# Plant-enriched film pouches retain more blueberry vitamin C in a refrigerated trial > Turmeric- and oregano-enriched chitosan–alginate films were compared with plain film and PET packaging. Higher vitamin C concentrations after 14 days at 4 °C were specific to that storage condition; the study found no consistent bacterial-count advantage. URL: https://foodradar.org/botanical-blueberry-films-vitamin-retention-and-validation-limits Language: en Author: FoodRadar Editorial Published: 2026-10-19T06:00:10.000Z Updated: 2026-10-24T20:56:44.070Z Source publication date: 2026-08-07 Category: Packaging Türkçe: https://foodradar.org/tr/botanical-blueberry-films-vitamin-retention-and-validation-limits Español: https://foodradar.org/es/botanical-blueberry-films-vitamin-retention-and-validation-limits Deutsch: https://foodradar.org/de/botanical-blueberry-films-vitamin-retention-and-validation-limits Italiano: https://foodradar.org/it/botanical-blueberry-films-vitamin-retention-and-validation-limits Русский: https://foodradar.org/ru/botanical-blueberry-films-vitamin-retention-and-validation-limits ## The experiment compared four packaging systems Blueberries stored in turmeric- or oregano-enriched film pouches contained more vitamin C than fruit in PET packaging after 14 days at 4 °C, according to a study published in Molecules on 7 August 2026. The laboratory experiment evaluated chitosan–alginate films as packaging for highbush blueberries. The researchers compared plain chitosan–alginate film, turmeric-enriched film and oregano-enriched film with commercial PET clamshell containers. Fruit came from one commercial supplier in Kraków, Poland. The experimental films formed ventilated pouches held together with mechanical clips. ## Storage conditions and replication define the comparison The refrigerated trial used 4 °C and 85 ± 5% relative humidity, with measurements after seven and fourteen days. Ambient storage used 22 °C and 50 ± 10% relative humidity, with results reported after seven days. Three separate packages were prepared for each combination of formulation, temperature and sampling time. Each package was one experimental replicate; repeated technical measurements were averaged within packages. All experimental films were cast from the same batch of film-forming solution. ## Vitamin C declined in every group The initial vitamin C concentration was 25.71 mg per 100 g of fresh fruit. After fourteen days at 4 °C, the reported concentrations were 14.31 mg/100 g with turmeric-enriched film, 13.43 mg/100 g with oregano-enriched film and 11.44 mg/100 g in PET packaging. Fruit in the plain film contained 12.10 mg/100 g. The authors describe the higher retention as specific to the tested refrigerated condition. Antioxidant assays gave different rankings: oregano film was associated with the highest ABTS result after seven days at 22 °C, while turmeric film gave the highest DPPH result under those conditions. The paper reports no uniform improvement across all measured quality attributes. ## Bacterial counts show no consistent film advantage Total viable bacterial counts were primarily associated with storage temperature and duration. Packaging type had no statistically significant main effect, and pairwise differences between packaging treatments were not significant. Interactions between packaging, time and temperature indicated that responses depended on the tested combination of conditions. The authors conclude that these results do not demonstrate antimicrobial efficacy of the active films. They identify yeast and mould enumeration and further microbiological evaluation among the work still needed. ## Oregano film absorbed more water, but release was not measured Oregano-enriched film had greater water uptake and swelling than plain or turmeric-enriched film. The authors link this to a stronger response to water exposure, while stating that the implications for release of active constituents were not determined. Migration into the fruit, release into package headspace and effects on fruit respiration were not directly measured. The paper also calls for sensory assessment and longer-term mechanical and functional stability testing. ## Cell tests provide a limited, short-term safety screen The team tested simulated gastrointestinal digestates of the films in thyroid- and colon-derived cell lines. The evaluated DNA-damage markers did not increase significantly under the short-term test conditions. The authors also report cell-cycle changes in the thyroid-derived cells and state that these changes alone cannot establish genotoxicity. The authors limit the safety conclusions to the selected cell lines, exposure period and measured endpoints. Chronic exposure and long-term human safety were not established. They declared no conflicts of interest and reported institutional support from the University of Agriculture in Kraków. ## Sources and rights - [Bioactive Chitosan-Alginate Films with Oregano or Turmeric: Effects on Blueberry Shelf Life and In Vitro Genotoxicity Profile](https://doi.org/10.3390/molecules31162751?utm_source=foodradar.org&utm_medium=referral&utm_campaign=editorial&utm_content=botanical-blueberry-films-vitamin-retention-and-validation-limits-en). Molecules. Aleksandra Such, Ewelina Węsierska, Magdalena Surma, Anna Winiarz, Aneta Koronowicz, Alejandro Rodríguez Pascual and Agnieszka Ewa Wiącek (2026). Bioactive Chitosan-Alginate Films with Oregano or Turmeric: Effects on Blueberry Shelf Life and In Vitro Genotoxicity Profile. Molecules 31(16):2751. DOI: 10.3390/molecules31162751. © 2026 by the authors. CC BY 4.0. Edited and translated by FoodRadar. 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