Comparison of qualitative traits, biological value, chemical compounds of sweet pepper fruit

J. Elem. s. 367–377 DOI: 10.5601/jelem.2012.17.3.01 367 COMPARISON OF QUALITATIVE TRAITS, BIOLOGICAL VALUE, CHEMICAL COMPOUNDS OF SWEET PEPPER FRUIT Halina Buczkowska1, Zenia Micha³ojæ2 1Chair of Vegetable Crops, Medicinal Plants 2Chair of Cultivation, Fertilization of Horticultural Plants University of Life Sciences in Lublin Abstract Sweet pepper fruits have a high biological value, a rich content of minerals. At present, large-fruit cultivars, distinguishable by a thick pericarp wall, high processing efficiency, good growth on fields, under covers, dominate in sweet pepper cultivation. The present research has been conducted to compare the qualitative traits, chemical composition of sweet pepper fruits of the Red Knight F1 cultivar grown in a greenhouse, on open field. The evaluation of qualitative traits, biological value, chemical composition demonstrated that fruits from the greenhouse cultivation were characterized by significantly larger fruit weight, weight of edible parts as compared to those harvested from a field, although they did not differ significantly in the pericarp thickness. Fruits produced on a field had a higher ratio of the technological to total fruit weight, which proves that the cultivar is an attractive choice for field cultivation of sweet pepper, suitable for processing. Pepper fruits from a field versus the ones grown in a greenhouse contained significantly less dry matter, reducing sugars but more vitamin C. The greenhouse-grown fruits contained higher levels of nitrogen, phosphorus, potassium, calcium, magnesium than those from a field. Key words: sweet pepper fruit, qualitative traits, biological value, chemical compounds. PORÓWNANIE CECH JAKOŒCIOWYVCH, WARTOŒCI BIOLOGICZNEJ ORAZ SK£ADU CHEMICZNEGO OWOCÓW PAPRYKI S£ODKIEJ Abstrakt Owoce papryki s³odkiej maj¹ du¿¹ wartoœæ biologiczn¹ i zawieraj¹ wiele sk³adników mineralnych. Aktualnie w uprawie papryki dominuj¹ odmiany wielkoowocowe o grubej prof. dr hab. Halina Buczkowska, Chair of Vegetable Crops and Medicinal Plants, University of Life Sciences, Akademicka Street 13, 20-950 Lublin, Poland, e-mail: 368 œciance owocni, du¿ej wydajnoœci technologicznej i nadaj¹ce siê do uprawy zarówno w polu, jak i pod os³onami. Celem pracy by³o porównanie cech jakoœciowych oraz sk³adu chemicznego owoców papryki s³odkiej odmiany Red Knight F1 uprawianej w szklarni oraz w otwartym polu. W badaniach dotycz¹cych oceny cech jakoœciowych owoców oraz wartoœci biologicznej i sk³adu chemicznego wykazano, ¿e owoce z uprawy w szklarni odznacza³y siê istotnie wiêksz¹ mas¹ oraz mas¹ czêœci jadalnej w porównaniu z zebranymi z pola, natomiast nie ró¿ni³y siê istotnie pod wzglêdem gruboœci perykarpu. W owocach stwierdzono wiêkszy udzia³ masy technologicznej w ca³kowitej masie owocu z pola, co potwierdza atrakcyjnoœæ tej odmiany do uprawy w polu na potrzeby przetwórstwa. Stwierdzono te¿ istotnie mniej suchej masy i cukrów redukuj¹cych, a wiêcej witaminy C w porównaniu z owocami ze szklarni. W owocach z uprawy szklarniowej wykazano wiêksz¹ zawartoœæ azotu, fosforu, potasu, wapnia i magnezu ni¿ z uprawy polowej. S ³ o w a k l u c z o w e : owoce papryki s³odkiej, cechy jakoœciowe, wartoœæ biologiczna, sk³ad chemiczny. INTRODUCTION Sweet pepper fruits are very tasty, healthy owing to their content of biologically active chemicals with antioxidant properties. The vegetable is an abundant source of vitamin C (KMIECIK, LISIEWSKA 1994, LEE, KADER 2000, BUCZKOWSKA, NAJDA 2002, GAJC-WOLSKA at el. 2005, 2007, PERUCKA, MATERSKA 2004, POKLUDA 2004, JADCZAK et al. 2010, MICHALIK 2010). Physiologically ripe fruits are abundant in carotenoid pigments (KMIECIK, LISIEWSKA 1994, PERUCKA, MATERSKA 2004, POKLUDA 2004). Sweet pepper fruits also contain phenolic compounds (PERUCKA, MATERSKA 2004). Moreover, pepper is an important source of minerals for humans (KMIECIK, LISIEWSKA 1994, BUBICZ et al. 1999, MICHALIK 2000, POKLUDA 2004, GAJC-WOLSKA et al. 2007, JADCZAK et al. 2010). At present, commercial production of sweet pepper is dominated by heterotic, large-fruit cultivars because consumers prefer large peppers with a thick pericarp. Most of the popular cultivars are well-adapted to growing under less favorable environmental conditions, they are cultivated both in greenhouses, on fields (BUCZKOWSKA 2007, GAJC-WOLSKA et al. 2007, KORZENIEWSKA, NIEMIROWICZ-SZCZYTT 2007, JADCZAK et al. 2010). The weight of the pericarp, i.e. the edible part of a pepper fruit, which determines the bio-technological efficiency of a given cultivar, its usefulness for industrial processing, is an important feature of sweet pepper (KMIECIK, LISIEWSKA 1994, NOWACZYK, NOWACZYK 2005, BUCZKOWSKA 2007, KORZENIEWSKA, NIEMIROWICZ-SZCZYTT 2007, JADCZAK et al. 2010). Numerous studies on the use, biological value of sweet pepper fruits have demonstrated their dependence on many factors, mainly cultivar-specific traits (KMIECIK, LISIEWSKA 1994, GAJC-WOLSKA, SK¥PSKI 2001, BUCZKOWSKA, NAJDA 2002, POKLUDA 2004, BUCZKOWSKA 2007, KORZENIEWSKA, NIEMIROWICZ-SZCZYTT 2007, JADCZAK et al. 2010), the weather course or microclimate conditions during the growth, ripening of fruits (GAJC-WOLSKA, SK¥PSKI 2002, BUCZKOWSKA 2007, GAJ-WOLSKA et al. 2007), plant nutrition (GOLCZ 2001, GOLCZ 369 et al. 2004a,b, PERUCKA, MATERSKA 2004, MICHA£OJÆ, HORODKO 2006), various treatments that stimulate the yielding (GAJC-WOLSKA et al. 2007). The present research aimed at comparing the qualitative traits, chemical composition of sweet pepper fruits of the Red Knight F1 cultivar grown in a greenhouse, on open field. MATERIAL, METHODS The material comprised sweet pepper fruits of the heterotic cultivar Red Knight F1 (Seminis Vegetable Polska S.A.). Fruits from agrotechnical experiments carried out in 2009, 2010 in an unheated greenhouse, on field were used for analytical determinations. Pepper plants were grown in a greenhouse, in 10 dm3 plastic cylinders, with 4 plants per m2. They grew on horticultural peat of the initial pH equal 4.6, later limed with CaCO3 to achieve pH 6.5. There were 20 plants of the cultivar Red Knight F1, a replication consisted of a pot with a single plant (an experimental unit). Transplants were planted onto the target location at the end of April, the experiment was terminated at the beginning of October. The following quantities of nutrients were applied during the whole growing season (in g plant–1): N – 10 in the form of KNO3, NH4NO3; P – 6.0 as Ca(H2PO4)2⋅H2O with the content of 20.2% P; K – 15 as KNO3, 37.3% K, 15.5% N; Mg – 7.0 in the form of MgSO4⋅H2O 17.4% Mg. The microelements were used as EDTA complexes – Fe, CuSO4⋅5H2O, ZnSO4⋅ ⋅7H2O, MnSO4⋅H2O, H3BO3, (NH4)2Mo7O24⋅4H2O at amounts as for peat subsoils. Microelements were introduced into the soil once before planting to the permanent place. Phosphorus was applied in the middle of plant setting, in the sixth vegetation week. A quarter dose of nitrogen, potassium,, magnesium was used before plant setting, wh (...truncated)