Comparison of Bulb Yield, Some Bioactive Compound and Elemental Profile of Taşköprü Garlic (Allium sativum L.) Grown in Greenhouse and Open Field Conditions

Abstract

Taşköprü garlic, which is among the Geographical Indications of Turkey, is one of the important sources of income for the people in the Kastamonu region. It (Allium sativum L.) has become an indispensable food in the kitchen with taste, a high peculiar pungent smell, a specific colour, flavon enhancing molecules. Also, it has been used for medicinal purposes due to having antioxidant capacity, sulphur compounds, and minerals. Moreover, it can preserve its superior properties for a long time due to its high dry matter compared to other garlic genotypes. This study was conducted to reveal the yield, storage duration, and nutritional elements of Taşköprü garlic bulbs grown in an open field (OF-TD; OF-KUC) and greenhouse conditions (GH-TD; GH-KUC) as well as to determine how some bioactive components including pigment, secondary metabolites, nitrogenous compound, simple reduced sugar, pyruvic acid, lipid peroxidation (MDA-malondialdehyde) and H2O2 (hydrogen peroxide), vary according to the growing environment in both cloves and fresh leaves. The results revealed that there were significant differences in the effects of habitat on all the parameters investigated (p<0.001). For instance, while nitrogenous compounds are high in OF-KUC and GH-KUC samples, OF-TD and GH-TD showed enrichment in pigment, pyruvate, glucose and secondary metabolites in the fresh leaves. In the cloves, while pigments and secondary metabolites content were found to be higher in OF-KUC and GH-KUC samples, the content of nitrogenous compounds, pyruvate and carbon were higher in OF-TD and GHTD samples. In terms of nutrients, the GH-KUC cloves were rich in K and P, while OF-TD samples were rich in N, Mg, S, and Si, and OF-KUC samples were the richest group in Ca, Na, Cl, Mn, Fe, Zn, Cu and Se. In terms of bulb yield and storage properties, the highest values were noted with OF-KUC and GH-KUC samples, and the lowest values of them were recorded with GH-TD samples. As a result, considering the first two highest values of the parameters analyzed in garlic samples, the OF-KUC and the OF-TD samples had the maximum values, but the GH-TD samples showed the lowest value. It can be concluded that by cultivating garlic in greenhouses, fresh green leaves with high nutritional value can be provided to the consumer at all seasons and products with high nutritional value, as well as products with a storage process / long shelf life can be obtained as in plants obtained from open areas.