LAUSR

Abstract Astaxanthin is one of the inputs that most influences the final prices of salmonids on the market and is unstable due to its sensitivity to various factors, such as temperature, which cause the loss of its bioactivity during feed processing and storage. Dilocarcinus pagei is a native crab that is commonly found in fish culture ponds and presents an attractive reddish-brown coloration. The objectives of the present study were to evaluate this crab as a natural source of astaxanthin and to assess how the stability of this pigment was affected by different vegetable oils (soy and sunflower) and butylhydroxytoluene (BHT) presence over a range of temperatures used in feed processing technology like extraction, cooking, extrusion and storage. Individuals of D. pagei were collected and homogenized. Carotenes were extracted from different samples using acetone. The extractions were analyzed using High-Performance Liquid Chromatography (HPLC). The percentages of remaining astaxanthin dissolved in soy and sunflower oils with or without BHT (0.1%) were estimated before and after being incubated at 50 °C. Astaxanthin dissolved in both oils with BHT were exposed to different temperatures between 25 °C and 180 °C. Samples were taken at different intervals of time and astaxanthin was measured at λmax490 nm by a spectrophotometer. The degradation rate of astaxanthin at each temperature in both oils was estimated. The results showed that D. pagei would be an alternative as a natural source of astaxanthin since its concentration values (231.5 μg/g dry matter) are similar to those present in other species commercially exploited. The two-ways Analysis of variance (ANOVA) showed that the presence of BHT (P = 0.03) and the oils (P