Effect of high hydrostatic pressure processing on the background microbial loads and quality of cantaloupe puree

- Presents first report on high pressure preservation of cantaloupe product as puree
- High pressure can effectively control microbial loads in cantaloupe puree.
- Combination of high pressure and refrigerated storage provides additional inactivation.
- Color parameters were affected by the high pressure treatment while soluble solid content and acidity remained unchanged.
- Cantaloupe industry can benefit using combination of high pressure with refrigeration.

The objective of this study was to investigate and evaluate the effects of high hydrostatic pressure (HHP) applied to cantaloupe puree (CP) on microbial loads and product quality during storage for 10 days at 4 °C. Freshly prepared, double sealed and double bagged CP (ca. 5 g) was pressure treated at 300, 400 and 500 MPa at 8 °C and 15 °C for 5 min. Microflora populations, soluble solid content, pH, color, antioxidant activity, appearance and aroma were measured at 1, 6, and 10 d of storage. Results showed that high pressure treatment of 300 MPa (8 °C and 15 °C) resulted in reduction of total aerobic plate count from 3.3 to 1.8 log CFU/g. The treatment reduced the populations of native aerobic plate count to non-detectable levels (detection limit 1 log CFU/g) at 400 MPa and 500 MPa pressures at 15 °C. Pressure treatment completely inactivated mold and yeast in puree below the limits of detection at day 1 and no regrowth was observed during 10 days of storage at 4 °C while mold and yeast in untreated puree survived during the storage. High pressure treatment did not show any adverse impact on physical properties as soluble solid content (SSC, 11.2 °Brix) and acidity (pH, 6.9). The instrumental color parameters (L*, a*, b*) were affected due to HHP treatment creating a slightly lighter product, compared to control, as indicated by higher L.* and lower a* values. However the change was not detected by the sensory panel while evaluating appearance scores. Pressure treatment did not affect the antioxidant capacity of puree product compared to control. Visual appearance and sniffing aroma test by panel revealed no adverse changes in the sensory parameters as a result of HHP treatment. HHP method described in this study appears to be a promising way to inactivate spoilage microorganisms in the cantaloupe puree and maintain quality. This study provides a viable option for preservation and marketing this product.

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