Hot water, UV-C and superatmospheric oxygen packaging as hurdle techniques for maintaining overall quality of fresh-cut pomegranate arils

BACKGROUND: In recent years there has been increasing consumer pressure to avoid the use of agrochemicals such as chlorine on fresh plant products for extending their shelf life. The combined use of eco-sustainable techniques may be an alternative. The effect of hot water (HW), ultraviolet-C (UV-C) light and high oxygen packaging (HO) on the overall quality of fresh-cut pomegranate arils stored under modified atmosphere packaging (MAP) for up to 14 days at 5 degrees C was studied. RESULTS: Arils extracted manually, washed with chlorine (100 mu L L1 NaClO, pH 6.5, 5 degrees C water), rinsed and drained were exposed to single or combined (double and triple) hurdle techniques. The HW treatment consisted of a 30 s immersion in water at 55 degrees C followed by air surface drying. A 4.54 kJ m2 dose was used for the UV-C treatment before packaging. Active MAP with initial 90 kPa O2 was used in the HO treatment. The respiration rate remained relatively constant throughout shelf life, with no differences among treatments. CO2 accumulation was higher within HO packages. HW induced a slight reduction in total soluble solids, while no changes in titratable acidity were found. HO-treated arils had the highest phenolic content, while the lowest was found in HW-treated arils. The lowest antioxidant activity was found in HW + UV-C + HO and the highest in UV-C + HO and HO treatments. HW alone or in combination with UV-C and HO inhibited mesophile, mould and yeast growth, while UV-C + HO was most effective for controlling yeast and mould growth. CONCLUSION: UV-C and HO either alone or in combination are promising techniques to preserve the quality of pomegranate arils for up to 14 days at 5 degrees C. (c) 2012 Society of Chemical Industry