The Effect of High Pressure Processing on Antioxidant Activity of Irish Potato Cultivars

Abstract

The effect of High Pressure Processing (HPP) on Irish potato cultivars’ antioxidant activity (AOA) was examined. High Pressure Processing at 600 MPa for 3 min was applied to two coloured (Rooster and Kerr’s Pink) and two white (Saxon and Gemson) Irish potato varieties. Antioxidant activity was assayed spectrophotometrically by ferric reducing antioxidant power and diphenyl-1-picrylhydrazyl methods. No statistically significant (p ≥ 0.05) change in antioxidant activity was observed in both the AOA methods irrespective of the HPP treatments, although a slight increase in the activity was noted in the majority of the HPP treated samples. This implies that HPP treatment has little role in improving the functional qualities, and can be tailored to improve the quality and safety of the commonly consumed potatoes.

High-Pressure Processing and Ultrasonication of Minimally Processed Potatoes: Effect on the Colour, Microbial Counts, and Bioactive Compounds

“…The antioxidant activity (AOA) of minimally processed potatoes, estimated by both the assays, varied depending on the cultivar and the type of the treatment, but changes were statistically insignificant after HPP or HPP/US treatment. These results are consistent with a previously published study on the impact of HPP at 600 MPa on the AOA of Irish potato cultivars [ 15 ]. Insignificant ( p > 0.05) changes had been observed in the AOA of aronia berry puree after HPP at 400 and 600 MPa [ 39 ], in mango nectars after HPP at 600 MPa [ 30 ], and in sweet potato nectar [ 24 ].…”

“…Potato tubers of the two cultivars, free of defects, were washed, hand-peeled, packaged in polyethylene/polyamide pouches and then vacuum sealed. HPP treatment was performed at 600 MPa (6000 bar) for 3 min at 10.6 °C (maximum temperature reached) as described in previous studies [ 14 , 15 ]. A commercial-scale high-pressure process (Hiperbaric 55HT, Miami, FL, USA) was used, located at HPP Tolling (St. Margaret’s, Co. Dublin, Ireland).…”

“…Previous studies from our group have demonstrated that HPP at 600 MPa had minimal effects on the proximate composition, antioxidants, and bioactive compounds of Irish potato cultivars, while it showed promising results regarding polyphenol oxidase inactivation [ 14 , 15 ]. This study is to investigate further the effect of HPP on its own and in combination with US (HPP/US) on the colour and microbial growth of minimally processed potatoes of the two most commonly grown potato varieties (Maris Piper (white cultivar) and Rooster (coloured cultivar)) in Ireland.…”

The Effect of High Pressure Processing on Polyphenol Oxidase Activity, Phytochemicals and Proximate Composition of Irish Potato Cultivars

“…HPP significantly increased the total phenolic content (TPC) by approximately 21%, 24%, 23%, and 17% in Saxon, Gemson, Rooster, and Kerr’s Pink potatoes, respectively, with respect to those untreated (Table 2). However, changes in the antioxidant activities were non-significant between the HPP treated and untreated potatoes [25], which was also observed by Wang et al 2012 in purple sweet potato nectars following HPP treatments. Significant increases in the TPC values following the HPP treatments have been observed in several fruits (or their products) and vegetables, including smoothies [17], pumpkins [24], pomegranate juices [10], fruit juice beverages [15], and strawberry puree [7].…”

“…Currently, HPP has been successfully employed to various fruit and vegetable purées and juices [7,8,9,10,11,12,13,14], fruit juice based beverages [15,16], smoothies [17], milk [18,19] cocoyam, Peruvian carrot and sweet potato [20] purple sweet potato nectar [21], peaches [22,23], and pumpkin [24]. In our previous work, we have shown that HPP had no significant ( p > 0.05) impact on the antioxidant activity of potatoes [25]. However, the effect of HPP on PPO inactivation, proximate composition, and bioactive phytochemicals (polyphenols and glycoalkaloids) of potatoes has not been explored.…”