THERMAL STABILITY OF ASTAXANTHIN IN OILS

REYNOSO C. M.; COLLINS P.; CALVO N. S.; RESNIK S.; DE AZEVEDO CARVALHO D.; CORTES-JACINTO E.

Montpellier

Congreso; Aqua 2018; 2018

World aquaculture society

Food rations for red rainbow trout incorporate from 30 to 100 mg of astaxanthin per kilogram. Consequently, astaxanthin is one of the inputs that most influences final prices of these salmonids on the market. During food processing, astaxanthin is unstable due to its sensitivity to various environmental factors, such as light, oxygen, acidity and temperature, which cause the loss of its bioactivity. In this context, it is necessary to find new sources of astaxanthin or to achieve a reduction in pigment loss during manufacturing processes. Dilocarcinus pagei is a native crab that is commonly found in fish culture ponds and presents an attractive reddish-brown coloration. The present research aims to study the concentration of astaxanthin present in this crab, and the stability of this carotenoid dissolved in sunflower, soy, and fish oils within temperatures important for fish food processing technology (extraction, cooking and extrusion temperatures), transporting and stoking.Individuals of D. pagei were collected and homogenized. Carotenes were extracted from different samples using acetone. The extractions were analyzed using HPLC-spectrophotometer and astaxanthin was quantified. Astaxanthin oil solutions were distributed into several closed test tubes and incubated at different temperatures between 25 and 180 °C. Samples were taken from each tube at different intervals of time and astaxanthin was quantified. The quantification method of astaxanthin was validated for sunflower and soybean oil but not for fish oil. Due to the variance between replicates and the consequent impossibility to estimate astaxanthin concentrations, the fish oil was excluded from the study of stability of astaxanthin at different temperatures. Astaxanthin dissolved in soy and sunflower oil showed a great stability in the studied range, from 25 to 180 °C, and astaxanthin was more stable in commercial soy oil than in sunflower oil. The information obtained in this study allows to estimate astaxanthin loss during fish food processing