Modificações na composição da torta de mamona em função do armazenamento e do teor de umidade.

Abstract

The meal is the main by-product of the productive chain of the castor (Ricinus communis L.), originated after the extraction of the oil of the seeds, being used all over the world as organic fertilizer and as protein supplement for livestock after detoxification. This research aimed to avaluate the chemical composition of castor seed meal when stored under different packing bags and in several humidity levels in the period of six months. Entirely casualized experimental design was used with three replications. Twenty four treatments were tested, arranged in a 3 x 2 x 4 factorial, with the following factors: Humidity levels (HL) - lower (6%), middle (14%) and high (22%); Packing bags - raffia and plastic; and Storage periods: 0, 2, 4 and 6 months. Castor seed meal (CSM) was evaluated regarding HL, ash, organic matter, nitrogen, phosphorus, potassium, gross protein and acidity. CSM humidity levels were significantly (P<0.01) influenced by packing system, there being increase under raffia packing (32.83 vs. 24.44%). When stored under high HL, CSM tended to mineralize quickly, promoting significant increase in ash content (6.21 for low vs. 9.91% for high) and consequently decreasing organic matter content (71.7 for low vs. 51.7% for high); however, this high HL influenced significantly its nutrient content for it contributed to the incidence of microorganisms, causing increase of NPK level and gross protein during long storage period. Acidity level increased along the whole storage time, according to increases in HL of CSM (7.63, 9.15 and 11.66 mgKOH/g of oil, for low, middle and high respectively) mainly in the nylon packing (10.43 vs 8.53 mgKOH/g of oil).