Analysis of the carbohydrates in an East African traditional beverage, togwa

In sub-Saharan Africa, togwa is a widely consumed beverage containing saccharified starch as a basis, being made from cereals and their malt flours. Togwa was prepared from maize flour and finger millet malt in a laboratory, and trace element and amino acid contents in the togwa were analyzed. The major constituents of togwa are carbohydrates, which are starch and starch hydrolysates that seem to be smoothly digested after ingestion. Carbohydrates in field and laboratory togwa were analyzed in detail by two different HPLC systems: normal phase chromatography and a gel permeation chromatography-multi angle laser light scattering system. Togwa was found to contain a very wide range of size distributions of molecules from glucose to starch that have molecular masses in the millions. It was concluded that togwa is an easily digestible and nutritious food.     

Chemical composition of distillers grains, a review

In recent years, increasing demand for ethanol as a fuel additive and decreasing dependency on fossil fuels have resulted in a dramatic increase in the amount of grains used for ethanol production. Dry-grind is the major process, resulting in distillers dried grains with solubles (DDGS) as a major coproduct. Like fuel ethanol, DDGS has quickly become a global commodity. However, high compositional variation has been the main problem hindering its use as a feed ingredient. This review provides updated information on the chemical composition of distillers grains in terms of nutrient levels, changes during dry-grind processing, and causes for large variation. The occurrence in grain feedstock and the fate of mycotoxins during processing are also covered. During processing, starch is converted to glucose and then to ethanol and carbon dioxide. Most other components are relatively unchanged but concentrated in DDGS about 3-fold over the original feedstock. Mycotoxins, if present in the original feedstock, are also concentrated. Higher fold of increases in S, Na, and Ca are mostly due to exogenous addition during processing, whereas unusual changes in inorganic phosphorus (P) and phytate P indicate phytate hydrolysis by yeast phytase. Fermentation causes major changes, but other processing steps are also responsible. The causes for varying DDGS composition are multiple, including differences in feedstock species and composition, process methods and parameters, the amount of condensed solubles added to distiller wet grains, the effect of fermentation yeast, and analytical methodology. Most of them can be attributed to the complexity of the dry-grind process itself. It is hoped that information provided in this review will improve the understanding of the dry-grind process and aid in the development of strategies to control the compositional variation in DDGS.     

Chemical composition of precipitation at Long Island,NY

Chemical analyses were performed on 387 sequential precipitation samples, both rain and snow, collected at Brookhaven National Laboratory, Long Island, New York, on 96 different days during the period from October 1983 to June 1985. The collection time for each individual sample was typically 30 min. The chemical species determined and the volume-weighted average and maximum concentrations (in parentheses) in units of μM were: H₂0₂:7(120), H₂CO:6(60), H⁺:51(500), N0₃ ^?:30(350), S0₄ ^2?:25(270), NH₄ ⁺:18(250), Ca²⁺:3(48), Na⁺:32(400), and Cl^?:37(380). A strong seasonal dependence was observed for H₂0₂ concentration, the maximum concentration in summer (120 μM) being 6 times greater than in winter. In addition, H₂0₂ concentration also exhibited a strong diurnal variation, with a maximum peaking in the afternoon and a minimum after midnight. These observations suggest that the production of H₂0₂ may be governed by photochemical activity. Nitrate concentration also displayed a strong diurnal variation, having a maximum around noon, but did not show a seasonal dependence. Relationships between various species and their possible sources are briefly discussed.     

Participatory monitoring of biodiversity in East African grazing lands

There are disagreements on the use of standard biodiversity monitoring methods to promote community participation. This study combined three methods to investigate questions why monitor biodiversity, what biodiversity to monitor and how participatory biodiversity monitoring can be promoted in central Uganda in East Africa. The question of why biodiversity should be monitored concerns the justification for monitoring, while the question of what to monitor concerns the choice of biodiversity variables, and the question of how to monitor biodiversity concerns the links between the data generated from monitoring and problems associated particularly with regard to community participation. The study selected landscape and sampling scales (i.e. plots) for participatory monitoring of biodiversity. Herders identified main landscape patches and plant species. Herder value‐weighted indicators, such as invasive species and range condition scores (i.e. composite indicators representing species palatability, composition, cover, density and richness) were used for measuring biodiversity in their grazing lands. To understand what biodiversity to monitor, we interpreted the correlation between biodiversity indicators and herder value‐weighted range conditions. Herders defined biodiversity from a utilitarian perspective, which is inconsistent with the conventional scientific goals of biodiversity conservation which focus on preservation of the total species pool. To address the question of how to monitor biodiversity, evidence from the folk taxonomy of sampled plant species and other proxy biodiversity indicators, including herder value‐weighted range condition scores, were compared to understand scale dependence. We inferred that the landscape scale monitoring was more sensitive to measuring biodiversity than the conventional scales of plots. Copyright © 2008 John Wiley & Sons, Ltd.     

Fatty acid composition of traditional and novel forages

Managing the fatty acid composition of grazing ruminant diets could lead to meat and milk products that have higher conjugated linoleic acid (CLA) concentrations, but forage fatty acid dynamics must be more fully understood for a range of forages before grazing systems can be specified. The fatty acid profiles of 13 different forages, including grasses, legumes, and forbs, grown under greenhouse conditions, were determined. Three separate harvests, at 3-week intervals, were made of each plant material. alpha-Linolenic [C18:3, 7.0-38.4 mg g(-1) of dry matter (DM)], linoleic (C18:2, 2.0-10.3 mg g(-1) of DM), and palmitic (C16:0, 2.6-7.5 mg g(-1) of DM) acids were the most abundant fatty acids in all species at each harvest, together representing approximately 93% of the fatty acids present. Concentrations of fatty acids declined as plants developed, but the fractional contribution of each fatty acid to total fatty acids remained relatively stable over time. Grasses had a uniform composition across species with a mean of 66% of total fatty acids provided by C18:3, 13% by C18:2, and 14% by C16:0. The fractional contribution of C18:3 to total fatty acids was lower and more variable in forbs than in grasses. Intake of fatty acid by grazing ruminants would be affected by the forage species consumed.     

Chemical composition of some traditional herbal drug preparations: essential oil and aromatic water of costmary (Balsamita suaveolens Pers.).

The compositions of the essential oil and the aromatic water of costmary (Balsamita suaveolens Pers.) cultivated in Tuscany were investigated. They represent the main ingredients of some traditional preparations sold commercially. The essential oil as such and the n-hexane extract of the aromatic water were analyzed by GC and GC-MS. Both samples were found to be rich in monoterpenes. Eighty-five compounds were identified, accounting for 95.1 and 95.4% of the essential oil and n-hexane extract of aromatic water, respectively. Carvone was the main compound (43.5% in the essential oil and 74.9% in the n-hexane extract of aromatic water). In addition, solid phase microextraction was used to sample the volatile organic compounds emitted from the fresh plant and from the aromatic water, and carvone was again the main component, amounting to 46.2 and 41.3%, respectively.     

Chemical composition, nutritive value, and toxicology evaluation of Mexican wild lupins.

The nutrient composition, toxic factors content, and nutritional and toxicological value of Lupinus splendens, L. rotundiflorus, L. elegans, L. simulans, L. exaltatus, L. reflexus, and L. madrensis species from Mexico were analyzed. The seeds of these species were a good source of protein. All the species showed a high lysine and tryptophan content, though sulfur amino acids were limiting. Cyanogenic glycosides were absent, and lectins, trypsin inhibitors, and tannins were present in low concentrations. Lupanine was the major alkaloid in almost all the samples, although sparteine was the major alkaloid in Lupinus reflexus (26.63 mg/g of sample). Cytisine was not found in any of the studied lupins. L. reflexus showed the highest acute toxicity, and L. elegans exhibited no toxicity as evaluated using a mice model. The alkaloid was reduced by hot-water extraction. The protein efficiency ratio in water-debittered seeds was relatively poor (1.1-1.5). These results suggest that the wild lupins studied represent a potential protein supply, and they could be domesticated and used for animal feed if the alkaloids were eliminated and the protein was supplemented with methionine, or if the lupins were used in mixture with cereals.     

Chemical composition of selected edible nut seeds

Commercially important edible nut seeds were analyzed for chemical composition and moisture sorption. Moisture (1.47-9.51%), protein (7.50-21.56%), lipid (42.88-66.71%), ash (1.16-3.28%), total soluble sugars (0.55-3.96%), tannins (0.01-0.88%), and phytate (0.15-0.35%) contents varied considerably. Regardless of the seed type, lipids were mainly composed of mono- and polyunsaturated fatty acids (>75% of the total lipids). Fatty acid composition analysis indicated that oleic acid (C18:1) was the main constituent of monounsaturated lipids in all seed samples. With the exception of macadamia, linoleic acid (C18:2) was the major polyunsaturated fatty acid. In the case of walnuts, in addition to linoleic acid (59.79%) linolenic acid (C18:3) also significantly contributed toward the total polyunsaturated lipids. Amino acid composition analyses indicated lysine (Brazil nut, cashew nut, hazelnut, pine nut, and walnut), sulfur amino acids methionine and cysteine (almond), tryptophan (macadamia, pecan), and threonine (peanut) to be the first limiting amino acid as compared to human (2-5 year old) amino acid requirements. The amino acid composition of the seeds was characterized by the dominance of hydrophobic (range = 37.16-44.54%) and acidic (27.95-33.17%) amino acids followed by basic (16.16-21.17%) and hydrophilic (8.48-11.74%) amino acids. Trypsin inhibitory activity, hemagglutinating activity, and proteolytic activity were not detected in the nut seed samples analyzed. Sorption isotherms (Aw range = 0.08-0.97) indicated a narrow range for monolayer water content (11-29 mg/g of dry matter). No visible mold growth was evident on any of the samples stored at Aw < 0.53 and 25 degrees C for 6 months.     

Characterization of volatile compounds of Mezcal, an ethnic alcoholic beverage obtained from Agave salmiana

Commercial mezcals (white, white with worm, rested, rested with worm, and aged) produced from Agave salmiana were analyzed by solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS). Thirty-seven compounds were identified, and nine of them were classified as major compounds of mezcal (MCM). Saturated alcohols, ethyl acetate, ethyl 2-hydroxypropanoate, and acetic acid form the MCM group. Minor compounds of mezcal group include other alcohols, aldehydes, ketones, large chain ethyl esters, organic acids, furans, terpenes, alkenes, and alkynes. Most of the compounds found in mezcals in this study are similar to those present in tequilas and other alcoholic beverages. However, mezcals contain unique compounds such as limonene and pentyl butanoate, which can be used as markers for the authenticity of mezcal produced from A. salmiana.     

Chemical composition of precipitation in a forest area of Chongqing,Southwest China

Experiments were carried.out in Chongging-a city seriously damaged by acid precipitation in southwest China — to explore chemical compositions of open bulk precipitation, throughfall and stemflow in a Masson pine (Pinus massoniana) forest. The results showed that annual mean pH values of and annual ion depositions in the three types of rain water were 4.47 and 50.6 g m^?2, 3.82 and 69.7 g m^?2, and 2.92 and 0.215 g m^?2 respectively. pH values demonstrated an obvious seasonal variation; they were lower in winter than in the rest of the year. Ca²⁺ and NH _inf4 ^sup+ together made up more than 80% of the total cation, while SO _in4 ^sup2? alone contributed over 90% to the total anion. This high level of SO _in4 ^sup2? in rain water in Chongqing, which outran those found in other cities in China, was closely related to the combustion of locally produced coal that contains 3 to 5% sulphur. Thus, acid precipitation in Chongqing is of a typical sulphuric-acid type.     

The distribution and abundance of soil nematodes in East African savannas

Summary Nematodes were sampled from sites under and between tree canopies in Tsavo National Park, Kenya. We tested the hypothesis that more nematodes would be present in the generally moister soil, under the canopy, with a larger biomass of green grass prevailing for many months of the year. We found that microbivorous nematodes comprised the bulk of the populations, approximately 90% of the total. Bacterivores were more numerous (approximately 3×10⁵ on average) versus fungivores (approximately 5×10⁴ on average) per m², to 10 cm depth. All four trophic groups (plant parasites and omnivore/predators in addition to the microbivore groups mentioned above) were significantly higher under acacia than baobab in a drier site, but not significantly different under the two tree species in a wetter site. Only bacterivores were significantly different with respect to distance from the tree, with higher numbers associated with the higher microbial biomasses under the tree canopies. These higher microbial biomasses were reflected in 2.5 times more potentially mineralizable N under the tree canopies at the drier site. We suggest that belowground detrital and microbivorous food webs in savannas may be similar to those in temperate grasslands. Further proof of this idea awaits more extensive research.     

Chemical composition, iron bioavailability, and antioxidant activity of Kappaphycus alvarezzi (Doty)

Kappaphycus alvarezzi, an edible seaweed from the west coast of India, was analyzed for its chemical composition. It was found that K. alvarezzi is rich in protein (16.24% w/w) and contains a high amount of fiber (29.40% w/w) and carbohydrates (27.4% w/w). K. alvarezzi showed vitamin A activity of 865 mug retinal equivalents/100 g of sample. It contained a higher quantity of unsaturated fatty acids (44.50% of the total), in which relative percentage of oleic acid was 11%, cis-heptadecanoic acid 13.50%, and linoleic acid 2.3% and 37.0% of saturated fatty acids (mainly heptadecanoic acid). K. alvarezziwas also found to be good source of minerals, viz 0.16% of calcium, 0.033% of iron, and 0.016% of zinc, which are essential for various vital biological activities. Bioavailability of iron by in vitro methods showed a higher efficiency in intestinal conditions than in stomach conditions. Ascorbic acid influenced higher bioavailability of iron. Successive extracts of n-hexane, acetone, ethyl acetate, ethanol, and direct extractables of chloroform/methanol (1:1 and 2:1) were screened for antioxidant activity using a beta-carotene linoleic acid model system (B-CLAMS), DPPH (alpha,alpha-diphenyl-beta-picrylhydrazyl) model system and hydroxyl radical scavenging activity. The chloroform/methanol (2:1) extract has shown 82.5% scavenging activity at 1000 ppm. Acetone fraction extracts at the 1000 ppm level showed 63.31% antioxidant activity in beta-carotene linoleic acid system. The acetone extract showed 46.04% scavenging activity at 1000 ppm concentration. In the case of hydroxyl radical scavenging activity, all the extracts showed better activity at the concentrations of 25 and 50 ppm, where at the 50 ppm level ethyl acetate extract showed 76.0%, acetone 75.12%, and hexane 71.15% activity, respectively. Results of this study suggest the utility of K. alvarezzi (Eucheuma) for various nutritional products, including antioxidant for use as health food or nutraceutical supplement.     

Chemical composition and biological activities of Arachis species

Arachis hypogaea , known as the peanut, is native to South America. Peanut contains several active components including flavonoids, phenolic acids, phytosterols, alkaloids, and stilbenes. Some therapeutic effects have been reported for peanut seed extracts, such as antioxidative, antibacterial, antifungal, and anti-inflammatory activities. This paper aims to give an overview of the chemical composition, focusing on secondary metabolites, and of the biological activity of A. hypogaea, to stimulate new studies about species of the Arachis genus.     

Chemical composition and flavor of ecuadorian cocoa liquor

The contribution of the chemical composition to the flavor of cocoa liquor from an Ecuadorian selfed population of clone EET 95 was investigated. Polyphenols, purine alkaloids, organic acids, and sugars were quantified, and the key sensory characteristics of cocoa were scored by a trained panel. Despite the short bean fermentation (2 days) commonly used for Arriba cocoa, acetic acid content was closely correlated to liquor pH, demonstrating its essential role in cocoa liquor acidification. Polyphenols were positively correlated to astringency, bitterness, and the green note and negatively correlated to the fruity character. Alkaloid and polyphenol levels fluctuated significantly within the selfed progeny and tended to be lower than those of the heterozygous clone EET 95 (inbreeding effect). These results support the idea that polyphenols might be essential to the overall perception of cocoa liquor characteristics and indicate that the composition and the sensory quality of cocoa liquor are the result of both a genotypic contribution and the conditions of fermentation and roasting.     

Chemical composition of acid precipitation in Central Texas

Studies were undertaken to determine factors affecting composition of acidic precipitation formation in the Austin area of Central Texas. The study was initiated to determine background levels of acid and alkalinity producing constitutents in an area with elevated natural dust levels from nearby limestone rock formations. Results showed normal rainfall pH values of 6.5 to 6.6 in the area, with extreme variations from 5.8 to 7.3. Significant Ca levels of 1 to 4 mg 1^?1 were observed from probably natural origin which appeared to have a buffering effect on acidity. Significant sulfate and nitrate ion concentrations occurred during the early stages of rainfall where rainfall pH was dependent on calcium-sulfate ratio.