Renata Vieira da Mota

Composition and Functional Properties of Banana Flour from Different Varieties

The chemical composition and some physico-chemical characteristics of the flour obtained from eight different banana varieties are presented. The flour was prepared by freeze-drying a homogenate of green banana pulp. Amylose, starch, dietary fiber, protein, ash, moisture and lipid contents were determined. Viscosity and gelatinization of starch were also investigated. Banana flour is rich in starch granules. Peak temperature of gelatinization varied from 68 to 76 °C according to the variety. All of them showed an increase in viscosity during cooling but the variety Ouro colatina showed more stability during shearing and cooling. Chemical composition of the flour also varied according to the variety. The range obtained were 61—76.5% starch, 19—23% amylose, 2.5—3.3% protein, 4—6% moisture, 0.3—0.8% lipids, 2.6—3.5% ashes, and 6—15.5% total fiber. Considering that the flour production is easier and faster than the isolation of the starch, it would be not only more practical but also less expensive to use the flour instead.

Physico-chemical characterization and bioactive compounds of blackberry fruits (Rubus sp.) grown in Brazil

Five blackberry cultivars (Rubus sp.) were evaluated for antioxidant capacity, bioactive compounds and composition. Ascorbic acid levels, consisting of dehydro-ascorbic acid, ranged from 9.8 to 21.4 mg.100 g-1 fresh weight. Cyanidin (66 to 80% of total flavonoids), epicatechin, quercetin and traces of kaempferol were the main flavonoids found in all cultivars. The five cultivars presented high antioxidant capacity in the β-carotene/linoleic acid system, with inhibition similar to the synthetic antioxidant BHT, at a 50 µM concentration. Caingangue cultivar presented high vitamin C and total phenolics content, while Guarani had the highest cyanidin, total anthocyanin and total flavonoids levels and also the highest antioxidant capacity. These cultivars also presented good TSS/TA ratios. From the data, at a quantitative level, blackberry can be considered a good source of bioactive compounds, as well as potentially beneficial to human health.

BIOCHEMICAL AND AGRONOMICAL RESPONSES OF GRAPEVINES TO ALTERATION OF SOURCE-SINK RATIO BY CLUSTER THINNING AND SHOOT TRIMMING

The control of leaf to fruit ratio by the practice of entire clusters removal from the vine upon berry set has been used in traditional vineyards in order to regulate yield and to improve chemical composition of the berries. Although this practice has been settled in temperate zones, little is known about grapevines behavior in tropical growing areas. The aim of this work was to evaluate the biochemical and agronomical responses of two Vitis vinifera cultivars (Merlot and Cabernet Sauvignon) grown in Caldas, Minas Gerais, Brazil, a new winegrape region. Grapevines were submitted to cluster thinning (0%, 50% and 75% of cluster removal) and trimming treatments (trimmed and untrimmed) imposed at pea size stage. The source-sink alteration by fruit removal and shoot trimming had impact on yield, leaf sugar metabolism and grape composition. Although there was an improvement in color intensity of the berries with reduction of fruit load, the cluster thinning practice should be avoided in vineyards grown in the south of Minas Gerais State without impairment of wine grape quality. On the other hand, shoot trimming practice should be recommended only for Merlot in order to improve sugar grapes from vines with no cluster removal.

Composição físico-química de uvas para vinho fino em ciclos de verão e inverno

Este trabalho teve como objetivo avaliar o potencial de maturacao das cultivares Pinot Noir, Tempranillo, Merlot, Cabernet Sauvignon, Syrah, Chardonnay e Sauvignon Blanc submetidas ao regime de dupla poda, em Cordislândia, regiao cafeeira do sul de Minas Gerais. As plantas foram submetidas a dois ciclos de producao, um de primavera-verao, compreendido entre agosto e janeiro, e outro ciclo de outono-inverno, entre janeiro e julho. Como parâmetros de qualidade, foram avaliados os diâmetros transversal e longitudinal da baga, acidez, acidos tartarico e malico, pH, solidos soluveis, antocianinas, fenolicos totais e os teores de glicose, frutose e sacarose. Todas as variedades apresentaram maiores teores de pH, solidos soluveis, acucares, antocianinas e fenolicos totais, e reducao nos diâmetros transversal e longitudinal na safra de inverno. A cultivar Syrah destacou-se das demais no conteudo de antocianinas e fenolicos totais tanto no verao quanto no inverno, entretanto apresentou o menor conteudo de acucares. A alteracao do ciclo de producao da videira atraves da tecnica da dupla poda para colheita, no periodo de inverno, na regiao cafeeira de Minas Gerais, favorece a maturacao dos frutos e melhora consideravelmente a qualidade das uvas para vinificacao.

Cabernet Sauvignon grapevine grafted onto rootstocks during the autumn-winter season in southeastern Brazilian

The change of grape (Vitis vinifera) harvest from summer to winter through double pruning management has improved the fine wine quality in southern Brazil. High altitude, late cultivar and grafting combination all need to be investigated to optimize this new viticulture management. For this purpose, this study was carried out during the 2011 and 2012 growing seasons in a high altitude region of the state of Minas Gerais, Brazil, using eight grafting combinations for five year old Cabernet Sauvignon vines. The stem water potential, photosynthetic rate and stomatal conductance were not affected by rootstock type. The rootstocks IAC 766 and 101-14 induced, respectively, the highest and lowest vegetative vigor in Cabernet Sauvignon, as shown by leaf area and pruning weight. In the 2011 growing season, the leaf chlorophyll contents were increased in IAC 766, whereas vines grafted onto 101-14 accumulated more leaf starch, probably due to reduced vegetative and reproductive growth. In general, rootstocks K5BB, 1045P, SO4 and IAC 766 had the highest yield as compared to 1103P and 101-14. Berries from the grapevine with the highest yield did not differ in pH, total soluble solids and acidity. The rootstocks did not influence the anthocyanins and total phenols in both growing seasons. Quality parameters were better in the 2011 than in the 2012 growing season due to better climatic conditions, mainly less rainfall. The best performance of Cabernet Sauvignon was achieved when grafted onto K5BB, 1045P, SO4 and IAC 766 rootstocks.

Effect of trellising system on grape and wine composition of Syrah vines grown in the cerrado region of Minas Gerais

Based on the concept that the trellising system affects not only sunlight interception and carbon assimilation, but also the fruitzone microclimate, which has a great impact on fruit composition and consequently on wine quality, the effect of two trellising systems - Vertical Shoot Position (VSP) and modified Geneva Double Curtain (GDC) - on wine and berry composition of Syrah grapes grown in Joao Pinheiro, Northeast region of Minas Gerais State, Brazil was investigated. The parameters such as pH, berry size and weight, and seeds total phenolic contents were not affected by the training system. The GDC system produced fruits with the highest Brix and lowest titratable acidity. Berries from the VSP system presented lower anthocyanin concentration than those from the GDC system. Similar results were found for the total phenolic content of the skin of grape berries from the VSP system. GDC wines were characterized by high anthocyanin content and red color, resulting in wines with high color intensity. These data suggest that in the tropical region of Minas Gerais state, with high temperature and high sunlight intensity, the trellising system, which protects bunches against excessive radiation, should be chosen.

Physiological and agronomical responses of Syrah grapevine under protected cultivation

The performance of Syrah grapevine under protected cultivation with different plastic films was evaluated during 2012 and 2013 seasons in South of Minas Gerais State. Agronomical and physiological measurements were done on eight years old grapevines, grafted onto ‘1103 Paulsen’ rootstock cultivated under uncovered conditions, covered with transparent and with diffuse plastic films. Both plastic covers induced the highest shoot growth rate and specific leaf area. The diffuse plastic induced greater differences on leaf area, pruning weight and leaf chlorophyll content as compared to uncovered vines. Grapevines under diffuse plastic also had the lowest rates of photosynthesis, stomatal conductance and transpiration. Leaf starch, glucose and fructose contents were not affected by treatment, but leaf sucrose was reduced by transparent plastic. The leaf and stem water potential were higher under diffuse plastic. In 2013, grapevines under diffuse plastic showed the highest yields mainly due to decreased rot incidence and increased cluster weight. Furthermore, berries under diffuse plastic showed the highest anthocyanins concentration. The use of diffuse plastic induces more agronomical benefits to produce Syrah grape under protected cultivation.

Fosfito de potássio no controle do míldio da videira e características físico-químicas de uvas Merlot

The objective of this work was to evaluate the effect of increasing doses of two formulations of potassium phosphite, on the severity of downy mildew of grapevine, yield and on physicochemical characteristics of Merlot grapes. Two formulations of potassium phosphite (Phi A and B) were evaluated at the doses 0, 1.2, 2.5, 3.7 and 5.0 g L-1 of P2O5, in comparison with a foliar fertilizer and fungicides, during the 2009/2010 and 2010/2011 crop seasons. There was a linear effect of phosphite doses on the reduction of the downy mildew severity, in the two crop seasons. The Phi A highest dose provided an average control of 60.5%, and Phi B, 57.7%, similar to the control by the fungicides (64.3%) and fertilizer (53.3%). In the first harvest, Phi B provided a greater productivity, while, in the second, it did not differ from the treatment with fungicides. Treatments only affected soluble solids, pH and total acidity of the grape must in the second season. Phi B and fungicides provided the highest levels of total soluble phenolic compounds at the grape peel, however, had no effect on the levels of anthocyanins. Potassium phosphite application increases total soluble solids and pH, reduces total titratable acidity of the berries, does not affect anthocyanin contents, and it is an effective alternative for the control of downy mildew, with response similar to that of fungicides.

Pruning management of Chardonnay grapevines at high altitude in Brazilian southeast

The agronomical responses of Chardonnay, a variety indicated for sparkling wine production, is influenced by the vineyard management and the edaphoclimatic conditions of the region. The objective of this study was to evaluate the effects of two pruning types (Royat and double Guyot) on vegetative and reproductive development of Chardonnay vine growing at high altitude in the Brazilian southeastern region. The experiment was carried out in a commercial vineyard located at 1,280 m of altitude in Divinolândia, Sao Paulo State, Brazil. The Chardonnay vines (clone 96), grafted onto 1103 Paulsen rootstock and trained in a vertical shoot positioning trellis system, were assessed. Vegetative vigor, bud fruitfulness, production and physicochemical composition of grapes were evaluated during 2014 and 2015 growing seasons. The Royat pruning induced higher vegetative vigor and increased the bud fruitfulness, the cluster number and the productivity of Chardonnay vine when compared to Guyot pruning. Even though the increase on yield was observed, there was no effect of pruning type on grape final quality. Therefore, the choice of pruning method in function of variety genetic characteristics and their interaction with environment can optimize the vineyard profitability. In the Brazilian southeast, the Royat system is the most suitable one to grow Chardonnay for sparkling wines production.

FRUIT COMPOSITION OF 'NIÁGARA ROSADA' AND 'FOLHA-DE-FIGO' GRAPEVINES UNDER DIFFERENT TRAINING SYSTEMS

ABSTRACT - This work aimed on evaluating the influence of training systems in berries composition of ‘Niagara Rosada’ and ‘Folha-de-Figo’ grapevines grown in Caldas, MG. Yield per plant; diameter, weight, temperature and potassium content of the berries; pH, soluble solids, reducing sugars, total acidity and organic acids of the must; anthocyanins and phenolic compounds of the skins and phenolic compounds of the seeds were evaluated in grapevines training in vertical shoot position, lyre trellis, pergola Veronese or simple string in 2006 and 2007 seasons. ‘Niagara Rosada’ and ‘Folha-de-Figo’ grapevines training in pergola Veronese and lyre trellis, respectively, showed higher yield than the other training systems under study. Ber-ries grown under the four different training systems were cooler than ambient temperature, resulting from partial or deep shade clusters. Berries harvested from pergola Veronese trellis system showed lower soluble solids and reducing sugars levels in both cultivars. These preliminary data show that training systems exerted little influence on berries composition.Index terms: Vitis labrusca, phenolic compounds, sugars, anthocyanins, management, quality.