This study aimed to evaluate the effect of gamma irradiation (GI) on the physicochemical, technological, antioxidant and microbiological characteristics of different whole sorghum flours (WSF), as well as to characterize the profile of chemical constituents by paper spray mass spectrometry (PS-MS). The doses applied interfered in the staining characteristics of the evaluated flours, providing the darkening of the same. For the other physicochemical, technological, and antioxidant parameters, no significant influence of the process was observed. The fingerprint obtained in both ionization modes had not been influenced by irradiation, being flavonoids, phenylpropanoids, amino acids, benzoic acid derivatives, carboxylic acids, and sugars tentatively identified. In microbiological terms, there was a reduction of molds, yeasts, and Bacillus cereus in irradiated WSF compared to control (non-irradiated). Therefore, the application of low doses of gamma irradiation represents an advantageous alternative for the conservation of WSF and maintenance of bioactive compounds identified by the PS-MS technique.

Green Cavendish banana peel and pulp flours were obtained by three drying methods: oven dryer at 70 °C; air fryer at 180 °C and domestic oven at 180 °C, being the latter two new possibilities. Bioactive constituents using paper spray ionization mass spectrometry (PS-MS), phenolic identification and quantification by ultra-performance liquid chromatography with UV-Visible detection (UPLC/UV-Vis) and antioxidant capacity were evaluated. Phenolic acids showed distinct thermal stability between the treatments. Gallic acid was the predominant compound, ranging from (29.56 to 1211.74 mg 100 g-1) and had higher concentration than that found in other bananas described in literature. Green Cavendish banana flour is an advantageous source of bioactive compounds and antioxidant capacity, especially its peel. 26 compounds were identified by PS-MS: phenolics, organic acids, sugars, amino acid, phytosterol, iridoid and coumarin derivatives. Green Cavendish banana flour has great functional potential, and the air fryer can be a promising alternative for drying.

In this work, the peels of ripe banana (Musa sp.), variety “Prata”, were used to prepare a flour, which was evaluated for its physicochemical characteristics and antioxidant activity. The characterization of its chemical profile was performed by a fast and simple method: paper spray-mass spectrometry. This flour had high carbohydrate content and total dietary fiber, and significant amount of total phenolic compounds with antioxidant activity. In addition, this flour exhibited higher water-holding, oil-holding and swelling capacities than those of fruit by-products reported in the literature. Fourier-transform infrared spectroscopy confirmed the presence of functional groups of cellulose, hemicellulose, and lignin, constituents of insoluble dietary fiber. By the paper spray-mass spectrometry technique, it was possible to suggest the presence of 26 substances such as organic acids, phenolic acids, flavonoids, sugars, quinones, and terpenoids. Thus, this study demonstrated that the ripe banana peel flour has potential application as an ingredient for functional foods.