Oxidative Stability of Microencapsulated Fish Oil during Refrigerated Storage

Abstract

Microencapsulation of fish oil was done by spray drying. Commercially available milk was used to form microsized emulsion. Ginger essential oil (0.25%) was used as source of antioxidant. Fish gelatin and maltodextrin were tested for their ability to serve as wall materials for microcapsules with milk protein. Encapsulation efficiency was improved significantly (P < 0.05) by the addition of fish gelatin/maltodextrin as wall material. Flow properties of fish oil encapsulate were passable to poor. Fatty acid composition of fish oil encapsulates showed protection of polyunsaturated fatty acids from oxidation. Oxidative stability of the fish oil encapsulates showed better protection against lipid oxidation (1.89 mg malonaldehyde/kg) for fish oil encapsulates prepared with fish gelatin and ginger essential oil and packed in vacuum condition than the control (5.41 mg malonaldehyde/kg) at refrigerated condition. It suggested that in addition to wall material, ginger essential oil also improved the oxidative stability of encapsulates. Practical Applications Fish oil represents a functional food, which contains important components for maintenance of good health and prevention of various diseases. Autoxidation of polyunsaturated fatty acids present in the fish oil leads to the development of volatile secondary oxidation products and limits the shelf life of the foods. Oxidative stability of fish oil is improved by the microencapsulation process and its shelf life can be extended when stored in cool environment. The microencapsulation of fish oil also provides a taste profile barrier eliminating fish oil taste and odor. The incorporation of fish oil in food products is becoming increasingly widespread and a large variety of products is being marketed. The present study provides information about the possibility of producing fish oil encapsulates by spray drying without affecting its stability by incorporating ginger essential oil as a natural antioxidant. It can be used for preparation of fish oil fortified food products.