Ozone treatment keeps firmness of minimally processed peach

Fresh cut fruit is a minimally processed product, generally characterized by a simple process in which whole fruit is washed and sanitized, peeled, cut, and packaged, but with a limited shelf life due to fruit metabolism, microbial contamination, enzymatic processes, and visual factors, loss of texture and nutritional quality. 

Fruit sanitization is a crucial step that can significantly reduce microbial load and subsequent transfer from the skin surface to the cut product. Ozone is an environmentally friendly antimicrobial agent that can be used as an alternative to chlorine in the fruit washing step. 

In this study, the indigenous 'Ottobrina' variety was used, a late-ripening yellow-fleshed Sicilian variety belonging to the PGI (Protected Geographical Indication) 'Pesca di Leonforte' ( Prunus persica (L.) Batsch). The fruits, individually ripened inside a protective paper bag, are characterized by firm, non-melting flesh and a distinctive flavor. 

The treatments

The effect of 3 mg L -1 of ozonated water on microbial reduction in treated peaches was evaluated and compared with treatments with sodium bicarbonate (6%), sodium hypochlorite (0.5%), and water washing alone.

After the treatments, the fruit was diced, treated with the antioxidants citric acid and ascorbic acid (3% and 2%, respectively) to prevent browning, and placed in PET trays.

The shelf life of fresh IV gamma peaches was monitored, during storage at 4°C for 7 days, by evaluating microbial growth, weight loss, physicochemical parameters (color, texture, total soluble solids, pH, titratable acidity) and sensory quality.

Results

Treatments on fruit before dicing, confirmed the sanitizing ability of ozone to reduce microbial growth by up to 2 log CFU ml -1 , showing similar logarithmic growth compared with hypochlorite and bicarbonate treatments. 

These results were confirmed on IV gamma peaches during 7 days of storage. Ozone treatment produced the statistically highest firmness during the entire storage period, independent of the anti-browning treatments. 

No significant differences were observed between treatments regarding weight loss of IV gamma peaches, total soluble solids, pH and titratable acidity. 

Sources

The use of ozonated water to extend freshcut ´Pesca di Leonforte´ peach shelf-life

Maria Allegra, Gloria Sciuto, Sara Trovato, Marcello Cutuli, Nicolina Timpanaro, Maria Concetta Strano 

CREA-OFA - Acireale, Italy 

5th International Conference on Fresh-Cut Produce: Maintaining Quality and Safety, Foggia (Italy), 3-6 June 2024, http://www.unifg.it/freshcut.2024

Picture

https://www.qualigeo.eu/prodotto-qualigeo/pesca-di-leonforte-igp/