Comparison of Peanut Compounds during Roasting and the Effect of Peanut Shells

Peanuts are widely used in a variety of processed foods, and their food properties are attributed to a variety of compounds that change in the roasting process. Here, we investigated the thermal changes in multiple categories of compounds in Virginia-type peanut seeds and peels during roasting using nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-tandem mass spectrometry (LC-MS/MS) as nontargeted analytical methods. Detectable taste and aroma compounds increased up to 2.1- (sucrose), 2.0- (glutamate + pyroglutamate), and 68-fold (4-methyl-5-thiazoleethanol) during roasting. Thermal changes characterizing the functional benefits of peanuts are evident, especially an increase in nicotinate (up to 15-fold) and flavonoids (up to 3.9-fold). Furthermore, the effect of the peanut shell on heat was shown by the different patterns of roasting changes in several compounds, including pyroglutamate, and the changes in amino acids and sugars related to the process of the Maillard reaction were more pronounced.