Table 2. Raw product quality of 'Orlando Seedless' and 'Thompson Seed- of the panelists preferred the texture of 'Thompson Seed less' grapes. less' to 'Orlando Seedless.' The texture of 'Orlando Seed less' was rated between "Neither Like Nor Dislike" and Titratable Soluble "Like Slgihtly." Many panelists objected to the thicker and Soluble acidity solids: solids (as% acidity tougher skin of 'Orlando Seedless', preferring the "crun- Cultivar (%) pH tartaric) ratio chier" texture of 'Thompson Seedless.' This texture type is a characteristic associated with slip-skin cultivars such as Orlando Seedless 16.8 3.30 0.60 28.0 'Orlando Seedless.' The texture is often influenced by Thompson Seedless 19.0 3.35 0.85 22.3 F-test * * * berry turgidity. Improved irrigaion practices, rapid cool ing of grapes after harvest, and shrink wrapping to pre *, significant at 5% level. vent moisture loss may lead to improved berry texture of 'Orlando Seedless.' None of the panelists seemed to notice There were no significant differences in flavor between any objectionable seed reminants. 'Orlando Seedless' and Thompson Seedless', although the Overall, this study suggests the color and flavor of 'Or flavor of 'Thompson Seedless' was rated a little higher lando Seedless' are of comparable quality to the standard (Table 1) and more people preferred the flavor of white seedless grape, 'Thompson Seedless.' Management 'Thompson Seedless' to 'Orlando Seedless'. The flavor of practices which would improve the cluster appearance and both cultivars was rated between "Like Slightly" and "Like texture of 'Orlando Seedless' need to be researched. Spec Moderately." Comments from some of the panelists indi ifically, rounder, looser clusers and "crunchier" berry tex cated that 'Orlando Seedless' had a slightly undesirable bit ture would be desirable. Text marketing research to deter ter and astrigent flavor imparted by the skin. 'Orlando mine acceptabiliy by consumers on a large scale needs to Seedless' did seem to taste a little sweeter to many of be undertaken before final conclusions on market poten panelists than 'Thompson Seedless.' This was due to a tial of 'Orlando Seedless' can be made. higher soluble solids:acidity ratio in 'Orlando Seedless' (Table 2). 'Orlando Seedless' actually had lower soluble Literature Cited solids than 'Thompson Seedless', but it also had much 1. Halbrooks, M. C. 1986. Viticulture in Florida: The next five years. lower acidity. Proc. Fla. State Hort. Soc. 99:189-192. The texture of 'Thompson Seedless' was definitely pre 2. Mortenson, J. A. and D. J. Gray. 1987. Orlando Seedless Grape. ferred to that of 'Orlando Seedless' (Table 1). Over 80% HortScience (in press). Proc. Fla. State Hort. Soc. 99:194-200. 1986. EFFECT OF BUNCH AND MUSCADINE GRAPE MATURITY ON FINISHED WINE R. P. Bates and R. Tejada Despite the compositional differences that exist within a cul Food Science and Human Nutrition Department tivar at different stages of maturity, the wine character was University of Florida, Gainesville. FL 32611 not dramatically affected by harvest maturity, if the must AND was standardized by chaptalization. The maturity-related ex J. A. MORTENSEN tremes in grape acidity (and to a lesser extent pH) are at Agricultural Research and Education Center, tenuated in the wines by cold stabilization (both species) and P.O.Box 388, Leesburg, FL 32749 fermentation (muscadine only). Consequently, mid to late and early to midseason harvesting is recommended for bunch Abstract. 'Stover1, 'Conquistador' (bunch, R. Euvitis) and 'Wel and muscadine grapes, respectively. In all cases crush pH der1, 'Noble' (muscadine, V. rotundifolia) cultivars were har should be restricted to between 3.0 and 3.5. vested at 3 or 4 day intervals over a 3 to 6 week period. Brix, pH, titratable acidity, g sugar/berry and berry weight were The chemical make up of raw material is quite influen followed during ripening. Chemical composition and wine tial in wine making and wine quality. The composition of analyses were obtained from these same cultivars at their the grapes depends on variety, climate, vineyard manage early, midseason and late harvest periods. Maturity date cor ment and biochemical processes during grape maturation related well with compositional data (R=0.90 to 0.99), except and can be assessed only by proper sampling techniques for pH. As ripening progressed, Brix and pH increased, while (4). The changes in chemical composition of grapes during titratable acidity decreased. This trend was less uniform in maturation have been extensively studied (1, 9, 10, 12). the uneven ripening 'Conquistador'. Composition data ob Flora and Lane (11) reported that in 'Cowart' (a mus tained with 100 berry samples which were hand crushed and cadine), as ripeness increased, the titratable acidity de pressed then blended and reanalyzed only approximated sub clined and pH, percent soluble solids (Brix), juice yield sequent large batch free run and press juice, respectively. and Brix/acid ratio increased. Carroll and Marcy (8) studied the chemical and physical changes during matura tion of muscadines, 'Noble' and 'Carlos'. They reported Florida Agricultural Experiment Station Journal Series No. 6671. that Brix, titratable acidity, Brix/acid ratio, pH, fructose, 194 Proc. Fla. State Hort. Soc. 99: 1986. glucose, and sucrose increased during ripening, while tit- blended juice was analyzed for Brix, pH, and titratable ratable acidity, malic acid, and tartaric acid concentrations acidity. In addition, the measurements of sugar per berry decreased. Pirie and Mullins (14) described the behavior and berry weight were used to determine maturity (13). of the total phenolic and anthocyanin content in the skin Compositional data on grapes and juice for each cultivar of grape berries in Vitis vinifera L. cv Shiraz. An increase were analyzed separately and correlation coeffecients in the accumulation of phenols and anthocyanins in the among appropiate parameters were estimated. skin accompanied maturation. Despite the important con tribution of phenols in the seed to the total phenols levels 1983 and 1984—Wine Preparation of the berry, the skin was the most important single source of phenols during wine making. Catalina et al. (9) reported Raw material. 'Stover', 'Conquistador', 'Welder' and an increase in juice yield, pH, reducing sugar, glucose, 'Noble' grapes were harvested from the same blocks as the fructose, protein, K, P, Ca, and Mg, and a decrease in 100 berry samples, stored at about 2° C for less than 5 days titratable acidity, iron, and zinc in Vitis vinifera cv. Palomino and transported to Gainesville. Crushing was performed during ripening. In addition to single parameters analyses, by passsing the fruit through a small manual grape crusher sugar/berry has been proposed recently as a particularly (in the case of small samples, 10 kg or smaller) or through useful measure of grape ripening (13). the rotary knife section of Runkles Model 17 Cider Despite these comprehensive studies on the ripening Crusher-press. The crusher was adjusted so that all berries behavior of wine grapes, there is little detailed data on were crushed but grape seeds were not broken. Three Florida-grown bunch and muscadine grapes. Experience methods of must extraction were used: 1) White wine has shown that the maturation of a given cultivar varies grape ('Stover' and 'Welder') were pressed immediately. from vineyard to vineyard throughout the State and even Crushed grapes were rack and cloth pressed at about 14.0 within a vineyard. The purpose of this study was to deter kg/cm2 for 10-20 min with 2 % rice hulls added; 2) For mine the ripening characteristics of the 4 major wine cul- 1984 red wines ('Conquistador' and 'Noble') hot pressing tivars and relate these compositional changes to wine com was used. The crush was placed in a steam jacketed kettle, position and quality. 0.072 g/kg crush of pectic enzyme (Klerzyme Liquid 200, GB Fermenation Industries Inc.) was added and the sam Materials and Methods ple was rapidly heated to 60° C and maintained for 25 min followed by pressing; 3) For 1984 red wines on-skins fer Muscadine cultivars (Welder and Noble) and two bunch mentation for 72 hr was used. The crushed sample was grapes (Stover and Conquistador) produced by typical cul placed in 20 to 60 liter covered plastic containers, inocu tivation practices (6) were harvested during the 1983 and lated with active rehydrated yeast and 0.072 g/kg of pectic 1984 seasons from the Agricultural Research and Educa enzyme and placed at 18° C. Three times a day the crush tional Center at Leesburg, Florida and processed at the was mixed. Pomace fermentation and hot pressings were Food Science and Human Nutrition Department, Univer finished by the rack and cloth operation described. sity of Florida, Gainesville. Must Preparation. White and red must were treated with 1984 Maturity Study. Fifty-three duplicate sets of one 250 and 100 ppm potassium metabisulfite, respectively, hundred berries per sample were studied in 1984 (10 sam during crushing (about 140 and 60 ppm SO2). The Brix ples of 'Stover', 7 of first picking 'Conquistador', 7 of sec was adjusted to 21 degrees with cane sugar after pressing, ond picking 'Conquistador', 15 of 'Welder', and 14 of for immediate press and hot press samples. In the case of 'Noble'). Samples were harvested at 3 to 4 day intervals for pomace treaments, the Brix was adjusted before skin con a period of 3 to 6 weeks from typical, specially marked, tact fermentation, based on the freshly crushed analysis vines. 'Conquistador' is uneven ripening, consequently, and yield data of previous years. In 1983 only, excessive two pickings were done. In the first picking, only the red must acidity was adjusted to about 0.9%, using a 21 °B berries were harvested and the green berries were allowed sugar solution. Samples were inoculated with 0.5 g/liter, to mature for the second picking.