Sood, MonikaSheetal2023-10-052023-10-052023-08-09Sheetal. 2023. Post Harvest Treatments of Essential Oils as Eco-friendly Alternative for Extending Shelf Life of Guava, M.Sc. Thesis, SKUAST-Jammu, India.37056https://krishikosh.egranth.ac.in/handle/1/5810198397The present investigation was carried out with the objective of extending the shelf life of guava fruits using different essential oils as eco-friendly alternative. Guavafruitsof cultivar “Lucknow-49” were harvested at colour turning stage andcoated with different concentrations of thymeand lemongrassoil comprising the following treatments: T1 (control), T2 (Thyme oil: 0.3%), T3 (Thyme oil: 0.6%), T4 (Thyme oil: 0.9%), T5 (Lemongrass oil: 0.3%), T6 (Lemongrass oil: 0.6%) and T7 (Lemongrass oil: 0.9%). The coated fruits were stored under ambient conditions and analyzed at a regular interval of 3 days to ascertain physico-chemical and organoleptic attributes. The physico-chemical analysis ofcoatedguava fruits revealed that the minimum meanphysiological loss in weight (3.13%), decay percentage (3.56%) and shrinkage index (5.87%) were recorded in T6whereas, T1 recorded the highest physiological loss in weight (10.21%), decay percentage (20.09%) and shrinkage index (9.26%). The lowest mean TSS (10.45ºBrix), titratable acidity (0.17%), reducing and total sugars (3.65 and 5.45%), ascorbic acid (197.02 mg/100g), total phenolic content (131.41 mg GAE/100g), antioxidant activity (55.45%) and pectin (1.13%)were recorded in T1however, highest mean TSS (11.92ºBrix), titratable acidity (0.27%), reducing and total sugars (4.38 and 5.93%), ascorbic acid (255.73 mg/100g), total phenolic content (154.11 mg GAE/100g), antioxidant activity (80.04%) and pectin(1.73%)were recorded in T6.Nomicrobial spoilage was detected upto 3 days of storage whereas, T1 recorded the highest mean total plate count (1.20× 103 cfu/g). Sensory evaluationrevealed that T6 (Lemongrass oil: 0.6%) recorded the highest meanscore for colour (7.41), flavour (7.78), taste (7.72), texture (7.77) and overall acceptability (7.66). Overall, T6 was best suited essential oil coating to retain quality as well as enhance the shelf life of guava fruits during storage.EnglishThesis