Progress 10/01/08 to 09/30/13
Outputs
Target Audience: Target audience is food scientists, juice processors and fruit producers. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Seven graduate students (Ph.D. and M.S. programs) participated in different studies (with authorship on publications). How have the results been disseminated to communities of interest? Research results have been presented at the Institute of Food Technologists Annual Meeting, the International Association for Food Protection Annual Meeting, local/regional presentations growers and juice processors. Results have also being disseminated by peer-review publications, two book chapters, and by knowledge transfer to processors via workshops. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Over a period of 5 years, we studied relevant processing and formulation alternatives to increase the quality and shelf-life of fruit juices, beverages and fruit sauces, focused on important fruits for the Northeast: apples, grapes, tart cherries, peaches and apricots. The studies were conducted with graduate students supported by qualified technicians and directed by faculty, in order to train students in scientific methods, fruit processing, quality evaluation, statistical analysis and scientific writing. Objective1: We investigated the effect of processing conditions and additives on the quality of grape, apple and tart cherry juices, focusing on their polyphenolic and antioxidant contents. For Concord and Niagara grape juices, harvesting, postharvest handling, and processing conditions had significant impact on the anthocyanin content, polyphenolic content and color of the final juice. For apple and tart cherry, we found a significant influence of variety on the quality of clear and pulpy juices. Methods to minimize oxidation and increase retention of healthful compounds were evaluated. Findings were presented at several IFT Annual Meetings and published. Objective 2: We developed processing technologies to produce pulpy juices from apples, Concord grapes and tart cherries. The effect of different varieties was assessed to determine which varieties responded better to the processing procedures. Pulpy juices were found to have higher soluble and insoluble fiber content with good stability over storage time. We also studied major factors that affect the quality of applesauce, a very popular product that requires consistent quality for enhanced consumer acceptability. The effect of variety, storage conditions and processing techniques were evaluated, and specific procedures to attain better consistency were developed. In addition, we researched the production of high quality nectars from selected varieties of peaches and apricots to develop shelf-stable beverages with better nutritional value (fiber, carotenoids, polyphenolics and antioxidants) due to their high fruit content. Results were presented at various IFT Annual Meetings. Objective 3: Several studies were conducted evaluating the use of ultraviolet treatment alone or in combination with microfiltration to enhanced quality and shelf-life of refrigerated apple juice and cider. Important factors that affect the efficiency of the ultraviolet treatment were also studied such as the level of insoluble solids in apple cider, the apple variety used, the degree of enzymatic browning, the addition of ascorbic acid (as an antioxidant) and the use of preservatives. Additional studies were conducted with Concord and Niagara grape juice to determine best alternatives to replace the traditional preservatives (sorbate and benzoate) in cold-packed juices with natural antimicrobials. Results have been presented at several professional meetings and several publications were produced.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Usaga, J., Manns, D.C., Moraru, C.I., Worobo, R.W., Padilla-Zakour, O.I. 2013. Effect of addition of ascorbic acid and selected preservatives on the efficiency of ultraviolet treatment of apple juice. Chicago, IL, USA: 2013 IFT Annual Meeting. Abstract 264-01.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Ferreira, L., Cooley, H.J., Padilla-Zakour, O.I. 2013. Effect of controlled atmosphere storage of apples (Malus domestica Borkh.) on physical and chemical parameters affecting applesauce rheological properties. Chicago, IL, USA: 2013 IFT Annual Meeting. Abstract 035-02.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2013
Citation:
Athiphunamphai, N., Padilla-Zakour, O.I. Physicochemical and rheological properties of applesauce: Effect of diced fruit addition prior to pulping. Chicago, IL, USA: 2013 IFT Annual Meeting. Abstract 035-26.
- Type:
Journal Articles
Status:
Published
Year Published:
2013
Citation:
Siricururatana, P., Iyer, M.M., Manns, D.C., Churey, J.J, Worobo, R.W., and Padilla-Zakour, O.I. 2013. Shelf Life Evaluation of Natural Antimicrobials for Concord and Niagara Juices. J. Food Protect. 76(1):72-78.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2012
Citation:
Zhao, D., Usaga Barrientos, J., Padilla-Zakour, O.I., Worobo, R.W., Moraru, C.I. 2012. Efficient reduction of Escherichia coli from apple cider by combining microfiltration with ultraviolet treatment. Providence, RI, USA: 2012 Annual IAFP Meeting. Abstract P3-62.
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Progress 10/01/11 to 09/30/12
Outputs
OUTPUTS: Peaches and apricots are popular fruits that provide significant amounts of beneficial phenolic and carotenoid compounds. Antioxidants, which include both phenolic and carotenoid compounds, have been found to reduce the risk of cardiovascular diseases and some cancers while carotenoids play a role in vision. Postharvest storage is challenging for these fruit since as they continue ripening off the tree, limiting their shelf life. Processing is a means to add value to these fruits by developing products for year-round fruit availability. A proportion of US peaches and apricots produced are used for production of puree and related products. Puree serves as the starting material for secondary products such beverages although production is challenging because it may involve juice extraction and clarification due to the high pulp and suspended solids content of these fruits. Peach and apricot beverages therefore include nectars, pulpy juices or mixed fruit turbid beverages where they represent a component of the fruit content. Growing public concern about obesity and other diet-related diseases has created a market for lower sugar or calorie versions of fruit products. Sugar reduction or substitution causes changes in taste and consistency, which may negatively affect the marketing, perception and consumption of low or reduced sugar products. There is limited information on the effect of these formula modifications on the phytochemical and nutritional value of the final products. Furthermore, the thermal treatment involved in the processing of nectars and the storage conditions during the shelf-life of the product may have detrimental effects on compounds susceptible to degradation by heat, light or oxidation. We investigated the composition and concentration of phenolic, antioxidant and carotenoid compounds in peach and apricot nectars with varying sucrose and fruit content. Phytochemical content and product quality were evaluated post-processing and over a 6-month storage period. We also assessed the suitability of selected varieties for nectar production. The findings are being disseminated through workshops to fruit and juice producers, through technical presentations at professional meetings and through publications. One graduate student participated this year on the research activities as part of a PhD project. PARTICIPANTS: Dr. Olga Padilla-Zakour, Project Director, Cornell University Dr. Ian Merwin, Collaborator, Cornell University. Other collaborators include NYS Department of Agriculture and Markets. Professional development: one Cornell University graduate student participated in the project this year, Oluranti Campbell, PhD candidate. TARGET AUDIENCES: Target audience is food scientists, juice processors and fruit producers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Nectars are defined as diluted juice beverages that contain fruit juice or puree, water and may contain sweeteners. They vary in appearance ranging from almost-clear liquid to beverages with high suspended solids, depending on the type of fruit and fruit content. We investigated the effect of the current trend of sucrose reduction and the use of sugar substitutes on the phytochemical content of lower calorie beverages. The puree produced from Harlayne apricot variety had high fruit soluble solids content which allowed for product formulation with little added sucrose. Despite the low soluble solids content of Redhaven peach puree, its low titratable acidity and high sugar-to-acid ratio, allowed for the manufacture of a peach beverage with high fruit content (>60%) and little added sugar. The low titratable acidity of peach puree negatively affected taste and malic acid was added to improve it. The standard nectars fulfilled USDA commercial item description while the reduced sucrose, 100-calorie versions, did not meet all stipulations, although they had >50% fruit content. Standard peach nectar had 130 calories while standard apricot nectar had 160 calories per serving. The two peach nectar treatments did not differ in total phenolic, antioxidant or carotenoid content as they had the same fruit content and the difference in sugar or water content was not enough to impact phytochemical stability. Total phenolics decreased over the storage time with hydroxycinnamates being the most stable compounds. Reduced sucrose nectar had more losses at 6 months (21%) than standard nectar (14%). Carotenoid compounds declined in storage, with degradation most evident in the provitamin A compounds. Losses were greater in reduced sucrose (32%) as compared to standard (24%) nectar. Peach nectar provided 7.2% RDA of vitamin A in standard and 6.8% in reduced sucrose versions. Apricot nectar was an excellent source, providing > 100% RDA in both standard and reduced sucrose forms. Fruit content was the determining factor in nectar phytochemical content. HPLC analyses showed that standard nectar was higher in almost all phenolic compounds after processing. The difference between treatments decreased with time with standard nectar at 6 months having only slightly higher phenolic content (30%) than the reduced sucrose product (26%). Carotenoid loss in storage was more pronounced in reduced sucrose (32%) than standard nectar (24%). This was attributed to starting fruit content, although the greater water content in reduced sucrose nectar (30%) could have some effect on the rate of lipid oxidation. Lutein and zeaxanthin, were lost within the first 3 months of the shelf-life study.
Publications
- Ferreira, L., Padilla-Zakour, O.I, Cooley, H.J. 2012. Changes in applesauce consistency due to apple variety and cold storage time. Las Vegas, NV, USA: 2012 IFT Annual Meeting. Abstract 275-28.
- Iyer, M. M., Sacks, G. L., Padilla-Zakour, O. I. (2012). Assessment of the Validity of Maturity Metrics for Predicting the Volatile Composition of Concord Grape Juice. Journal of Food Science 77(3):C319-25.
- Padilla-Zakour, O. I., Sullivan, E. K., Worobo, R. W. (2012). Juices and Functional Drinks. Production of Specialty Foods: Processing Technology, Quality, and Food Safety (pp. 239-71). Dallas, TX: Taylor and Francis.
- Usaga Barrientos, J.,Moraru, C.I., Worobo, R.W., Padilla-Zakour, O.I. 2012. Efficiency of ultraviolet treatment of apple cider: effects of concentration of suspended insoluble solids and enzymatic browning. Las Vegas, NV, USA: 2012 IFT Annual Meeting. Abstract 293-04.
- Athiphunamphai, N., Cooley, H.J., Padilla-Zakour, O.I. 2012. Effect of Heat Treatment and Extractor Rotational Speed on the Composition and Rheological Properties of Applesauce. Las Vegas, NV, USA: 2012 IFT Annual Meeting. Abstract 230-13.
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Progress 10/01/10 to 09/30/11
Outputs
OUTPUTS: NYS is the third largest grape producing state in the country. Of all processed grapes in NYS, 65.6% is destined to the juice industry. Niagara, a hybrid of native species (Vitis labrusca), is the leading variety for white grape juice in the US due to its unique aroma and flavor and it is the major cultivar in New York State; hence making New York the 2nd largest producing state. Color, clarity, and health benefits from polyphenols in juice are important for consumer acceptability. Juice components can react over time producing haze that may settle out and precipitate; thus, filtration is necessary to produce commercial clear products. Standard diatomaceous earth (DE) filtration, traditionally used in juice processing for final filtration is highly efficient and very effective. However, there are several drawbacks due to safety restrictions in handling the material, cost of storage, delivery, and waste disposal, and operation challenges. Product quality relies on the grade and amount of DE, causing its quality to be very variable. In addition, the system could plug up easily and would need to be disassembled for cleaning, resulting in significant losses of valuable juice and increased operational costs. Cross-flow filtration (CFF) is a pressure-driven membrane technology with applications in the juice industry. The advantages of CFF over traditional clarification methods include reduced processing time and enzyme usage, increased juice yield, and elimination of filter aid and filter presses. Cross-flow filters are also easy to clean and operate, can act as microbiological filters to reduce or eliminate spoilage microorganisms, depending on the pore size of the membrane, and can be used as cold-sterilizing microfilters; therefore, eliminating the need for heat pasteurization. Through the activities of this project we aimed to improve the quality of Niagara grape juices using CFF. We evaluated the efficiency of ceramic and polymeric CFF against traditional DE filtration to improve overall quality of Niagara grape juices, working with industry collaborators. The findings are being disseminated through workshops to grape and juice producers, through technical presentations at professional meetings and through publications. One graduate student participated this year on the research activities as part of a PhD project. PARTICIPANTS: Dr. Olga Padilla-Zakour, Project Director, Cornell University. Other collaborators include NY Wine and Grape Foundation and National Grape Cooperative. Professional development: one Cornell University graduate student participated in the project this year, Passaporn Siricururatana, PhD candidate. TARGET AUDIENCES: Target audience is food scientists, juice processors and fruit producers PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
We evaluated ceramic and polymeric cross-flow filters against traditional diatomaceous earth filtration to assess improvements in overall quality of Niagara grape juice, in combination with the ascorbic acid or sulfite as antioxidants. We also evaluated the effect of glass or PET packaging materials to extend the shelf-life of juices under the conditions studied. Polymeric (0.45-um pore size) and ceramic membranes (0.2-um, 0.01-um) were evaluated. Juices were filtered with optimized pressure at 25C. Prior to juice processing, grapes were treated with either 80 ppm potassium metabisulfite or 500 ppm ascorbic acid (AA). Samples were analyzed for brown color (Abs 430nm), Hunter L, a, b color values, turbidity, total phenolic content, antioxidant capacity (ORAC assay), and phenolic profile using HPLC analysis. Sensory evaluations were also conducted. Sulfited juices had significantly higher turbidity than AA treated juices but lower total phenols, antioxidant capacity, and phenolic compounds throughout the 24-week shelf life study. Among AA treated juices, filtration type did not affect juice color (both brown color and Hunter color) and turbidity; however CFF juices resulted in lower total phenols and antioxidant capacity compared to DE filtered juices. Brown color increased significantly over 24 weeks and juices packages in PET bottles were darker than those packaged in glass bottles. Turbidity, total phenols, and antioxidant capacity were stable over storage while phenolic compounds identified by HPLC analysis increased significantly which could due to the degradation of larger polyphenols. Acceptance test showed that all juices were rated equally for color, flavor, and overall acceptability. In addition, all juices had similar preference ratings. Therefore, ascorbic acid could potentially be used as sulfite substitute. Using ceramic CFF instead of DE filtration produced juice with equal or better quality than standard sulfited juice, thus providing a more sustainable operation.
Publications
- Siricururatana, P., Padilla-Zakour, O.I. 2011. Cross-flow microfiltration effect on quality of N.Y. wines. Book of Abstracts. 2011 IFT Annual Meeting, June 11 - 14, New Orleans, LA.
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Progress 10/01/09 to 09/30/10
Outputs
OUTPUTS: Concord and Niagara grapes are the most important grape varieties for juice production in New York State. Consumer preference for all-natural products has prompted increased investigation of natural preservatives for extending the shelf life of foods and beverages. Therefore we focused on evaluating the efficacy of natural preservatives and processing aids in cold-filled still and carbonated Concord and Niagara grape juices, which have traditionally been preserved with pasteurization and chemical preservatives. In addition, we studied harvesting and processing methods to provide alternative procedures for the production of high quality Niagara grape juice. Through the activities of this project, viable methods to produce Concord and Niagara juice with enhanced quality have been studied in collaboration with industry partners. The findings are being disseminated through workshops to grape and juice producers, through technical presentations at professional meetings and through publications. Three graduate students have participated this year on the research activities as part of their MS and PhD projects. PARTICIPANTS: Dr. Olga Padilla-Zakour, Project Director, Cornell University. Dr. Gavin Sacks and Dr. Randy Worobo, Collaborators, Cornell University. Other collaborators include NY Wine and Grape Foundation, National Grape Cooperative and Welch's. Professional development: three Cornell University graduate students participated in the project this year, Passaporn Siricururatana and Meera Iyer, PhD candidates, and Kristin Alongi, MS graduate. TARGET AUDIENCES: Target audience is food scientists, juice processors and fruit producers PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
We assessed the efficacy of traditional and natural preservatives in pasteurized cold packed juices inoculated with yeast to maintain microbial stability over 6-month storage at 18C. Commercial Concord and Niagara grape juices were inoculated with a spoilage yeast cocktail comprised of Dekkera, Kluveromyces, Brettanomyces, and the preservative-resistant Zygosaccharomyces at 100 CFU/mL and 100000 CFU/mL. The following agents were added to still juices: no preservative (negative control), 0.05% potassium sorbate + 0.05% sodium benzoate (positive control), 0.1% or 0.2% cultured dextrose (MicroGardTM 730), 250 ppm dimethyl dicarbonate (DMDC), 10 ppm or 20 ppm natamycin (NatamaxTM), and a combination treatment of 250 ppm DMDC + 10 ppm or 20 ppm natamycin. Carbonated juice was treated with controls and with the combination of 250 ppm DMDC + 10 ppm natamycin. Samples were incubated at 20C and yeast were enumerated on acidified potato dextrose agar (pH 3.5) every two weeks. Turbidity, pH and Brix were measured as indicators of juice quality. Juices were deemed spoiled when yeast counts exceeded 1 million CFU/mL. Cultured dextrose was not effective at levels tested. While DMDC and natamycin afforded shelf life extension individually, the combination treatment was more effective. In still juices, a shelf life of 120-130 days and 50-70 days was observed for the low and high yeast inoculums respectively, as compared to 150-160 days for the positive control. In carbonated juices, combination treatment results matched those of the positive control (161 days). For Niagara juice, DMDC was as effective as sorbate/benzoate to prevent juice spoilage up to 6 months. Results indicate that utilizing a processing aid with a natural antimicrobial may offer the same extended shelf-life as traditional preservatives for cold-filled Concord and Niagara grape juices. For Niagara grape juice research, we studied harvest method (handpick vs mechanical), harvest date (early vs late), 80 ppm sulfite or 500 ppm ascorbic acid (AA) addition, use of hot-break prior to pressing and pasteurization temperature. Grapes were treated, crushed, depectinized, pressed, pasteurized, and cold stabilized. Juices were filtered, pasteurized by hot-filling, and stored at 18C. Hot-packed juices were analyzed for color, turbidity, total phenolics, and antioxidant capacity using the ORAC assay at 0, 12, 24 weeks. Sensory evaluations were conducted using triangle and ranking tests. Data was analyzed by ANOVA and significant differences among means determined by Tukey's test. Phenolic content and ORAC values of late harvest juices were 35-38% higher than early harvest juices. AA juices had 13-36% higher phenolic content and antioxidant capacity than sulfited samples. Hot-break produced juices with significantly higher (10-13%) phenolic contents and ORAC values. Turbidity and brown color increased significantly over 24 weeks; other attributes remained unchanged. Harvesting method, pasteurization and hot-break temperature did not affect juice quality as confirmed by sensory results. Optimized handling and processing are essential to produce high quality Niagara grape juices.
Publications
- Iyer, M. M., Sacks, G. L., Padilla-Zakour, O. I. 2010. Impact of Harvesting and Processing Conditions on Green Leafy Volatile Development and Phenolics in Concord Grape Juice. Journal of Food Science 75(3):C297-C304.
- Alongi, K.S., Padilla-Zakour, O.I., Sacks, G.L. 2010. Effect of concentration prior to cold-stabilization on anthocyanin stability in Concord grape juice. J. Agric. Food Chem. 58(21):11325-11332.
- Siricururatana, P., Churey, J.J., Worobo, R.W., Padilla-Zakour, O.I. 2010. Effect of postharvest and processing methods on Niagara grape juice quality. Institute of Food Technologists Annual Meeting & Food Expo, Chicago, IL. Abstract 233-11.
- Iyer, M., Churey, J.J., Worobo, R.W., Padilla-Zakour, O.I. 2010. Shelf-life evaluation of natural antimicrobials for Concord grape juice. Institute of Food Technologists Annual Meeting & Food Expo, Chicago, IL. Abstract 074-02.
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Progress 10/01/08 to 09/30/09
Outputs
OUTPUTS: Concord grape juice is a principle agricultural commodity of New York State. New York is the second largest producer of Concord grapes in the US and more than 90% of the crop is processed into juice. The occurrence of an herbaceous off-flavor in select bottles of New York State Concord grape juice in 2007 prompted efforts to identify and quantify the related aroma compounds, and to determine ways to control or minimize their formation during juice production. In addition, we are evaluating grape handling and processing parameters to retain healthful attributes such as phenolic compounds, anthocyanins and antioxidant capacity in both Concord and Niagara juices. Through the activities of this project, viable methods to produce Concord and Niagara juice with enhanced quality have been studied in collaboration with industry partners. The findings are being disseminated through workshops to grape and juice producers, through technical presentations at professional meetings and through publications. Three graduate students have participated this year on the research activities as part of their MS and PhD projects. PARTICIPANTS: Dr. Olga Padilla-Zakour, Project Director, Cornell University Dr. Gavin Sacks, Collaborator, Cornell University Other collaborators include NY Wine and Grape Foundation and National Grape Cooperative. Professional development: three Cornell University graduate students participated in the project this year, Passaporn Siricururatana and Meera Iyer, PhD candidates, and Kristin Alongi, MS student. TARGET AUDIENCES: Target audience is food scientists, juice processors and fruit producers PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
The detection of an herbaceous off-flavor in freshly processed New York State Concord grape juice threatens to impair consumer acceptability and sales of this healthful fruit-based product. We aimed to identify and minimize the compounds responsible for this off-flavor. Empirical evidence suggested that the herbaceous flavor is due to elevated levels of the six-carbon alcohols and aldehydes generated from enzymatic oxidation of polyunsaturated fatty acids. The concentrations of these green leafy volatiles (GLVs) under various harvesting maturities (11.4 to 16.3 Brix) and juice processing conditions (hot-press at 60C, hot-break at 77-82C, pasteurization regimes) were quantified to determine the main conditions resulting in elevated levels. New York Concord grapes were processed into juice; solid phase extraction (SPE) of the juice and GC-MS analysis enabled GLV quantification. Other parameters (Brix, pH, acidity, total phenolics, monomeric anthocyanins, and polymeric color) were measured in the juices as quality indices. All trials were conducted in duplicate or triplicate to allow statistical analysis. Trans-2-hexenal, the most odor-active GLV in this analysis, displayed significantly lower levels in juice with increasing ripeness of the grapes (R2=0.91, p<0.01). During processing, the greatest levels of trans-2-hexenal were observed immediately upon grape crushing; levels in the must were detected at 569 ng/mL. Trans-2-hexenal levels were 3-6 times greater in hot break juices than hot press, with values ranging from 89-206 ng/mL in the former and 27-35 ng/mL in the latter. Time-temperature variations for pasteurization did not significantly alter GLV levels. The results of this work have broad applications, as it further elucidates the volatile profile of Concord grapes while also providing insight on industrial grape juice processing optimization. It is prudent to assure harvesting of grapes in excess of 15.5 Brix for optimal flavor profile. The crushing of the grapes to generate the must is associated with the highest GLV levels over the course of processing and suggests that it may be possible to optimize crushing and/or handling conditions of the must to minimize GLV levels in the final juice. Our results indicate that hot break procedures are associated with no significant increase in total phenols or monomeric anthocyanins. Furthermore, we observed that hot break procedures resulted in elevated GLV levels as compared to hot press procedures; this in turn suggests that hot break procedures are not a prudent recourse for New York State Concord juice processors. GLV content is not impacted by equivalent pasteurization time and temperature, suggesting that thermal deactivation of GLV-producing enzymes has occurred in earlier processing stages.
Publications
- Siricururatana, P. and Padilla-Zakour, O.I. 2009. Effect of processing on the quality and stability of stability of shelf-stable pulp-rich apple juice. Institute of Food Technologists Annual Meeting & Food Expo, Anaheim, CA. Abstract 153-07.
- Iyer, M., Sacks, G., and Padilla-Zakour, O.I. 2009. Herbaceous flavor development in Concord grape juice. Institute of Food Technologists Annual Meeting & Food Expo, Anaheim, CA. Abstract 153-15.
- Padilla-Zakour O. 2009. Good Manufacturing Practices. In: N. Heredia, I. Wesley, S. Garcia, editors. Microbiologically safe foods. Hoboken: Wiley. P395-415.
- Padilla-Zakour, O.I. 2008. Juice processing techniques and their effect on flavor and phytochemicals. Institute of Food Technologists Annual Meeting & Food Expo, New Orleans, LA. Abstract 204-01.
- Siricururatana, P. and Padilla-Zakour, O.I. 2008. Pulpy juices from grapes and tart cherries as healthier alternatives to clear juices. Institute of Food Technologists Annual Meeting & Food Expo, New Orleans, LA. Abstract 133-05.
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Progress 10/01/07 to 09/30/08
Outputs
OUTPUTS: Consumers are interested in healthier food choices and in ways to increase consumption of fruits and vegetables. Consumers are knowledgeable and selective regarding the functional and health benefits of fruits and their processed products and therefore, processing methods need to be developed to increase the nutritional value of juices. One viable alternative is to produce a juice that is closer to whole fruit, but also offers the convenience of a shelf-stable product Pulp-rich apple juices could provide consumers healthy juice alternatives to clear juices and beverages if the processing is optimized. The pulpy apple juice offers additional antioxidant content, phenolic content and dietary fiber in a convenient shelf-stable package. This healthier juice might also increase the satiety factor due to the higher soluble fiber content. Through the activities of this project, viable methods to produce pulpier apple juice have been developed. The findings are being disseminated through workshops to juice producers, through technical presentations at professional meetings and through publications. One graduate student has participated this year on the research activities as part of her MS project. PARTICIPANTS: Dr. Olga Padilla-Zakour, Project Director, Cornell University Professional development: one Cornell University graduate student participated in the project this year, Passaporn Siricururatana, who finished her MS degree and is continuing with her Ph.D. program. TARGET AUDIENCES: Target audience is food scientists, juice processors and apple producers PROJECT MODIFICATIONS: This project is being revised to broaden the focus to include other fruits and beverages.
Impacts
Apples are excellent natural sources of fiber and health-promoting phytonutrients. However, processed apples, especially clear juices, are considerably lower in these compounds. Alternative processing for healthy, shelf-stable juices that retain nutritious compounds is essential. We studied processing methods and evaluated storage quality of juices from four apple varieties, Cortland, Empire, Golden Delicious and McIntosh, during 24-week storage at 18C to determine the best treatment for optimal quality. Juices were processed in duplicate as clear (pectinase treated) and pulp-rich. A turbo extractor was used to produce pulp-rich juice with/without steam blanching and/or pectinase/amylase treatment. All juices were pasteurized by hot-filling at 85C in 10-oz glass bottles. Whole fruit and juices were analyzed for pH, acidity, soluble solids, color, turbidity, viscosity, dry matter, pectin content, settled solids, total phenolics, and antioxidant capacity. Juices were evaluated at 0, 12, and 24 weeks including sensory evaluations using acceptance and ranking tests. Processing decreased phenolic content and antioxidant capacity of juices with retention of 80-100% in pulp-rich samples and 27-59% in clear juices. Phenolic content and antioxidant capacity in pulp-rich juices was 1.4-3.6 times that of clear juices during 24 weeks. Phenolic content, in mg gallic acid equivalent/100 g juice, ranged from 33.4-138 and 23.1-55.0 juice for pulp-rich and clear juices, respectively, while antioxidant capacity, expressed as mg vitamin C equivalent antioxidant capacity/100 g, ranged from 41.5-193 and 28.8-70.0 for pulp-rich and clear juices. Blanching treatments resulted in significantly higher phenolic content and antioxidant capacity. Pectin content of pulp-rich juices (18.1-191 mg galacturonic acid/100 g) was comparable to that of whole fruits (186-279 mg galacturonic acid/100g), while there was none in clear juices. Sensory evaluation showed pulpy juices were acceptable from consumer's viewpoint.
Publications
- Merwin, I.A., Valois, S., Padilla-Zakour, O.I. 2008. Cider apples and cider making techniques in Europe and North America. Horticultural Reviews (J. Janick, ed.) v34:365-415.
- Siricururatana, P. 2008. Quality and stability of shelf-stable pulp-rich fruit juice. M.S. Thesis, Cornell University.
- Worobo, R.W. and O.I. Padilla-Zakour. 2007. The Great Debate: Treatment Success Is Proven. American Fruit Grower, Vol 127, No. 7 (July), p. 12-13.
- R.W. Worobo and O.I. Padilla-Zakour. 2007. Cider Pasteurization. Response to Pasteurization is no silver bullet. American Fruit Grower Magazine. Vol 127, No. 4 (April), p.34.
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Progress 10/01/06 to 09/30/07
Outputs
Fermented cider is typically made using a blend of different types of apples including a portion of cider variety apples which are high in tannins or phenolic content, although the availability of special cider apples in the US is limited. One approach to replace cider variety apples is to use alternative methods to increase the content of phenolic compounds in cider made from only dessert fruit. One method is to add tannins extracted from grapes or oak to the finished cider. We evaluated the effect of tannin addition (at 100 ppm) on the quality of cider made from Liberty apples, a dessert variety that is used for fresh consumption and cider making. Three commercial tannins (powders) were studied: gallotannins (Tanin Plus), ellagotannins (Galalcool SP), and proanthocyanidins (Biotan). Ciders were evaluated for physiochemical differences as well as by a sensory panel. Significant differences were found in the flavor, color and amount of phenolic compounds present in the
ciders. The tannins added color and flavor to the base Liberty cider. Addition of the tannins resulted in an increase of total phenolic content by 70 ppm compared to control cider. Panelists perceived Galalcool SP as the cider with the most mouthfeel and was the least preferred. The panelists preferred Tanin Plus significantly over the other ciders. Minimally processed apple cider must be pasteurized or UV treated to ensure its safety. To extend the refrigerated shelf-life of juices, addition of dimethyl dicarbonate at 200-250 ppm is an alternative as this chemical sterilant if very effective against spoilage mircroorganisms. We studied the use of a combination of UV treatment at 14 mJ/cm2 with the addition of dimethy dicarbonate up to 250 ppm (treatments currently being used to deliver a safe apple juice and to extend refrigerated shelf-life) on the retention of water soluble vitamins in apple juice. The combination method resulted in better vitamin retention compared to UV or
dimethyl dicarbonate treatments applied alone.
Impacts
Commercial tannins increased the phenolic content of the fermented ciders and seemed to increase the overall preference of the ciders, based on the sensory evaluations where panelists preferred the ciders with added commercial tannins. The tannins did not affect the acidity of the cider, but did alter its color. Tannins are an important component that affects the flavor profile of the cider and usually come from cider variety apples. However, where these apples are in limited supply, commercial tannins seem to be a promising alternative. Adding tannins can increase the quality of ciders made from dessert varieties as well as extend the product line when only a limited number of apple varieties are available. For minimally processed refrigerated apple juice, the application of UV treatment followed by the addition of dimethyl dicarbonate at 250 ppm resulted in a safe product with increased shelf-life and better retention of water soluble vitamins. These findings are
being disseminated through workshops to cider producers, through technical presentations at professional meetings and through publications.
Publications
- Valois, S., Merwin, I. and Padilla-Zakour, O.I. 2007. Apple mash fermentation and heating affect the physiochemical properties and flavor of fermented cider. Institute of Food Technologists Annual Meeting & Food Expo, Orlando, FL. Abstract 006-03.
- Mohd Adzahan, N., Worobo, R.W and Padilla-Zakour, O.I. 2007. Effects of dimethyl dicarbonate addition on the retention of water soluble vitamins in juice systems. Institute of Food Technologists Annual Meeting & Food Expo, Orlando, FL. Abstract 189-63.
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Progress 01/01/06 to 12/31/06
Outputs
We evaluated fermentation methodologies advantageous for increasing the extraction of phenolic compounds and therefore improving the quality of cider produced from dessert fruit. Four treatments were evaluated: 1-control (juice fermentation at 12C); 2-mash fermentation; 3-heating the mash to 70C followed by fermentation; 4-heating the mash, pressing the juice followed by fermentation. Three apple varieties were selected: Golden Delicious, Liberty (red skin) and Chisel Jersey (hard cider apple with high phenolic content). Sulfites (50 mg/L), nutrients and yeast were added for proper fermentation control. Finished samples were bottled and analyzed for pH, acidity, turbidity, color, phenolic content, phenolic profile by HPLC, acid profile by HPCE, ethanol content, and evaluated by a sensory panel. Mash fermentation did not significantly increase the total phenolic content, but did alter the composition of phenolic compounds and therefore the sensory properties.
Treatments where mash was heated increased the phenolic content by twofold as well as the amount of different phenolic compounds, notably procyanidin B2. Cider color was significantly affected, especially in Liberty cider, where hot press and mash samples were reddish. Sensory analysis showed that only for Golden Delicious the mash or heating increased the preference value of the cider. On a second project, we evaluated the use of a cold sterilant in juice and its effect on quality. Dimethyl dicarbonate (DMDC) is an effective anti-microbial agent that controls a wide range of microorganisms. It constitutes a non-thermal processing method approved by FDA to be used in wine and juice for shelf-life extension and to comply with juice HACCP regulations. It is considered a processing aid because in aqueous solutions it hydrolyzes into carbon dioxide and methanol. However, DMDC effect on vitamins in beverages is unknown. We studied the effect of DMDC concentration on the retention of
soluble vitamins in vitamin-rich beverages and juice systems. Water, 12Brix sugar plus 0.4 percent malic acid solution, and 12Brix apple juice were fortified with ascorbic acid, thiamine (B1), riboflavin (B2), nicotinic acid (niacin or B3) and pyridoxine (B6) at no more than double the recommended daily dietary intake. DMDC was added (0, 50, 100, 150, 200, 250 mg/L) to solutions and juice, mix well and allowed to stand for 3 h at 25C for proper treatment and hydrolysis of DMDC. Vitamin quantification was immediately conducted by capillary zone electrophoresis (HPCE). In general, the addition of DMDC improved the retention of vitamins in juice systems. The retention was not significantly affected by the concentration of DMDC in water and aqueous solutions except for nicotinic acid, where dosage of 150 mg/L or higher improved retention from 87 to 96 percent. For apple juice, the concentration of DMDC had a significant effect for all vitamins, with the greatest improvement observed for
riboflavin fortified samples from 64 percent (control) to 95 percent (at 250 mg/L) retention, and the lowest for pyridoxine from 89 percent (control) to 97 percent retention at the highest concentration.
Impacts
Utilization of the processing aid and cold sterilant DMDC in vitamin fortified beverages and juices offers benefits that include safety, shelf-life extension and soluble vitamins (C and B-group) retention, which might improve quality and function of healthy products. This non-thermal technique is especially useful for minimally processed juices such as refrigerated apple cider, to retain the fresh flavor and natural nutrients. Fermented (hard) cider is traditionally made from cider apples which are rich in tannins but demand higher prices. Dessert apples, which are readily available, could be used to produce hard cider if more phenolic compounds could be extracted to add complexity. Mash heating and mash fermentation treatments could be used to produce a cider from dessert apples with more body and mouthfeel to use in blending to improve insipid ciders. These treatments have significant effects on the chemical and sensory properties of the finished ciders, and can be
used to make multiple styles of cider from a single apple blend or apple variety.
Publications
- Valois, S., Merwin, I.A. and Padilla-Zakour, O.I. 2006. Characterization of fermented cider apple cultivars grown in upstate New York. J. Am. Pomological Soc. 60(3):113-128.
- Valois, S. and Padilla-Zakour, O.I. 2006. Effect of nitrogen supplementation and fermentation temperature on the quality of fermented apple cider. Institute of Food Technologists Annual Meeting & Food Expo, Orlando, FL. Abstract 078F-12.
- Bonsi, I. and Padilla-Zakour, O.I. 2006. Effects of processing on total dietary fiber content of apple products. Institute of Food Technologists Annual Meeting & Food Expo, Orlando, FL. Abstract 039-G29.
- Adzahan, N.M. 2006. Effects of ultraviolet treatment on water soluble vitamin retention in aqueous model solutions and apple juice. Ph.D. Dissertation, Cornell University.
- Valois, S. 2007. Nitrogen fertilization effects on the quality of cider apples and the effect of processing treatments on the quality of fermented cider made from dessert apples. Ph.D. Dissertation, Cornell University.
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Progress 01/01/05 to 12/31/05
Outputs
We evaluated the retention of total phenolic content and antioxidant capacity in apple juice and cider produced by different processing techniques. Products were made in duplicate from McIntosh apples. Pressed juice was processed into clarified (depectinized and filtered through 0.45 um membrane) and natural style (cloudy), packaged in glass bottles and pasteurized by hot-filling at 85 C. Fresh-pressed cider was processed as control, flash pasteurized (71 C for 6 seconds) or UV irradiated. Total phenolic content and antioxidant capacity were determined and expressed as mg gallic acid equivalents (GAE)/100 g(ml) while antioxidant capacity was expressed as mg Vitamin C Equivalent Antioxidant Capacity (VCEAC). Total phenolic content and antioxidant capacity in fresh fruit were 131 mg GAE/100 g and 223 mg VCEAC/100 g, respectively. Cider and juice retained an average of 38 and 32 pct of total phenols and approximately 23 and 26 pct of antioxidant capacity. We also
evaluated the rate of degradation for ascorbic acid, thiamine and pyridoxine in water solutions and apple juice when exposed to UV at various doses. UV treatment was performed using a CiderSure model 3500 UV with various flow rates ranging from 2.8 kg/min to 15.8 kg/min. The UV dose (1.3 to 78.1 mJ/cm2) was calculated based on the irradiance and exposure time. Duplicate samples of individual vitamin solutions (10 to 25 mg/100ml), a mixture of vitamins, malic acid and sucrose solutions, and apple juice were treated and analyzed by HPCE. UV treatment resulted in consistent losses of vitamins with increasing levels of dose. The degradation pattern fits the first order reaction model. Ascorbic acid was most affected by UV with fortified juice showing 66 pct loss at about 7 mJ/cm2, while thiamine and pyridoxine losses were 27 and 9 pct, respectively. We studied the effect of nitrogen supplementation and fermentation temperature on the overall quality of fermented cider. Extracted Liberty
apple juice was divided into treatments. Low and high nitrogen levels were used at three different temperatures (12 C, 15 C, 25 C) and fermented in duplicate. Low nitrogen treatment received no additional nitrogen, while high nitrogen treatment received up to 400 mg/L supplementation as diammonium phosphate. Sulfites (50 mg/L), nutrients and yeast were added for proper fermentation control. After fermentation, samples were bottled and analyzed for pH, acidity, turbidity, color, total phenols, alcohol level, and acids. A sensory panel was conducted to detect off flavors and preference among treatments. The high nitrogen fermentations had significantly lower pH values and higher titratable acidity levels due to the presence of lactic and phosphoric acids. The alcohol content increased by 0.75 pct with decreasing temperature. Low nitrogen samples were lighter, more yellow, and less turbid. The high nitrogen samples had 15 pct less phenolic content. A sensory panel significantly preferred
the 12 C low nitrogen and the 18 C high nitrogen samples. Off flavors were detected in samples fermented at 24 C.
Impacts
Total phenolic content and antioxidant capacity is reduced during processing of apple products. Current juice production methods result in large losses of healthful antioxidants with retention of just one quarter of the original levels found in apples and therefore better juice extraction methodologies need to be developed. Pasteurization, UV treatment and clarification did not change the levels of phenolic compounds present in apple juice and therefore juice producers can choose any of these technologies based on their targeted market. UV treatment offers an alternative for safe treatment of minimally processed juices but healthful compounds such as vitamins can be significantly reduced by this process, hence the need to minimize UV dose. For fermented cider production, nitrogen supplementation and temperature control during fermentation can be easily used by producers to modify the delicate flavor profile and manufacture different styles of hard ciders. Lower
temperature fermentations produced ciders perceived to have less off flavors and were preferred over ciders fermented at higher temperatures.
Publications
- Valois, S. and Padilla-Zakour, O.I. 2005. Pasteurization methods to stabilize bottled fermented apple cider. Institute of Food Technologists Annual Meeting & Food Expo, New Orleans, LA. Abstract 36E-44.
- Adzahan, N.M., Worobo, R.W. and Padilla-Zakour, O.I. 2005. Effect of ultraviolet dose on water soluble vitamins in model solutions and apple juice. Institute of Food Technologists Annual Meeting & Food Expo, New Orleans, LA. Abstract 99E-6.
- Bonsi, I. and Padilla-Zakour, O.I. 2005. Retention of total phenolic content and antioxidant capacity in processed apple products. Institute of Food Technologists Annual Meeting & Food Expo, New Orleans, LA. Abstract 36E-47.
- Bonsi, I. A. 2005. Effects of processing on quality of apple products: apple juice, cider and sauce. M.S. Thesis, Cornell University.
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Progress 01/01/04 to 12/31/04
Outputs
We continued to study the quality of cider apple varieties typically used for fermented cider production to assess their potential for single variety use or for blending with commercial varieties. To evaluate the effect of growing season, apple varieties analyzed the previous year were tested again. Seventeen traditional European and six indigenous North American cider apples grown in New York were analyzed for firmness, weight, total phenolic content and antioxidant capacity. Extracted juice was tested for total acidity, total soluble solids, pH, total phenolic content and antioxidant capacity. The results were similar to the previous year although substantial differences were observed on some varieties. Firmness measurements for apples ranged from 4.5 to 12.7 kg. Average fruit weight range from 35 to 222 g while the total phenols varied from 234 to 3200 mg GAE/100g and antioxidant capacity from 81 to 1700 mg vitamin C equivalent per 100 g fresh fruit. Soluble solids
ranged from 8.3 to 15.7 Brix, pH from 2.6 to 4.6 and acidity from 0.15 to 2.45 percent as malic acid. Phenolic content and antioxidant capacity of the extracted juice were significantly lowered than the values measured in the fresh fruit. We evaluated the effect of various pasteurization treatments on the microbial stability and quality of bottled fermented cider prepared without chemical preservatives. Fermented cider (6.5 percent alcohol) was pasteurized and packaged in ten ounce glass bottles using two methods: hot-fill-hold and water bath process. Ciders were hot-filled at 60C, 63C, and 65.5C with a hold time of 3 min before cooled in 24C water. Bottled cider samples were pasteurized in a water bath at 74C for 10, 20, and 30 min and submersed in 74C water for 5 min. Bacteria, yeast, and mold counts were measured before and after treatments. Ciders were analyzed for pH, titratable acidity, residual sugars, alcohol, Hunter color and evaluated by a sensory panel to determine if
panelists could find a difference between the methods. All trials were conducted in duplicate. All hot-fill-hold and bottle pasteurization methods eliminated spoilage organisms that might decrease the shelf life, indicating a short process at low temperature is sufficient to stabilize the cider. There were no significant differences between the treatments in analytical measurements. Taste panels showed a noticeable difference between treatments and control as well as between pasteurization treatments. Lower temperatures and shorter times resulted in best quality. In another study we evaluated the loss of ascorbic acid in minimally processed apple juice when exposure to UV at the energy level required to achieve a 5-log reduction of E. coli O157:H7 is used. UV treatment was performed using a Cider Sure model 3500 UV machine at 14 mJ/cm2 power intensity. Duplicate samples of ascorbic acid fortified apple juice were treated and analyzed the same day. Samples were protected from heat,
light and sodium sulfite was added as an antioxidant after treatment. UV treatment resulted in significant losses of ascorbic acid up to 42.5 percent.
Impacts
The apple varieties studied provide a guideline for selecting and blending cider apples grown in New York to achieve a specific target flavor profile in a fermented cider. Cider varieties are excellent sources of phenolic compounds and antioxidants, and offer a wide range of options to increase the complexity of the fermented ciders. In addition, fresh cider apples might find a niche with consumers looking for produce with high phenolic and antioxidant capacity. Small wineries or cider producers could use a short time in bottle pasteurization, which would only require a source of hot water, or a low temperature hot packing line in order to have a stable hard cider while maintaining flavor profile and eliminating use of preservatives. Although UV has been proven to reduce E. coli O157:H7 in apple juice, concern on nutrient loss is also important. Many factors can affect the actual UV exposure, such as concentration of ascorbic acid and phenolic compounds which absorb
UV light. The efficiency of this treatment will depend heavily on the type of compounds contained in the juice.
Publications
- Valois, S. and Padilla-Zakour, O.I. 2004. Effects of apple juice processing on the quality of fermented cider. IFT Annual Meeting & Food Expo, Las Vegas, NV. Abstract 31-1.
- Adzahan, N.M., Worobo, R.W. and Padilla-Zakour, O.I. 2004. Effect of ultraviolet treatment on ascorbic acid in apple juice. IFT Annual Meeting & Food Expo, Las Vegas, NV. Abstract 49H-10.
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Progress 01/01/03 to 12/31/03
Outputs
We have tested different methods to produce extended shelf-life refrigerated apple cider and short shelf-life apple cider that will not require refrigeration, without the use of preservatives. The techniques investigated would be appropriate for small-scale processors. Raw apple cider was prepared from Crispin and Empire apples. The 8 treatments studied were flash pasteurization at 71C x 6 sec, hot fill at 63C with 5 min hold, 14 mJ/cm2 UV exposure, extended UV exposure, addition of 250 ppm dimethyl dicarbonate (commercial cold sterilant, processing aid), and combination treatments. Treated samples were stored at 18C for 8 weeks and at 4C for 16 weeks. Juice samples were evaluated for microbiological counts, chemical and physical analysis and informal taste panels. Thermal pasteurization was effective in reducing microbial counts but hot-filling produced a cider with double the shelf-life. UV treatments did not increase the shelf-life due to limited action against
yeast. Dimethyl dicarbonate was effective against bacteria and yeast providing extended shelf-life under refrigerated storage only. The flavor of unheated samples was fresher than the hot-filled cider, which was still very good. We conducted research to evaluate the effect of various pre-fermentation juice treatments on the quality of hard cider, with the ultimate goal of minimizing the use of sulfites, which are not allowed in organic production. Extracted apple juice was treated with ultraviolet light, microfiltration (0.45 um) and pasteurization (71C x 6 sec, 85C x 60 sec) to eliminate unwanted microorganisms prior to fermentation, and compared against standard sulfiting practice and natural fermentation. Microbiological counts were measured before and after treatments. After fermentation, samples were bottled with a cold sterilant and kept refrigerated until analyzed. Samples were analyzed for chemical, physical and sensory quality. Pasteurization eliminated most microorganisms in
the juice. Filtering and sulfiting lowered all yeast and bacterial counts. UV eliminated most lactic acid bacteria but was not as effective against wild yeast. All treatments had significantly different results from the natural control fermentation in chemical analyses, but not from each other. We studied the quality of cider apple varieties grown in New York for fermented cider production to assess their potential for single variety use or for blending with commercial varieties. Twenty-two traditional European and nine indigenous North American cider apples grown were analyzed for firmness and weight. Extracted juice was tested for total acidity, total soluble solids, pH, and total phenolic compounds. The firmness measurements for apples ranged from 5.5 to 12.7 kg. The average weight was 94 g., from the range of 33 to 200 g. Results show that 21 of the cultivars, including all North American apples are sharp or bittersharp, having 0.45 % malic acid or more. The soluble solids ranged
from 9.4 to 18.9Brix and pH from 2.7 to 4.4. North American varieties had values in the lower end of soluble solids and pH ranges. Total phenolic compounds ranged from 180 mg/L to 1150 mg/L.
Impacts
It is possible to manufacture apple cider that will keep without refrigeration for 4-8 weeks if good sanitary conditions are kept and the juice is hot-filled at 63C. To extend the shelf-life of refrigerated cider up to 10-16 weeks at 4C, with the same quality as flash pasteurization, it is possible to use hot-filling at 63C alone or in combination with UV, or to use the combined treatments of UV plus the addition of dimethyl dicarbonate at 250 ppm. Fermented ciders produced from juice treated by pasteurization, UV, or microfiltration were similar to sulfited cider, with slight differences in chemical composition and sensory attributes, therefore, they could be used as alternative juice treatments to sulfiting prior to fermentation, and possibly be the first steps in organic cider production. The apple varieties studied provide a guideline for selecting and blending cider variety apples grown in New York to achieve the target flavor profile in a fermented cider.
Publications
- Valois, S. 2003. Fermented apple cider: effect of juice processing on quality and characterization of selected apple varieties. M.S. Thesis, Cornell University, Ithaca, NY.
- Valois, S. and Padilla-Zakour, O.I. 2003. Characterization of apple juice from European and North American apple cultivars used for fermented cider. 2003 IFT Annual Meeting Book of Abstracts, Abstract 104B-5, p. 257.
- Padilla-Zakour, O.I., Tandon, K.S., Worobo, R.W. 2003. Increasing the shelf-life of sweet apple cider without adding preservatives. 2003 IFT Annual Meeting Book of Abstracts, Abstract 86-6, p.212.
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