Effect of preservation method on the shelf life of avocado (Persea americana mill) flesh powder

Abstract

Avocado, being a climacteric fruit, faces challenges like seasonal availability, limited shelf life, and sensitivity to handling, resulting in supply inconsistencies and potential waste. Therefore, this study aimed to preserve quality parameters of avocado flesh powder with the application of different packaging materials and storage temperatures while controlling the browning reaction in avocado flesh. Three methods were used to avoid browning in avocado pieces as citric acid, SMS, and ascorbic acid. Later, pieces were dried at 60±2°C for 5 hours and 30 minutes in a conventional oven, followed by grinding and sieving to obtain fine powder. Powder was packed using in Polyethylene Ziplock bags and vacuum seal bags and stored at ambient (27°C), refrigeration (4°C) and freezing (-18°C) temperatures to extend the shelf life. The physicochemical, functional, and microbial characteristics of avocado powder were evaluated using standard and recognized methods throughout a four-week storage period. Citric acid treatment showed the best results (L*; 32.08±0.71, a*; 30.53±0.02, b*; -1.62±0.85) proving it as the best method for inhibiting browning of avocado flesh. The physicochemical, functional, and microbial characteristics of avocado powder were evaluated using standard and recognized methods throughout a four-week storage period. Notable fluctuations were observed in powder properties with different temperature and packaging material during the storage period. Vacuum packaging in freezer storage at -18°C proved to be the most successful in sustaining the quality of avocado powder among two packaging evaluated in this study showing strong activities against physicochemical (moisture content; 5.92%, pH; 5.51, peroxide value; 8.085 meq O2/kg), and functional properties (DPPH radical scavenging activity; 20.88% and total phenol content; 166.9 mg GAE/g). Vacuum packaging at -18°C also demonstrated remarkable potential in maintaining the overall quality of the product compared to powder maintained at 27°C. Vacuum packaged avocado powder maintained at -18°C showed accepted color values (L* dark/light; 49.82±0.07, a* red/green; -0.520±0.22, b* yellow/blue; 16.155±0.94) after 4 weeks. Therefore, citric acid treatment was recommended for browning control in avocado flesh. Storage at -18°C was recommended for prolonged quality retention together with the utilization of vacuum packaging.