ABSTRACT The purpose of this study was to develop and improve protein concentration techniques for two industrial by-products with the potential for use in fish feed. In particular, we chemically characterized crambe meal and sunflower meal and their protein concentrates. Three different protein concentration methods were tested: isoelectric pH (pHi), acid pH and alkaline pH. For crambe and sunflower meals extraction using the pHi method was most efficient in terms of protein yield and crude protein content in the concentrates; this method also increased lysine and methionine content in the concentrates. The water holding capacity of the sunflower protein concentrate was greater than that of the crambe protein concentrate. The crambe protein concentrate had a foam-formation capacity of 15%, which stabilized at 6% after 90 minutes. The protein concentration method also reduced total phenolic content by approximately 50% in the concentrates compared with the meals. Therefore, we conclude that protein concentration using the pHi method is the most efficient technique for crambe and sunflower meals, and the use of this technique can decrease total phenolic compounds while improving meal quality for fish feeding.

Studies on pollen viability are useful for breeding Crotalaria juncea L. since they provide information that will increase the chance of successful intraspecific crossing. The aim of this study was to evaluate pollen viability in C. juncea accessions cultivated in Rio Grande do Sul, Brazil. Inflorescences of 10 accessions of C. juncea were collected, fixed in absolute ethanol: glacial acetic acid (3:1) for 72 h at room temperature and placed in 70 % ethanol. Analysis of pollen viability was performed with slides of anthers using the squashing technique and staining with acetic orcein 2 % and Alexanders stain. Means were compared using the Tukey test (p≤0.05). Pollen viability was high and significantly different among the accessions; the highest value was 99.67 % and the lowest 45.34 %. However, unviable pollen grains were also observed in all accessions.

Los estudios de la viabilidad del polen son útiles para el mejoramiento genético de Crotalaria juncea L., porque proveen información que aumentará la oportunidad de cruces intraespecíficos exitosos. El objetivo de este estudio fue evaluar la viabilidad del polen de accesiones de C. juncea cultivadas en Rio Grande do Sul, Brasil. Las inflorescencias de 10 accesiones de C. juncea fueron recolectadas, fijadas en etanol absoluto: ácido acético glacial (3:1) por 72 h a temperatura ambiente, y colocadas en etanol al 70 %. El análisis de viabilidad del polen se realizó en rebanadas de anteros mediante la técnica de aplastado y teñidas con orceina acética al 2 % y tinción de Alexander. Las medias se compararon con la prueba de Tukey (p≤ 0.05). La viabilidad del polen fue alta con diferencias significativas entre las accesiones; el valor más alto fue 99.67 % y el menor 45.34 %. Sin embargo, en todas las accesiones se observaron granos de polen no viable.