The use of colorants in products of animal origin is justified by the improvement in the color of foods since this attribute is considered a quality criterion. These additives can be produced using industrial effluents as substrates and appropriate organisms, such as Rubrivivax gelatinosus. Oxycarotenoids represent a class of carotenes responsible for the pigmentation of animals and vegetables. R. gelatinosus grows in fish industry effluent with the resulting production of a bacterial biomass containing oxycarotenoids. The purpose of this study was to compare the use of two drying processes - spray and freeze drying - to obtain powder biomass in terms of the process parameters (yield, productivity, and product recovery) and the product characteristics (color, proximate composition, and oxycarotenoids). No difference was detected in the yield between these techniques, while productivity was higher using spray drying. Higher product recovery and moisture were achieved with freeze drying, while ash was higher with spray drying. The freeze dried biomass was redder, darker and less saturated than the spray dried biomass. No difference in oxycarotenoids was detected between the biomasses. Although it results in lower recovery rate, spray drying was faster and more productive, and it provided the same yield as freeze drying, which makes it the method of choice for obtaining R. gelatinosus biomass.

No abstract

Color is an important attribute in food acceptance. It can is a quality attribute since things are perceived based on sensory impressions (BARUFFALDI; OLIVEIRA, 1998). Carotenoids are the natural pigments responsible for yellow, orange, and red colors in foods, pharmaceuticals, cosmetics, and animal feed. They consist of two classes of molecules: carotenes, which are strictly hydrocarbons, and xanthophylls or oxycarotenoids, which contain oxygen (JOHNSON, 2007). Besides being widely used as colorants, some carotenoids can also be used to enrich foods due to their antioxidant properties, to the fact that they act as vitamin A precursor are considered beneficial for health, among other things (NIIZU, 2003; VALDUGA et al., 2009). The use of colorants in animal feeds provides typical pigmentation improving their consumer acceptance (MOTTA; VIDAL; MATTOS, 2009). For instance, canthaxanthin and bixin may be added to poultry feed to enhance egg yolk color and to broiler chicken feed to enhance skin and meat color, thus aggregating commercial value to these products (GARCIA et al., 2009; CARNEIRO, 2010). β-caroten and asta xanthin are the main pigments used in aquaculture (AKSU; EREN, 2007). These synthetic pigments are generally used to provide color to salmonids and trouts to make them more attractive to consumers (TAKAHASHI; TSUKAMOTO; TABAT, 2008). Resumo O uso de corantes em produtos de origem animal justifica-se pela melhora na cor dos alimentos, uma vez que este atributo é considerado um critério de qualidade. Estes aditivos podem ser produzidos utilizando efluentes industriais como substratos e organismos adequados, como Rubrivivax gelatinosus. Oxicarotenóides representam uma classe de carotenos, responsáveis pela coloração de animais e vegetais. R. gelatinosus cresce em efluente de indústria de pescado produzindo biomassa contendo oxicarotenóides. O objetivo deste experimento foi comparar duas metodologias para obter a biomassa seca-atomização e liofilização-em relação aos parâmetros do processo (rendimento, produtividade, recuperação) e sobre as características dos produtos (cor, composição centesimal, oxicarotenóides). As técnicas não diferiram quanto ao rendimento, enquanto que a produtividade foi maior para a atomização. A maior recuperação e a maior umidade foram obtidas pela liofilização, enquanto que a concentração de cinzas foi maior com a atomização. A biomassa liofilizada foi mais vermelha, mais escura e de cor menos saturada. Não houve diferença entre os conteúdos de oxicarotenóides. Embora resulte em uma menor recuperação, a atomização foi mais rápida, mais produtiva e apresentou rendimento equivalente à liofilização, o que a torna o método de escolha para a obtenção de biomassa de R. gelatinosus.