Preparacion De Polvo De Yema De Huevo Por Mini Spray Dryer

Preparation of powdered egg yolk using a mini spray dryer
Estudo da obtenção de ovo em pó usando mini spray dryer
Rene Maria IGNÁRIO1, Suzana Caetano da Silva LANNES1* Abstract
Powdered egg is used as an emulsifying agent in emulsion formulations. It is an excellent source of high quality protein, of which the yolk contains 44% and the egg white 56%. Spray drying is a widely applied method fordrying aqueous or organic solutions and emulsions in the chemical and food industries. Spray drying can be used to preserve food or simply as a rapid drying method. The objective of this work was to study the viability of obtaining powdered egg yolk powder using a Büchi B-190 Mini Spray Dryer. The egg yolk protein was evaluated by the semi-micro Kjeldahl method. It was concluded that the use ofthe Büchi B-190 Mini Spray Dryer to produce powdered egg yolk is perfectly feasible. Keywords: spray dryer; powdered egg; egg yolk.

Resumo
Ovo em pó pode ser usado como agente emulsificante. É uma excelente fonte de alta qualidade protéica contendo 44% na gema e 56% na clara. Spray dryer é um método amplamente usado para secar soluções aquosas ou orgânicas, emulsões, na indústria química ealimentícia. Spray dryer pode ser usado para preservar alimentos ou simplesmente como um método rápido de secagem. O objetivo deste trabalho foi estudar a viabilidade de obtenção de gema de ovo em pó utilizando o Büchi B-190 Mini Spray Dryer. O teor de proteínas da gema de ovo foi analisado pelo método semi-micro Kjeldahl. Concluiu-se o uso do Büchi B-190 Mini Spray Dryer para a obtenção de gema deovo em pó é perfeitamente viável. Palavras-chave: spray dryer; ovo em pó; gema.

1 Introduction
Eggs perform multiple functions in making and processing foods – they emulsify as well as add color, tenderness and flavor. Powdered egg is used as an emulsifying agent in emulsion formulations, increasing their stability, properties and economy. It is an excellent source of high quality protein, 44%found in the yolk and 56% in the egg white3. In addition, powdered egg is widely used in processed foods thanks to its microbiological safety and reduced volume2. The processes employed in the production of dried egg include pan drying, foam-drying, freeze-drying, and spray-drying, the latter being frequently used5 Guardiola. In this process, a liquid droplet is dried rapidly as it comes intocontact with a stream of hot air. The small size of the liquid droplets allows for very rapid drying and the residence time of the material inside the spray dryer is in the order of seconds. The dried material is separated from air in a cyclone separator. The drying rate and the time required for drying depend on the temperature of the droplet being dried TOLEDO13. Heat can damage the product ifcontact with high temperature drying air is long, denaturing the egg yolk lipoproteins, a problem that has logically been related to poorer emulsifying properties MOROS10. For a laboratory scale system, a small device such as the B-190 Mini Spray Dryer is particularly interesting to produce small volumes of product within a short time. This device can handle spray drying processes in 50 mL batch volumesand up to 1 L of solution per hour and, thanks to its glassware, makes the complete drying process from the two fluid nozzles down to the collection vessel visible. The product parameters resulting from this drying method are affected by the instrument settings, and are therefore usually optimized through trial and error BÜCHI1. Because egg yolk functionality is determined mostly by its proteinfraction, our study was aimed at determining the technical viability of using the Büchi B-190 Mini Spray Dryer to produce powdered egg yolk suitable for stabilizing mayonnaiselike emulsions.

2 Materials and methods
White eggs (120) were purchased in a single lot at a local supermarket and stored in a domestic refrigerator at 5 °C. The amount of protein was evaluated by the Kjeldahl technique,...