Low-Pressure Plasma Treatment Increased the Quality and Characteristic Flavor of Lyophilized Lemon Slices

Abstract

Low-pressure plasma (LPP) treatment was implemented as a nonthermal technology to preserve the organoleptic and nutritional qualities of lyophilized lemon slices. Effects of LPP treatment on the basic quality and flavor characteristics of lyophilized lemon slices stored for 7 d were evaluated. Fresh lyophilized lemon slices were prepared as a reference. The total titratable acids and sugars were in the range of 1.00∼1.11 mg/mL and 190.21∼197.37 mg/mL. The total phenolic content and Vc gradually decreased during storage from 1.74 to 1.33 mg/mL and 0.53 to 0.31 mg/mL. LPP had minor effects on total sugars and total titrate acids but prevented the storage losses of vitamin C (Vc) and phenols. A total of 35 volatile organic compounds were identified with C10 monoterpenoids being the major compounds. C6-C9 aldehydes corresponding to a green grassy aroma gradually decreased with increasing storage time. The gallery plot confirmed the different compositions of volatile organic compounds in LPP-treated samples. LPP-treated lemon slices had a higher content of preferred aromatic substances (terpinen-4-ol, α-terpineol, α-terpinene, and limonene) with a citrus-like flavor. These results demonstrated the positive effect of LPP treatment on retaining the flavor characteristics of lemon slices.