Vegetables and Tubers

The present investigation was carried out to determine the possible bioactive components of tuber of Ruellia tuberosa L. (Acanthaceae) using GC-MS analysis. Twenty five compounds were identified. The prevailing compounds in the ethanol extract of tuber of R. tuberosa were Lupeol (68.14%), Stigmasterol (8.89%), á-Sitosterol (3.99%), Sucrose (2.24%), Cholest-5-ene, 3-bromo-, (3á- (2.24%), Octadecane, 2-methyl- (2.10%), Nonadecane, 2-methyl- (1.93%), Eicosane, 2-methyl- (1.79%) Heptacosane (1.43%) and Heptacosane (1.29%).

The objective of this paper is to report the first methodological approach to identifying archaeological carbonized dried and cooked vegetative storage organs. Three economically important South American tuber crops, manioc (Manihot esculenta Crantz), sweet potato (Ipomoea batatas (L.) Lam.) and white potato (Solanum tuberosum L.), were selected for experimental drying, cooking, charring, and parenchymatous tissue analysis. Microscopic examination reveals multiple distinctive cellular and tissue alteration forms. They are the result of cell wall degradation, cell rupture, cell separation, and starch gelatinization during processing and charring. Eight cellular and tissue alteration types and 22 variants are described – the majority of which are diagnostic for identifying drying and cooking methods.

Light yellow-flesh, matured sweet potato was used in a lab osmotic pre-treatment in sodium chloride (NaCl) solution with varying salt concentrations. The samples were subsequently dried via oven-drying. Measurements of residual calcium were taken. The dried potato slices (1 kg each of the representatives) were ashed in a muffle furnace at temperature of about 570°C for 30 mins. Solutions of the ashes were made by properly stirring with little volumes of distilled water in a beaker respectively. When the suspended solids were present in sufficient amounts to clog the nebulizer, the sample was allowed to settle and the supernatant liquid analyzed directly. The results obtained after AAS determination of calcium contents by checking absorbance against the concentration in a standard curve were analyzed using three factor design statistical analysis. Results show that potato slices of about 6mm thickness should be adopted since it yields potato products with relative higher calcium content than 2 mm and 4 mm thickness. The concentration of the salt solution should be adjusted to 10% m/v strength, as results to products with relatively higher calcium content. Where SSC of 10% m/v couldn't give product with required texture, 20% m/v could be alternative. Time of soaking should be within 20-40 minutes since the nutrition (Calcium) of the product is improved within this resident duration. Generally, to ensure potato products with more conserved calcium and required texture, potato slice thickness of 6 mm, salt solution concentration of about 10 to 20% m/v, and soaking time within 20-40 minutes should be adopted during pretreatment processing.

Emesis encompasses the forceful expulsion of the contents of stomach via the mouth or sometimes the nose. The adverse effects of currently available anti-emetic agents potentiate the natural product researchers to explore the natural anti-emetics with fewer side effects. The presented communication constitutes a review on anti-emetic effect of two hundred and forty five plants belonging to seventy-eight families found in different parts of the world. It also outlined the anti-emetic effect of plant extracts and isolated secondary metabolites studied through a variety of animal models of emesis. The reported anti-emetic plants in different countries and cultures and the scientific studies on extracts may help in the identification of promising single chemical compound(s) that may be used as a potential leads for developing safe anti-emetic agents in future. Moreover the reported secondary metabolites having the same effect may open the door for the search of same secondary metabolite...

Cassava (Manihot esculenta Crantz) is the staple food source for over 850 million people worldwide. Cassava contains cyanogenic glucosides and can be toxic to humans, causing paralysing diseases such as konzo, and even death if not properly processed. Konzo epidemics are often associated with times of drought. This may be due to a greater reliance on cassava as it is drought tolerant, but it may also be due to an increase in cyanogenic glucosides. Episodic droughts are forecast to become more common in many cassava-growing regions. We therefore sought to quantify the effect of water-stress on both yield and cyanogenic glucoside concentration (CNc) in the developing tubers of cassava. Five-month-old plants were grown in a glasshouse and either well watered or droughted for 28 days. A subset of droughted plants was re-watered half way through the experiment. Droughted plants had 45% fewer leaves and lower tuber yield, by 83%, compared with well-watered plants. CNc was 2.9-fold higher in the young leaves of droughted plants, whereas CNc in tubers from droughted plants was 4-fold greater than in tubers from well-watered plants. Re-watered plants had a similar biomass to control plants, and lower CNc than droughted plants. These findings highlight the important link between food quality and episodic drought.