Fertilization with Humic Acids in Production Changes the Quality of Fresh and Stored Sweet Pepper Fruits (Capsicum annuum L.)

The objective of this study was to assess the impact of humic acid treatment on the physical and biochemical parameters of 'Cuccino Orange' pepper fruits before and after storage, which is crucial since the majority of peppers are stored and not sold directly after harvest. The application of humic acid did not result in any discernible changes in fruit length, width, or dry weight. However, it did significantly enhance pericarp thickness post-storage, particularly in the Humistar treatment, which was connected to higher water contents. The control (C) treatment exhibited the highest water loss, with a value of 5.2% after storage. The sugar composition of the samples exhibited alterations, with increased sucrose and decreased glucose observed in the C treatment, accompanied by reductions in total sugar in the biostimulant treatments. Significant decreases were observed in ascorbic and citric acids, while malic and tartaric acids exhibited increased levels in all treatments. Phenolic content analysis revealed that Humistar treatment exhibited increased total phenolics (31.8%) after storage compared to the control, indicating that humic acid may enhance phenolic accumulation. The specific phenolics, such as chlorogenic acid, exhibited variable changes, thereby highlighting the complex metabolic interactions. The results indicate that humic acid treatments can enhance post-harvest quality by improving structural integrity, water retention, and metabolic content, contributing to a longer shelf life and higher nutritional quality. Further research is necessary to elucidate the underlying mechanisms and to extend these findings to other fruit types and storage conditions.