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Freshly cut potatoes tend to brown during processing and preservation, which is an important issue worldwide. Ultrasound (US) combined with L-cysteine (L-Cys) treatment (US-L-Cys) has been reported to inhibit the browning of fresh-cut potatoes in our laboratory. However, the underlying mechanism remains to be elucidated. Untargeted metabolomics, a popular high-throughput technique, has been used to investigate the biochemical changes that are closely associated with the browning of fresh-cut fruits and vegetables. The present study investigated the effect of US-L-Cys treatment on the browning index (BI), related enzyme activities, total phenolic content, antioxidant capacity, malondialdehyde (MDA) content, and relative electrical conductivity of fresh-cut potatoes during 6-d storage. Metabolomics was used to compare the metabolites of US-L-Cys-treated and control samples on days 0 and 6. The results showed that US-L-Cys treatment reduced BI; decreased polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase activities; maintained high total phenolic content; increased antioxidant capacity; and decreased MDA content and relative electrical conductivity in fresh-cut potatoes during storage. Metabolomic analysis revealed that tyrosine and amino acid metabolisms were enriched. Higher levels of alanine and lower levels of dopamine were observed in US-L-Cys-treated samples compared with control samples. Therefore, depressed tyrosine and activated alanine metabolisms may be involved in the mechanism through which US-L-Cys inhibits the enzymatic browning of fresh-cut potatoes during storage. • US-L-cys decreased PPO, POD, and PAL activities. • US-L-cys improved antioxidant capability and reduced the damage of cell membranes. • US-L-cys suppressed tyrosine metabolism and activated alanine metabolism. [ABSTRACT FROM AUTHOR]

This study explores the influence of incorporating L-cysteine (L-Cys), chitosan (CTS), and citric acid (CA) on the enzymatic modification of potato starch (EPS) films to enhance anti-browning properties. Four types of EPS composite films were evaluated for preserving fresh-cut potato slices at low temperatures to inhibit browning. Their thermal, physiochemical, mechanical, and digestibility properties were assessed. Results indicate that the addition of CTS, CA, and L-Cys improved the anti-browning activity of the EPS films by increasing film thickness and reducing water vapor permeability (WVP), oxygen transmission rate (OTR), ultraviolet (UV) transmittance, and tensile strength (TS). Furthermore, these additives improved the film's microstructure, resulting in reinforced intermolecular interactions, increased elongation at break, heightened crystallinity, enhanced thermal stability, and favorable gastrointestinal digestibility. Overall, EPS/CTS/L-Cys/CA composite films show promise as edible packaging materials with effective anti-browning properties. [Display omitted] • EPS/CTS/L-Cys/CA films elevated the anti-browning efficacy of the EPS films. • EPS/CTS/L-Cys/CA films exhibit enhanced affinity for water and film-forming agents. • The addition of L-Cys, CTS, CA improved crystallinity and thermal stability of film. • EPS/CTS/L-Cys/CA composite film had favorable solubility and digestion potential. [ABSTRACT FROM AUTHOR]

The combinational effects of kojic acid and lauroyl arginine ethyl ester hydrochloride (ELAH) on fresh-cut potatoes were investigated. Kojic acid of 0.6% (w /w) effectively inhibited the browning of fresh-cut potatoes and displayed antimicrobial capacity. The color difference value of samples was decreased from 175 to 26 by kojic acid. In contrast, ELAH could not effectively bind with the active sites of tyrosinase and catechol oxidase at molecular level. Although 0.5% (w /w) of ELAH prominently inhibited the microbial growth, it promoted the browning of samples. However, combining kojic acid and ELAH effectively inhibited the browning of samples and microbial growth during the storage and the color difference value of samples was decreased to 52. This amount of kojic acid inhibited enzyme activities toward phenolic compounds. The results indicated that combination of kojic acid and ELAH could provide a potential strategy to extend the shelf life of fresh-cut products. • Combinational effects of kojic acid and ELAH were probed during the storage of fresh-cut potato. • Combination of kojic acid and ELAH effectively inhibited enzymatic browning and microbial growth of fresh-cut potato. • The mechanism underlying the combinational effects of kojic acid and ELAH was elucidated at molecular level. • The study sheds light on the preservation of fresh-cut products using a combined approach. [ABSTRACT FROM AUTHOR]

Enzymatic browning causes a decline in consumer's acceptance of fresh-cut products. Previous study showed reactive oxygen species (ROS) is associated with enzymatic browning, and prohibitin (PHB) is involved in ROS formation. However, whether PHB influences the enzymatic browning is still unknown. In this paper, changes of StPHB3 transcript levels after cutting were investigated, then stphb3 mutants were constructed through CRISPR/Cas9 and the browning difference between stphb3 mutants and wild type was compared, finally the mechanism of PHB influencing the browning was explored. The results showed that the transcript levels of StPHB3 were enhanced in potato (cultivar Desiree) tubers after fresh cutting. Mutation of StPHB3 caused lower browning, less production of soluble quinones, decreased malondialdehyde (MDA) content, increased 1,1-Diphenyl-2-picrylhydrazyl (DPPH) inhibition, and increased total phenol contents. Additionally, polyphenol oxidase (PPO) activity and StPOT32 gene transcript level were also reduced after disturbing StPHB3 gene expression. StPHB3 was found to be located within the chloroplast same as the predominant location and activation site of PPO protein. Yeast two-hybrid (Y2H) and Co-Immunoprecipitation (Co-IP) assays showed StPHB3 interacted with PPO. And mature PPO contents were decreased in stphb3. These results suggest that suppression of StPHB3 can alleviate the browning of fresh-cut potatoes by enhancing the antioxidant activity and inhibiting PPO activation. [ABSTRACT FROM AUTHOR]

Postharvest quality deterioration is the major reason for food loss and waste, which hinder global food security, environmental sustainability and human health. Spray-induced gene silencing (SIGS) is a technique involving spraying double-stranded RNA (dsRNA) onto the plant surface for targeted RNA interference, providing a new solution for pests and disease control in agriculture products. Here, fresh-cut browning, which is a common and visible quality deterioration in potatoes, was taken as the indicator for the exploratory SIGS technology in postharvest quality deterioration control. The polyphenol oxidase (PPO) encoding genes StPPO and StPPOD , and the phenylalanine ammonia-lyase (PAL) encoding gene StPAL2 , were identified as important transcripts associated with the browning process in freshly-cut potatoes of the Yunshu 505 cultivar. Inhibition of StPPO and StPAL2 using dsRNA-PPO and dsRNA-PALX resulted in a decrease in the expression levels of the two genes, consequently leading to reduced activities of polyphenol oxidase and phenylalanine ammonia-lyase, as well as a decrease in the brown index. Spraying a mixture of these two dsRNAs demonstrated browning control capabilities similar to those of ascorbic acid. The distribution of dsRNA-Cy5 in cells confirmed its uptake and internalization by fresh-cut potatoes. In addition, the application of dsRNA-MYB12 resulted in a reduction of up to 78 % in tuber StMYB12 levels and decreased StPPO and StPAL1 expression. Spraying dsRNAs effectively reduced fresh-cut browning, highlighting the potential application of SIGS in reducing the browning of fresh-cut potatoes. • dsRNA- StPPO decreased polyphenol oxidase activity and the browning index. • dsRNA-Cy5 could be taken up and internalized by fresh-cut potato. • Spraying the dsRNA mixture for controlling browning is equivalent to using ASA. • StMYB12 act as transcriptional activator regulating StPPO and StPAL2 expression. [ABSTRACT FROM AUTHOR]

Highlights • Purslane extract greatly inhibited fresh-cut potato browning during 4 °C storage. • Purslane extract significantly suppressed the activities of PPO, POD and PAL. • Purslane extract could retain the membrane permeability, MDA content. • Medium concentration of purslane extract inhibited browning. Abstract Enzymatic browning is a crucial reaction affecting the quality of fresh-cut fruit and vegetables. Purslane is an edible Chinese folk medicine with extensive distribution and containing a lot of polyphenols and alkaloids. However, little research on its' anti-browning effect on fresh-cut food was reported. In this study, the effectiveness of 0.05% (w/w) purslane aqueous extract treatment efficiently inhibited the activities of polyphenol oxidase (PPO), peroxidase (POD) and phenylalanine ammonia-lyase (PAL), the membrane integrity was effectively maintained, and malondialdehyde (MDA) content increases was retarded during whole storage period at 4 °C. Oddly, the higher purslane extract concentration, the lower endogenesis phenolic content. Additionally, thirty polyphenols and fifty-six alkaloids were found in purslane aqueous extract by LC-MS/MS. All results suggest that purslane aqueous extract is a promising nutritive anti-browning agent for fresh-cut potato. [ABSTRACT FROM AUTHOR]

Enzymatic browning of fresh-cut potatoes (Solanum tuberosum L.) is an urgent problem to be solved in the potato industry. The transcript level of snakin-2 (StSN2) increased with prolonged fresh-cut potato storage time, and StSN2 overexpression reduced the enzymatic browning of fresh-cut potato compared to wild type (WT). Further studies suggested that overexpression of StSN2 effectively enhanced polyphenol oxidase (PPO), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) activity, decreased phenolic and soluble quinone contents. The measurement of total free amino acid results showed that the contents of proline, isoleucine, and gamma-aminobutyric acid were increased, and the contents of cystine, methionine, and tyrosine were decreased in StSN2- overexpressing transgenic lines. Quantitative phosphoproteome analysis showed that 1515 proteins were phosphorylated in transgenic fresh-cut potato. Among them, 123 kinases were found to change phosphorylation levels, and a kinase-substrate network of serine/arginine proteins and mitogen-activated protein kinases was predicted. Our results indicated that overexpression of StSN2 inhibited the enzymatic browning of fresh-cut potatoes by enhancing antioxidant enzyme activity and decreasing phenolic and soluble quinone contents while also changing vital kinase and other protein phosphorylation levels. This study demonstrated a new function of StSN2 and provided target genes for enzymatic browning resistance breeding of potatoes. • StSN2 overexpression reduced the enzymatic browning of fresh-cut potato. • Overexpression of StSN2 effectively enhanced antioxidant enzyme activity and decreased phenolic and soluble quinone contents. • The content of total free amino acid was changed in StSN2 overexpression tuber. • 1515 proteins including 123 kinases were changed phosphorylated level in StSN2 overexpression tuber. [ABSTRACT FROM AUTHOR]

• Ascorbic acid (AsA) treatment inhibited StGST but enhanced StPHO1 and StLOX5 gene expression. • AsA-treated samples had higher levels of starch content and starch metabolism. • AsA treatment increased amylase and lipoxygenase activity. • AsA treatment inhibited sucrose degradation and fatty acid synthesis. Ascorbic acid (AsA) inhibits wound healing in fresh-cut potatoes (FCP); however, the comprehensive regulatory mechanisms of the chemical during wound healing remain unclear. Here, physiobiochemical, transcriptomic, and metabolomic analyses were performed. In total, 685 differentially expressed genes (DEGs) and 1921 differentially accumulated metabolites (DAMs) were identified between control and AsA-treated samples. The level of the majority of DEGs expression and DAMs abundance in AsA-treated samples were similar to data of newly cut samples. The collective data indicated that the AsA treatment inhibited wound healing in FCPs by regulating glutathione metabolism, enhancing starch metabolism, and inhibiting phenylalanine metabolism, sucrose degradation, and fatty acid synthesis. Major genes and metabolites affected by AsA treatment included StGST , StPAL , StPHO1 and StLOX5 , and starch, sucrose, and linoleic acid. AsA treatment increased starch content and amylase and lipoxygenase activity and decreased free fatty acid level. Our research provides fundamental insights into wound healing mechanisms in FCP. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fresh-cut potato of 'Minshu' cultivars is more resistant to browning than 'Huangjin'. • The anti-browning related enzyme activities of 'Huangjin' were higher than 'Minshu'. • The membrane lipid peroxidation of 'Huangjin' is higher than 'Minshu'. • The cells ultrastructure of 'Minshu' is more intact than 'Huangjin'. In this study, the browning degrees of fresh-cut potatoes of different cultivars were investigated. Fresh-cut potatoes of the 'Huangjin' cultivar exhibited a higher browning index and sensory quality deterioration over time compared with 'Minshu' potatoes. 'Huangjin' exhibited a higher activity of browning-related enzymes such as polyphenol oxidase, tyrosinase, peroxidase, phenylalanine ammonia-lyase, phospholipase D (PLD), and lipoxygenase (LOX) than 'Minshu'. Furthermore, 'Minshu' exhibited lower H 2 O 2 and malonaldehyde (MDA) contents, lower membrane lipid degradation and peroxidation, and delayed browning, attributable to its low PLD and LOX activities. The ultrastructure of 'Minshu' cells remained intact 7 h after cutting, while that of 'Huangjin' cells was severely damaged, and 'Minshu' cells exhibited more Golgi complexes and black particles than 'Huangjin' cells. Moreover, 'Huangjin' cells exhibited numerous multivesicular bodies, which were nonexistent in 'Minshu' cells. The results show that 'Minshu' potatoes feature a lower browning-related enzyme activity than 'Huangjin', and a tough cell structure to resist post-cut browning. [ABSTRACT FROM AUTHOR]

Enzymatic browning is problematic for the fresh-processed potato (Solanum tuberosum L.) industry. Previously, we identified a serine protease inhibitor gene StSPI128 , which may alleviate potato browning. Therefore, the effects of StSPI128 on potato browning and browning-related factors were investigated by overexpressing the gene in this study. The results showed that overexpression of StSPI128 significantly alleviated potato browning and increased phenolic content. However, not all the decreases in protease activities or accumulations of total free amino acid and tyrosine caused by StSPI128 -overexpression were significant among three transgenic lines. Besides, overexpression of StSPI128 reduced PPO activity in potatoes. Moreover, overexpression of StSPI128 increased the total antioxidant abilities and membrane stability, elevated SOD and CAT activities, and decreased ROS and MDA accumulation. In vitro experiments demonstrated that the variation in browning-substrates and PPO activities did not induce the differences in potato browning. These results indicated that enhanced expression of StSPI128 alleviated potato browning mainly by increasing antioxidant ability, not via altering browning substrates or PPO activities. This work suggested that StSPI128 is a promising potential target for browning control in fresh-processed potatoes. • Enhanced expression of StSPI128 delayed the browning of fresh-cut potatoes. • Overexpressed (OE)- StSPI128 reduced PPO activity and elevated phenolics in potatoes. • OE- StSPI128 enhanced the total antioxidant ability and lowered MDA content. • OE- StSPI128 increased CAT and SOD activities, and reduced ROS accumulation. • OE- StSPI128 inhibited potato browning mainly via increasing total antioxidant ability. [ABSTRACT FROM AUTHOR]

The flesh colour and phenolic metabolism in potato tuber during curing and after cut were investigated. Result indicated that postharvest curing not only changed phenolic metabolism during curing, but also improved fresh-cut colour for 12 days after fresh cut. Significantly lower PAL and higher phenolic content and PPO activities during curing treatment and fresh-cut potatoes were detected compared to the control, which lead to the lower browning in the slices from curing treated potatoes. HPLC analysis revealed that amounts of total phenolics, chlorogenic acid, gallic acid and protocatechuic acid were induced by curing and highly accumulated in the curing treated potatoes. Our results demonstrated that phenolic metabolism played an important role in the control of browning of fresh cut potato after curing. [ABSTRACT FROM AUTHOR]

[Display omitted] • Low frequency ultrasound (LFU) enhanced antibrowning effect of AsA in fresh-cut potato; • LFU combined with AsA inhibited PPO activity more effectively than AsA treatment; • AsA loss in fresh-cut potato was weakened under LFU mediation; • LFU combined with AsA treatment reduced cellular membrane permeability; • LFU combined with AsA treatment kept low solute migration during storage. Ascorbic acid (AsA) is generally used as an antibrowning agent for fresh-cut potato (FCP). However, its browning inhibitory effect is temporary because of its rapid consumption during redox processes. In this study, the effect of browning inhibition in FCP slices was evaluated using low frequency ultrasound (LFU; 40 kHz, 200 W, 3 min) and AsA (0.2%, w/v) treatments alone or in combination. The results showed that LFU combined with AsA (LFU-AsA) treatment could achieve a better antibrowning effect than either treatment alone (higher L* , lower a* and Δ E*), and there was no adverse effect on texture properties. LFU-AsA treatment not only inhibited the activity of PPO more effectively than AsA treatment, but also enhanced the antibrowning effect by retaining higher AsA content. Moreover, it also maintained membrane integrity by limiting lipid peroxidation and solute migration during storage. Overall, LFU-AsA treatment would be a promising method in food preservation industries. [ABSTRACT FROM AUTHOR]

Although fresh-cut potato is extremely popular, it is highly prone to browning, severely affecting its quality and shelf life. Nitrogen treatment can inhibit fresh-cut potato browning. Potato browning from the perspective of transcriptome-wide N6-methyladenosine (m6A) methylation has not yet been reported. This study performed transcriptome-wide m6A-sequencing of fresh-cut potato from nitrogen-treated group (1 h N 2) and control group (1 h CK and 0 h CK) to reveal the m6A methylation modification features, and determine the methylation sites of the differentially methylated genes (DMGs). Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that the DMGs in 1 h CK vs 0 h CK and 1 h N 2 vs 1 h CK were mainly enriched in the isoflavonoid and betalain biosynthesis pathways, respectively. The m6A modifications in potato were mainly enriched around the 3′-untranslated region and stop codons of the coding sequence. The DMG expression was further verified by quantitative real-time polymerase chain reaction (qPCR), while the methylation sites were determined using SELECT qPCR. This study is the first to reveal the transcriptome-wide m6A profile of potato, which may provide new insight into inhibiting fresh-cut potato browning using nitrogen treatment from the perspective of m6A methylation. • The first to reveal the transcriptome-wide m6A profile of potato. • The m6A modifications in potato were mainly enriched around 3′-UTR and stop codons of CDS. • It found difference in methylation at m6A1792 site of tubulin beta-2 chain-like by SELECT qPCR. [ABSTRACT FROM AUTHOR]

• Short-term warming (SW) inhibited browning of fresh-cut potato. • SW treatment reduced PPO activity and total phenol content. • SW treatment enhanced expression of the SPI gene and SPI activity. • SW treatment reduced SP activity and the contents of nine free amino acids. • SW treatment inhibited de novo synthesis of tyrosine. Potatoes cut immediately after being taken out from cold storage easily undergo browning. Researchers have reported that long-term warming alleviates the browning of fresh-cut potatoes. However, long-term warming is not commercially applicable. The present study investigated the effect of short-term warming (SW) at 25 °C for 12 h on the browning of fresh-cut potatoes. The browning index of potatoes stored at 4 °C for 8 months was tested. The analysis revealed that SW efficiently blocked enzymatic browning by inhibiting polyphenol oxidase (PPO) activity, decreasing total phenolic content and malondialdehyde (MDA) content, and increasing peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity, and 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,20-azino-bis (3-ethylben zothiazoline) 6-sulphonic acid (ABTS) inhibition rates. Moreover, SW treatment induced the expression of the serine protease inhibitor (SPI) gene and enhanced SPI activity, increased the soluble protein content and decreased free tyrosine, and lysine content in fresh-cut potatoes during the 5 d storage at 2∼4 °C. The contents of glutamic acid, aspartic acid, and proline in the fresh-cut potatoes increased after SW treatment. Furthermore, the amino acid complementation experiments showed that tyrosine and lysine aggravated browning while glutamic acid and aspartic acid reduced browning. The SW treatment reduced the activity of chorismate mutase (CM), repressed the transcript levels of CM synthesis-related genes (CM1 and CM2), and inhibited free tyrosine synthesis. These results indicate that SW treatment alleviates the browning of potato tubers after cold storage probably due to its influence on PPO, metabolism of tyrosine, other FAAs and phenolics, and antioxidants. [ABSTRACT FROM AUTHOR]

• Isoleucine (Ile) could significantly delay the browning of fresh-cut potato. • Ile treatment inhibited PPO activity partially by chelating Cu2+. • Ile treatment suppressed PPO activity by interacting with amino acid residues of PPO. • Ile treatment improved the antioxidant capacity of fresh potato. Fresh-cut potatoes are susceptible to enzymatic browning. In this study, the effect of isoleucine (Ile) on the browning of fresh-cut potatoes was evaluated, and the mechanism by which Ile influenced the browning was revealed. Results showed that exogenous Ile application could reduce the browning of fresh-cut potato chips. At 2–4 °C, control chips had lost saleability on day 1, while 1.0 % Ile treated chips were still acceptable on day 4. Ile alleviated the decrease of tyrosine, prevented the production of brown pigments, and inhibited the browning of potato mashes. The addition of Ile to potato mash decreased polyphenol oxidase (PPO) activity, which was partially recovered after adding copper acetate. Molecular docking showed that Ile could bind with the amino acid residues of PPO. Moreover, Ile treatment increased the activity of catalase (CAT) and peroxidase (POD), improved 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) inhibition rate, and decreased the malondialdehyde (MDA) content. This is the first research to demonstrate that Ile has potential to be used as a natural anti-browning agent and its mechanisms include decreasing PPO activity by chelating Cu2+ and interacting with the PPO amino acid residues, and improving the antioxidant capacity. [ABSTRACT FROM AUTHOR]

Fresh-cut potatoes (Solanum tuberosum L.) are appreciated by consumers for their convenience and freshness. In the process of home cooking and food industry, different cutting styles of potato are needed. In order to explore the effect of cutting styles on quality, antioxidant activity, membrane lipid peroxidation, and browning in fresh-cut potatoes, potatoes were cut into pieces, strips, slices and the whole potatoes were used as control. The results indicated that vitamin C content of pieces, strips, and slices potatoes was gradually reduced, while glutathione content increased significantly (P < 0.05) compared with whole potatoes. Simultaneously, cutting induced phenylalanine ammonia-lyase activity and further enhanced phenol content by 40.48%, 74.88%, and 108.86% in pieces, strips and slices, respectively. And this combined with the enhancement of superoxide dismutase, catalase, ascorbate peroxidase, and glutathione reductase activity, which contributed to the total antioxidant capacity increasing by 1.37–1.46 times compared with control. Furthermore, the increase of lipoxygenase, polyphenol oxidase and peroxidase activity induced by cutting resulted in malondialdehyde content accumulation and browning phenomenon. In conclusion, the degree of membrane lipid peroxidation and browning was slice > strip > piece. Therefore, this study provides useful information to illuminate the mechanism of quality change and browning in fresh-cut potatoes subjected to different cutting styles and makes suggestions on the appropriate cutting style for commercial or home use of potatoes. [Display omitted] • Wounding stress induced the accumulation of phenols of potato. • Wounding stress improved the antioxidant capacity of potato. • This work reveals physiological changes in potato with different cutting styles. • This work reveals the mechanism of quality change in wounded potato. [ABSTRACT FROM AUTHOR]

• Evaluating the effects of photodynamic technology on fresh-cut potatoes. • Photodynamic treatment with edible curcumin presents prominent bactericidal efficacy. • Further delving into the effects on antioxidant ability and contents. • Curcumin-based photodynamic treatment maintained the commercial quality of produce. This study evaluated the feasibility of curcumin based photodynamic sterilization technology (PDT) applied to fresh-cut potato slices. Potato samples with 30 μmol L-1 curcumin solution were exposed to 420 nm light emitting diodes (LED) at a total dose of 0.7 kJ cm−2. Results showed that PDT inactivated 2.43 log CFU mL−1 of Escherichia coli (BL 21) and 3.18 log CFU mL−1 of Staphylococcus aureus and maintained the color, texture, weight as well as total solid content of treated potatoes. Additionally, loss of phenols and flavonoids was significantly prevented, increasing the total antioxidant capacity. This was attributed to changes in enzyme activity that PDT decreased the activity of polyphenol oxidase (PPO) and peroxidase (POD) by 59.7% and 47.8% and increased the activity of phenylalanine ammonia-lyase (PAL). Therefore, curcumin-based PDT has the potential to maintain the commercial quality of producing and achieving microbiological safety. [ABSTRACT FROM AUTHOR]

This study has demonstrated the potential of several controlled atmospheres for reducing the respiration rate and browning in minimally processed potatoes (cv. Monalisa) during a 14-day storage period at 4°C. The gas combinations tested were 2.5/0, 2.5/5, 5/0, 5/10, 10/0, 10/10, 80/0, 80/10, 80/20, 90/0, and 90/10 (kPa O2/kPa CO2; N2 balance). Compared to the control atmosphere (synthetic air), minimally processed potatoes stored under the controlled atmosphere composed of 80kPa O2/10–20kPa CO2 afforded the best results in terms of reduced respiration rates (−68% RO2 and −84% RCO2), antibrowning activity (−35% in total surface color change), and mechanical properties (−37% potato hardening) after storage at 4°C for 14 days. Significant decreases in acidity (higher pH values) compared to the fresh product were found at the end of the storage in the minimally processed potatoes stored under low O2/high CO2 and high O2/high–low CO2 conditions. In contrast, dry matter determinations showed no water losses in any of the experimental gas treatment batches. [Copyright &y& Elsevier]

• 3-Mercapto-2-butanol is a novel, safe, and effective anti-browning agent. • 3-Mercapto-2-butanol can prevent fresh-cut potatoes from browning for 5 d. • The inhibitory effect of 3-mercapto-2-butanol was close to sodium bisulfite. Enzymatic browning is one of the essential issues affecting the quality of fresh-cut produce. In this study, we identified a novel, safe, and effective anti-browning agent, 3-mercapto-2-butanol, which can prevent fresh-cut potatoes from browning for 5 d under the concentration of 25 μL L−1 at 5 °C. The inhibitory effect of 3-mercapto-2-butanol was close to sodium bisulfite. 3-Mercapto-2-butanol was further identified as a competitive inhibitor which directly inhibited the activity of polyphenol oxidase (PPO) by enzyme kinetic analysis, and the expression levels of PPO-related genes (POT32 and POT33) were decreased after 3-mercapto-2-butanol treatment. Besides, the concentration of enzymatic browning substrate tyrosine (Tyr) in the potato chips was found significantly higher in 3-mercapto-2-butanol treatment group than in the control group. We speculated that 3-mercapto-2-butanol could reduce the consumption of Tyr by inhibiting the activity of PPO. Our finding not only provided a novel and safe anti-browning agent candidate (3-mercapto-2-butanol) to efficiently solve the browning issue for fresh-cut food products, but also preliminarily revealed its mechanism in browning inhibition. [ABSTRACT FROM AUTHOR]

• Short-time high oxygen pretreatment on potato tuber greatly inhibited fresh-cut potato browning during 4 °C storage. • High oxygen pretreatment significantly suppressed the activity of PPO, enhanced PAL activity and antioxidant capacity. • High oxygen pretreatment could retain the membrane permeability, MDA content. • Oddly, only high concentration of oxygen was effective for anti-browning. The surface browning usually occurs on fresh-cut potato during storage. The effect of short-time high oxygen pretreatment on anti-browning of fresh-cut potato slices was investigated. The whole potato tubers were firstly immersed in the oxygen concentration of 21%, 60% and 80% for 20 min. Then, the potatoes were peeled, cut and stored at 4 °C for 8 days. The results showed that the short-time 80% oxygen pretreatment possessed significantly anti-browning effect by retarding the increase of polyphenol oxidase (PPO) activity and the accumulation of malondialdehyde (MDA) content, maintaining the cell integrity. Meanwhile, the 80% oxygen treatment could increase the activities of phenylalanine ammonia lyase (PAL) and peroxidase (POD), and the total phenolic content. Importantly, the 80% oxygen treatment could effectively improve the antioxidant capacity. Overall, all results suggest that the short-time high oxygen pretreatment holds great promise on anti-browning of fresh-cut potato. [ABSTRACT FROM AUTHOR]