Physical and chemical evaluation and consumer acceptance of 'Valencia' oranges grown under organic and conventional production systems/Avaliacao fisica e quimica e aceitacao pelo consumidor de laranjas 'Valencia', produzidas sob sistemas de cultivo organico e convencional

The objective of the research was to investigate the influence of cultivating systems (organic and conventional) on physical and chemical attributes, and consumer acceptance of 'Valencia' oranges (Citrus sinensis (L.) Osb.). The orchards were field planted in Montenegro, Brazil, in July 2001. Plants are spaced 2.5m in the row by 5.0m between rows, totaling 0.25ha each orchard. Evaluations were made using fruit samples collected in September and October of 2011, and October of 2012. The physical and chemical attributes evaluated were: juice contents (TS), soluble solids (SS), titratable acidity (AT), ratio SS/AT and color index in the peel (ICC). The oranges' consumer acceptance was determined by untrained evaluators using a nine-point hedonic scale, where the degree in which they 'like' or 'dislike' the product is expressed. The experimental design was completely randomized. As results, oranges showed parameters of quality accordingly to international standards. The physical and chemical attributes were not different between conventional and organic systems for most attributes evaluated. Consumer acceptance was satisfactory in all attributes evaluated (all above 70%). The differences observed on the physical and chemical attributes were not perceived by the evaluators; therefore, there is no distinction on the acceptability of the fruits by consumers despite of the cultivation system. Key words: Citrus sinensis, acceptance test, fruit quality. O objetivo foi verificar a influencia do sistema de cultivo, organico e convencional, sobre as caracteristicas fisicas e quimicas e sobre a aceitacao pelo consumidor de laranjas 'Valencia' (Citrus sinensis (L.) Osb.). Os pomares foram instalados no municipio de Montenegro, em julho de 2001, em espacamento de 2,5mx5,0m, cada um possuindo uma area de 0,25ha. As avaliacoes foram realizadas a partir de amostras de frutos colhidas em setembro e outubro de 2011 e em outubro de 2012. Os parametros fisicos e quimicos analisados nos frutos foram: teor de suco (TS), teor de solidos soluveis (SS), acidez titulavel (AT), relacao SS/AT e indice de cor da casca. A avaliacao da aceitacao das laranjas foi realizada com avaliadores nao treinados, e utilizando escala hedonica de nove pontos, que expressam o grau de gostar ou desgostar do produto. O delineamento experimental foi completamente casualizado. Os frutos apresentaram parametros de qualidade adequados aos padroes internacionais e nao diferiram entre si quanto as suas caracter