Habanero peppers (Capsicum chinense) are a unique group of cultivated plants diversified in various traits of interest. Fruit color depends on maturity, ranging from light to dark green and then in varying shades of red, yellow, orange, or chocolate (Crosby, 2008). Some Habanero peppers supply a unique fruity flavor and distinct aroma making them popular additions to various dishes (Andrews, 1995; Crosby, 2008; Greenleaf, 1986). Moreover, Habanero peppers are gaining popularity as a potential ingredient in salsa combinations and even serving as a candidate in the industrial extraction of capsaicin for various products (Sanatombi and Sharma, 2008). However, few Habanero pepper breeding programs exist worldwide, limiting the potential exploitation of this diverse germplasm. Despite this fact, success has been achieved in various areas such as nematode resistance (Fery and Thies, 2006) and quality characteristics such as color, flavor, decreased levels of capsaicin, and elevated β-carotene content as in TAM Mild Habanero (TMH) (Crosby et al., 2005). Because peppers can contain both capsaicinoids (capsaicin and DHC) and flavonoids (quercetin and luteolin), they provide a good model for examining the potential health benefits of these compounds.
Factors influencing capsaicin content in fruits include genotypic differences, geographical location, fruit maturity, and compartmentalization within fruit (Huffman, 1977; Monforte-Gonzalez et al., 2010). Within fruit tissue, capsaicin is unevenly distributed, concentrated in placental and cross-wall regions (Huffman, 1977). Monforte-Gonzalez et al. (2010) reported that placental regions of fruit possess an ability to channel inorganic forms of nitrogen (nitrate) into secondary metabolites contributing to capsaicin content. Capsaicinoid synthesis and content within fruit tissue occurs more actively between 20 and 40 d after anthesis as fruits increase in size and maturity (Sukrasno and Yeoman, 1993) with environmental stresses, such as water deficiency, contributing to various levels (Howard, 2001).
Flavonoids have been previously characterized as a group of polyphenolic substances produced as a result of secondary metabolisms (Materska and Perucka, 2005; Ross and Kasum, 2002). They are found in the thylakoid membrane of chloroplasts (Havsteen, 1983). Between 4000 and 5000 different flavonoids have been described (Hollman and Katan, 1999), providing color and flavor to many fruits and vegetables. Factors affecting flavonoid variation in fruits include the genotype, degree of maturity, processing methods, storage conditions (Ross and Kasum, 2002), light, and levels of nitrogen in soils (Amiot-Carlin et al., 2007). In a typical pepper flavonoid analysis, quercetin and luteolin are usually the two most prevalent compounds identified within fruit tissue with values increasing up to 800 mg·kg−1 in different Capsicum annuum genotypes (Howard, 2001; Lee et al., 1995). Results from Lee et al. (1995) also provide evidence that C. annuum fruit generally contains higher flavonoid levels than those of C. chinense. Howard (2001) suggested a positive correlation generally exists between quercetin and luteolin concentrations in fruit tissue. Other reports from Howard (2001) support the idea that flavonoid contents can decrease continuously during maturation, yet appreciable amounts can still exist when peppers are consumed. According to Pietta (2000), flavonoid intake by humans can vary between 50 and 800 mg·d−1. As Hertog et al. (1992) discussed, more reliable studies are needed to determine the potential role of flavonoids in combating human cancer and occurrence in different foods.
Although many studies have been conducted analyzing capsaicin and flavonoid concentrations in different Capsicum fruits (Contreras-Padilla and Yahia, 1998; Cooper et al., 1991; Harvell and Bosland, 1997; Hertog et al., 1992; Howard et al., 2000; Kurian and Starks, 2002; Lee et al., 1995, 2005; Poyrazoglu et al., 2005; Sanatombi and Sharma, 2008; Singh et al., 2009; Zewdie and Bosland, 2000), few studies have actually evaluated Habanero peppers for capsaicin and flavonoid concentrations when grown in different environments. Before this study, our group had limited phytochemical data for these five experimental hybrids. Therefore, our quantitative analyses were intended to reveal potential differences in phytochemical concentrations among them and in comparison with a popular commercial control. To our knowledge, there have not been any reports to date indicating a direct correlation between fruit color or fruit size and phytochemical expression. 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 human 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 wanted to determine the best environment to enhance the concentrations of these phytochemicals within fruit tissue and ultimately identify good candidates for introduction as new Habanero cultivars.
Amiot-CarlinM.J.MargotatA.TourniaireF.2007Flavonoids in food and wine p. 107–116. In: Desjardins Y. (ed.). Proc. 1st Intl. Symp. Human Health Effects of F&V. Acta Hort. 744 ISHS
AndrewsJ.1995Peppers: The domesticated Capsicums. University of Texas Press Austin TX
AntoniousG.F.LobelL.KochharT.BerkeT.JarretR.L.2009Antioxidants in Capsicum chinense: Variation among countries of originJ. Environ. Sci. Health B44621626
Ben-ChaimA.BorovskyY.FaliseM.MazourekM.KangB.C.ParanI.JahnM.2006QTL analysis for capsaicinoid content in CapsicumTheor. Appl. Genet.11314811490
Contreras-PadillaM.YahiaE.M.1998Changes in capsaicinoids during development, maturation, and senescence of chile peppers and relation with peroxidase activityJ. Agr. Food Chem.4620752079
CooperT.H.GuzinskiJ.A.FisherC.1991Improved high-performance liquid chromatography method for the determination of major capsaicinoids in Capsicum oleoresinsJ. Agr. Food Chem.3922532256
CrosbyK.M.2008Pepper p. 221–248. In Prohens J. and F. Nuez (eds.). Vegetables II: Fabaceae Liliaceae Umbelliferae and Solanaceae. Springer New York NY
de SousaJ.A.MalufW.R.2003Diallel analyses and estimation of genetic parameters of hot pepper (Capsicum chinense Jacq.)Scientia Agrícola60105113
FeryR.L.ThiesJ.A.2006Notice of release of ‘Tigerpaw-Nr’ a root-knot nematode resistant Habanero-type pepper. USDA Agricultural Research Service Cultivar Release 9 Jan
GreenleafW.H.1986Pepper breeding. In: Bassett M.J. (ed.). Breeding vegetable crops. AVI Publishing Co. Westport CT
HertogM.G.L.HollmanP.C.H.VenemaD.P.1992Optimization of a quantitative HPLC determination of potentially anticarcinogenic flavonoids in vegetables and fruitsJ. Agr. Food Chem.4015911598
HoshmandA.R.2006Single-factor experimental designs p. 27. In: Design of experiments for agriculture and the natural sciences. 2nd Ed. Taylor & Francis Group LLC. Boca Raton FL
HowardL.R.2001Antioxidant vitamin and phytochemical content of fresh and processed pepper fruit (Capsicum annuum) p. 209–233. In: Wildman R.C. (ed.). Handbook of nutraceuticals and functional foods. CRC Press Boca Raton FL
HowardL.R.TalcottS.T.BrenesC.H.VillalonB.2000Changes in phytochemical and antioxidant activity of selected pepper cultivars (Capsicum species) as influenced by maturityJ. Agr. Food Chem.4817131720
HuffmanV.L.1977Volatile components and pungency in fresh and processed jalapeño peppers (Capsicum annuum). PhD diss. Texas A&M University College Station TX
LeeJ.J.CrosbyK.M.PikeL.M.YooK.S.LeskovarD.I.2005Impact of genetic and environmental variation on development of flavonoids and carotenoids in pepper (Capsicum spp.)Sci. Hort.106341352
MaterskaM.PeruckaI.2005Antioxidant activity of the main phenolic compounds isolated from hot pepper fruit (Capsicum annuum L.)J. Agr. Food Chem.5317501756
Monforte-GonzalezM.Guzman-AntonioA.Uuh-ChimF.Vazquez-FlotaF.2010Capsaicin accumulation is related to nitrate content in placentas of Habanero peppers (Capsicum chinense Jacq.)J. Sci. Food Agr.90764768
PoyrazogluE.S.YemisO.KadakalC.ArtikN.2005Determination of capsaicinoid profile of different chilli peppers grown in TurkeyJ. Sci. Food Agr.8514351438
SAS Institute Inc2008SAS 9.2 users guide. 2nd Ed. SAS Institute Inc. Cary NC
SinghS.JarretR.RussoV.MajetichG.ShimkusJ.BushwayR.PerkinsB.2009Determination of capsinoids by HPLC-DAD in Capsicum speciesJ. Agr. Food Chem.5734523457
ZewdieY.BoslandP.W.2000Evaluation of genotype, environment, and genotype-by-environment interaction for capsaicinoids in Capsicum annuum LEuphytica111185190