# The Effect of Storage Time on the Quality of Low-Sugar Apple Jams with Steviol Glycosides

## TL;DR

This study shows that replacing up to 40% of sugar in apple jams with steviol glycosides maintains quality and safety during storage, supporting low-sugar food production.

## Contribution

The novel contribution is demonstrating that up to 40% sugar replacement with steviol glycosides in apple jams maintains microbiological safety and sensory acceptability over 6 months.

## Key findings

- Replacing up to 40% of sugar with steviol glycosides maintains microbiological safety with colony counts <10 CFU/g.
- Jams with 10–30% steviol glycoside substitution retained desirable apple aroma and sweetness during storage.
- Vitamin C content degraded by 33–66% during storage, but jams remained sensorially acceptable after 6 months.

## Abstract

This study investigated the effect of storage time on the quality of low-sugar apple jams partially substituted with steviol glycosides (SGs). Apple jams were prepared with 0%, 10%, 20%, 30%, and 40% sugar replacement using highly purified SGs (95.1%). The jams were evaluated immediately after production and after 3 and 6 months of storage at 22 °C in the dark. Physicochemical analyses included dry matter, total soluble solids, vitamin C, total ash, pH, titratable acidity, malic acid, and color parameters (L*, a*, b*). Sensory and microbiological assessments were also carried out. During storage, the dry matter content significantly decreased from 41.4% (control) to 35.6% (40% SGs), while titratable acidity increased from 10.69° to 16.73° (p < 0.05), and pH values remained stable (3.15–3.29). Vitamin C content decreased significantly (from 0.56 mg/100 g to 0.19 mg/100 g; 33–66% degradation). The color of jams became lighter with increasing SG substitution (L* increased from 17.19 to 24.73; ΔE up to 9.66) and slightly darkened after storage (ΔL ≈ −1.0). Microbiological analysis confirmed complete safety, with total colony counts < 10 CFU/g and no presence of Listeria monocytogenes or coagulase-positive Staphylococcus. Sensory evaluation by a trained panel (10 assessors, aged 34–56 years, with similar training in fruit and vegetable preserve evaluation) showed that jams with 10–30% SG substitution maintained desirable apple aroma and sweetness, whereas higher SG levels enhanced metallic odor (0.12–0.95 c.u.) and bitterness (0.2–1.9 c.u.) while slightly reducing apple flavor intensity (p < 0.05). Despite these differences, all jams remained acceptable after 6 months of storage. Overall, replacing up to 40% of sucrose with steviol glycosides provided microbiological stability, controlled color changes, and acceptable sensory quality, supporting the production of low-sugar jams in line with clean-label and sustainability trends in modern food technology.