Bruno Bianch Loureiro

Obtenção e caracterização de farinha de casca de uva e sua utilização em snack extrusado

This study aimed to characterize grape skin flour (GSF) and the effect of its inclusion in an extruded snack, with regard to the nutritional, technological and sensory parameters. Grape pomace from the cultivar Marselan (Vitis vinifera), obtained during the winemaking process, was used to obtain the grape skin flour. The in natura pomace was dried in a forced air oven at 55 °C for 24 hours. The skins were separated from the seeds using 2 mm and 3 mm sieves, and the skins subsequently ground in a micro mill at 27.000 rpm (particles < 1 mm) and stored at –18 °C. The grape skin flour obtained was submitted to a chemical analysis (moisture, ash, protein, lipids, total dietary fibre, carbohydrates, pH, phenolic compounds and colour). The GSF was included in the formulation of an extruded snack at levels of 9% and 18%, substituting the corn flour, representing 5% and 10% fibre, respectively. The snacks were evaluated for colour, texture and acceptance. A microbiological analysis for coliforms at 45 °C and Salmonella was carried out on the test formulations. Fibre (58.01%), ash (12.46%) and carbohydrates (17.62%) were the main constituents of the grape skin flour, which had a pH value of 3.51. The phenolic compounds resveratrol (6.14 mg.g–1), luteolin (5.16 mg.g–1) and kaempferol (3.01 mg.g–1) were detected in the largest amounts in the GSF, indicating the presence of antioxidants in the flour. The snack containing 9% (5% fibre) of GSF showed the best results for acceptance with respect to the attributes of colour, aroma and texture as compared to the standard snack. The addition of GSF to extruded snacks is feasible and of interest due to its nutritional enrichment (fibre and phytochemicals) and aggregation of value to a byproduct discarded by wineries.

Grape Pomace Skins and the Effects of Its Inclusion in the Technological Properties of Muffins

ABSTRACT The present study evaluated the incorporation of 5, 7.5, and 10% of Riesling skin flour (RSF) and Tannat skin flour (TSF) as wheat flour replacement in muffins. The flour was evaluated for gluten content and Alveograph parameters. The finished products were evaluated for chemical composition and technological properties, and a sensory analysis was performed. All samples presented higher dietary fiber content than wheat flour, and this was mainly in the form of soluble dietary fiber. The inclusion of grape skin flour decreased the lightness of the flour and increased the lightness values (L*) of the muffin crumbs and crusts. The hardness of the muffins that incorporated RSF and TSF muffins increased as the percentage of the skin flour increased. There was a decrease in the cohesiveness value as the skin flour percentage increased. Consumers did not perceive the levels of substitution. The results of the sensory analysis indicated that grape skin can be added to the ingredients of muffins without changing the color, taste, flavor, texture, and overall acceptability of the final product.

Crambe (Crambe abyssinica) and sunflower (Helianthus annuus) protein concentrates: production methods and nutritional properties for use in fish feed

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.

Farelo de tungue in natura ou detoxificado na alimentação de carpa húngara (Cyprinus carpio)

This study evaluated the partial replacement of animal meal by tung meal as protein source in feeding Hungarian carp. The treatments consisted of the inclusion of in natura or detoxified tung meal (obtained after chemical treatment applied to tung meal) as well as the reference treatment in which the protein basis was composed of meat and bone pork meal and fish meal. The feeding period was 63 days. During 30 experimental days no difference was observed in growth indicators among animals fed the control diet or with chemically treated tung meal, however, the consumption of diets with in natura tung meal caused reduced performance until the end of the experimental period. After 63 days of feeding, some growth indicators were also are lower for the treatment containing treated tung meal compared to control. Biochemical analysis in plasma and liver revealed increased triglycerides, glycogen, glucose and use of other sources, possibly amino acids, as precursors in the production of energy when animals consumed the diet with in nature tung meal in relation to others, which reflected in lower levels of protein and higher fat deposition in the carcass. Regarding the activity of digestive enzymes, trypsin showed increased activity in the treatment with in natura tung meal and acid protease, chymotrypsin, amylase and lipase were not changed in any of the treatments.