Mindaugas Visockis

This study aimed to evaluate the effects of different pretreatment methods on the yield and chemical composition of Nigella sativa L. (i.e., black cumin) cold-pressed oil. Different pretreatment methods used included convection heating, microwave, ultrasound and pulsed electric fields (i.e., PEF); we investigated their effects on key parameters, including oil yield, fatty acid composition, total phenol and flavonoid content, peroxide value, acidity and antioxidant activity. However, no single pretreatment method was found to be better than all others. Instead, ultrasonication and pulsed electric fields (PEF) showed significant advantages. Ultrasonication showed the highest total phenolic content and improved oxidative stability, while PEF improved flavonoid content and antioxidant activity. Therefore, these findings suggest that a combination of several pretreatment options should be considered depending on specific industrial goals related to quality improvement and sustainability. This research also contributes to the existing knowledge on Nigella sativa L. oil processing and provides additional insights for optimizing extraction technique.

With the current upsurge in the desire to foster healthy lifestyles and consume nutritious food products, the food industry has been propelled to develop novel food processing technologies. In our study, we critically evaluated the influence of pulsed electric field (PEF) processing by comparing it to conventional thermal pasteurization protocols—low temperature, long time (LTLT), high temperature, short time (HTST), and microfiltration (MF)—and its ramifications on the nutritional properties inherent in raw milk, which comprises vitamins, whey protein, amino acids, cholesterol, and fatty acids. A significant difference in β-lactoglobulin content was observed in PEF-treated liquid whey samples compared to those treated with high-temperature (HT) pasteurization, where 4.8-fold reduction with a concentration of 0.80 mg/mL was observed. Liquid whey samples treated with PEF, LTLT, HTST and MF retained β-lactoglobulin content, PEF-treated samples yielded 3.85 mg/mL, while HTST, LTLT, and MF-treated samples had β-lactoglobulin content of 3.62 mg/mL, 3.63 mg/mL, and 3.62 mg/mL compared to raw whey control (RWC) at 3.81 mg/mL. The concentrations of nutritional properties, like vitamins (A, D, E), amino acids, cholesterol, and fatty acids, remained approximately consistent across all the pasteurization methodologies. Moreover, the bacterial viability in the context of various pasteurization methodologies was scrutinized, with an absence of colonies observed in whey specimens subjected to thermal pasteurization. PEF-treated samples exhibited a substantial 1.6-log reduction in coliform colony count to less than 4 CFU/mL after curd reduction, in contrast to raw milk samples.