Estimative of the nutritional value of agroindustrial byproducts by using in vitro gas production technique

Resumo

The objective of this work was to determine the total carbohydrates fractions and to estimate the digestion rate of non-fibrous carbohydrates of agroindustrial byproducts by using the gas production technique. The agroindustrial byproducts evaluated were the following: cashew, passion fruit, pineapple, barbados cherry, annatto and melon, and each sample was incubated in quadruplicate. After mixing all contents thoroughly, the bottles were placed in an incubator at 39ºC, and connecting the lid of each bottle to a pressure sensitive switch, a solenoid valve and a vent stem connector. Gas pressure measurements were made at 0, 3, 6, 12, 15, 18, 22, 26, 30, 34, 40, 48, 60, 72, 96 e 120 hours post-inoculation. Blanks and an internal standard were included to enable adjustments in variation among readings. There was a high variation in nutritional composition of agroindustry byproducts, that cashew and annato presented the highest protein contents (159.3 and 135.3 g/kg of dry matter, respectively). Mellon and cashew presented the lowest values of total gas production (9.60 and 12.85 mL, respectively); and annato, pineapple and passion fruit presented highest gas volume (32.80; 28.16 and 22.54 mL, respectively), being the greatest percentages of phases from B2 fraction (64.27; 81.25 and 67.49%, respectively). Among the byproducts, pineapple and annatto stand out for the highest contribution of fibrous carbohydrate for total gas production, being B2 the main energy source for microbial growth, which is degraded at a slower rate than non-fibrous carbohydrate.