Microbiological and qualitative aspects of minimally processed pomegranate seeds
Among minor fruit tree species, pomegranate (Punica granatum L.) has gained an increased importance since several studies have indicated the health potential of its juice. However the particular structure of the fruit represents a serious obstacle to its utilization since the edible part cannot easily be separated from both exocarp and mesocarp. In the last years increasing attention has been paid to the possibility to offer ready-to-eat products to the market in order to fit the consumer requirements. The potential of pomegranate seeds to be transformed into ready-to-eat products have been investigated by several authors. In the present work we focus our attention on the aptitude of some local varieties grown in Sicily to be used for this purpose and on microbiological profiles of the obtained products. Pomegranate fruits, belonging to two local germplasm accessions from Sicily, namely 'Primosole' and 'PG-CT5', were picked at commercial maturity and stored for 4 weeks at 4°C until processing. After storage, the fruits were rinsed in water, carefully cut at the equatorial zone and processed with a commercial arils separator (Pomeke ltd). The mechanically extracted seeds were collected in a tray, mixed to assure uniformity and subjected to different washing solution treatments (distilled water, chlorinated water and citric acid solution); an unwashed sample was used as control. After washing the seed samples were deprived of water excess by means of a manual spin and packaged in trays under ordinary atmosphere. Packaged samples were stored at 4°C and 75% relative humidity for 15 days. Sampling was carried out on 0, 5, 10 and 15 days of storage to count yeasts and moulds, aerobic mesophilic bacteria and Enterobacteriaceae. Respiration of the processed product was estimated by measurement of CO2 concentration in the packages. As expected, the respiration of the processed product, expressed by CO2 concentration within the package, showed a large increase during the storage period. Despite slight differences found among washing treatments, the microbial counts of minimally fresh processed arils were in compliance with the recommended microbial limits of total plate counts, proposed by CNERNA-CNRS guideline for fresh-cut vegetables, throughout the storage time.
Continella, A., Restuccia, C., Brighina, S., Pannitteri, C. and La Malfa, S. (2018). Microbiological and qualitative aspects of minimally processed pomegranate seeds. Acta Hortic. 1209, 379-384
Punica granatum, germplasm, bacterial analysis, ready-to-use products