Design and evaluation of a semi-continuous vacuum frying system to produce high-quality chips from ripened fruits: Application to plantain

Batch vacuum frying (VF) systems often face limitations in throughput and operational efficiency, whereas conventional atmospheric frying (AF) of plantains causes excessive browning, high oil uptake, and loss of sensory and nutritional quality, especially in ripe and overripe fruits. This study aimed to design, construct, and evaluate a semi-continuous VF system suitable for processing ripened plantains. The equipment, constructed from AISI 304 stainless steel, was integrated with pneumatic actuators and a sealed airlock system (SAS) to enable continuous operation under controlled vacuum. System performance was assessed through thermal and energy analyses, as well as evaluation of the vacuum generation and condensation subsystems. Plantain at three ripening stages (RS1, RS2, and RS3) were characterized (moisture, total soluble solids (TSS), and physicochemical quality), then vacuum-fried in high-oleic palm oil (HOPO) under different temperature–time combinations. The resulting chips were analyzed (oil content, color, texture, and sensory attributes), and a multicriteria desirability model was applied to determine optimal frying conditions. Compared with AF, the VF system reduced energy consumption by 32.6 %. Optimal frying conditions were 135 °C/3 min for RS1, 135 °C/5 min for RS2, and 125 °C/7 min for RS3. Chips produced under these conditions had low oil content (≤0.16 kg oil kg −1 dry matter), crisp texture, desirable light color (ΔE∗ > 20), and high sensory acceptability. Techno-economic indicators, including Internal Rate of Return (IRR) and Net Present Value (NPV), confirmed the economic feasibility of the technology. Overall, the system demonstrated scalability and sustainability for small- and medium-sized enterprises (SMEs). • Designed and validated a semi-continuous vacuum fryer for plantains. • Energy analysis showed 32.6 % savings vs. atmospheric frying. • VF improved chip quality by lowering oil, browning, and preserving texture. • Optimal conditions by ripeness: 135 °C/3 min, 135 °C/5 min, 125 °C/7 min. • The innovative system proved feasible with positive economic outcomes.