IMPACT OF 3D PRINTING ON HUMMUS SHELF-LIFE AND THE ROLE OF NATURAL ESSENTIAL OILS COMPONENTS IN TRADITIONAL AND 3D PRINTED HUMMUS PRESERVATION

Hummus, a traditional Middle Eastern dish, is valued for its nutritional benefits. This study investigated the impact of 3D food printing on hummus shelf life and assessed the antimicrobial efficacy of components of essential oils (CEO)— citral and limonene applied individually (4 % and 8 % w/w), their 1:1 mixture (4 % and 8 % w/w), and a 1:1 limonene–thymol combination (2% w/w)— tested in both free and nanoencapsulated forms. All treatments exhibited increases in microbial counts over time; however, samples containing CEOs showed a measurable delay in microbial proliferation compared with untreated controls. Citral, particularly at the higher concentration (8 %), demonstrated the greatest antibacterial activity among the single compounds, achieving 2.4–2.8 log reductions in total aerobic counts (TAC) and approximately 3 log reductions in yeast and mold counts by Day 6. Limonene alone showed weaker effects (≤ 1 log) against total aerobic bacteria, whereas when combined with citral, the combination produced moderate inhibition (≈ 1.3 log decrease in TAC). The limonene–thymol treatments (1 % each) exhibited the most consistent and prolonged antimicrobial effects, especially in encapsulated form, achieving 1.6–1.8 log TAC and up to 5.9 log reductions in yeast and mold counts by Day 18. Encapsulation enhanced the stability and sustained release of the active components, contributing to extended preservation. 3D-printed and non-printed samples displayed comparable microbial trends throughout storage, indicating that 3D printing neither increased contamination risk nor reduced antimicrobial efficacy. Lactic acid bacteria (LAB) counts reached the spoilage limit (6 log CFU/g) by day 12 in the control samples, while all treated samples did so by day 18, except those treated with citral, which remained below this threshold, confirming their microbial stability. Overall, the encapsulated limonene–thymol formulation provided the most potent and sustained antimicrobial protection, suggesting its potential to enhance the shelf-life stability of both 3D-printed and conventional hummus.