title: Effect of high hydrostatic pressure processing on the background microbial loads and quality of cantaloupe puree.
abstract: 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 10days at 4°C. Freshly prepared, double sealed and double bagged CP (ca. 5g) was pressure treated at 300, 400 and 500MPa at 8°C and 15°C for 5min. Microflora populations, soluble solid content, pH, color, antioxidant activity, appearance and aroma were measured at 1, 6, and 10d of storage. Results showed that high pressure treatment of 300MPa (8°C and 15°C) resulted in reduction of total aerobic plate count from 3.3 to 1.8logCFU/g. The treatment reduced the populations of native aerobic plate count to non-detectable levels (detection limit 1logCFU/g) at 400MPa and 500MPa 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 10days 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.
authors.affiliation: Residue Chemistry & Predictive Microbiology Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, United States. Electronic address: Sudarsan.mukhopadhyay@ars.usda.gov.
authors.forename: Sudarsan
authors.initials: S
authors.lastname: Mukhopadhyay
authors.affiliation: Residue Chemistry & Predictive Microbiology Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, United States. Electronic address: Kimberly.sokorai@ars.usda.gov.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Sokorai
authors.affiliation: Food Safety Intervention Technology Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, United States. Electronic address: Dike.ukuku@ars.usda.gov.
authors.forename: Dike
authors.initials: D
authors.lastname: Ukuku
authors.affiliation: Residue Chemistry & Predictive Microbiology Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, United States. Electronic address: Xuetong.fan@ars.usda.gov.
authors.forename: Xuetong
authors.initials: X
authors.lastname: Fan
authors.affiliation: Residue Chemistry & Predictive Microbiology Research Unit, U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, United States. Electronic address: Vijay.juneja@ars.usda.gov.
authors.forename: Vijay
authors.initials: V
authors.lastname: Juneja
mesh_terms: D000975:Antioxidants / Q000032:analysis; D015169:Colony Count, Microbial; D003116:Color; D028463:Cucumis melo / Q000737:chemistry / Q000382:microbiology*; D005506:Food Contamination / Q000517:prevention & control*; D005511:Food Handling / Q000379:methods* / Q000592:standards; D005516:Food Microbiology / Q000379:methods* / Q000592:standards; D005519:Food Preservation / Q000379:methods* / Q000592:standards; D063427:Food Quality; D005638:Fruit / Q000737:chemistry / Q000382:microbiology*; D005658:Fungi / Q000254:growth & development*; D006863:Hydrogen-Ion Concentration; D006874:Hydrostatic Pressure; D011786:Quality Control; D013696:Temperature; D013997:Time Factors; D015003:Yeasts / Q000254:growth & development
chemical_list: D000975:Antioxidants
keywords: Cantaloupe puree; High pressure processing; Microbial load; Quality