Neidi Garcia Penna

Desenvolvimento e validação de um método analítico para a determinação de histamina em vinhos utilizando cromatografia líquida de alta eficiência com detecção por fluorescência

A rapid and efficient method for the analysis of histamine in wines using HPLC with fluorescence detection after derivatization was developed and validated. The method LOD and LOQ values were 0.25 and 0.50 mg L-1 respectively. The repeatability and intermediary precision for the instrument and for the method presented RSD values of 3.7 and 2.9%, and 6.0 and 5.6%, respectively. The recoveries were 95.5 and 89.9% for the fortification levels of 2 and 10 mg L-1. The method was applied to determine the histamine content in Cabernet Sauvignon wines, which presented values between 1.2 and 5.7 mg L-1.

Polifenóis totais e avaliação sensorial de suco de uvas Isabel tratadas com ultrassom

Grape juice in Brazil is a product widely consumed for their sensory and nutritional characteristics, however, treatments during processing can cause loss of phenolic compounds important in defining these characteristics. Ultrasound is cited as a possible elicitor of these compounds, since the mechanical stress caused by acoustic cavitation and microstreaming stimulates the plant defense responses that lead to synthesis of these substances. In this study, different power densities (53 and 113 W.cm-2) and exposure times (1, 5 and 10 minutes) of ultrasound were applied in Isabel grapes and its effect on the total polyphenols content and sensory aspect of the juices was evaluated. The ultrasound caused an increase of up to 83% in total polyphenols content, improving the sensory characteristics of juices, being chosen as preferred by the tasters.

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.

Physicochemical, Antioxidant and Sensory Quality of Brazilian Blueberry Wine

Currently, Rio Grande do Sul state is the main producer of blueberry in Brazil. Practically all production is commercialized in fresh state and only a small portion is subject to processing. The blueberry wine making process is an alternative to expand the beverage industry and offers to the consumer a value-added product as well as a new market for Brazilian blueberry producers. The objectives of this study were to produce wines from blueberries and to evaluate the effect of deacidification (with calcium carbonate) and chaptalization (with glucose syrup or sucrose) on physicochemical characteristics, antioxidant content, and sensory parameters. Samples were analyzed for total soluble solids, pH, total titratable acidity, total sugar content, alcohol content, monomeric and total anthocyanin, total flavonols, total phenolic compounds and antioxidant activity by DPPH and FRAP methods. The use of calcium carbonate caused a reduction in total titratable acidity, while the use of glucose syrup resulted in wines with low alcohol content. The blueberries wine from Climax and Aliceblue cultivars had higher content of anthocyanin when produced with glucose syrup. The use of calcium carbonate and glucose syrup also provided wines more appreciated by tasters in relation to color. With regard to flavor, George and Aliceblue were the cultivars with lower preference under the control treatments (without carbonate and sugar). The presence of phenolic compounds may have provided a positive influence on wine flavor, once the more preferred wines presented the greater phenolic content.

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.

Características físico-químicas e propriedades funcionais tecnológicas do bagaço de mirtilo fermentado e suas farinhas

The industrialization of fruit allows consumers to continue enjoying their functional benefits for longer, but most often these procedures produce industrial wastes that are not normally utilized. Therefore this study aimed to physicochemical characterization, determination of antioxidant activity, anthocyanins and polyphenols in blueberry pomace from the production of fermented beverages and flour obtained from this bagasse, as well as the functional properties of technological and microbiological stability of flour. Flours fruit and bagasse were obtained from the dehydration in an oven at 60 oC for 36 hours and ground into micro mill refrigerated at 4 oC. The physicochemical characteristics were observed from the analyzes of moisture, protein, lipid, ash, acidity, pH and soluble solids. The antioxidant activity was determined by DPPH and total polyphenols by the Folin-Ciocalteu. The results showed that both blueberry, as bagasse, have a high water content. The blueberry showed 61.67 mg/100g in anthocyanins, polyphenols in EAG/100g 431.43 mg and 3.83 mg/mL of antioxidant activity, while the bagasse obtained 57.32 mg/100g, 297.20 mg EAG/100g, 5.61 mg/mL, respectively. Flours showed microbiological stability during storage and functional properties of very good technology, enabling the creation of new products. Therefore the use of industrial waste has many advantages as add value and minimize environmental impact.

Acute Consumption of Bordo Grape Juice and Wine Improves Serum Antioxidant Status in Healthy Individuals and Inhibits Reactive Oxygen Species Production in Human Neuron-Like Cells

Few studies investigated the biological effects of American grape cultivars. We investigated the metabolic response after acute consumption of grape juice or wine from Bordo grapes (Vitis labrusca) in a placebo-controlled crossover study with fifteen healthy volunteers. Blood samples were collected 1 hour after the intake of 100 mL of water, juice, or wine to measure TBARS, ABTS, FRAP, glucose, and uric acid levels. To evaluate differences in cellular response, intracellular reactive species production (DCFH-DA) and metabolic mitochondrial viability (MTT) were assessed after exposure of human neuron-like cells (SH-SY5Y) to juice or wine. Glycemia was reduced after juice or wine consumption, whereas blood levels of uric acid were reduced after juice consumption but increased after wine consumption. Juice and wine consumption reduced plasma lipid peroxidation and increased plasma antioxidant capacity (ABTS and FRAP assays). Furthermore, juice inhibited H2O2-induced intracellular production of reactive species (RS) and increased the viability of SH-SY5Y cells. In contrast, wine (dealcoholized) exhibited a per se effect by inducing the production of RS and reducing cell viability. These results indicate a positive impact of acute consumption of Bordo juice and wine on human oxidative status, whereas only juice had protective effects against oxidative stress-induced cytotoxicity.

MINERAIS DE VITIS VINIFERA CULTIVADAS NA FRONTEIRA DO RIO GRANDE DO SUL

Vitis vinifera Cabernet Sauvignon, Pinot Chardonnay e Sauvignon Blanc foram analizadas durante oito (8) anos, com o objetivo de quantificar Nitrogenio(N), Fosforo(P), Potassio (K), Calcio (Ca), Magnesio (Mg), Ferro (Fe), Cobre (Cu), Sodio (Na), Manganes (Mn), Boro (Bo) e Zinco(Zn) nos peciolos. As amostras peciolares foram secas numa estufa com circulacao de ar a aproximadamente 70°C e moidas. Nitrogenio foi determinado pelo metodo microkjeldahl, Fosforo por colorimetria, Potassio e Sodio por emissao de chama, Calcio, Magnesio, Ferro, Cobre, Manganes e Zinco por espectrometria de absorcao atomica e Boro por colorimetria usando curcumina como derivatizante. Valores medios dos oito (8) anos encontrados na materia seca (MS) foram para Cabernet Sauvignon (g/100g): 1,59N, 0,76P, 3,28K, 0,93Ca, 0,28Mg e em mg/100g: 11,52Fe, 4,18Cu, 85,08Na, 70,17Mn, 2.07B e 13,97Zn; para Pinot Chardonnay (g/100g): 1,26N, 0,47P, 3,20K, 0,82Ca, 0,31 Mg e em mg/100g: 15,25Fe, 3,25Cu, 63,73Na, 42,91Mn, 2,08B e 11,13Zn; para Sauvignon Blanc (g/100g): 1,51 N, 0,49P, 2.29K, 0,79Ca, 0,32Mg e em mg/100g: 16,01 Fe, 5,91 Cu, 76,02Na, 70,61 Mn, 1,91 B e 11,9Zn.