Scientia Horticulturae 144 (2012) 10–18 Contents lists available at SciVerse ScienceDirect Scientia Horticulturae journa l homepage: www.elsevier.com/locate/scihorti A comparative study among landraces of Phaseolus vulgaris L. and P. coccineus L. based on molecular, physicochemical and sensory analysis for authenticity purposes a,∗ b a a a c A.G. Mavromatis , I.S. Arvanitoyannis , V. Chatzitheodorou , A. Kaltsa , I. Patsiaoura , C.T. Nakas a Lab of Genetics & Plant Breeding, School of Agricultural Sciences, University of Thessaly, Fytokou St., N. Ionia, Greece b Lab of Food Technology, School of Agricultural Sciences, University of Thessaly, Fytokou St., N. Ionia, Greece c Lab of Biometry, School of Agricultural Sciences, University of Thessaly, Fytokou St., N. Ionia, Greece a r t i c l e i n f o a b s t r a c t Article history: The common and runner beans are the two most widely cultivated species because of their highly nutri- Received 16 September 2011 tive value for humans and animals. This study was undertaken to interpret data from physicochemical, Received in revised form 12 June 2012 sensory and molecular (DNA) analyses toward evaluating, characterizing and separating 5 common bean Accepted 13 June 2012 (Phaseolus vulgaris) and 5 runner bean (Phaseolus coccineus) landraces, cultivated under organic growing conditions. Furthermore, an attempt was made to determine patterns and interrelationships among the Keywords: quality traits and sensory characteristics to get a better insight into the most effective discrimination P. vulgaris between common and runner bean landraces, by means of multivariate analysis (Principal Component P. coccineus Analysis and Discriminant Analysis). Organic culture In this study an accurate and effective discrimination of bean cultivars and Phaseolus species was possi- Plant breeding Physicochemical analysis ble using different methodologies. PCA was found to be the most informative either by using exclusively Sensory analysis physicochemical data (92% of variability) or in conjunction with sensory data (99.4% of variability). P. RAPD markers vulgaris is characterized by 6 parameters (intensity, juiciness, sweetness, brightness, bitterness and con- PCA (Principal Component Analysis) sistency) whereas P. coccineus by odor, tenderness and metallic taste. Molecular analysis (MA) proved DA (Discriminant Analysis) to be a fast and informative method only for discrimination of the Phaseolus species whereas (DA) highlighted the most important characteristics per cultivar and species. © 2012 Elsevier B.V. All rights reserved. 1. Introduction dietary fibers which greatly improve gut health-cardiovascular and gastrointestinal (GI) physiology (Kutos et al., 2002). Further- The genus Phaseolus comprises several wild and cultivated more, the sufficient nutritive composition and various uses of beans species such as Phaseolus vulgaris L. (common or kidney bean), in different culinary forms (canned or frozen grain and pod, dry Phaseolus coccineus L. (scarlet runner bean), Phaseolus acutifolius seeds) make it an interesting crop for consumers and processors (tepary bean) and Phaseolus lunatus (lima bean) (Alvarez et al., (Escribano et al., 1997). Since the consumption of beans in Europe 1998). The common and the runner bean are the two most is mainly based on imports (Negri and Tosti, 2002), several Euro- widely cultivated species because of their highly nutritive value pean countries are currently focused on agricultural products of for humans and animals (Broughton et al., 2003). Dry beans are controlled (PDO) or guaranteed origin (PGI) because consumers an important source of proteins, being part of human diet all over have progressively increased their demands for safe and healthy the world (Singh, 2001). Dry mature seeds provide a relatively products endowed with specific quality characteristics (Escribano greater amount of higher quality protein ranging from 17% to 32% et al., 1997; Piergiovanni et al., 2000). which makes them an excellent complement for diets rich in cere- Nowadays, a high demand for organic food is mainly oriented als (Moraghan & Grafton (2001). Therefore, beans have a major to products of plant origin. The number of experiments on organic role in human diet especially in developing countries where they culture of beans is limited and as a consequence few data are are considered a low cost protein source. Moreover, dry beans available regarding the final cooking quality of beans. The descrip- provide high quantities of carbohydrates, vitamins, minerals and tion of cooking quality for beans depends on certain parameters associated with the bean physicochemical characteristics like hard- ness, moisture content, cooking time, water absorption, hydration ∗ capacity (Casanas˜ et al., 1999). Moreover, characteristics such Corresponding author. Fax: +30 24210 93114. E-mail address: [email protected] (A.G. Mavromatis). as seed size, color, shape, textural properties and cooked-bean 0304-4238/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.scienta.2012.06.024 A.G. Mavromatis et al. / Scientia Horticulturae 144 (2012) 10–18 11 flavors greatly affect the consumer’s acceptance (Mkanda et al., discriminating most effectively between common and runner 2007). Medium and large seeded dry bean cultivars occurring in bean landraces by means of multivariate analysis. P. vulgaris and P. coccineus, are preferred by consumers probably because they have been reported to hydrate rapidly and taste sat- 2. Materials and methods isfactorily (Kigel, 1999). Dietary value is also important for most of the consumers. According to Grela and Gunter (1995), the P. The agronomic and nutrient value based on physicochemical coccineus species has slightly lower protein and higher ash con- and sensory properties were determined in 5 common bean lan- tent compared to P. vulgaris. However, it should be noted that the draces (P. vulgaris) and estimated in comparison to 5 runner bean composition of seeds varies from cultivar to cultivar and heavily (P. coccineus) ones for two years under organic culture environ- depends on the area of cultivation. The variation recorded in the ment. In the organic experimental field of the University of Thessaly genetic material of beans as to the content of seeds protein is sig- (Velestino), a three year rotation scheme (Vicia sativa–Triticum nificant ranging from 14% to 36% (Kelly and Bliss, 1975; Crocomo durum–P. vulgaris) had been applied at the previous years, with- et al., 1977). The obtained results revealed that the quality of beans out any input of agrochemical or fertilizer (followed the protocol according to the consumers depends on many factors prevailing of growing practices for organic farming (Council Reg (E.E.C.) at the time of harvest such as storage, processing technology as 2092/91)). At the two growing seasons, systemically irrigation was well as biotic and abiotic factors affecting growth in plants. It has applied using 430–450 mm of water per experimentation period, been shown that environmental conditions (temperature, humid- by means of the surface drip method. The experimental design ity, soil conditions) also affect the quality and nutrients of the was a randomized complete block with three replications and grain which reaches the consumer (Kigel, 1999). Among bean cul- each cultivar was sown in a single row plot with 25 plants. The tivars, landraces are advantageous in terms of particular properties distance used between rows (80 cm) and plants (50 cm) was inter- especially when cultured under organic environment, such as high mediate of the commonly applied practice for the two Phaseolus quality and nutritional characteristics, local adaptation and low species. input requirements (Mavromatis et al., 2010; Arvanitoyannis et al., 2007). The capability of grouping and separate bean cultivars and 2.1. Physicochemical properties species on the basis of quality attributes is very important for consumers and plant breeders. For consumers the interest resides Two months after harvesting, a seed sample (100 g) per culti- in healthy diet planning and consumption of beans as potential var was counted using an electronic seed counter/weighing and functional food. For plant breeders this information is of great transferred to measuring cylinder where 100 ml distilled water importance for synthesis of complementary compounds and qual- had been added. The density of bean seeds was calculated and ity characteristics through intra or inter-specific hybridization. The expressed as g/ml according to the procedure/formulae of Bishnoi separation and characterization of species and cultivars is often and Khetarpaul (1993). Bean samples (100 g per variety) were based on the description of their morphological, physiological soaked in deionised water for 24 h at room temperature. After soak- and biochemical characteristics are assessed with multivari- ing, the increase in water volume was recorded and the seed density ate statistical analysis such as Principal Component Analysis, (g/ml) was determined (Bishnoi and Khetarpaul, 1993). The swelling (PCA), Multidimensional scaling (MOS) and Discriminant Analysis coefficient was determined as the percentage ratio of increase in the (DA). volume of water in bean seeds both before and after hydration. The Another process for differentiation and characterization of hydration coefficient of bean seeds was calculated as the percentage species and cultivars is the molecular analysis based on RNA, DNA ratio of increase