Determination of theobromine in cocoa residues

Gerritsma, K. W.; Koers, James M.

doi:10.1039/an9537800201

Cited by 9 publications

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“…Theobromine and caffeine contents in the cocoa beans and cocoa products were determined before and after cleaning through Sep-pak C 18 cartridge. Also, the total theobromine content was determined by Geritsama and Koers' method (6). Six replicate estimations were done for each sample, and the data were analyzed by t test to compare two samples (caffeine) and by one-way analysis of variance followed by Duncan's new multiple range test (20) to compare three samples for statistical significance.…”

Section: Preparation Of Working Standard Caffeine Solutionmentioning

confidence: 99%

“…In 1921, Wadsworth (5) developed a titramatric method for the determination of theobromine in cocoa. Gerritsma and Koers (6) improved this method by using chloroform in an ammonical medium, instead of trichloroethane, for the alkaloid extraction. Holmes (7) used water-boiled extracts clarified with lead acetate in determining purine bases by the titrametric method.…”

Section: Introductionmentioning

confidence: 99%

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Improved High-Performance Liquid Chromatography Method to Determine Theobromine and Caffeine in Cocoa and Cocoa Products

Naik

2001

J. Agric. Food Chem.

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At present, the commonly used HPLC method for the analysis of caffeine and theobromine contents in aqueous cocoa extracts employs direct application of the extracts on the column. This practice gradually reduces the efficiency of the column and shortens its life. Also, this method gives inflated values due to interfering substances and difficulty in achieving baseline resolution. In the improved method, the interfering cocoa pigments are effectively removed by passing the aqueous extract through a Sep-pak C(18) cartridge. Subsequent injection on a C(18) reverse-phase column employing acetonitrile and water (20:80) as the mobile phase reduces the analysis time without affecting either resolution of the peak or the accuracy of caffeine and theobromine determination or achieving baseline resolution. Therefore, this method is ideally suited for rapid routine analysis of cocoa and its products.

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Section: Preparation Of Working Standard Caffeine Solutionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Improved High-Performance Liquid Chromatography Method to Determine Theobromine and Caffeine in Cocoa and Cocoa Products

Naik

2001

J. Agric. Food Chem.

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“…The minor dry season in Ghana coincides with the early/mid stage of pod development as the bulk of pods initiate development in the main wet season (April to June) and pods take approximately 5-6 months after pollination to reach maturity (Fig. 3.4) (Gerritsma, 1995;Toxopeus, 1985;. The net positive effect of temperature on yield suggests that temperature-driven stimulation of pod development had a stronger effect than the negative effects of higher temperature on net assimilation.…”

Section: Climate Drives Absolute Maximum Water-limited and Attainable...mentioning

confidence: 99%

Drivers of cocoa yield under current and future climates

Asante

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Cocoa (Theobroma cacao L.) is one of the world's most important agricultural commodity tree crops with the largest share of global production concentrated in West Africa. Current on-farm yields in this region are low and are expected to decrease in response to climate change through decreasing climate suitability. Previous studies identified numerous climate, soil and agronomic management factors limiting cocoa yields on farmer fields, however, the relative importance of these factors in explaining variation in yields which is relevant for prioritizing interventions is largely unknown. Additionally, effects of temperature, rainfall and atmospheric carbon dioxide concentration [CO2] on cocoa tree physiology and productivity are poorly understood. As a consequence, possible implications of climate change for cocoa productivity and adaptationshave not yet been considered. Climate-induced geographic shifts in the West African cocoa belt may have serious implications for farmers, cocoa supply and forests. This thesis therefore aimed to: (1) assess how current climate, soil and management factors affect current cocoa yields; (2) quantify the cocoa yield gap and the factors that can narrow the gap; and (3) assess the impacts of projected changes in climate and the underlying rise in atmospheric concentration [CO2] on future cocoa production. In this thesis, on-farm data on cocoa yield were combined with simulations with a cocoa crop growth model.It was found that under current climate, agronomic management was the dominant determinant of on-farm cocoa yields in Ghana, more so than environmental (climate and soil) conditions whilst climate effects on yields were stronger than soil effects. Nonetheless, the role of environmental conditions on cocoa yield becomes more important with increasing yields, such that the most productive cocoa farms tend to be the ones whose yields are most climate sensitive. Large cocoa yield gaps were found on farms revealing large opportunities to increase yield beyond current levels. Maximum water-limited yield gaps were much larger than yield gaps attainable in high-input and low-input systems. Climate factors were the important drivers of the absolute maximum water-limited and attainable yield gaps in high-input systems, but not in low-input systems. Relative yield gaps (maximum water-limited, attainable in high-and lowinput systems) were reduced by management practices, particularly cocoa tree density and black pod control. This shows that improved agronomic practices offer opportunities to substantially vi increase production of present-day cocoa plantations.Under future climate by mid-century ( 2060), large increases in potential water-limited yields and gains in area suitable for growing cocoa were expected, particularly when assuming full effects of elevated CO2 and under wetter climate-change scenarios. Impacts were expected to follow a (south) east -west gradient with projected yield increases and in area suitable for cocoa being most positive for Cameroon, followed by Nigeria (excep...

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Considine

1982

Foods and Food Production Encyclopedia

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Determination of theobromine in cocoa residues

Abstract: GERRITSMA AND KOEKS 201* We found that the extraction with tetrachloro-ethane must be finished in one day. If the mass.of cocoa residues were allowed to stand overnight with tetrachloro-ethane, results were irregular.

Cited by 9 publications

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Improved High-Performance Liquid Chromatography Method to Determine Theobromine and Caffeine in Cocoa and Cocoa Products

Improved High-Performance Liquid Chromatography Method to Determine Theobromine and Caffeine in Cocoa and Cocoa Products

Drivers of cocoa yield under current and future climates

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