Effect of Illite Treatment on Quality Characteristics and Antioxidant Activity of Broccoli (Brassica oleracea L. var. italica) Sprouts

Microgreens have recently gained popularity owing to their reliable economic and nutritional value. This study aimed to increase the quality of microgreen broccoli via treatment with different concentrations (1%, IPB-1; 3%, IPB-3; 5%, IPB-5; or 7%, IPB-7 w/v) of illite—a natural mineral powder. The results showed that the illite treatments considerably increased the content of mineral elements, such as Ca, P, and K; of vitamin C; and of free amino acids; and also increased the total weight of the broccoli sprouts. The content of sulforaphane, a bioactive compound, also increased by up to 47% with illite treatment, with the highest increase being in the IPB-5 group. However, several of the parameters were lower in the IPB-7 group. Aromatic compounds were categorized by functional groups such as hydrocarbons which numbered 36, 30, 34, 28, and 30 in the control, IPB-1, IPB-3, IPB-5, and IPB-7 groups, respectively. We found 16, 15, 15, 13, and 14 sulfides, including dimethyl sulfide, in the control, IPB-1, IPB-3, IPB-5, and IPB-7 groups, respectively. Additionally, aldehydes, comprising seven compounds, were detected in the IPB-1, IPB-3, IPB-5, and IPB-7 groups. Illite treatment significantly increased the activities of antioxidants such as DPPH and the polyphenol content of the microgreens. These results indicate a potential role for appropriate illite doses in microgreen treatment to address multinutrient deficiencies and to increase the quality of microgreen vegetables.