Tlehema Gwandu UmbaydaAnthony Daniel FungaAlinanuswe Joel Mwakalesi2026-07-062026-07-062025-10https://www.suaire.sua.ac.tz/handle/20.500.14820/7677A signicant portion o globally produced ruits are lost between the armer and consumer, necessitating solutions like natural edible coatings or preservation due to their low cost and less toxicity. Tis study aimed to assess whether the combination o macadamia nut oil and chitosan posed synergistic eects on physicochemical properties o tomato ruits or the macadamia nut oil alone. A completely randomized design (CRD) with eight treatments was employed: S1 (control), S2–S4 (combined macadamia nut oil and chitosan coating), S5–S7 (macadamia nut oil coating), and S8 (chitosan). Te experimental setup was conducted over 20 days at rerigeration (4°C) and postharvest shed conditions (23.8°C–30°C, 65.8%–97.5% RH). Te coating solution made up o a combination o 2.5% v/v macadamia nut oil and 1% w/v chitosan showed signicant dierences (p ≤ 0.05) in slowing down the changes in pH rom 3.95 to 4.3, total chlorophyll content rom 0.19 mg/100 to 0.12 mg/100 mL, and lipid peroxidation rom 13.5 to 19.71 meq/kg. Moreover, coating solutions made by macadamia nut oil alone, especially with 1% v/v, showed the smallest increases in total soluble solids (SS) and total sugar content, and also they exhibited the smallest decreases in titratable acidity (0.64 to 0.08 g/L), ripening index (5.78 to 84.74), total carotenoids (17.02 to 24.585 μg/g), and rmness (355 N to 130 N). Comparative analysis indicated that 1% v/v macadamia nut oil had higher mean dierences (p < 0.05) or most physicochemical parameters than coating solutions comprising 2.5% v/v macadamia nut oil and 1% w/v chitosan. However, this nding highlighted that the combination o macadamia nut oil with chitosan oers a synergistic eect on specic crucial parameters (pH, total chlorophyll content, and lipid peroxidation) compared to macadamia nut oil alone. Further studies could investigate the an- timicrobial eect o tomatoes treated with a combination o macadamia nut oil and chitosan.enedible coatingsfirmnessphysicochemicalpostharvest shedrefrigerationArticle