Yuzu (Citrus junos) undergoes traditional processing to create preserved yuzu with a sugar content of 50%. This study aimed to produce low-sugar yuzu syrup using artificial or natural sweeteners instead of sugar. Among artificial sweeteners, maltitol showed minimal browning and lack of deposition at high temperatures. The addition of xanthan gum (0.2%) and carboxymethyl cellulose (0.2%) resolved the issue of layer separation and viscosity decrease of yuzu syrup. Alternatively, grain syrup, a natural sweetener, improved viscosity and homogeneity without the additives. Yuzu syrups were developed using yuzu juice and preserved yuzu, with maltitol (20~40%) or grain syrup (50~70%) as the sweetener. Yuzu syrups containing 35% maltitol (M35) or 55% grain syrup (G55) had less than 5% and 10% free sugar, respectively. These syrups exhibited taste patterns similar to commercial yuzu syrup in analysis using an electronic tongue. Furthermore, M35 and G55 contained yuzu flavonoids at concentrations of 19.82 mg/g and 24.09 mg/g, respectively. Antioxidant activity (DPPH, ABTS radical scavenging) of M35 and G55 was equivalent to 10.55, 17.59 mg/100 g of Vitamin C and 97.39, 33.92 mg/100 g of Vitamin C, respectively. Consequently, M35 and G55 offer promising alternatives to preserved yuzu, providing low-sugar yuzu syrups enriched with functional ingredients.

The objective of this study was to investigate the quality characteristics of Campbell Early grape-added traditional Korean wines (yakju) prepared with different yeasts and pretreatments. The first pretreatment (A) was prepared by crushing the grapes, the second method (B) was prepared by heating the grapes at 60~70℃ for 30 minutes, and the third method (C) was prepared by freeze-concentrating grape juice. The pH of the fermented wines ranged from 3.77 to 4.10, and the total acidity of the samples ranged from 0.32 to 0.62%. The a value (redness) ranged from –0.40 to 17.89, which was higher in Campbell Early-added samples than in the controls (grapes not added). Total polyphenol content was the highest in samples prepared by crushing or heating Campbell Early grapes with ES22, and the total flavonoid contents were the highest in samples prepared by crushing Campbell Early grapes with ES22. The anthocyanin contents were also the highest in the samples fermented by heating Campbell Early grapes. ABTS and DPPH radical scavenging activities were also the highest (84.08 and 77.56%, respectively) in samples fermented by heating Campbell Early grapes.