Kale is a vegetable that has high nutrition content, and balanced fertilization is essential to ensure high yield and quality of agricultural products. Curly kale, less known than regular leaf kale, is a new possibility for consumption. However, little is known about the influence of the type of fertilization on nutritional characteristics. This study aims to evaluate the influence of using organic fertilizers on the productivity, microbiological, and physico-chemical characteristics of Darkibor hybrid curly kale. The treatments consisted of three sources of organic fertilizers, one of organomineral fertilizer, and the control (without fertilization). The highest productivity was observed for kale that was treated with fertilizer in the organomineral composition in all harvests. For microbiological analyses, there was no contamination in all treatments, following legislation. There was no significant difference between treatments for the physicochemical composition, highlighting the high levels of phenolic compounds and proteins in curly kale. There was no difference between treatments regarding the mineral content of the leaves. Organic and organomineral fertilizers made it possible to produce curly kale with adequate physicochemical composition, free from microbiological contamination and heavy metals.

The consumption and cultivation of curly kale in Brazil is recent and information on production systems and their acceptance by the consumer are scarce. The aim of this work was to evaluate the sensory characteristics of curly kales cultivated using the conventional and hydroponic systems, considering the treatments: cultivation under the conventional system, without fertilization (A), conventional system with organic fertilizers (C, E) and hydroponic system (F). The harvests were performed at 60, 90 and 120 days after planting for the plants cultivated using the conventional system and at 30 days for the hydroponic system. The total chlorophyll index content and the sensory analyses of ranking of difference and acceptance were analyzed. The lowest chlorophyll index in the curly kales was verified for the one cultivated under the hydroponic system. In the ranking test, the darkest green color was obtained for the curly kale produced using the conventional system and for the attributes aroma, sweet and bitter taste and crunchiness, there was no significant difference.

Curly and smooth kale hybrids grown in both field (conventional) and hydroponic systems were sensory-analyzed using the descriptive and affective sensory technique. The treatments comprised hydroponic-cultivated Darkibor (A), Darkibor cultivated in field (B), HS2O (C), Arielli (D) and Kobe (E), these last three cultivated under conventional system (field-cultivated). The panelists indicated the significant attributes that described the differences in kale sensory profiles. Darkibor (A) and Arielli (D) kale leaves had the lightest green color. Regarding their format, the kales were classified into smooth and curly. Both the Darkibor grown in field (B) and Arielli (D) had the most intense bitter taste. Darkibor (A) showed the highest intensity for sweet taste, followed by Arielli (D). The field-cultivated Darkibor (B) ranked the highest crispness and mouthfeel (sensation produced by a particular food in the mouth). The color and texture of the kale leaves affected purchase intention by the consumer, and the color showed a difference among the kales, with Darkibor kale (A) receiving the lowest score. Darkibor (A) obtained lower buying-likelihood scores, reinforcing that color affects consumers’ purchase intention.