Amazonian peach palm seeds methods comparation of water content determination by quadratic plateau regression¹

Comparação de métodos de determinação do teor de água de sementes de pupunha por meio de modelo de regressão quadrática-platô

ABSTRACT

Given the recalcitrant nature of peach palm seeds, which results in high sensitivity to desiccation, more effective approaches to seed quality monitoring are extremely important and justify the need to provide an efficient method to determine their moisture content. For seeds which are considered to be larger (thousand seed weight > 200 g), seed preparation is required, but it is impractical owing to endocarp hardness. The objective of this work was to compare methods of evaluating the moisture content of peach palm seeds, aiming to identify an straightforward method for the species. Different seed preparation and drying methods (oven method at 105 ± 3 °C, low temperature at 103 ± 2 °C, and high temperature at 130 ± 2 °C) were tested. For all methods tested, the beginning of weighing took place after the first hour, and continued until the mass of each repetition became constant for two consecutive measurements. The data were analyzed by nonlinear quadratic plateau regression to evaluate the stabilization period of water content. Thus, the oven method at 130 °C for four hours (with whole seeds) is recommended.

Key words
Bactris gasipaes; Oven method; Recalcitrance; Water content; Drying period