91A-1 |
Stability studies on astaxanthin obtained from fermented shrimp wastes |
R. E. ARMENTA1, S. Huerta1, G. F. Gutiérrez2, and I. Guerrero-Legarreta1. (1) Departamento de Biotecnología, Universidad Autónoma Metropolitana, Iztapalapa, Apartado Postal 55-535, Mexico D.F., 09340, Mexico, (2) Departamento de Graduados en Alimentos, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Prol. Carpio y Plan de Ayala, Mexico D.F., Mexico Astaxanthin is a carotenoid widely used in the food and feed industries. It is mainly marketed for salmonid pigmentation. Natural sources of astaxanthin are abundant, such as shrimp wastes obtained from fish farming and catching in Mexican seashores, where this residue is a severe pollution problem. Lactic ensilation of wastes is an alternative to stabilize the pigment for further extraction. It also improves pigment extraction yields. The objective of this study was determine the stability of astaxanthin obtained from fermented shrimp wastes, subjected to various conditions of illumination, oxygen availability, and temperature, using the synthetic astaxanthin as control. Astaxanthin extracted from fermented shrimp wastes was subjected to three factors and three levels: illumination (darkness, daylight, and sun exposure); oxygen availability (two vacuum levels and air storage); and temperature (15, 25 and 45ºC). Astaxanthin and its degradation product, astacene, were quantified using a HPLC system fitted with a reverse phase column. Sun exposure, storage under daylight, and at 45°C were the main factors and levels affecting astaxanthin degradation to astacene. After 8 weeks of storage under day light, 74.8% of natural astaxanthin and 64.5% of the synthetic astaxanthin were transformed to astacene. Almost all the natural pigment and 83.73% of the synthetic pigment was lost when samples were stored at 45ºC. Storage in darkness, in absence of oxygen and at 15ºC were the best storage conditions to prevent pigment oxidation, keeping circa 90% original astaxanthin concentration; the second best set of conditions (keeping 67% of the natural pigment) was storage at 25°C and reduced oxygen concentration (not vacuum). Natural astaxanthin obtained from fermented shrimp wastes presented good stability. Although it oxidized faster than the synthetic pigment, its stability could be improved by antioxidant and polymer addition, in the same way as the commercial synthetic astaxanthin is treated.
Session 91A, Food Chemistry: Enzymes, vitamins and plant pigments
|