Superheated Steam Pretreatment as a Promising Technique to Improve the Physicochemical Properties of Corn Germ Oil

Abstract

Thermal pretreatment of oilseeds is of utmost importance in the process of edible oil production. This study explores the effects of superheated steam (SHS) pretreatment on both the oil yield and microstructural characteristics of corn germ, as well as the quality alterations in extracted oils. Corn germs were SHS-pretreated at 120–210°C for 30 to 120 s. Analysis of the oils demonstrates that SHS pretreatment significantly enhances the oxidative stability index (OSI) and total phenolic content (TPC), whereas the R value, peroxide value (PV), p-anisidine (p-AnV), conjugated diene, and conjugated triene markedly decreased (p < 0.05). Furthermore, there was a significant decrease (p < 0.05) in the contents of β-carotene, tocopherols, and phytosterols compared to the untreated sample, with the highest reductions being 18.9%, 38.8%, and 18.8%, respectively. On the basis of these physicochemical properties, Pearson correlation coefficient and principal component analysis (PCA) were performed. SHS pretreatment at 180–210°C may be the appropriate temperature condition for corn germs. Overall, SHS pretreatment may be a promising alternative method for enhancing oil yield and oxidative stability of corn germ oils. Practical Application: The present work provides valuable insights that could inform the development of high-quality corn germ food products and guide the selection of suitable SHS parameters for preserving corn germ quality. This study provides theoretical guidance for the SHS pretreatment with potential industrial applications.