The aim of the study was the optimisation of Spirulina platensis drying on convective hot air through the response surface methodology. The responses were thiobarbituric acid (TBA) and phycocyanin loss percentage values in final product. Experiments were carried out in perforated tray drier with parallel air flow, and the wet samples thickness and drying air temperatures were in range of 3-7 mm and 50-70°C, respectively. The statistical analysis showed significant effect (P < 0.05) for air temperature and samples thickness. In the best drying condition, 55°C and 3.7 mm, presented the phycocyanin loss percentage and the TBA values of approximately 37% and 1.5 mg MDA kg )1 , respectively. In this drying condition, the fatty acids composition of the microalgae Spirulina did not show significance difference (P > 0.05) in relation to fresh biomass. The lipid profile of dried product presented high percentage of polyunsaturated fatty acids (34.4%), especially the gamma-linolenic acid (20.6%).

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The aim of this work was to study the convective drying of anchovy (Engraulis anchoita) fillets and to evaluate the final product characteristics through its biochemical and functional properties. The drying temperatures were of 50, 60 and 70°C, and the fillet samples were dried with the skins down (with air flow one or the two sides) and skins up (with air flow one side). The drying experimental data were analyzed by Henderson–Pabis model, which showed a good fit (R2 > 0.99 and REQM < 0.05). The moisture effective diffusivity values ranged from 4.1 × 10–10 to 8.6 × 10–10 m2 s−1 with the skin down and 2.2 × 10–10 to 5.5 × 10–10 m2 s−1 with the skin up, and the activation energy values were 32.2 and 38.4 kJ mol−1, respectively. The product characteristics were significantly affected (p < 0.05) by drying operation conditions. The lower change was in drying at 60°C with air flow for two sides of the samples and skin up. In this condition, the product showed solubility 22.3%; in vitro digestibility 87.4%; contents of available lysine and methionine 7.21 and 2.64 g 100 g−1, respectively; TBA value 1.16 mgMDA kg−1; specific antioxidant activity was 1.91 mMDPPH g−1 min−1, and variation total color was 10.72.

Recebido em 8/3/09; aceito em 12/8/09; publicado na web em 11/1/10 ENZYMATIC MODIFICATION ON RICE FLOUR SEEKING THE PRODUCTION OF RESITANT STARCH. The aim of this work was to study the enzymatic modification on rice flour using lipase pancreatic and amyloglucosidase to obtain resistant starch. For this, Response Surface Methodology (RSM) was used to determine the best operating conditions for each enzyme. For lypase pancreatic, the highest value for resistant starch (45%) was achieved within 2 h reaction at pH 7 using an enzyme/substrate ratio of 4% (w/w) and Dp= 100/200 tyler. For amyloglucosidase, optima conditions corresponded to an enzyme/substrate ratio of 0,006 mL/g and Dp= 100/200 tyler at 45 o C, yielding 57% of resistant starch in 2 h reaction. These results show the potential of using both enzymes to modified rice flour, increasing the resistant starch in about 5.7 folds in relation to the flour without treatment (resistant starch=10.6%).Keywords: amyloglucosidase; modifying native starches; debranching. INTRODUÇÃOO interesse do consumidor em alimentos específicos que possuam um papel na manutenção da saúde tem crescido nos últimos anos. Os chamados "alimentos funcionais" referem-se a estes gêneros alimentícios, os quais podem proporcionar benefícios nutricionais, dietéticos e metabólicos específicos, e contribuir para o controle e a redução do risco de doenças.1,2 O arroz (Oryza sativa, L.) é uma das principais fontes de calorias e proteínas na alimentação de mais da metade da população mundial. Entre os cereais, apresenta maior digestibilidade, maior valor biológico e a mais elevada taxa de eficiência proteica. 3O Brasil, no ano de 2008, alcançou uma produção de arroz de aproximadamente 12,1 milhões de toneladas. Para que o arroz seja aceito pelo consumidor, torna-se necessário seu processamento, o que resulta em alguns subprodutos como a casca, o farelo e grão quebrados, que correspondem a 14-15% do total, o que representa um valor superior 1,8 milhões de toneladas. Estes grãos são utilizados em grande parte para alimentação animal e na produção da farinha de arroz. 4,5 Na farinha de arroz, os carboidratos são representados basicamente pelo amido, que é formado por cadeias de amilose e amilopectina, responsáveis por muitas das propriedades do produto final. O segundo componente em maior quantidade na estrutura da farinha de arroz é a proteína, respondendo por cerca de 7-9% da sua composição. Segundo a legislação brasileira, a farinha de arroz pode ser denominada e vendida como amido de arroz, em função do seu alto teor de amido e a dificuldade de se extrair as proteínas. Atualmente, vem crescendo o interesse dos pesquisadores em quantificar estas frações do amido nos alimentos, visando avaliar o seu real consumo e correlacionar estes achados com a nutrição e a saúde dos indivíduos. Englyst e Cummings 6 desenvolveram pesquisas a respeito das frações do amido, assim como suas classificações e propriedades. O amido é classificado em função da sua estrutura físico-química e da sua susceptibilidade à hid...

Summary The anchovy (Engraulis anchoita) is a pelagic fish and due to its abundance in South America shows a sustainable exploitation. The enzymatic hydrolysis of anchovy protein associated to the drying technique in spouted bed was analysed in order to obtain products with the best characteristics. The drying conditions were inlet air temperature, concentration and flow rate of suspension. The degree of hydrolysis of the anchovy suspension was of 3.8%, and its available lysine and specific antioxidant activity were of 86 g kg−1protein and 4.31 mmDPPH kg−1 min−1, respectively. In spouted bed drying, the lowest reduction in available lysine (9%) and loss of specific antioxidant activity (8%) were found at 90 °C, and suspension concentration and flow rate of 65 g L−1 and 200 mL h−1, respectively. The dried product was characterised as a protein source of high biological value due to the essential amino acids profile.