Pierre EFFA ONOMO

Identification of Methylxanthines and Phenolic Compounds by UPLC-DAD-ESI-MS OTOF and Antioxidant Capacities of Beans and Dark Chocolate Bars from Three Trinitario×Forastero Cocoa (Theobroma cacao L.) Hybrids

Simon Perrez Akoa, Jules Christian Djoko Kouam, Martine Louise Ondobo, Jude Manga Ndjaga, Pierre François Djocgoue, Pierre Effa Onomo

RePEc: Research Papers in Economics

Interest on Trinitario cocoa has continuously increased due to the fact that some genotypes of this group had inherited some characters of vigorosity from Forastero and the flavor grade of Criollo. The pronounced incompatibility between Trinitario clones orientates research on the crossing of Trinitario clones with other varieties of cocoa in order to increase productivity and cocoa beans quality. Polyphenols and methylxanthines are bioactive compounds responsible for the health benefits of cocoa and cocoa based products. Cocoa is a crop with a high content of bioactive compounds in the plant kingdom. This study aims at correlating genotypes, methylxanthines and polyphenols as well as antioxidant activity of beans and dark chocolate derived from Trinitario×Forastero hybrids. Total polyphenol content and total condensed tannin contents were determined by spectrophotometric methods. Individual bioactive compounds were identified by UPLC-DAD-ESI(+)-MS both in beans and dark chocolate bar. Results showed differences within beans of dark chocolate and between beans and dark chocolate. Beans from the hybrid (♀)SNK10×(♂)IMC67 recorded the highest polyphenol content (49.18±1.55mg CatE/g) considering the two matrices. The highest concentration of condensed tannins (22.81±0.69 mgCatE/g) was recorded in beans obtained from the hybrid (♀)ICS40×(♂)UPA134. Dark chocolate bar from beans of the hybrid (♀)ICS40×(♂)UPA134 was the richest in condensed tannins (18.25±0.71 mg CatE/g). The total polyphenol and total condensed tannin contents, the chemical composition as well as the antioxidant activity could be genotype-dependent and were affected negatively during roasting. In fact, roasting decreased the polyphenol content and consequently the antioxidant activity. (-)-epicatechin, theobromine, ferulic and chlorogenic acids and their derivatives, procyanidin C1, caffeine and salicylic acid 3-O-glucose/galactose were identified in beans and/or dark chocolate.

• #food chemistry and fat analysis
• #theobroma
• #chemistry
• #food science

A bioformulation of oyster shell, neem, sida, and citronella extracts boosts cocoa (Theobroma cacao L.) seedling development and resistance to black pod disease caused by Phytophthora megakarya

Ebenezer Tatiekam Foka, Tatiana Flore PACHA MAGNI, Paul Martial Téné Tayo, Aristide Dzelamonyuy, Pierre Effa Onomo, Thaddée Boudjeko and 1 more

Journal of Natural Pesticide Research

Phytophthora megakarya is the major destroyer of cocoa production in Central and West Africa. The present study evaluated the efficacy of a bioformulation called Optimized Bio Formulation Prime (OBF') containing oyster shell extract and plant extracts (neem seed, sida weed and citronella) with tween80, on cocoa seedling production. The formulation was tested for stability and activity and it appears that it is stable at 25 o C and reduces the growth of Phytophthora megakarya by 55% when used at 1 µL/mL. OBF' exerts its fungicidal activity by inhibiting protein synthesis and ATPase/H + pump activity of Phytophthora megakarya . The GC-MS analysis of OBF' showed the presence of compounds among which citral and geraniol which have antimicrobial and insecticidal activity. After two weeks, the length and number of secondary roots of the germinated seeds had significantly increased. In addition, the use of OBF' in the in planta assay significantly increased leaf surface area. Detached leaf analysis of these seedlings showed a significant reduction in disease severity index of about 79% compared to untreated plants with OBF'. It was found that OBF' induce PR proteins such as β-1,3-glucanases and peroxidases. A significant increase in polyphenol and polyphenol oxidase activities was also observed in OBF' treated plants. This work demonstrated the stability at 25°C and the efficacy of the OBF' formulation in the management of cocoa black pod disease and, subsequently, increasing the robustness of cocoa plant seedlings against Phytophthora megakarya by priming them with increased defense markers. OBF’ may help to protect cocoa seedlings production.

• #cocoa and sweet potato agronomy
• #food chemistry and fat analysis
• #plant parasitism and resistance
• #phytophthora

Discriminating three lab scale dark chocolate bars from fine Cameroon cocoa hybrids using sensorial evaluation and organic acid content

Simon Perrez Akoa, Renaud Boulanger, Jude Manga Ndjaga, Pierre Effa Onomo, Marc Lebrun, Eliane Flore Eyenga and 3 more

Journal of Food Science and Technology

• #food chemistry and fat analysis
• #meat and animal product quality
• #proteins in food systems
• #aroma

Biofungicide Based Calcium, <i>Azadirachta indica</i> and <i>Sida acuta</i> Against <i>Phytophthora megakarya</i>

Ebenezer Tatiekam Foka, Paul Martial Téné Tayo, Tatiana Flore Magni Pacha, Aristide Dzelamonyuy, Sylvain Leroy Kamdem Sado, Pierre Effa Onomo and 2 more

Plant pesticides are a complementary means to other control methods and an alternative to chemical control. The identification of potential plants that can be used in plant protection against pests is increasing enormously, but the availability of bioformulations is low. The new products developed for plant protection aim to protect them against a larger range of pathogens and include elicitors. The objective of this study is to produce an optimal emulsion bioformulation based on neem (<i>Azadirachta indica</i> A. Juss.), Sida (<i>Sida acuta</i> Burm. F.) and calcium, that can be used for plant protection against pests. The surface plot of the four factor simplex lattice designs data help to construct significant linear models for stability and activity. The best formulation was selected and optimize. The four Factor mixture designs and stability as well as activity models showed that the best formulation has neem oil (No) 12% (v/v), neem aqueous extract (Ne) 9% (w/v), sida weed hydroalcoholic extract (Se) 9% (w/v), Oyster shell’s calcium-rich extract (Ca) 6% (w/v) and tween-80 (Tw) 24% (v/v) with the production process “AQ + (Tw+No)”. Therefore, the optimize formulation has No 12% (v/v), Ne 9% (w/v), Se 9% (w/v), Ca 4.5%(w/v), calcium oxide (CaO 1.5% (w/v) and Tw 24% (v/v) with the production process “(Tw+No) + AQ”. The best formulation and the optimize one at ambient temperature have 100% of stability and a significant dose dependent activity (<I>P</I> <0.05) against plant pathogens. Apply optimize formulation at 1% on the detached cocoa leaves before inoculation with <i>Phytophthora megakarya</i> reduces disease severity index from 4.2 to 1.5. These results suggest that our models and bioformulation can be useful for <i>T. cocoa</i> protection against <i>P. megakarya</i>, the causal agent of black pod disease.

• #plant pathogens and resistance
• #agriculture, plant science, crop management
• #seed and plant biochemistry
• #adenylate kinase

Flavan-3-ol and flavonol analysis in healthy and infected parents and progenies of cocoa leaves (Theobroma cacao L.) with Phytophthora megakarya Bras. and Grif

Jules Christian Djoko Kouam, Jude Manga Ndjaga, Simon Perrez Akoa, Martine Louise Ondobo, Pierre Effa Onomo, Pierre François Djocgoue and 2 more

Tropical Plant Pathology

• #cocoa and sweet potato agronomy
• #food chemistry and fat analysis
• #traditional and medicinal uses of annonaceae
• #flavonols

Allelopathic Effect of Three Wild Plants (&amp;lt;i&amp;gt;Azadirachta indica&amp;lt;/i&amp;gt;, &amp;lt;i&amp;gt;Tithonia diversifolia&amp;lt;/i&amp;gt; and &amp;lt;i&amp;gt;Thevetia peruviana&amp;lt;/i&amp;gt;) on Tomato (&amp;lt;i&amp;gt;Lycopersicum esculentum&amp;lt;/i&amp;gt; Mill.) Growth and Stimulation of Metabolites Involved in Plant Resistance

Georges Yannick Fangue-Yapseu, Romaric A. Mouafo-Tchinda, Martin Kenné, Pierre Effa Onomo, Pierre François Djocgoue

American Journal of Plant Sciences

The aim of this study was to determine the allelopathic effects of Azadirachta indica oil and aqueous extracts of Tithonia diversifolia and Thevetia peruviana on the growth and stimulation of metabolites involved in tomato plant resistance. Randomized in blocks within a shaded area, the different treatments prepared at 10% and 15% (v/v and w/v) in water were subsequently applied on tomatoes seeds to monitor the effect on germination, and on tomatoes leaves to monitor the effect on growth and resilience of the plants. The result showed that in stressful conditions all the treatments significantly inhibit (p T. diversifolia at 10% promotes a better aerial and root growth in tomato plants, T. peruviana at 15% induces the activation of resistance mechanisms in tomato plants by increasing protein levels to 104.5%, phenol levels to 183.33% and peroxidase enzyme activity to 586.15%. Therefore, allelopathic compound of wild plants would be a good alternative for growth promotion and resistance of tomato crops.

• #allelopathy and phytotoxic interactions
• #plant parasitism and resistance
• #chemical synthesis and alkaloids
• #allelopathy

Effect of Cattle Manure Wood-Ash Compost on Chemical, Physical and Microbial Properties of Two Acid Tropical Soils

Blaise Pascal Bougnom, Aristide Molemb Nemete, Guy Faustin Mbassa, Pierre Effa Onomo, François‐Xavier Etoa

Agricultural Journal

• #composting and vermicomposting techniques
• #compost
• #manure
• #soil water

Effects of Cattle Manure Wood-Ash Compost on Some Chemical, Physical and Microbial Properties of Two Acid Tropical Soils

Blaise Pascal Bougnom, Aristide Molemb Nemete, GuyFaustin Mbassa, Pierre Effa Onomo, François‐Xavier Etoa

International Journal of Advances in Scientific Research and Engineering

A field study was conducted to assess the potential of cattle manure wood-ash compost in order to improve soil fertility and productivity in two areas in the centre region of Cameroon distant of 200 km. The farms were amended with four types of compost, C1 (100% cattle manure compost), C2 (95% cattle manure with 10% wood ash admixture), C3 (90% cattle manure compost and 10% wood ash admixture), and C4 (85% cattle manure compost and 15% wood ash admixture). Soybean was the growing plant during the experiment which lasted three months. After the harvesting, physical, chemical, biological and plant parameters were evaluated. The compost significantly increased soil pH, Electrical conductivity, total organic carbon, total nitrogen, concentrations of Ca 2+ , Mg 2+ , K + , Na + , and total phosphorus. The composts also had a stimulatory effect on the total soil bacteria and fungi, cellulase and protease activities. Improvement soil physical, chemical and microbial parameters enhanced biomass production and yield. In summary, cattle manure wood-ash composts could be used for alleviating soil acidity and improve soil fertility of tropical acid soils. Future research is needed to address its sustainability in a long-term study.

• #agriculture and rural development research
• #compost
• #manure
• #soil water

Virulence Test of Some Phytophthora Megakarya Isolates on Cocoa (Theobroma Cacao L.) Hybrid Pods

Pierre Effa Onomo, Jude Manga Ndjaga, Martine Louise Ondobo, Jules Christian Djoko Kouam, Pierre François Djocgoue

IOSR Journal of Biotechnology and Biochemistry

Phytophthora megakarya is an Oomycete which has a negative impact on Cameroon cocoa production. An assessment of the level of virulence of different isolates of P. megakarya in mono or coinfection was performed on some hybrids of cocoa (Theobroma cacao L.) obtained from reciprocal crosses. The isolates tested on eight cocoa hybrids obtained by hand pollinisation were Bakoa, Le4 and Lebdi. Contents of soluble amino acids, sugars, polyphenols and proline were determined using standard methods in mono or coinfected cocoa pods. This study revealed that, the development of the necrotic area in the cortex of cocoa pods was genotype-dependent and isolate-dependent after infection. For this reason, the classification in terms of virulence of isolates was the following: Lebdi<Le4<Bakoa. However, SNK 413 x T 79/501 and T 79/501 SNK 413 hybrids were the most tolerant while UPA 134 x ICS 40 and T 79/467 SNK 13 hybrids proved to be the most sensitive to threeP. megakarya isolates. Bakoa + Le4 combination was the most aggressive among the other combinations.Groupings of samples were observed using principal component analysis (PCA) and hierarchical cluster analysis.Significant and negative correlations were found between necrosis and three biochemical metabolites (total polyphenols, soluble sugars, Proline andsolubleamino acids) in cocoa hybrids suggesting that these metabolites could be considered as markers of resistance in T. cacao/P. megakarya interactions.

• #cocoa and sweet potato agronomy
• #phytoplasmas and hemiptera pathogens
• #food chemistry and fat analysis
• #theobroma

Heterosis and Heritability of Chemical Quality of Butter Derived from Some Cocoa (Theobroma Cacao L.) Clones

Pierre Effa Onomo, Mbia Ronelle Fabiola, Achu Mercy Bih, Martine Louise Ondobo, Kancsi Germain

Zenodo (CERN European Organization for Nuclear Research)

Butter from dry cocoa beans of five cocoa (Theobroma cacao L.) clones and their intercrossed hybrids were analyzed for chemical quality (acid, peroxide and iodine) in order to gain insight on the heterosis and broad-sense heritability values for these traits. Standard procedures were used for estimation of the lipid content and the indices. Hybrid F20 had the highest lipid content (59.7%) while the parent SCA12 and hybrid F12 had the lowest with 44.5 and 45% respectively. The acid index varied between 19.4 and 28.8 mg KOH/g, iodine index from 10.2 to 30.5 g/100g and peroxide index from 0.3 to 7.3 meq.g O2/kg. The acid index was higher than recommended limits for edible oils, iodine index lower and peroxide index within the international norms for conventional oils. Hybrids F12, F40 and F79 presented a positive mid-parent heterosis for acid index while F14, F13, F20 and F79 showed it for peroxide index. With regards to best-parent heterosis, only F40, F13 and F79 for acid index and F14 and F13 for peroxide index showed positive heterosis effect. For iodine index, about 71 % of hybrids showed a positive mid-parent heterosis. The acid and peroxide indices showed high heritability (while the iodine index had moderate heritability) estimates and this heritability could be said to be cytoplasmic except for the reciprocal hybrids F13 and F79 (acid index). The Principal component analysis categorized two distinct groups of six individuals each. Quality characteristics were moderate for butter obtained from the first cluster and lower for the second one. When all these quality parameters are taken into account, F79 and its reciprocal hybrid F13 showed the highest hybrid vigour. Their parents can be therefore considered as the best combination for producing hybrids with high nutritional oil quality vigour.Read Complete Article at ijSciences: V52016061043 AND DOI: http://dx.doi.org/10.18483/ijSci.1043

• #food chemistry and fat analysis
• #cocoa and sweet potato agronomy
• #theobroma
• #heterosis

Phenolic content and heritability of resistance in four hybrid populations of &lt;i&gt;Theobroma cacao&lt;/i&gt; L. after leaves inoculation with &lt;i&gt;Phytophthora megakarya&lt;/i&gt; Bras. et Grif

M.L. Ondobo, Pierre Effa Onomo, PF Djocgoue, Jude Manga Ndjaga, Thaddée Boudjeko, Denis Omokolo Ndoumou

International Journal of Biological and Chemical Sciences

Cocoa is cultivated in Cameroon for its broad beans. The commercialization of cocoa seeds constitutes a major source of income to farmers. Nevertheless, cacao black pod disease caused by Phytophthora megakarya is responsible of about 80% of cocoa production loss in Cameroon without any protection method. To assess the resistance of cocoa plants against this pathogen, necrotic lesions and phenolic content were conducted on 3 clones (SNK16, ICS40, Sca12) and their progenies (families F40, F12, F20 and F25) after leaves inoculation. The existence of strong hybrid vigour has been shown. All hybrid genotypes manifested a positive heterosis effect for this symptom suggesting the existence of hybrid vigour. Some hybrids like F40.6, F40.7, F40.8, F40.9, F40.10, F12.10, F12.15, F20.7, F20.10, F25.2, F25.5 and F25.7 were characterized by localized lesions. A negative correlation between the size of necrotic lesions and the total phenolic compound was demonstrated. Three genotypes of the F40 family (F40.8, F40.9 and F40.13), one of the F12 (F12.15) and two of the F25 (F25.2 and F25.8) had small lesions and high concentrations of phenols. These six genotypes can be considered as elite clones with high tolerance to P. megakarya. The values of the heritability of lesion size and the total phenolic content in offsprings don’t show the maternal effect.Keywords: Cocoa, Phytophthora megakarya, heterosis, heritability, necrosis, phenols

• #cocoa and sweet potato agronomy
• #food chemistry and fat analysis
• #theobroma
• #biology

Change in amino acids content during germination and seedling growth of Cola sp.

Pierre Effa Onomo, Nicolas Niemenak, Denis Omokolo Ndoumou, R. Lieberei

AFRICAN JOURNAL OF BIOTECHNOLOGY

Accessions of Cola acuminata and Cola anomala were analysed based on the variation of free amino acids during germination and seedling growth. These compounds were determined by high performance liquid chromatography (HPLC) methods. In the non-germinated seeds of C. acuminata , arginine (Arg) was the major amino acid found in all six accessions and valine (Val) was the least present, while in C. anomala , gamma ()-aminobutyric acid (GABA) was predominant and isoleucine (Ile) was less abundant. During germination, the seeds of the two species accumulated large amount of GABA and very little tryptophan. Principal component and cluster analyses of Cola sp. categorized the accessions into two groups distinguishing the two Cola species. The differences between the groups were related not only to the absence/presence of histidine (His) and phenylalanine (Phe), but also to amide amino acids asparagine (Asn), glutamine (Gln) and Arg contents. In Cola sp., free amino acids varied significantly during these two processes indicating their high utilization. These metabolites can be considered as crucial in the control of germination. Keywords : Cola sp., amino acids, germination, seedling growth African Journal of Biotechnology Vol. 9(35), pp. 5632-5642, 30 August, 2010

• #gaba and rice research
• #plant genetic and mutation studies
• #seed and plant biochemistry
• #germination

Purine alkaloids and phenolic compounds in three Cola species and Garcinia kola grown in Cameroon

Nicolas Niemenak, Pierre Effa Onomo, Fotso, R. Lieberei, Denis Omokolo Ndoumou

South African Journal of Botany

Accessions of Cola acuminata, Cola nitida and Cola anomala were analysed based on the variation of polyphenol and alkaloid contents in order to gain insight on the genetic relationships within and between the taxonomic entities. These compounds were analysed at 280 nm by HPLC using a Photodiode Array Detector (PDA). Catechin, epicatechin, theobromine and caffeine were detected in Cola seeds. Among the three species, C. nitida is found to be highest in flavonoid and caffeine content while C. anomala possessed high amount of theobromine. Catechin was the dominant flavonoid. Caffeine was the major alkaloid in Cola seeds and was considered as one of the signature compounds due to its concentration range. The average concentrations in C. acuminata, C. nitida and C. anomala accessions were 11066 ± 3166, 13761 ± 2728 and 7013 ± 2369 mg/kg FW respectively. Garcinia kola seeds displayed higher levels of total phenolic compounds compared to Cola sp. and lacked purine alkaloids and catechin. The former displayed many unidentified polyphenolic compounds most of which were apolar. Principal component and cluster analyses of Cola sp. categorized accessions into two groups. The first chemotype encompassed C. anomala accessions and exhibited high theobromine content. The second cluster enclosed C. nitida and C. acuminata accessions and displayed high caffeine and catechin contents. Genetic distances between the accessions varied from 0.0 to 1.26. The importance of Cola phenolic compounds and alkaloids in food chemistry and chemotaxonomy is discussed.

• #natural compound pharmacology studies
• #synthesis of organic compounds
• #carbohydrate chemistry and synthesis
• #theobromine

Isoenzyme Variability of Three Cola (Cola acuminata (Pal. de Beauv, Schott and Endlicher), Cola nitida ((Vent) Schott and Endlicher) and Cola anomala (Schott and Endlicher)) Germplasm in Cameroon

Pierre Effa Onomo, Nicolas Niemenak, Denis Omokolo Ndoumo .

Pakistan Journal of Biological Sciences

• #african botany and ecology studies
• #cola (plant)
• #anomala
• #botany

Morphological Variability of Cola acuminata ((Pal. De Beauv) Schott and Endl.) Germplasm in Cameroon

Pierre Effa Onomo, Nicolas Niemenak, Denis Omokolo Ndoumo .

Pakistan Journal of Biological Sciences

• #seed and plant biochemistry
• #african botany and ecology studies
• #germplasm
• #cola (plant)