Color Quality of Fresh and Processed Foods - American Chemical

Chapter 4

Color Quality of Maraschino Cherries Downloaded by KTH ROYAL INST OF TECHNOLOGY on August 24, 2015 | http://pubs.acs.org Publication Date: June 13, 2008 | doi: 10.1021/bk-2008-0983.ch004

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M. Monica Giusti and Ronald E. Wrolstad 1

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Department of Food Science and Technology, The Ohio State University, 2015 Fyffe Road, Columbus, OH 43210 Department of Food Science and Technology, Oregon State University, 100 Wiegand Hall, Corvallis, OR 97331-6602 2

Maraschino cherry processing involves immersion of cherries in a brine solution to extend their shelf life, resulting in color loss. Color is typically replaced with Allura Red (FD&C Red No.40) or erythrosine (FD&C Red No.3), depending on the market. However, manufacturers of maraschino cherries have sought natural colorants which could serve as acceptable alternatives to the use of artificial dyes. This task was challenging due to the residual SO from manufacturing and pH (3.5) which favor pigment degradation. We evaluated red radish anthocyanin extracts (RAE) to color primary and secondary bleached cherries. Color analysis (CIELch), showed that RAE imparted color extremely close to that of FD&C Red No. 40, for ~6 mo storage. The high pigment stability (halflives of 29-33 wk) was attributed to the acylated anthocyanins in RAE. Color quality depended on the bleaching process, anthocyanin concentration and exposure to light. Anthocyaninrich maraschino cherries may have added value as a functional food because of their more natural character and their high phytonutrient content. 2

© 2008 American Chemical Society

In Color Quality of Fresh and Processed Foods; Culver, C., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2008.

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Downloaded by KTH ROYAL INST OF TECHNOLOGY on August 24, 2015 | http://pubs.acs.org Publication Date: June 13, 2008 | doi: 10.1021/bk-2008-0983.ch004

Maraschino Cherries History and Production Maraschino cherries are a type of candied fruit made from fresh cherries. The term "Maraschino Cherries" originally referred to Marasca cherries that were preserved in liqueur, a practice begun in Dalmatia centuries ago. Today, this term is used to describe cherries which have been dyed with a food colorant, impregnated with sugar and packed in sugar syrup flavored with oil of bitter almonds or a similar flavor. The cherries are also preserved with small amounts of sodium benzoate and/or potassium sorbate. Maraschino cherries, as we know them today, differ considerably from the original product prepared many years ago in Dalmatia. The delicately colored and flavored liqueur was made from fruit, ground pits, bark, and leaves of the Marasque cherry tree. This extract was then used to flavor and color cherries similar to the Royal Anne variety cultivated in the USA (7). The Marasca cherry was consumed as a delicacy by royalty and the wealthy. These cherries made their way into the United States in the late 1800s and were served in fine hotels and upscale restaurants. By the turn of the century, American producers were experimenting with different ways to produce similar cherries in the USA using a variety of liqueurs and flavorings. Most of the production was done in the Eastern USA using cherries imported from Italy. Around that time, cherries were already growing in the western Coast of the USA as well as in Michigan. However, these new cherries did not match the texture characteristics of the Italian brined cherries that had dominated the market. Therefore in the late 1920's Ernest Wiegand, a researcher at Oregon State University, developed a brining process (2), that made possible the commercialization of a fruit otherwise highly perishable, in a very attractive and stable form. Although the maraschino process was inspired by the European product, the brining process provided a higher quality, more uniform cherry, which USA manufacturers colored and flavored to produce the distinctive commercial product. The cherry-producing districts of Oregon soon experienced an increasing interest in the preparation of cherries for maraschino use. During the 1930 season, approximately 10,000 barrels (1,136 Tons) of cherries were bleached in Oregon. Some of these were shipped to the East coast, furnishing an outlet for a great portion of the Northwest's increasing Royal Ann cherry crop (3). In 1992, the State of Oregon was the second major producer of sweet cherries (52,000 Tons) in the USA, after Washington (97,000 Tons), from a nation-wide production of 205,400 Tons (4), and more than 50% of the Oregon production (28,000 Tons) was destined for brining. For 2004, the major producers were Washington, California, Oregon and Michigan and the total cherry production in the USA added to 282,060 Tons (5). About 30% of those cherries were brined.


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Maraschino Cherry Processing Among the hundreds of cherry varieties around the world, the ones used for brining are usually the light sweet cherries, such as the Royal Ann, Rainier or Gold varieties. These varieties typically exhibit a yellow/blush color on their skin, as compared to other deep red varieties. However, most cherries are suitable for maraschino cherry processing. Sweet cherries destined for maraschino or similar processing are harvested either by hand or machine before full ripeness and placed in a brine solution containing between 1 and 1.5% sulfur dioxide and 3000 to 5000 ppm of calcium salts. The brine bleaches the fruit to a pale yellow color, and it also acts as a preservative during subsequent storage. Calcium acts as a hardening agent, increasing fruit firmness (6,7). After a period of several weeks to two years, the fruit is removed and "finished" into the final product (8). Cherries are a very delicate fruit and they bruise easily and non-uniform discoloration from incompletely bleached cherries were frequently obtained. To improve the color quality of maraschino cherries, Oregon State University food scientists Beavers and Payne developed a secondary bleaching process that completely eliminated bruise marks and other dark skin discolorations from brined sweet cherries. After the first brining process, cherries are leached in water and placed in acidified sodium chlorite. This process made it possible to produce high quality, brightly colored maraschino and fruit cocktail cherries from fruit otherwise considered undesirable for these products (7-9). After the bleaching process the cherries are ready for finishing into maraschino cherries. They are removed from the brine, rinsed with water and graded. The fruit is leached in running water to remove most of the sulfur dioxide. At this point of the process cherries are firm, and lack cherry color and flavor. Therefore flavoring (cherry and/or almond food flavors), coloring and sweetening agents are added. Potassium sorbate and sodium benzoate are used as preservatives, and citric acid is used to adjust the pH to acidic conditions (pH usually between 3.4 and 3.8). The cherries are finally bottled and pasteurized (7, 6).

Coloring Maraschino Cherries Maraschino cherries are typically red, althought many other colors can also be produced. For a long time, FD&C Red No. 4 (Ponceau SX) was the colorant of choice for maraschino cherry producers. This synthetic colorant had a brilliant red color with unusual resistance to the destructive influences of food ingredients and heat (10). However, the use of this colorant was banned in the USA in 1976 because of unresolved safety questions (11), and FD&C Red No. 3 (erythrosine)



46 and FD&C No. 40 (Allura Red) have been used since, FD&C Red No. 40 being the colorant of choice for maraschino cherries because of its solubility properties. There is considerable demand for food colorants from natural sources that can serve as alternatives to the use of synthetic dyes due to both legislative action and consumer concerns over the use of synthetic additives. Interest in the use of natural extracts as coloring agents has intensified because of their possible health benefits. However, finding a natural red colorant that can effectively replace FD&C Red No. 40 has proved to be a difficult task, because few natural materials have its bright red color unmixed with other tones (72). The use of natural colorants such as cochineal, concord grape extract, other anthocyanins, and some carotenoids has been studied { 1 2 - 1 4 ) . Relatively good stability has been obtained (between 3 and 6 months of storage); however, limitations have been found trying to reproduce the desired hue.

Major Challenges Faced by Natural Colorants Manufacturers of maraschino cherries have sought a natural colorant which could serve as acceptable alternative to the use of FD&C Red No. 40, which gives the product its attractive color. This is a challenging task since processors wanted to match the hue of the Allura Red colored cherries and have a reasonable shelf life for a product that can be packed in glass and stored at ambient temperatures. Also, the matrix offers it own challenges since the pH is 3.5 (higher than the typical pH ranges for anthocyanin applications) and the residual S 0 after processing, which can lead to pigment degradation. Acylated anthocyanins, particularly those with cinnamic acid acylations, have been found to possess increased stability (15-17). These pigments may impart desirable color and stability for commercial food products. Examples of suitable acylated anthocyanin sources are red radishes, red potatoes, red cabbage, black carrots, and purple sweet potatoes. Among these, radishes and red potatoes stand out as potential alternatives for the use of FD&C Red No. 40 (Allura Red) because of the hue that can be produced with these extracts in solution. Radish and potato extracts imparted color characteristics to model juices at pH 3.5 extremely close to those of Allura Red (75). 2

Advantages of Radish Anthocyanins as Natural Alternatives to Color Maraschino Cherries Our worked focused on the evaluation of radish anthocyanins as potential alternatives to the use of FD&C Red No. 40 to color maraschino cherries. This



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source was selected based on the information available in the literature regarding their pigment composition. The pigments in radish were reported as acylated pelargonidin derivatives. Among all anthocyanin aglycones, pelargonidin is the one that posses the shortest wavelength of maximum absorption in the visible range, with a hue closer to orange / orange-red. Addition of acylation has been shown to cause a bathochromic shift (an increase in the wavelength of maximum absorption). For pelargonidin, this would result on a change toward a more red color, while we would expect a more purple red color on most other acylated anthocyanins. In addition, the acylation would be expected to increase the stability, protecting the oxonium ring from the attack of water and sulfites, and ameliorating the effects of the increase in pH to 3.5. The chemical structure of radish anthocyanins was elucidated by use of chromatography, spectral characteristics, molecular mass and nuclear magnetic resonance (18, 19). All this combined information allowed us to determine the identity of the pigments as peiargonidin-3-sophoroside-5-glucoside mono acylated with p-coumaric or ferulic acid or di-acylated with p-coumaric or ferulic acid plus a malonic acid (Figure 1). In addition, we determined the close proximity between hydrogens of the pyrilium ring of the anthocyanidin and hydrogens in the cinnamic acid acylating the pigment. This supports the hypothesis that acylation may enhance anthocyanin stability by folding of the molecule so that the acid can protect the pyrilium ring, or by stacking of the molecules with a similar result.

Figure 1. Chemical structure of pelargonidin-3-sophoroside-5-glucoside acylated with p-coumaric acid and malonic acidfound in radish.

The color characteristics of the pelargonidin aglycones as well as the glycosylated and acylated derivatives were evaluated, and we were able to confirm that acylated pelargonidin derivatives, or more specifically, the pigments in radish closely resemble the color characteristics of FD&C Red No. 40 (17).


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Color Quality of Maraschinos Colored With a Radish Extract Red radish anthocyanin extract (RAE) was used to color brined cherries as an alternative to FD&C Red No. 40 (17, 20). Primary and secondary bleached cherries were colored with two different concentrations of radish anthocyanins (600 and 1200 mg anthocyanin/L syrup) to compare the color quality to that obtained with FD&C Red No. 40 (200 ppm). Color and pigment stability of secondary bleached cherries and syrup colored with RAE were evaluated during storage (25°C) in the dark and exposed to light.

Important

Considerations:

The processing of maraschino cherries was done in collaboration with the maraschino cherry industry to assure the use of practices that would be applicable to the industry. The pH of maraschino cherries can range from 3.5 to 4.0. Since anthocyanin tinctorial power and stability are favored by low pH values, we chose to manufacture cherries at pH 3.5, the lowest pH within the typical ranges used by the industry. Prior to coloring, brined cherries were washed several times to drastically decrease the free sulfur dioxide level (from 3,500 and 2000 ppm for primary and secondary bleached cherries, respectively, to less than 480 ppm after washing) to minimize the detrimental effects on color and also to reduce the risks for allergic reactions. This level was further reduced during the following steps of the manufacture of maraschino cherries. After washing, the sweetening process begins. It is very important that this process be done gradually to avoid damage to the cell integrity and texture characteristics of the cherry. This process is done under controlled temperature conditions (40°C) to favor infusion of the sugar at a rate of 3 degree brix every 12 hours. At the end of the sweetening process, flavors and colors are added, and allowed to equilibrate for 4 days. Finally, cherries and syrup are bottled, pasteurized and stored at room temperature (Figure 2). Color characteristics (CIELAB, chroma and hue angle) of cherries were measured on a ColorQuest Hunter spectrophotometer set up for reflectance specular included measurements using illuminant C and 10 degree observer angle. Cherries were drained and placed in a 5 cm pathlength optical glass cell and 4 repeated measurements were taken for each sample. Color characteristics and haze of syrup were measured on the same instrument using a 1 cm pathlength optical glass cell under transmittance mode using illuminant C and 10 degree observer angle. Radish anthocyanin extracts imparted cherries and syrup color characteristics extremely close to those obtained with FD&C Red No. 40 (Figures 3 and 4). The color characteristics of primary and secondary bleached cherries were markedly different, with primary bleached cherries showing a high



Figure 2. Major changes on cherry color during manufacturing of maraschino cherries. ^Photograph by Lynn Ketchum, Oregon Agricultural Experiment Station (See page 4 of color inserts.)


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chroma (26.8) and a yellow hue, while secondary bleached cherries were close to white in color with a chroma of only 2.4. The lower concentration (600 mg anthocyanin/L syrup) of radish anthocyanins gave cherries and syrup the closest color characteristics to FD&C Red No. 40. Monomeric anthocyanin degradation followed first-order kinetics, with halflives of 29 and 33 wk for syrups colored with RAE CI and RAE C2, respectively

Figure 3. Color characteristics of primary and secondary bleached cherries before and after coloring with radish anthocyanins or FD&C Red No. 40. Reflectance specular included mode, Illuminant C and 10 ° observer angle.

Figure 4. Color of syrup ofprimary and after coloring with radish Transmittance measurements, 1 cm

and secondary bleached cherries before anthocyanins or FD&C Red No. 40. Illuminant C, 10 observer angle, pathlength. 0



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Figure 5. Changes in chroma and lightness of syrup samples colored with radish anthocyanin extracts (600 mg anthocyanin/L = RAE CI; 1200 mg anthocyanin/L = RAE C2) or FD&C Red No. 40 (200 ppm, RED 40) over a year of storage under the dark or exposed to light.

(17, 20). Higher anthocyanin concentration exerted a protective effect on color stability. Exposure of syrup samples to light slightly increased monomeric anthocyanin degradation. However, the half lives of syrups colored with RAE CI were not significantly affected by light exposure, while the half life of syrups colored with RAE C2 were 1.5 times shorter than when stored in the dark. In samples exposed to light a precipitated material was observed after 50 weeks of storage, suggesting that light exposure favored formation of larger polymers that came out of solution. Color stability of secondary bleached cherries and syrup were monitored during a year of storage under dark condition or exposed to light. Color characteristics remained similar to FD&C Red No. 40 for about 6 months of


52 storage at room temperature, and light exposure had little effect on color stability (Figures 5 and 6).


Maraschino Cherries With Added Value Interest in anthocyanin-rich foods and extracts has intensified because of their possible health benefits. Anthocyanins are potent antioxidants and may be chemoprotective. Optimizing health and performance through the diet is believed to be one of the largest and most lucrative markets in the US, and throughout the world, Findings of acylated anthocyanins with increased stability have shown that these pigments may impart desirable color and stability for commercial food products. Maraschino cherries with bright attractive and stable red color were obtained with radish extract. Radish imparted color characteristics to model juices extremely close to those of Allura Red. The increased stability of these pigments together with their added value due to potential beneficial effects opens a new window of opportunity for use of these extracts in a variety of food applications.

References 1.

2. 3.

4.

5. 6.

7. 8. 9.

Filz, W. F.; Henney, E. N.. Home Preparation of Maraschino Cherries; Station Bulletin 497; Agric. Exp. Stn. Oregon St. College: Corvallis, OR 1951; pp 3-11. Rose, S. Capitol Press, Salem, OR, August 29, 1975. Bullis, D. E.; Wiegand, E. H. Bleaching and Dyeing Royal Ann Cherries for Maraschino or Fruit Salad Use; Station Bulletin 275; Agric. Exp. Stn, Oregon St. Agric. College: Corvallis, OR 1931, pp 4-29. OSU Extension Service. Commodity data sheet. Sweet Cherries. Extension Economic Information Office, Oregon St. Univ.: Corvallis, OR 1994, 51105194. National Agricultural Statistics Service (NASS), USDA, 2005 Wiegand, E. H.; Bullis, D. E. Maraschino Cherries Methods for Bleaching and Dyeing; Station Bulletin 32; Agric. Exp. Stn., Oregon St. Agric. College: Corvallis, OR 1930, pp 1-6. Beavers, D. V.; Payne, C. H. Food Technol., 1969, 23, 175-177. Anonymous. Oregon's Agric. Prog. 1968, 15, 2. Beavers, D. V.; Payne, C. H; Milleville, H. P. Procedure for Secondary Bleaching Brined Cherries with Sodium Chlorite; Circular of Information 632; Agric. Exper. Stn., Oregon State University: Corvallis, OR, 1970, 1-7.



53 10. Yang, H. Y.; Ross, E.; Brekke, J. E. Cherry Brining and Finishing; Circular of Information 624; Agric. Exper. Stn., Oregon State University, Corvallis, OR 1966, 1-7. 11. Rumore, M. M. Pharm. Technol., 1992, 16, 68-82. 12. LaBell, F. Food Process., 1993, June, 88-89. 13. McLellan, M. R.; Cash, J. N.. J. Food Sci., 1979, 44, 483-487. 14. Sapers, G. M. J. Food Sci., 1994, 59, 135-138. 15. Rodriguez-Saona, L. E.; Giusti, M. M.; Wrolstad, R. E. J. Food Sci., 1999, 64, 451-456. 16. Giusti, M. M.; Wrolstad, R. E. Biochem. Eng. J., 2003, 14, 217-225. 17. Giusti, M. M.; Wrolstad, R. E. J. Food Sci., 1996, 61, 688-694. 18. Giusti M. M.; Wrolstad R. E. J. Food Sci., 1996, 61, 322-326. 19. Giusti, M. M.; Ghanadan, H.; Wrolstad, R. E. J. Agric. Food Chem., 1998, 46, 4858-4863. 20. Giusti Hundskopf, M. M. MS Thesis, Oregon State University, Corvallis, OR, 1995.


Color Quality of Fresh and Processed Foods - American Chemical

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