Anais do Simpósio Latino Americano de Ciências de Alimentos
Anais do 14 SLACA - Simpósio Latino Americano de Ciência de Alimentos

Caryocar brasiliense (pequi) grows in the Brazilian central plain (Cerrado) and other adjacent regions. The edible part of the fruit is the inner mesocarp that covers the seeds, very popular in local culinary and also used to produce several derivatives, like liqueurs, canned pieces, spicy cream and others. Although rich in nutrients, the external mesocarp and the peel are not appropriate for consumption and are largely discarded, generating big amounts of solid wastes. This work aimed to characterize nutrient content of pequi’s wastes, assessing total carbohydrate concentration (Dubois), reducing sugars (ADNS), total protein (Bradford) and total phosphates (Jacintho), as well as the presence of bioactive or toxic compounds using the bioassay with Artemia salina, in order to evaluate the potential of this waste as a suitable substrate for bioethanol production. Fermentation conditions were optimized in 100 mL Erlenmeyer flasks, using a Saccharomyces cerevisiae strain S-05 and substituting the carbohydrate source in fermentation broth with the studied wastes. An experimental design which combined two factors (mesocarp concentration and fermentation time), at three levels each (1, 5, 9% and 24, 48, 72 hours, respectively) was performed, while three responses were measured for each level combination: cell growth, substrate consumption and ethanol yield. Results were expressed as response surfaces. Total carbohydrate content (40.9 mg/g), reducing sugars (30 mg/g), protein (0.1 mg/g) and phosphates (0.034 mg/g), confirmed the nutritional content of pequi wastes and their potential as a substrate for ethanolic fermentation. No toxicity was observed in mesocarp samples, which displayed survival values above 80% in all Artemia salina cultures. Fermentation process showed ethanol yield values ranging between 9.14 and 11 % (w/v) – without and with alpha-amilase pre-treatment, respectively. These results confirm the suitability of pequi wastes as a rich nutrient source for fermentation processes and the possibility to expressively reduce waste volumes.