Efeito da temperatura de pré secagem sobre o teor de fibra da silagem de milho

Abstract

Dry matter is the name given to the fraction of food excluding its natural moisture. Pre-drying in a food analysis laboratory is carried out in a forced air circulation oven with variable temperatures, according to the literature, between 55 °C and 65 °C. However, increasing the drying temperature can promote a non-enzymatic browning reaction, known as the Maillard reaction, which occurs between protein and one of the components of the vegetable cell wall, forming substances that can be dosed as lignin, overestimating the content. fiber in foods. Therefore, the objective of this work was to verify whether increasing the pre-drying temperature from 55 °C to 65 °C has effects on the contents of neutral detergent fiber, acid detergent fiber and nitrogen and protein insoluble in acid detergent. The corn silage samples were pre-dried in a forced air circulation oven at two temperatures, 55 °C and 65°C. After drying, the samples were ground in a Willey mill using a sieve with 1mm diameter holes. The processed samples were placed in plastic containers with identification and subsequently the contents of dry matter, neutral detergent fiber, acid detergent fiber, nitrogen and protein insoluble in acid detergent were analyzed. The experimental design used was completely randomized with two treatments (drying at 55 °C and 65 °C), and six replications per treatment. The results were subjected to analysis of variance and the means comparei using the F test at 5% probability, using the statistical program R 3.4.2. According to the average percentage values presented, no significant differences (p > 0.05) were observed for the NDF and ADF contents of pre-dried corn silage in a ventilated oven at temperatures of 55 °C and 65 °C. The average values of acid detergent insoluble nitrogen (NIDAFDA) and acid detergent insoluble protein (PIDAFDA) differed statistically (p < 0.05) between the evaluated treatments (drying temperature). However, there was no significant difference when expressed based on dry matter, NIDAMS and PIDAMS for the different drying temperatures. It was concluded that the drying temperature of corn silage at 65 °C can be used without changing the fiber, nitrogen and protein contents bound to the cell wall when the results are expressed based on dry matter.