Biochemical traits useful for the determination of genetic variation in a natural population of Myracrodruon urundeuva

The objectives of this work were to analyze seeds from 20 trees of aroeira (Myracrodruon urundeuva Fr. All.) of a natural population located in the region of Selvíria, State of Mato Grosso do Sul, Brazil, in order to evaluate their protein, lipid and carbohydrate contents, and to estimate their genetic variation. A completely randomized experimental design consisting of 20 treatments (families) was set up, with two replications. Four types of proteins were detected: albumin (35.0 to 107.3 mg/g seed), globulin (3.4 to 9.3 mg/g), prolamin (60.0 to 135.2 mg/g) and glutelin (118.0 to 286.0 mg/g). The lipid content varied between 200 and 334 mg/g seed. The total sugars also varied (26.5 to 46.3 mg/g seed), with a predominance of polyols (arabinitol, mannitol, glucitol and xylitol). The main monosaccharides detected were glucose and arabinose. Total hydrolysis of the sugars indicated the presence of neutral arabinan and xylan oligosaccharides. The starch content varied from 0.35 to 1.58 mg/g seed. These biochemical traits showed considerable genetic variability, indicating that only the collection of seeds from many different trees can provide a representative sample of the population for conservation and genetic improvement.

Storage protein profile and amino acid content in wild rice Oryza glumaepatula

- The objective of this work was to determine the total protein profile and the contents of the four major protein fractions (albumin, globulin, prolamin and glutelin) and of the amino acids in the endosperm of the rice wild species Oryza glumaepatula. The experiment was performed with 29 accessions of this species, collected from 13 Brazilian locations, and two commercial cultivars. Protein samples were prepared using dried, polished, and ground grains to obtain homogeneous, dry flour used in the preparation of extracts. Oryza glumaepatula accessions were identified with the highest levels of total protein, albumin and glutelin protein fractions, and amino acids (with the exception of tryptophan) in comparison to the two analized rice cultivars. The albumin and glutelin profiles in SDS-Page were distinct between rice cultivars and O. glumaepatula. This wild species has the potential to increase the nutritional quality of rice storage protein through interspecific crosses.

Polipeptídeos e proteínas com influência na qualidade da espuma da cerveja e métodos analíticos utilizados no seu estudo

A review of polypeptides and proteins that influence, direct or indirectly, beer foam quality, as well as the most relevant analytical methods used in their study, are presented. Protein Z, LTP1 and hordein/glutelin fragments originated from malt have a direct influence on beer foam quality. Other proteins, like malt hordeins and albumins and wheat puroindolines, are, to some degree, also important for beer foam quality. Protein hydrophobicity is pointed out as a key parameter to enhance foam quality. Electrophoretic, chromatographic and immunological analytical methods are currently used to study polypeptides and proteins present in barley, malt, wort, beer, and foam. Best results are obtained when combinations of these methods are applied.

Chemical and nutritional evaluation of kernels of bocaiuva, Acrocomia aculeata (Jacq.) Lodd.

Protein characterization and results of proximate composition and mineral analyses of fruit kernels of bocaiuva, Acrocomia aculeata (Jacq.) Lodd., are reported. The kernels presented high contents of oil (51.7%), protein (17.6%) and fiber (15.8%). The seeds´ soluble proteins were isolated according to their solubility. The main separated proteins were globulins (53.5%) and glutelins (40.0%). Moreover, the presence of low molecular mass proteases in these two fractions was shown by the SDS-PAGE method. The assays of protease-inhibitory and hemagglutinating activities showed that bocaiuva´s protein fractions were not resistant to trypsin or chymotrypsin activities and that both had low lectin content. The globulin in vitro digestibility assay resembled a casein standard. Neither globulin nor glutelin enzymatic hydrolyses increased significantly (p < 0.05) after heat treatment. Threonine and lysine are the most limiting amino acids, respectively from two major protein fractions of the bocaiuva kernel, globulin (47.1% amino acid score) and glutelin (49.5% amino acid score), in terms of the theoretical profiles for children in the age range of 2 to 5 years recommended by the FAO/WHO. Bocaiuva kernels are found to be rich in calcium, phosphorus and manganese compared to some fruit nuts such as cashew and coconut.