Calcium supplementation can be used as a means of reducing the absorbable energy value of chocolate. Supplementation with 2.25% CaCO3 had no effect on the taste of chocolate, was well tolerated by the subjects, and reduced LDL cholesterol in a short-term study.

To reveal its flavor, coffee has to be roasted. In fact, the green coffee bean contains all ingredients necessary for the later development of coffee flavor. It is now widely accepted that free amino acids and peptides are required for the generation of coffee aroma. However, the mechanisms leading to defined mixtures of free amino acids and peptides remain unknown. Information pertaining to the identification of precursor proteins is also lacking. To answer some of these questions, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was used to follow the fate of green coffee proteins. Two conditions were considered: roasting and incubation of green coffee suspensions at 37 degrees C. Coffee beans were observed to acquire the potential to spontaneously release H(2)O(2) upon polymerization of their proteins during roasting. Fragmentation of proteins was also observed. Conversely, H(2)O(2) was found to control polymerization and fragmentation of green coffee proteins in solution at 37 degrees C. Polymerization and fragmentation patterns under the two conditions were comparable. These observations suggest that the two conditions under study triggered, at least to some extent, similar biochemical mechanisms involving autoxidation. Throughout this study, a unique fragmentation cascade involving the 11S coffee storage protein was identified. Generated fragments shared an atypical staining behavior linked to their sensitivity to redox conditions.

Coffee flavor is the product of a complex chain of chemical transformations. The green bean has only a faint odor that is not at all reminiscent of coffee aroma. It contains, however, all of the necessary precursors to generate the unmistakable coffee flavor during roasting. The levels and biochemical status of these precursors may vary in relation to genetic traits, environmental factors, maturation level, postharvest treatment, and storage. To improve our understanding of coffee flavor generation, the sensory and biochemical impact of maturation was assessed. Maturation clearly favored the development of high-quality flavor in the coffee brew. A specific subclass of green coffee beans, however, generated high-quality coffee flavor irrespective of maturation. Biochemical aspects were examined using a dynamic system: immature and mature green coffee suspensions were incubated under air or argon. On the analytical side, a specific pool of flavor precursors was monitored: chlorogenic acids, green coffee proteins, and free amino acids. A link between maturation, the redox behavior of green coffee suspensions, and their sensory scores was identified. Compared to ripe beans, unripe beans were found to be more sensitive to oxidation of chlorogenic acids. Aerobic incubation also triggered the fragmentation or digestion of the 11S seed storage protein and the release of free amino acids.

Objective: To compare, in humans, the digestibility of moderate amounts of cocoa butter (30.7 gad) consumed in the form of chocolate as part of a normal western diet with that of a well-absorbed fat (corn oil); and hence determine whether, by virtue of its apparent low absorption, cocoa butter can be considered to be a low calorie fat. Design: Randomised, two-period crossover metabolic study, conducted under free-living conditions, but with strict control over food intake. Setting: Metabolic Unit, Nestle  Research Center Lausanne. Subjects: Twelve healthy men were selected from volunteers at the Nestle  Research Center and all subjects completed the study. Intervention: Two treatment periods of two weeks each: cocoa butter and control periods, with strict dietary control separated by a two week wash out period. Results: No differences (P b 0.05) were observed in faecal weight (wet or dry), faecal fat nor in defecation frequency between treatments (cocoa butter and corn oil). Cocoa butter at a dose of 30.7 gad in the form of black chocolate, consumed between two meals, was found to have a similar digestibility to that of corn oil (99 % of corn oil digestibility). Conclusion: Cocoa butter, consumed as black chocolate within a normal mixed diet, has a high digestibility, similar to that of corn oil, and a digestible energy value of 37 kJag in man. Thus, cocoa butter cannot be considered to be a low-calorie fat.

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