Chemical Differentiation of Plant Latexes and Their Anti-herbivory Activity against Thrips Frankliniella occidentalis

Despite the extensive studies on latex, some fundamental questions on their chemical specialization and the factors influencing this specialization have yet to be investigated. To address this issue, latexes and their bearing tissues from diverse species were profiled by 1HNMR and GC-MS. Additionally, the antiherbivory activity of these materials was tested against thrips (Frankliniella occidentalis Pergande, 1895). The multivariate data analysis showed a clear separation between latexes and leaves from the same species. Conversely, the chemical profiles of latexes from different species were highly similar, that is, they displayed much less metabolic species-specificity. These shared chemical profiles of latexes were reflected in their overall higher mortality index (80.4% ± 7.5) against thrips compared with their bearing tissues (55.5% ± 14.9). The metabolites correlated to the antiherbivory activity of latexes were triterpenoids and steroids. However, the activity could not be attributed to any single terpenoid. This discrepancy and the reduction of the latex activity after fractionation suggested a complementary effect of the compounds when in a mixture as represented by the latex. Additionally, aqueous fractions of several latexes were found to possess simple spectra, even with only 1 metabolite. These metabolites were determined to be organic acids that might be involved in the modulation of the rate of latex coagulation, potentially increasing the sealing and trapping effects of the latex.

Investigation of the process of latex coagulation by cationic surfactants

In the articlethe estimation of coagulating ability using cationic electrolytes is shown.It was found that in the case of using low molecular weight cationic electrolyte, the completeness of the release of rubber from latex is achieved at their consumption of 20–30 kg/t of rubber. A feature of the behavior of cationic surfactants in the latex coagulation has been established. It is shown that the consumption of cationic surfactants corresponds to the consumption of polymer cationic electrolytes. Also, a hypothesis was put forwardthatcationic surfactants violate the aggregate stability of latex systems and the mechanism of action, which is basedon the interaction of cationic surfactant micelles with latex globules carrying anionic surfactants on the surfaceis proposed.The use of cationic surfactants can eliminate the use of sodium chloride in the industry of separating emulsion styrene-butadiene rubber from latex, as well as solve some environmental problems.The final stage of theinvestigationwas to determinethe parametersof rubber compounds and vulcanizates based on the rubber. These rubbers, rubber compounds and vulcanizates correspond to standard parameters.

Perceived extension needs of rubber production among farmers in Delta State, Nigeria

The need to develop a sustainable exploitation system for the Nigerian rubber farmers requires that extension services should be available to assist the farmers in specific areas that can help them function effectively and improve productivity. The study investigated the perceived extension needs of rubber production farmers in Delta state Nigeria. The specific objectives of the study were to determine sources of information on rubber production, varieties of rubber clones cultivated by the respondents, perceived extension needs of rubber farmers, and constraints to rubber production. A multi stage sampling technique was used to select 120 rubber farmers as respondents for the study. Data were analysed using frequency, percentages, means and Pearson Product Moment correlation analysis. Results showed that majority of the respondents (85.5%) were male, married (83.3%) and had average farming experience of 14 years. The NIG801 and NIG800 varieties were the local clones majorly cultivated and the GT1 and PB217 varieties were the exotic clones majorly cultivated. Findings also showed that respondents need production information on use of formic acid for latex coagulation (66.7%), use of ammonia for latex preservation (73.3%) and marketing information (60.8%). The constraintsindicated by the respondents were problem of land tenure (81.7%), lack of adequate credit facilities (70%), fire outbreaks (72.5%) among others. The result of the hypothesis showed that age (r = 0.199) had a positive significant relationship with farmers’ extension needs. It was recommended that extension personnel should be trained on techniques of rubber production in order to deliver effectively to the farmers. Key words: extension needs, rubber, farmers, Delta, Nigeria

FWHM Dimentional Analysis From Scattered Light Intensity Profile for Dry Rubber Content Determination in Natural Rubber

Dry Rubber Content (DRC) describes a rubber particle percentage in natural rubber latex. In this paper, the relation between forward light scattering profiles of natural latex and rubber contents is reported for dry rubber content latex. The profile, characterized by Full Width at Half Maximum (FWHM), is increasing linearly with respect to rubber content. The measurement was performed immediately after latex being tapped with necessary addition of acetic acid. This addition was meant to prevent latex coagulation. There is a high linear correlation between DRC and FWHM of both domain: one and two dimension. This is indicated by correlation factor which are higher than 0.9 for both of domains and sufficient in DRC determination.

PENGARUH KONSENTRASI HCl DAN Ph PADA EKSTRAKSI PEKTIN DARI ALBEDO DURIAN DAN APLIKASINYA PADA PROSES PENGENTALAN KARET

Abstrak: Durian adalah tanaman yang tahan terhadap iklim kering sehingga dapat tumbuh di daerah tropis seperti Indonesia. Albedo durian merupakan sumber pektin yang potensial karena di dalamnya terkandung senyawa pektin. Untuk menguraikan pectin dalam albedo durian dapat dilakukan dengan proses ekstraksi asam karena kemungkinan terjadinya pectin jauh lebih sedikit daripada ekstraksi basa. Pada penelitian ini akan dilakukan ekstraksi pectin dengan bahan baku albedo durian yang bertujuan untuk mengetahui pengaruh variasi kosentrasi pelarut dan PH dari albedo durian, mendapatkan kondisi operasi optimum dari ekstraksi pectin albedo durian dan membandingkan data waktu pengentalan karet dengan menambahkan pectin atau tanpa pektin. Penelitian dilakukan dengan waktu ekstraksi 60 menit dengan temperatur ekstraksi 90 0C dan massa albedo durian 20 gram. Variasi perubah yang digunakan adalah konsentrasi pelarut HCl (0,2; 025; 0,3 dan 0,35N) dan variasi PH (1,2; 2; 2,5 dan 3). Pectin yang diperoleh kemudian diaplikasikan untuk proses pengentalan karet dengan variasi pectin yang digunakan adalah sebagai berikut (1:5; 2:5; 3:5 dan 4:5). Kadar pektin yang didapat pada penelitian ini berkisar antara 3,09 g-17,91 g. Kadar metoksil yang dihasilkan dari penelitian ini adalah 2,430%-3,13%, sedangkan kadar galakturonat yang dihasilkan dalam penelitian ini adalah 67,65%-82,02% dan waktu pengentalan karet tercepat adalah 5 menit dengan rasio pectin dan karet adalah 5:5. Kata kunci : Pektin, ekstraksi asam, metoksil, galakturonat Abstract: Pectin is a complex polysaccharides compound which contained in plant cell walls. It is used in food manufacturing processes, adsorbent for waste water treatment and coagulant for rubber industry. Albedo durian was one of the potential sources of pectin, because albedo durian is consist of pectin compound. Acid extraction process was used to decompose pectin compound which contained in albedo durian. In this research, twenty grams of albedo durian was reacted with hydrochloric acid using stirred tank reactor. This process was conducted at temperature 90 0C for 1 hour in various solvent concentration and PH. The purpose of this research was to study the effect of solvent concentration and PH in pectin extraction process and the effect of adding pectin in process of latex coagulation. The result showed that the higher PH and solvent concentration, the higher yield of pectin. The maximum yield of pectin which was obtained in this research is 89.55%. The methoxyl contain and galacturonic which was obtained in this research between 2.430-3.13% and 67.65-82.02%, rescpectively. The Minimum time for latex coagulation about 5 minute using ratio pectin and latex 5:5. Keywords : Pectin, acid extraction, methoxyl, galacturonic