLC) was applied for the quantitative determination of the individual phenolic compounds. Sub-fraction 2 has the highest phytochemical contents as well as antioxidant activity. All tested phytochemicals had positively correlated to antioxidant activity. HPLC analysis showed that the phytochemicals in the fractionated extracts varied by the sugarcane cultivars. The main flavonoid substances found in the fractionated extracts were epicatechin, catechin, quercetin, resveratrol, myricetin and rutin while gallic acid was the main phenolic substance. The obtained information is useful for further studies and applications.

Evaluation of some phytochemicals in raw and cooked Ipomea batatas (Lam), (Sweet potato), Solanum tuberosum (Irish potato) and Dioscorea cayenensis (Yellow yam)

Cooking induces numerous phytochemical changes in food. This study is aimed at determining the amount of phytochemicals present in raw and cooked sweet potato, Irish potato and yellow yam. The amount of tannin, alkaloids, saponin, flavonoids and phenol were determined in raw and cooked samples of each food crop. The result showed that tannin, alkaloids, saponin, flavonoids, phenol contents was high in Irish potato and sweet potato but was far much present in Irish potato, while it was seen in minute quantity in yellow yam. The values obtained for each phytochemicals in each food sample raw and cooked respectively, in mg/100g were; Yellow yam: Tannins (0.10 and Nil), Alkaloids (2.00 and 0.51), Flavonoids (1.18 and 0.87), Saponins (2.00 and 1.02) and Phenols (0.72 and 0.10). Sweet potato: Tannins (0.32 and 0.28), Alkaloids (2.17 and 0.62), Saponins (2.10 and1.58), Flavonoids (1.28 and 0.97) and Phenols (1.42 and 0.72). Irish potato: Tannins (0.55 and 0.49), Alkaloids (2.17 and 0.81), Saponins (4.00 and 2.13), Flavonoids (5.00 and 2.91) and Phenols (2.00 and 0.91). The % loss of phytochemicals after cooking were; Yellow yam: Tannins (Nil), Alkaloids (74.5), Saponins (49.0), Flavonoids (26.3) and Phenols (86.1). Sweet potato: Tannins (12.5), Alkaloids (71.4), Saponins (24.8), Flavonoids (24.2) and Phenols (49.3). Irish potato: Tannins (10.0), Alkaloids (62.7), Saponins (46.8), Flavonoids (41.8) and Phenols (54.5). These results indicate that boiling of the samples seems to reduce their phytochemical contents as the raw samples showed higher amounts of the phytochemicals. The results also revealed that Tannins are more stable to heat across the 3 food samples, followed by Flavonoids, Saponins, Phenols and Alkaloids. The loss in some of the phytochemicals after cooking did not significantly affect the nutritional quality of the food samples.

Effects of Different Extracting Solvents on Non-Phenolic Phytochemical Profiles of Selected Nigerian Spices and Spice-treated Foods

The aim of this research was to investigate the impact of extraction solvents on the non-phenolic phytochemical profiles of selected spices (Ocimum viride, Monodora myristica, Monodora tenuifolia and Tetrapleura tetraptera) and spice-treated foods in southern part of Nigeria. The spice samples were processed into powder for antioxidant screening. The spice extracts were obtained from the samples using 5 extracting solvents [distilled water, 95 % methanol, acetone / hexane (1:1 v/v), n-hexane / methanol / acetone (2:1:1, v/v/v) and acetone / water / acetic acid (70:29.5:0.5, v/v/v)]. Water extracts were obtained from beef, pork and fluted pumpkin leaves. The alkaloid, saponin, oxalate and phytate components of the spice extracts and the spice-treated foods were evaluated using standard methods. The laboratory analyses were performed at analytical laboratory, National Centre for Energy Research and Development, University of Nigeria, Nsukka during the 3rd quarter of 2020. The percentage yield of the extracts were low (0.32 - 0.96 %) and varied widely among extracting solvents, spices and spice-treated foods. M. myristica and T. tetrpleura had the highest yield, 0.96, in methanol extracts. Phytochemical contents differed significantly (p < 0.05) among spices, extracts of the same spice and among spice-treated foods. Spices had high contents of oxalate (2.0 – 7.0 mg/100 g), alkaloid (0.8 – 5.76 mg/100 g) and phytate (2.14 – 3.88 mg/100 g) but relatively low content of saponin (0.03 – 0.736 mg/100g). Methanol alone or in combination with other solvents extracted higher amounts of phytochemicals (0.96 %) than other solvent mixtures from the spices. Phytochemical contents of spice-treated foods were in the order: vegetable > rice > pork > beef.

Effect of Elevated CO2 on Biomolecules’ Accumulation in Caraway (Carum carvi L.) Plants at Different Developmental Stages

Caraway plants have been known as a rich source of phytochemicals, such as flavonoids, monoterpenoid glucosides and alkaloids. In this regard, the application of elevated CO2 (eCO2) as a bio-enhancer for increasing plant growth and phytochemical content has been the focus of many studies; however, the interaction between eCO2 and plants at different developmental stages has not been extensively explored. Thus, the present study aimed at investigating the changes in growth, photosynthesis and phytochemicals of caraway plants at two developmental stages (sprouts and mature tissues) under control and increased CO2 conditions (ambient CO2 (a CO2, 400 ± 27 μmol CO2 mol−1 air) and eCO2, 620 ± 42 μmol CO2 mol−1 air ppm). Moreover, we evaluated the impact of eCO2-induced changes in plant metabolites on the antioxidant and antibacterial activities of caraway sprouts and mature plants. CO2 enrichment increased photosynthesis and biomass accumulation of both caraway stages. Regarding their phytochemical contents, caraway plants interacted differently with eCO2, depending on their developmental stages. High levels of CO2 enhanced the production of total nutrients, i.e., carbohydrates, proteins, fats and crude fibers, as well as organic and amino acids, in an equal pattern in both caraway sprouts and mature plants. Interestingly, the eCO2-induced effect on minerals, vitamins and phenolics was more pronounced in caraway sprouts than the mature tissues. Furthermore, the antioxidant and antibacterial activities of caraway plants were enhanced under eCO2 treatment, particularly at the mature stage. Overall, eCO2 provoked changes in the phytochemical contents of caraway plants, particularly at the sprouting stage and, hence, improved their nutritive and health-promoting properties.

INVESTIGATION OF THE PHYTOCHEMICAL CONTENTS AND ANTIMICROBIAL EFFECTS OF TELFAIRIA OCCIDENTALISON MICROORGANISMS

The rise in several deadly diseases like infections by multidrug-resistant bacteria implies re-inventing the wheel on drug discovery. Perhaps, extensive research has been dedicated to identifying alternatives to mitigating the effects of antibiotics resistance. Over the years, plants have contributed significantly to traditional medicine, proven effective in human health care, and were extensively used as alternative antibiotics in certain conditions. Thus, the current studys primary purpose is to determine the phytochemical contents and the antimicrobial activity of T. occidentalison microorganisms, including Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The result of the phytochemical analysis conducted on the leaf and seed of T. occidentalisrevealed alkaloids, tannin, steroids, flavonoids, phenol, and saponins. However, it was found that tannins and phenol were mainly deposited in the plants seed. Also, the antimicrobial analysis conducted revealed that S. aureus was more vulnerable to the ethanol, acetone, and hot aqueous extracts of T. occidentalis. At the same time, P. aeruginosa and C. Albicans showed sensitivity to ethanol and acetone exposure but failed to react to the hot aqueous extracts. The study concludes that the observed biological reactions shown by the aqueous extracts of T. occidentaliscorroborate the traditional application of this plant as an alternative antibiotic.

Extraction of the Metabolites from Medicinal plant Euphorbia leaf

The antimicrobial, phytochemical contents of extracts obtained from the leaf extract of mature Euphorbia pilulifera (E. pilulifera) were examined in this research work. Using ethyl acetate extracts of the leaves of Euphorbia pilulifera, phytochemical metabolites were studied. Further using chromatography, different components were separated and its antimicrobial activity was studied. Different types of bacterial organisms were used for evaluating the antimicrobial activity. The results indicated that leaf extracts are more sensitive towards organisms. Thus the presence of phytochemicals in the leaf extract can be used for the treatment of different diseases.