(Capsicum Chinense) Peppers Fruits Include Genotypic Differences, Geo- Justin D
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HORTSCIENCE 47(5):574–579. 2012. Thies, 2006) and quality characteristics such as color, flavor, decreased levels of capsaicin, and elevated b-carotene content as in TAM Environmental and Genotypic Mild Habanero (TMH) (Crosby et al., 2005). Because peppers can contain both capsaici- Variation of Capsaicinoid and noids (capsaicin and DHC) and flavonoids (quercetin and luteolin), they provide a good Flavonoid Concentrations in Habanero model for examining the potential health benefits of these compounds. Factors influencing capsaicin content in (Capsicum chinense) Peppers fruits include genotypic differences, geo- Justin D. Butcher, Kevin M. Crosby1, Kil Sun Yoo, graphical location, fruit maturity, and com- and Bhimanagouda S. Patil partmentalization within fruit (Huffman, 1977; Monforte-Gonzalez et al., 2010). Within fruit Vegetable and Fruit Improvement Center, Department of Horticultural tissue, capsaicin is unevenly distributed, con- Sciences, 1500 Research Parkway, Suite 120A, College Station, TX 77845 centrated in placental and cross-wall regions (Huffman, 1977). Monforte-Gonzalez et al. A.M.H. Ibrahim (2010) reported that placental regions of fruit Department of Soil and Crop Sciences, 370 Olsen Boulevard, 2474 TAMU, possess an ability to channel inorganic forms Texas A&M University, College Station, TX 77843 of nitrogen (nitrate) into secondary metabo- lites contributing to capsaicin content. Cap- Daniel I. Leskovar saicinoid synthesis and content within fruit Vegetable and Fruit Improvement Center, Department of Horticultural tissue occurs more actively between 20 and Sciences, Texas AgriLife Research Center, 1619 Garner Field Road, Uvalde, 40 d after anthesis as fruits increase in size and TX 78801 maturity (Sukrasno and Yeoman, 1993) with environmental stresses, such as water defi- John L. Jifon ciency, contributing to various levels (Howard, Vegetable and Fruit Improvement Center, Department of Horticultural 2001). Flavonoids have been previously charac- Sciences, Texas AgriLife Research Center, 2415 E. Highway 83, Weslaco, terized as a group of polyphenolic substances TX 78596 produced as a result of secondary metabo- lisms (Materska and Perucka, 2005; Ross and Additional index words. phytochemical analysis, capsaicin, dihydrocapsaicin, luteolin, quercetin, Kasum, 2002). They are found in the thyla- genotype · environment interaction koid membrane of chloroplasts (Havsteen, Abstract. Habanero peppers have become increasingly popular in the United States for 1983). Between 4000 and 5000 different flavo- supplying unique flavors and high levels of pungency. As consumption of this product noids have been described (Hollman and Katan, increases, development of improved cultivars with elevated phytochemicals will likely 1999), providing color and flavor to many result in additional demand from consumers. This study evaluated fruit size, capsaici- fruits and vegetables. Factors affecting flavo- noid, and flavonoid concentrations in six Habanero (Capsicum chinense) genotypes noid variation in fruits include the genotype, grown at three different Texas locations: College Station, Uvalde, and Weslaco. Five of degree of maturity, processing methods, stor- these Habanero experimental hybrids (H1-red, H2-orange, H3-orange, H5-dark orange, age conditions (Ross and Kasum, 2002), light, and H6-yellow) were developed at Texas A&M University with genetic improvement in and levels of nitrogen in soils (Amiot-Carlin et al., 2007). In a typical pepper flavonoid numerous traits of interest, and Kukulkan F1 (Kuk-orange) was included as a commercial control. In general, H1-red had the largest fruits in these locations. Capsaicin and analysis, quercetin and luteolin are usually dihydrocapsaicin (DHC) concentrations were highest in Kuk-orange followed closely by the two most prevalent compounds identi- H5-dark orange and were lowest in H6-yellow. Fruit at Weslaco was larger and contained fied within fruit tissue with values increas- more capsaicin and DHC than those produced in Uvalde or College Station. Although ing up to 800 mgÁkg–1 in different Capsicum flavonoid contents were variable and low in all genotypes and locations, H3-orange showed annuum genotypes (Howard, 2001; Lee et al., the most stability for use in future crossing schemes to compete against Kuk-orange for this 1995). Results from Lee et al. (1995) also characteristic. Our results suggest that variation in phytochemicals in fruit tissue of provide evidence that C. annuum fruit gen- Habanero genotypes can be exploited by selecting in an appropriate environment. erally contains higher flavonoid levels than those of C. chinense. Howard (2001) sug- gested a positive correlation generally exists Habanero peppers (Capsicum chinense)are in various traits of interest. Fruit color de- between quercetin and luteolin concen- a unique group of cultivated plants diversified pends on maturity, ranging from light to dark trations in fruit tissue. Other reports from green and then in varying shades of red, Howard (2001) support the idea that flavo- yellow, orange, or chocolate (Crosby, 2008). noid contents can decrease continuously Received for publication 31 Aug. 2011. Accepted Some Habanero peppers supply a unique during maturation, yet appreciable amounts for publication 23 Jan. 2012. fruity flavor and distinct aroma making them can still exist when peppers are consumed. The present research report was based on work popular additions to various dishes (Andrews, According to Pietta (2000), flavonoid in- supported by the Cooperative State Research, Edu- 1995; Crosby, 2008; Greenleaf, 1986). More- take by humans can vary between 50 and cation, and Extension Service, U.S. Department over, Habanero peppers are gaining popularity 800 mgÁd–1. As Hertog et al. (1992) dis- of Agriculture under Agreement No. 2009-34402- as a potential ingredient in salsa combinations cussed, more reliable studies are needed to 19831, ‘‘Designing Foods for Health’’ through the and even serving as a candidate in the in- determine the potential role of flavonoids in Vegetable & Fruit Improvement Center, Texas dustrial extraction of capsaicin for various combating human cancer and occurrence in AgriLife Research. products (Sanatombi and Sharma, 2008). How- different foods. Our gratitude and appreciation includes the work provided by Alfredo Rodriguez and Shinsuke ever, few Habanero pepper breeding programs Although many studies have been con- Agehara at the Weslaco and Uvalde AgriLife exist worldwide, limiting the potential exploi- ducted analyzing capsaicin and flavonoid Centers, respectively. tation of this diverse germplasm. Despite this concentrations in different Capsicum fruits 1To whom reprint requests should be addressed; fact,successhasbeenachievedinvarious (Contreras-Padilla and Yahia, 1998; Cooper e-mail [email protected]. areassuchasnematoderesistance(Feryand et al., 1991; Harvell and Bosland, 1997; Hertog 574 HORTSCIENCE VOL. 47(5) MAY 2012 et al., 1992; Howard et al., 2000; Kurian and five different environmental parameters (max- completely colored, and turgid at the time of Starks, 2002; Lee et al., 1995, 2005; Poyrazoglu imum and minimum air temperatures, relative harvest. After fruit weights were measured et al., 2005; Sanatombi and Sharma, 2008; humidity, solar radiation, and precipitation) on each genotype, all samples were stored at Singh et al., 2009; Zewdie and Bosland, 2000), throughout the experiment, as seen in Figures –80 °C until analysis could ensue. few studies have actually evaluated Habanero 1 through 4. Being interested in material more Capsaicinoid extraction and analysis. peppers for capsaicin and flavonoid con- for fresh markets, fully colored, matured, fresh Capsaicinoids (capsaicin and DHC) were ex- centrations when grown in different envi- fruits were harvested from each of the six tracted as described by Singh et al. (2009) ronments. Before this study, our group had separate, 10-foot row plots. All fruit speci- with some modifications. All extraction pro- limited phytochemical data for these five ex- mens were selected that appeared healthy, cedures used tissue from five fresh, smashed perimental hybrids. Therefore, our quantitative analyses were intended to reveal potential differences in phytochemical concentrations among them and in comparison with a pop- ular commercial control. To our knowledge, there have not been any reports to date in- dicating a direct correlation between fruit color or fruit size and phytochemical expres- sion. Because most Habanero studies focus predominantly on capsaicinoid (capsaicin and DHC) expression, we wanted to expand and include two important flavonoids (quercetin and luteolin) routinely found in pepper tissue that have become increasingly linked to hu- man health. Because fruit size has become an important component of commercial pepper production, we also wanted to increase the practical applications for this experiment and accurately portray the size of harvested fruit by measuring fruit weights. Furthermore, we Fig. 1. Average monthly maximum and minimum air temperatures during May to Aug. 2009 in CS wanted to determine the best environment to (College Station), UV (Uvalde), and WE (Weslaco). enhance the concentrations of these phyto- chemicals within fruit tissue and ultimately identify good candidates for introduction as new Habanero cultivars. Materials and Methods Plant material. Five advanced Habanero experimental hybrids fixed for various traits of importance to the seed industry and one commercial control were chosen for evalua- tion. The diverse