Abstract

Mariana Toma*, Mihaela Sumedrea, Mihaela Paraschiv, Dorel Hoza, Ligia Ion, Adriana-Eliza Nițu, Cristina Vapor, Simona Popescu, Daniela Veringă, Angela Mohora, Ivona Mazilu, Ion Viscol

ABSTRACT

Background: Cultivated highbush blueberries (Vaccinium corymbosum L.) represent an essential component of functional smart nutrition due to their outstanding abundance of micronutrients, total phenolics, and anthocyanins. However, high post-harvest perishability necessitates efficient preservation strategies. Objective: This study evaluated the chemical composition of fresh organic blueberry varieties ('Duke' and 'Elliot') over two consecutive seasons (2024 and 2025) and examined their processing performance across two primary technological routes: convective dehydration and pasteurization. Materials and Methods: Fresh fruits were supplied by the Pitesti-Maracineni Institute, and experimental processing was carried out at the "Horting" Institute, Bucharest. Convective dehydration was conducted at 60°C (air velocity 2 m/s), yielding whole dried fruits and functional fruit powders. Pasteurization was utilized to manufacture clean-label confitures, high-viscosity jams, toppings, and syrups using raw organic cane sugar. Biochemical indicators—total soluble solids (TSS), titratable acidity (TA), total sugars (TS), Vitamin C, total phenolic content (TPC), and total anthocyanin content (TAC)—were monitored using standardized refractometric, volumetric, spectrophotometric, and colorimetric methods. Results: Baseline screening revealed exceptionally high values of antioxidants, with the 'Elliot' cultivar showing superior TPC (mean of 5927.59 mg GAE/kg) and TAC (mean of 2990.60 mg/kg) compared to 'Duke' (mean TPC 4109.94 mg GAE/kg; mean TAC 2852.70 mg/kg). Dehydration kinetics showed highly consistent drying durations across seasons; however, 'Elliot' recorded a slightly higher mass reduction (+0.15%) due to its immediate processing post-harvest, while pre-storage of 'Duke' at 4°C naturally lowered its initial cell water. Crucially, cultivar morphology dictated processing suitability: the thin-skinned, juicy 'Elliot' berries collapsed during whole-fruit boiling, proving ideal for jams, syrups, and toppings, whereas the firm-fleshed 'Duke' excelled in premium whole-fruit confitures. Conclusion: Both convective drying and pasteurization successfully concentrate valuable natural sugars and bio-compounds without critical structural or nutritional impairment, delivering 100% natural, additive-free functional snacks aligning with modern consumer demands for preventative health and metabolic homeostasis.