Thin layer chromatographic studies of the pungent principles of Ceylon chillies (Capsicum species)

There are many varieties of cultivated chillies in Ceylon and the pungency of the fruit varies markedly with species, colour and size. A thin layer chromatographic study has been undertaken of the hot principles of Capsicum species found in Ceylon. This study shows that there are three compounds in Capsicum species other than capsaicin (vanillyl amide of isodecenoic acid) which give similar colour reactions as capsaicin. In Capsicum annuum, variety grossum, the hot principle, capsaicin is not detected by this method but instead, two other compounds are present which in a concentrated extract are responsible for the pungency of the fruit. Major variations in the relative concentrations of those pungent principles as determined semi-quantitatively, in the different varieties of Ceylon chillies have been discussed.

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Zusammenfassung Auf Ceylon wird eine Reihe von Paprikasorten kultiviert, deren Schärfe deutlich mit der Sorte, der Farbe und der Größe variiert. Mit Hilfe der Dünnschichtchromatographie wurden die die Schärfe bedingenden Komponenten der auf Ceylon vorkommenden Capsicum-Spezies untersucht. Diese Untersuchungen ergaben, daß in den Capsicumsorten drei von Capsaicin abweichende Komponenten vorliegen, die ähnliche Farbreaktionen wie das Capsaicin ergeben. In Capsicum annuum var. grossum konnte mit dieser Methode Capsaicin nicht nachgewiesen werden, statt dessen jedoch zwei andere Komponenten, die in einem konzentrierten Extrakt für die Schärfe der Früchte verantwortlich sind.Die große Variationsbreite der relativen Konzentration dieser scharfen, halbquantitativ bestimmten Komponenten ceylonesischer Paprikasorten wird diskutiert.

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Résumé Il'y a plusieurs variétés des piments cultivés a Ceylan et le piquent de fruit varie selon l' éspèce, la couleur, et la taille. Une étude chromatographique sur couche mince des composants (piquents) d' espèce Capsicume de Ceylan indique trois composants sans compter capsaicin (l'acide isoduenoic de vanillyl amide) qui repondent dans la même façon vis à vis der réactions colorantes. Dans le cas du Capsicum annuum de varieté grossum, le composant piquent capsaicin n'est pas décelé par cette methode, par contre, on y trouve deux autres composants qui, dans un extrait concentré, sont responsables pour le piquent du fruit. Les variations relatives des concentrations de composants piquents, determinées semi-quantitativement dans les differents variétés des piments de Ceylan sont décrites.

     

Procedure for Maximizing Oocyte Harvest for In Vitro Embryo Production in Small Ruminants

Possible effects of repeated hormonal treatments and laparoscopic ovum pick-up (LOPU) on the efficiency of oocyte recovery rate and quality were determined in sheep and goats. In six adult Merino sheep and five Criolla goats, ovarian status was synchronized by a prostaglandin F(2 alpha) analogue and the insertion of an intravaginal sponge 48 h later. Follicle development was stimulated by a single dose of FSH (60 mg NIH-FSH-P1) plus a single dose of equine chorionic gonadotrophin (eCG; 300 UI). The first FSH/eCG doses were administered 48 h after the sponge insertion, being repeated every 4 days to complete a total of four treatments in sheep and three in goats. Follicles in both ovaries were categorized according to their diameter and follicular fluid was aspirated under laparoscopic observation without a vacuum pump. In sheep, during a 12-day-period, a total of 347 follicles were aspirated with a recovery rate of 46.9%. In goats, during an 8-day-period, 219 follicles were aspirated with a recovery rate of 45.6%. In both species, there were no significant differences in the number of aspirated follicles, oocyte recovery rate and good quality oocyte recovery rate. However, in sheep the oocyte recovery rate was higher for large follicles, whereas in goats no such effect was detected. In summary, current results indicate that retrieval of oocytes can be maximized, without affecting oocyte quality, by repeating 'oneshot' FSH/eCG regimes and LOPUs at intervals as short as 4 days.     

Influence of inclusion level of barley in wheat-based diets and supplementation of carbohydrase on growth performance,nutrient utilisation and gut morphometry in broiler starters

ABSTRACT

1. The influence of barley inclusion level and supplementation of a multi-component non-starch polysaccharide degrading enzyme on performance and nutrient utilisation in broilers was investigated. Normal-starch hulled barley was evaluated with five levels of inclusion (0, 141, 283, 424 and 565 g/kg) in a wheat-based diet and two levels of enzyme supplementation (0 and 150 g/tonne of feed; a 5 × 2 factorial arrangement of 10 dietary treatments). All diets were equivalent in metabolisable energy and digestible amino acid contents. A total of 400, one-d old male broilers (five cages/treatment; eight birds/cage) were used in the experiment.

2. Regardless of enzyme supplementation, weight gain (WG) increased up to 283 g/kg of barley and was reduced afterwards (P < 0.01). Increasing levels of barley resulted in greater (P < 0.001) gain per feed (G/F). Enzyme addition increased WG (P < 0.05) and G/F (P < 0.001) at each barley inclusion level.

3. Birds fed diets with 0 and 565 g/kg barley showed the lowest and highest (P < 0.001to 0.05) digestibility for all nutrients measured, respectively. Digestibility of all nutrients was improved by enzyme supplementation at each barley inclusion level (P < 0.05). The nitrogen-corrected apparent metabolisable energy improved with increasing inclusion of barley (P < 0.001) and supplemental enzyme (P < 0.01). Increasing inclusion of barley increased the relative weight of gizzard (P < 0.001) and reduced jejunal digesta viscosity (P < 0.001). Supplemental enzyme (P < 0.001) reduced digesta viscosity.

4. The optimum inclusion level of barley, with respect to growth performance, was 283 g/kg of diet. Increasing barley inclusion improved nutrient and energy utilisation, possibly through lowered digesta viscosity and better function of the gizzard. Feed efficiency and nutrient and energy utilisation can benefit from carbohydrase supplementation in barley-based diets, regardless of barley inclusion level.     

A Coordinated Research Programme to develop methodologies for an integrated approach to improve small scale market oriented dairy systems in developing countries

A five-year Coordinated Research Project (CRP) entitled ‘Integrated approach for improving small scale market oriented dairy systems’ is currently being implemented by the Food and Agriculture Organization and the International Atomic Energy Agency, through their Joint Programme on ‘Nuclear Techniques in Food and Agriculture’. The objectives are to (a) identify and prioritize the constraints and opportunities in the selected dairy farms; (b) determine the most important limiting factors; (c) develop intervention strategies; (c) assess the economic impact of the interventions; (d) develop methodologies for recording and demonstrating the economic impact; and (e) promote the adoption and dissemination of proven strategies and methodologies. Fifteen institutes in developing as well as developed countries are participating in the project, through ten research contracts (Bangladesh, Cameroon, Pakistan, Paraguay, Peru, South Africa, Sri Lanka, Tanzania, Tunisia and Venezuela), one technical contract (Peru) and four research agreements (Malaysia, UK, USA and Uruguay). The initial phase of the project, which focused on the conduct of Participatory Rural Appraisals and Economic Opportunity Surveys in the countries of the research contract holders, has now been completed. This paper describes the background to the CRP approach and the procedures used for developing, initiating and implementing this project.     

Fish navigation in the vertical dimension: can fish use hydrostatic pressure to determine depth?

Fish live in complex volumetric habitats, and as such, face a challenging environment through which to navigate. This problem might be simplified if fish could monitor their depth and determine their position within the water column. One possible cue that they could use to ascertain their vertical position is hydrostatic pressure, which varies linearly with depth. Until recently it was assumed that fish were incapable of using hydrostatic pressure to measure depth as they do not possess a mechanism to sense absolute pressure. However, in a recent article by G. Taylor et al., we describe a novel mechanism whereby fish could determine their depth by using the rate in change of pressure mediated by changes in swim‐bladder volume, together with their vertical speed. This mechanism requires fish to be able to sense changes in pressure using their swim‐bladder. Here, we examine fish sensitivity towards hydrostatic pressure by reviewing the literature from behavioural and physiological experiments. This research suggests that fish are acutely sensitive to the magnitude and sign of hydrostatic pressure changes, via changes in the volume of the swim‐bladder. We argue that fish have the necessary physiological measurements to sense the rate in change of pressure, meaning they are able to use the mechanism proposed by Taylor et al. to determine their vertical location. This has profound implications for the study of navigation through volumes, by providing a reliable global cue that fish can use to determine their depth.     

Pond‐raised Hybrid Catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus,Do Not Respond to Microbial Phytase Superdosing

Two experiments were conducted in consecutive years to evaluate the responses of hybrid catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus, to “superdosing” of 6‐phytase added to existing commercial catfish feeds. In each experiment, two diets with or without a phytase superdose (2500 and 5000 phytase units/kg, respectively) were compared. In Experiment 1, fingerlings (mean weight: 59 g/fish) were stocked in 17 0.4‐ha earthen ponds at 17,290 fish/ha and were fed once daily to apparent satiation for 198 d. In Experiment 2, fingerlings (mean weight: 47 g/fish) were stocked in 10 0.4‐ha ponds at 24,710 fish/ha and were fed for 128 d. In both experiments, there were no significant differences in total feed fed, gross yield, final fish weight, survival, or Blood packed cell volume between fish fed diets with or without phytase. The diets also had no significant effects on pond water column total phosphorus or chlorophyll a concentrations, but soluble reactive phosphorus concentrations were significantly higher in ponds receiving the phytase diet in Experiment 2. Phytase superdosing of nutritionally complete feeds does not appear to have additional benefits beyond the standard phytase dose on production characteristics or packed cell volume of pond‐raised hybrid catfish and had no beneficial effects on water quality.     

Methane oxidation activity and bacterial community composition in a simulated landfill cover soil is influenced by the growth of Chenopodium album L.

Oxygen availability in landfill cover soil is a major limitation to the growth and activity of methanotrophs as methane oxidation is an aerobic microbial process. Plants tolerant to high concentrations of landfill gas (LFG) may play an important role in improving methane oxidation within landfill cover soil and reducing emission of methane, a greenhouse gas, from it. In this study, the effect of an LFG tolerant plant Chenopodium album L. on methane oxidation activity (MOA) and bacterial community composition in landfill cover soil was investigated. Soil samples from four simulated lysimeters with and without LFG and plant vegetation were taken at 4 stages during the plant's development cycle. Results showed that the total number of culturable bacteria in soil could be significantly increased (P < 0.05) by the growth of C. album. The total number of methanotrophs and MOA in soils with LFG was significantly higher (P < 0.05) than in soils without LFG on sampling days 90, 150 and 210. The total number of methanotrophs and MOA in lysimeters with LFG added increased in the presence of C. album when the plant entered the seed setting stage. Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) gel patterns of 16S rDNA gene fragment and band sequencing analyses showed apparent differences in soil bacterial communities in the presence of LFG and plant vegetation. Members of the genus Methylosarcina were found to be the active and dominant methanotrophs in rhizosphere soil of C. album with LFG, while Methylococcus, Methylocystis, and Methylosinus were the primary methanotroph genera in LFG soil without C. album. Thus, C. album appears to select for specific methanotrophic bacteria in the presence of LFG. Soil MOA and microbial diversity can also be significantly affected by the presence of this plant.