The Effectiveness of Ozone and Acidulant Treatments in Extending the Refrigerated Shelf Life of Fresh‐Cut Potatoes

Abstract

The objective of the study was to determine the effectiveness of acidulant dip treatments (with or without aqueous ozone) to reduce enzymatic browning and to extend the shelf life of fresh-cut potato slices during refrigerated storage (4 °C) for 28 d. Potato slices subjected to aqueous ozone (2 ppm) had significantly (P≤ 0.05) higher L-values and lower a-values, but ozone did not appear to have any effect on aerobic plate counts (APCs) or polyphenol oxidase (PPO) activity. NatureSeal (NS) and sodium acid sulfate (SAS) were the most effective acidulant treatments in reducing browning (significantly [P≤ 0.05] higher L-values, lower a-values, and browning index values) regardless of ozone treatment. NS and SAS also had lower PPO activity compared to other treatments on days 0 and 28, and significantly (P≤ 0.05) lower APCs (≤2.00 log CFU/g) over refrigerated storage. Therefore, the SAS treatment was comparable to NS, a commercially available product, and showed promise as an effective antibrowning dip to reduce browning and spoilage in fresh-cut potato products. Practical Application: A 1% SAS dip treatment which included 1% citric and 1% ascorbic acid was found to be an effective antibrowning dip for fresh-cut potatoes along with NatureSeal®'s PS-10, compared to other treatments. They were both effective in maintaining low microbial counts over refrigerated storage. Additionally, aqueous ozone washes (2 ppm) showed significant benefits to reduce browning; however, ozone did not affect microbial counts or PPO enzyme activity. Therefore, the SAS treatment could have potential use in the fruit and vegetable industry to reduce browning and spoilage in fresh-cut potato products.

Effect of anti‐browning agents and package atmosphere on the quality and sensory of fresh‐cut Birgit and Lady Claire potato during storage at different temperatures

“…As for a * and b * values, potato a * value did not differ much between the applied solutions, while b * value showed minor increase in potatoes immersed in both salt solutions in comparison with control, indicating its positive effect on yellowness retention. Similar results were reported in Calder, Skonberg, et al () study, where samples immersed in distilled water and distilled water with ozone had significantly lower b * values during storage than samples treated with ABA NatureSeal and sodium acid sulfate.…”

“…According to the above, it can be concluded that the oxygen reduction present in vacuum and MA packaged samples along with application of sodium chloride and sodium ascorbate ABA contributed to the reduction of the potato browning during storage, what is in accordance with results of Calder, Skonberg, et al ().…”

“…Comparing the samples treated with different ABA, the highest L * values were obtained in samples treated with sodium ascorbate. Calder, Skonberg, Davis‐Dentici, Hughes, and Bolton () treated potato slices with different ABA (ascorbic acid, citric acid, catechin, SAS, and NatureSeal‐PS 10) as well as ozone and also observed the L * value increase in treated samples compared to control (samples treated with distilled water and distilled water with ozone) during refrigerated storage (4°C) for 28 days. Rocculi et al, () used citric acid, ascorbic acid, and l ‐cysteine for browning prevention of FCP and after 24 hr air exposure all treated samples showed higher L * values compared to control.…”

Comparison of Sodium Acid Sulfate and UV-C Treatment on Browning and Storage Quality of Fresh-Cut Potatoes

“…Our results also suggested that 2.5% SAS significantly decreased the extent of browning in potato slices after 25 d storage, which confirmed the results of previous reports [21,25,26]. PPO, a key regulation factor in the process of browning, catalyzed the oxidation reaction with oxygen and phenolic compounds and promoted accumulation of quinones, which react with other substances continually leading to the polymerization of quinones [27,28].…”

“…The maximum PPO activity in potato occurred at pH 6.8, while it was nearly inactive when pH was below 4.0 [31]. Previous research has demonstrated that SAS is a stronger acidulant (pKa = 2.0) when compared with ascorbic acid (pKa = 4.1) and citric acid (pKa = 3.1) [26]. There is a possibility that SAS treatment can decrease the pH level and PPO activity of the potato tissues, thus, leading to alleviated surface browning.…”