4. Conclusions
The proximate composition of both defective and non-defective coffee beans was evaluated. No significant differrences in protein levels were detected for defective and non-defective beans, after correction for caffeine and trigonelline nitrogen. Significant differences were observed for ash contents of the coffee samples, with the highest values found for black beans. Non-defective coffee beans presented higher lipids contents than defective ones. After roasting, protein and ash contents remained approximately constant. There was a slight decrease in the oil content of non-defective beans,while the others remained relatively constant. Also, no differences were observed in the fatty acids compositions of all samples, crude and roasted. Thus, it can be concluded that there are only slight variations in composition of defective coffee beans compared to non-defective ones. Regarding oil quality parameters, values for crude coffee oil are within standards used in the trading of other edible oils, except for unsaponifiable matter content and free acidity, which presented high values. However, these values should be lowered with refining of the oil. Thus, both the oil and the resulting waste solids can be deemed suitable for use in formulations in the food and pharmaceutical industries after minor processing.
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