Progress 09/01/04 to 08/31/07
Outputs
Initial experimental trials with pineapple var. Red Spanish were conducted in order to determine the effect of juice pasteurization (76o C for 15 min.) before fermentation on aroma and flavor of fresh fruit wines. Sensorial evaluation of these wines reflected that the non pasteurized products retained aroma characteristics from pineapple fruit, whereas the pasteurized products were more similar in aroma and flavor to white wines made from grapes. During fermentation of these initial trials, different phase formation patterns were observed for each experimental condition, thus suggesting different ethanol production rates. However, additional experiments indicated that pasteurization only increased precipitation rate of organic matter present in the juice, probably because of the decomposition of pectin and proteins that promotes suspension of particulates in the pineapple must. We found that in non-pasteurized pineapple juice, a bacillus type bacterium resistant to
metabisulfite grew during fermentation, which seems to be responsible for some odors typical of the Red Spanish pineapple variety. Formal experimental trials were conducted to evaluate the effect of yeast strains on appearance, flavor, aroma and general acceptance of fresh fruit wines made from pineapple, orange and mango. Wines were prepared by using standard procedures described elsewhere and evaluated by a group of trained panelists using the Modified 20 Point Scale developed at the University of California, Davis. Results obtained during the reported period indicated that the wines made from the native (criolla) orange are the most promising products. For trials with different yeast strains, using this orange variety, total scores in the UC Davis scale ranged from 12.95 to 15.40. For these trials a p-value below 0.05 was obtained, all of which indicates that there are significant differences between the different yeast treatments. The best rated wine was the one fermented with
yeast EC-1118. The total scores of each wine made from the Red Spanish pineapple variety were in the range of 10 to 14.4. The best rated wines, fermented with yeasts EC-1118 and IVC-GRE, received 14.29 and 14.36, respectively. A p-value over 0.05 related to wine yeast treatment indicated that there were no significant differences between these values. This result was observed with all the parameters measured except for general quality, which had a p-value less than 0.05. The group of panelists considered that pineapple wines made with EC-1118 and IVC-GRE were much better in terms of general quality than the others. No such promising results were obtained with the mango varieties used, mainly because the product seemed to be very susceptible to oxidation. Unexpected and unpleasant flavors and aromas were obtained in the wines produced with Edwards and Palmer varieties. During this period, we also evaluated the effects of other clarification methods (gelatin, activated carbon and
microfiltration), in addition to the bentonite treatment, on the appearance of orange wines. Microfiltration was the treatment with best results; with this treatment we obtained products of superior visual appearance.
Impacts
Puerto Rico is a small island with very limited space dedicated to agricultural activity. Great fragmentation of the available land exists; the result is the existence of many small farms. These and other characteristics make it difficult for local farmers to provide competitive prices for their products. Exportation of tropical fruits seems to be a good alternative for local farmers because of the uniqueness of these commodities on the global market, which permits higher sales prices. However, the survival and increase of tropical fruit agriculture on the island is highly influenced by global agricultural activity. One effective way to overcome this drawback is to market value-added export products from these same tropical fruits. Although wines and brandies are usually made of grape juice, other fruits can be used to make these types of alcoholic beverages. Among all tropical fruits, mangoes, pineapples and oranges are fine alternatives to produce superior wines and
brandies because of their high sugar content and strong and well defined aroma. Puerto Rico is an ideal place for the production of high quality wines and brandies from tropical fruits. Although the island is still the leader in rum production in the world, sugarcane is no longer the main agricultural crop. The development of high quality wines and brandies from tropical fruits will open new and more stable markets for Puerto Rican agriculture. Research for the production of high quality wines and brandies from these tropical fruits can also benefit other tropical and subtropical areas in the United States.
Publications
- No publications reported this period
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Progress 01/01/06 to 12/31/06
Outputs
Experimental trials were continued to evaluate the effect of microorganism strain on appearance, flavor, aroma and general acceptance of fresh fruit wines. Pineapple, mango and orange wines were prepared by using standard procedures described elsewhere and evaluated by a group of trained panelists using the Modified 20-Point Scale developed at the University of California, Davis. Results obtained to date indicate that the wines from the native (criolla) orange are the most promising products. For trials with different yeast strains using this orange variety, total scores in the UC Davis scale ranged from 12.95 to 15.40. These are good results; many commercial grape wines are usually bellow 14. For these trials a p-value below 0.05 was obtained, all of which indicates that there are significant differences among the different yeast treatments. The best rated wine was the one fermented with yeast EC-1118. Because all the wines were similar in appearance to white grape
wines, original aging experiments of these products are not conducted in traditional wood barrels; instead, malolactic fermentations are being conducted in glass vessels. Preliminary evaluations indicated a positive impact on flavor characteristics of these wines, but experiments are still under way. Not so promising results were obtained with the mango varieties used, mainly because the product seemed to be very susceptible to oxidation. Unexpected and unpleasant flavors and aromas were obtained in the wines produced. We are planning to repeat these experiments using other mango varieties (different from Edwards and Palmer) during the next harvesting period (summer 2007). We also evaluated the effect of clarification methods (other than bentonite treatment) on the appearance of orange wines. Clarification methods evaluated included gelatin, activated carbon and microfiltration treatments. Evaluation was performed by both turbidity determination and panelist visual appreciation.
Products of superior appearance characteristics were obtained with the microfiltration treatment. In order to explain the formation of different phase patterns of previous experiments during fermentation of pasteurized and non-pasteurized pineapple must, we did a new set of experiments. These phase patterns suggested different production rates of ethanol and carbon dioxide due to cell growth behavior. Experimental trials were conducted in a 2x2 factorial design at two levels of pasteurization (pasteurized and non-pasteurized) and two levels of sulfite (with and without sulfite). Results indicated that pasteurization had no significant effect on the different fermentation rates, as opposed to addition of sulfites, which delayed the beginning of ethanol production (up to 36 hours), increased the maximum sugar consumption rate and decreased the overall ethanol productivity. Probably the pasteurization only increased precipitation rate of organic matter present in the juice. That can be
explained in terms of the decomposition of pectin and proteins that promote suspension of particulates in the pineapple must.
Impacts
Although wines and brandies are usually made of grape juice, other fruits can be used to make these types of alcoholic beverages. Among tropical fruits, mangoes, pineapples and oranges are fine alternatives for producing superior wines and brandies because of their high sugar content and strong and well defined aroma. Puerto Rico is an ideal place for the production of high quality wines and brandies from tropical fruits. Although the island is still the leader in rum production in the world, sugarcane is no longer the main agricultural crop. The development of high quality wines and brandies from tropical fruits will open new and more stable markets for Puerto Rican agriculture. Research for the production of high quality wines and brandies from these tropical fruits can also benefit other tropical and subtropical areas in the United States.
Publications
- Perez, Juan M. (2006). Efecto de pasteurizacion y adicion de sulfitos en la fermentacion de un vino de pina.
- Rivera-Garcia, Javier H. (2006). Determinacion de los indices de maduracion de la naranja (Citrus sinensis (L.) Osbeck) para la elaboracion de un vino de frutas.
- Olivero-Verbel, Rafael (2006). Optimizacion del proceso de clarificacion en la elaboracion de un vino de naranja criolla.
- Ramirez-Nino, Miguel A. (2006). Caracterizacion de un vino de pina (variedad espanola roja) pasteurizados y sin pasteurizar elaborados con diferentes cepas de Sacharomyces cerevisiae.
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Progress 01/01/05 to 12/31/05
Outputs
Several experimental trials were done to evaluate the effect of microorganism strains on appearance, flavor, aroma and general acceptance of dry fresh fruit wines. Wines were prepared by using standard procedures described elsewhere and evaluated by a group of trained panelists using the Modified 20 Point Scale developed at the University of California, Davis. The total score of each wine made from the Red Spanish pineapple variety was over 10. The best rated wines, fermented with yeasts EC-1118 and IVC-GRE, scored 14.29 and 14.36, respectively. These are relatively good results because many commercial wines usually scored close to these. However, a p-value over 0.05 related to wine yeast treatment indicates that there are no significant differences between these values. The same response was observed with all the parameters measured except with general quality, which had a p-value less than 0.05. General quality is based on the personal preferences of each panelist.
Therefore, even when, statistically, panelists as a group cannot discriminate between wines using the objective established parameters in the modified scale, they (as a group) can statistically discriminate in terms of their own preferences. The group considered wines with EC-1118 and IVC-GRE much better in quality than the others. The order in which panelists ranked these wines in the overall results of the UC Davis scale coincided perfectly with the order of their own preferences. On the basis of that agreement, we concluded that IVC-GRE and EC-1118 yeast strains are the best selections from the yeasts evaluated for pineapple wines made from the Red Spanish variety. Similar results were obtained for wines made from Valencia oranges. In this case, the panelists were not able to discriminate between wines in any of the characteristics except appearance. All orange wines ranked relatively good, ranging from 11.84 to 13.56. Color and appearance ranked very high, as well as acescence,
sweetness and body. Aroma and flavor ranked as acceptable. In order to establish the effects of pasteurization of juice before fermentation, we conducted experiments with two different yeasts to produce wines from pasteurized and non-pasteurized pineapple juice. The aroma of wines that came from pasteurized media was very similar to that from white wines made from grapes, whereas the wines from non-pasteurized juice had an aroma which more resembled pineapple wine. In these experiments, we observed different patterns of phase formation during fermentation between the pasteurized and non-pasteurized trials. This fact suggested different rates of yeast activity during fermentation. In a second experiment performed to measure cell growth at different time intervals, we found that in non pasteurized pineapple juice, a bacillus type bacterium grew during fermentation. This bacterium is resistant to the addition of metabisulfite, the compound added to the fruit juice to prevent bacterial
growth during yeast fermentation. The bacterium seems to be responsible for some odors typical of the Red Spanish pineapple variety because this aroma is present in Petri dishes where the microorganism grew.
Impacts
Puerto Rico is a small island with very limited space dedicated to agricultural activity. Great fragmentation of the available land has resulted in the existence of many small farms, which in addition to farm characteristics, make it difficult for local farmers to provide competitive prices for their products. Exportation of tropical fruits seems to be a good alternative for local farmers because of the uniqueness of these commodities on the global market, which permits higher sales prices. However, the survival and increase of tropical fruit production on the island is highly influenced by global agricultural activity. One effective way to overcome this drawback is to export value-added products from these tropical fruits. While wines and brandies are usually made of grape juice, other fruits can be used in the elaboration of these alcoholic beverages. Among all tropical fruits, mangoes, pineapples and oranges have the higher potential for the production of superior
wines and brandies because of their high sugar content and strong and well defined aroma. Puerto Rico is an ideal place for the production of high quality wines and brandies from tropical fruits. While the island is still leader in rum production in the world, sugarcane is no longer the main agricultural crop. The development of high quality wines and brandies from tropical fruits will open new and more stable markets for Puerto Rican agriculture. Research for the production of high quality wines and brandies from these tropical fruits can also benefit other tropical and subtropical areas in the United States.
Publications
- Nieves, I., I. Rivera, J.M. Perez, and J. Huertas_Miranda. 2005. Evaluation of the Effect of Sulfite Addition and Must Pasteurization in Yeast Performance of Pineapple Wine Fermentation. (Poster) Annual Meeting of the American Institute of Chemical Engineers, Cincinnati, Ohio.
- Rivera-Garcia, J. H. and J. Huertas-Miranda. 2005. Determinacion de los Indices de Maduracion de la Naranja Valencia (Citrus sinensis) para la Elaboracion de Vinos y Brandys de Frutas. (Poster) Annual Meeting of the Puerto Rican Society of Agricultural Sciences (SOPCA). Perez, J. M. and J. Huertas-Miranda. (2005). A Study of the Effects of Pasteurization and Addition of Sulfites During Fermentations of Pineapple Juice with Saccharomyces cerevisiae. (Poster) Annual Meeting of the Puerto Rican Society of Agricultural Sciences (SOPCA).
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Progress 01/01/04 to 12/31/04
Outputs
Experimental trials were conducted in order to establish the effect of juice pasteurization before fermentation on aroma and flavor of fresh fruit wines. Montrachet Red Star (ATCC 36026) yeast strain was used to ferment pineapple juice of the Red Spanish variety. The juice was obtained by maceration and filtration of the fruit pulp. Fructose was added to reach a 22 degree Brix concentration . Two experimental conditions were performed, one with fresh juice and the other with pasteurized juice. Pasteurization was done at 76 degree Celsius for 15 min. Potassium metabisulfite was added to both media prior to inoculation, at a ratio of 75 mg/L. Whereas no formal sensory analysis has yet been done by the panelist group during the reporting period, informal evaluation reflected significant differences in aroma and flavor between the two products. Non pasteurized trials seemed to retain aroma characteristics from pineapple fruit whereas the pasteurized trials were more
similar in aroma and flavor to white wines made from grapes. During fermentation, different phase formation patterns were observed for each experimental condition. This phenomenon suggested different production rates of ethanol and carbon dioxide due to cell growth behavior. A second experiment was conducted to determine cell growth profiles. In this experiment, 10 mL samples were transferred to test tubes immediately after inoculation. These samples were incubated at 26 degree Celsius for 48 h and used to estimate cell growth by using standard plate count method. For both experimental conditions, yeast presented similar cell growth profiles. However, cells of the pasteurized medium seemed to reproduce at a higher rate than the cells of the non-pasteurized medium. There was a reduction of CFU/mL during the first six hours in both experimental conditions, followed by the usual increment during the exponential phase. During the reported period, graduate and undergraduate students
participating in the project received extensive training in fermentation theory and sensory analysis techniques. We have also initiated the processes of purchasing materials and equipment, and the selection of members and design of training for the sensory evaluation panel.
Impacts
Because this project is on its initial stages, there is not enough data to report significant impact. However, it is expected that the project will have significant impact on agricultural economic growth of Puerto Rico and other US tropical areas where pineapple, oranges and mangoes are cultivated. The development of high quality wines and brandies from these fruits will open new markets. The preliminary results obtained during the reported period were presented in a poster session of the American Institute of Chemical Engineers (AICHE) Annual Meeting in Austin, Texas (November 7-12, 2004): Montanez, S., Nieves I., Rivera, I., Huertas-Miranda, J. (2004). Effect of pasteurization of pineapple media on later cell growth of yeast.
Publications
- No publications reported this period
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