Optimisation of Storage Parameters for Walnuts Under Controlled Ozone and Temperature Conditions

This study aimed to optimise ozone treatment and storage temperature conditions for preserving the quality of Kazakhstani Early-Maturing walnuts. The experiments examined ozone concentration (0.50 and 1.0 mg/m3), treatment duration (30 and 60 min), and storage temperature (+10 and +25 °C). Organoleptic, physicochemical, and microbiological characteristics were assessed using standard methods, with statistical analysis performed via regression and multifactorial approaches. Results showed that ozone treatment did not adversely affect sensory qualities but significantly reduced yeast microflora counts by 2–3 times (p < 0.05), improving microbiological stability. Oxidative degradation was inhibited, and rancidity was prevented. The optimal parameters were determined as an ozone concentration of 0.50 mg/m3, treatment duration of 30 min, and storage at +10 °C. Under these conditions, the acid value was 4.40 mg KOH/100 g, the peroxide value 21.0 mmol ½O/kg, and the moisture content 2.0%, all within acceptable limits. These findings confirm that ozone treatment is an effective and eco-friendly method for extending walnut shelf life and maintaining product quality during storage.