Comparative Analysis of Japanese Quince Juice Concentrate as a Substitute for Lemon Juice Concentrate: Functional Applications as a Sweetener, Acidifier, Stabilizer, and Flavoring Agent

This research examined the viability of Japanese quince juice concentrate (JQJC) as an innovative alternative to lemon juice concentrate (LJC). Given the rising consumer demand for natural food ingredients, this study focused on a thorough analysis of the nutritional and functional characteristics of JQJC in comparison to LJC. The chemical analysis indicated that JQJC possesses a total soluble solids (TSS) content of 50.6 °Brix, with fructose and glucose, to a greater extent, being the primary contributors to its solids content. In contrast, LJC had a TSS of 39.8 °Brix and also contained glucose and fructose. Additionally, malic acid is a principal component of JQJC’s acidity, determined at 20.98 g 100 g−1 of fresh weight (FW), while LJC mostly contained citric acid at a concentration of 30.86 g 100 g−1 FW. Moreover, the ascorbic acid content quantified in JQJC was eight times greater than that observed in LJC. The assessment of antioxidant activity, utilizing the DPPH• and FRAP assays, indicated that JQJC exhibits scavenging activity nearly eleven times higher than that of LJC, suggesting its superior antioxidant capacity. The total phenolic content for JQJC was quantified at 2189.59 mg 100 g−1 FW, significantly (p < 0.05) exceeding the 262.80 mg 100 g−1 FW found in LJC. The analysis identified 16 individual phenolic compounds in JQJC, highlighting the dominance of epicatechin, chlorogenic, and protocatechuic acids with concentrations ranging from 0.16 to 50.63 mg 100 g−1 FW, contributing to a total individual phenolic content of 114.07 mg 100 g−1 FW. Conversely, LJC is characterized by substantial contributions from hesperidin, eriocitrin, and, to a lesser extent, quercetin-3-O-rutinoside, yielding a phenolic content of 109.65 mg 100 g−1 FW. This study presents strong evidence supporting the utilization of JQJC as a functional substitute for LJC across a variety of product categories, including beverages, jams, and other food items. The findings indicate that JQJC has the potential to enhance product development targeted at health-conscious consumers while optimizing the utilization of a relatively underexplored fruit crop.