Cocoa fermentations in Ghana and Trinidad as well as anaerobic fermentation-like incubations of fresh cocoa beans in Germany were carried out under controlled conditions. Samples of beans were taken during the course of these treatments and determinations were made as to acidification (pH, acetic acid content), proteolysis (free a-amino nitrogen, peptide nitrogen and SDS electrophoresis of the protein peptides) and flavour potential (gas chromatography of the highly volatile compounds, in particular isopentanal and organoleptic analysis after thin layer roasting). A positive correlation between acidification, proteolysis and the development of flavour potential during anaerobic fermentation can be demonstrated in principle. However, the flavour potential is increased if the temperature rise is comparatively slow in both normal fermentation and laboratory incubation. Strong acidification and high accumulation of amino acids and peptides were not essential for a good flavour potential. The isopentanal content proved to be a useful indicator of the progress of normal fermentation in the tropics. These findings can be interpreted on the basis of earlier results about germination-like processes in the protein vacuoles, pre-and post-mortem subcellular structures and the special characteristics of acetic acid diffusion. Conclusions which are relevant to the practice of cocoa fermentation are discussed in more detail.

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Recent interest in the development of the tallow tree (Pentadesma butyracea S ) as an oil-tree crop has stimulated agronomic and chemical studies of the tree and the fat obtained from its seeds. Tallow fat extracted from local seeds has been analysed for its chemical and physical constants and fatty acid composition. These characteristics have been compared with those of the better known cocoa butter and shea butter. Dry tallow kernels, shea butter kernels and cocoa beans contained 50, 52.1 and 53.4% fat, respectively. Tallow fat and shea butter are similar in several of their characteristics, particularly slip point, saponification number, solidification point and fatty acid composition; but tallow fat has a much lower unsaponifiable matter content (1.5-1.8 %) than shea butter (7.3-9.0 %). Both are markedly different from cocoa butter and cocoa butter replacement fats in respect of their melting points and fatty acid composition. Cooling curves of 3: 1, 1 : 1, and 1 : 3 mixtures of tallow fat and cocoa butter indicate poor compatibility between the two fats.

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Various isolates of Cacao Swollen Shoot Virus (CSSV) were detected without difficulty in leaves of Theohroma cacao L. by ELISA and immunosorbent electron microscopy (ISEM) using an antiserum to severe strain lA. Many isolates were detected with relatively high values at dilutions of 1 :30, whereas some other isolates were hardly or not at all detected at this dilution. Strain lA was detected at dilutions of up to 1 :2560 of crude leaf extracts. All isolates yielding high reactions seem to be serologically closely related to strain lA. Strains of the mottle-leaf type (AD 191, AD 196, AD 7, AD 36, AD 135, Kpeve) and others were poorly detected; their relationship to strain lA is discussed. A close correlation was found between results obtained by ELISA and ISEM. ZusammenfassungNachweis und Vergleich verschiedener ghanaischer Isolate des Cacao Swollen Shoot Virus (CSSV) mit ELISA und IEM unter Verwendung eines Antiserums gegen den CSSV-Stamm IA Verschiedene CSSV-Isolate wurden in Kakaoblattern {Theohroma cacao L.) unter Verwendung von Antiserum gegen den CSSV-Stamm lA mit ELISA und Immunosorbent Electron Microscopy (ISEM) sicher nachgewiesen. Viele Isolate waren in wenig verdlinntem Rohsaft (1 :30) mit hohen Werten, andere dagegen nicht oder nur sehr schwach nachweisbar. Der CSSV-Stamm IA reagierte in Rohsaft noch bis zur Verdunnung von 1 :2560 deutlich. Die Isolate AD 191, AD 196, AD 7, AD 36, AD 135 und Kpeve waren trotz starker Symptomausbildung nicht zuverlassig nachweisbar. Dies ist durch deren sehr niedrige Viruskonzentration bei gleichzeitigem serologischen Unterschied zum U.S. Copyright Clearance Center Code Statement: 003 l-9481/85/1401-0079$02.50/0 ^0 SAGEMANN, LESEMANN, PAUL, ADOMAKO and Owusu Siamm iA bedingt. In symptomlosen Blattbereichen infizierter Kakaoblatter der anfalligen Sorte Amelonado konnte der CSSV-Stamm lA nieht mit dem ELISA nachgewiesen werden. Das Virus diirfte daher im Wirt sehr ungleichmafiig verteilt sein (vgl. auch: DALE 1962). Zwischen den Ergebnissen des ELISA und ISEM bestand eine gute Korrelation.