a b s t r a c tPea (Pisum sativum L. var. Laguna) seeds were submitted to extrusion process at 129, 135 and 142 C and modifications on the proximate composition and nutritional parameters were evaluated. Peas were a good source of protein (24 g/100 g), amino acids (sulphur amino acids were the limiting ones), dietary fibre (18 g/100 g), carbohydrates (53 g/100 g), energy (330 kcal/100 g), riboflavin and thiamine (0.1 e0.2 mg/100 g). Pea seeds also contained non-nutritive compounds such as a-galactosides (4 g/100 g), phytic acid (0.4 g/100 g) and trypsin inhibitor activity (2 TIU/mg). Extrusion cooking caused a slight increase of protein and fat content, whilst it reduced dietary fibre, thiamine and a-galactosides, and led to negligible trypsin inhibitor activity (TIA) levels. The protein quality of pea measured by biological indexes (net protein utilisation, net protein ratio, relative net protein ratio, true protein digestibility and biological value) was not affected by extrusion treatments. Protein quality measured by chemical indexes (chemical score and protein digestibility corrected amino acid score) decreased in processed peas. Among extruded peas, those processed at 135 C presented the highest chemical indexes. Therefore, the aforementioned condition could be considered adequate for the manufacture of novel pea-derived products with high nutritive value.

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Yerba mate is defined as the product constituted by the dried, slightly roasted, and milled leaves ofIlex paraguariensis. However, the fruits of this species are often found in the commercial product. Nowadays the fruits are considered a byproduct. The objective of this work was to obtain the preliminary data of minerals, lipids, methylxanthines and polyphenols in the ripe fruits ofI. paraguariensis. The results showed a considerable amount of total dietary fiber (42.0±1.6 g/100 g) and nutritionally valuable minerals: potassium (1324±15 mg/100 g), iron (6.4±0.5 mg/100 g), magnesium (168±15 mg/100 g), calcium (150±12 mg/100 g), copper (1.1±0.1 mg/100 g), zinc (2.3±0.3 mg/100 g), and sodium (1.3±0.1 mg/100 g). The lipid content was 4.5 g/100 g. Oleic acid was the predominant unsaturated fatty acid (38.74±0.75 g/100 g). Linoleic acid (1.83±0,01 g/100 g) was also present. Methylxanthines were quantified: caffeine (0.118±0.001) and theobromine (0.0125±0.0002) g/100 g. The total polyphenol content was0.717±0.001 g/100 g. The results obtained in this work suggest the potential value of the fruits ofI. paraguariensisfor the development of novel products in the food and pharmaceutical industries. This paper aims to contribute to the scientific knowledge of a natural by-product from industry regarding the need of foods and medicines for the new millennium.

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Myofibrillar proteins of sea salmon were incubated with malonaldehyde (MDA) at 27°C from 0 to 8 h. Microstructural modifications were investigated by transmission electron microscopy. Protein solubility in the presence of sodium dodecyl sulfate (SDS), urea and ␤ ␤ ␤ ␤ ␤-mercaptethanol (ME), SDS-polyacrylamide gel electrophoresis (PAGE), and available lysine determinations were performed to analyze the chemical nature of these alterations. Results showed noteworthy microstructural changes and protein aggregation, involving myosin and other myofibrillar proteins. A large proportion of these aggregates was insoluble when treated with SDS, urea, and ME, suggesting the presence of nondisulfide covalent bonds. A reduction in the available lysine content was evidenced because of the reaction of ⑀ ⑀ ⑀ ⑀ ⑀-amino groups with MDA.