Vacuum frying reduces oil uptake and improves the quality parameters of carrot crisps

Recent consumer trends towards healthier and low fat products have had a significant impact on the snack industry. The objective of this study was to examine the most important quality parameters of vacuum and atmospheric fried carrot slices in order to identify the specific advantages of vacuum technology. Said parameters include oil uptake, colour changes, and trans α and β-carotene degradation. Equivalent thermal driving forces were used (ΔT = 60 °C and 80 °C) to compare the processes, maintaining a constant difference in temperature between the oil and the boiling point of water at the working pressure. The results showed that vacuum frying can reduce oil content by nearly 50% (d.b.) and preserve approximately 90% of trans α-carotene and 86% of trans β-carotene. This process also allowed for the raw carrot colour to be preserved, which was reflected by good correlations between a∗ and trans β-carotene content, b∗ and trans α-carotene content, and hue and total carotenoid content.