Browning Of Fresh-cut Lettuce Research Articles

Integration of metabolome and transcriptome profiling reveals the effect of 6-Benzylaminopurine on the browning of fresh-cut lettuce during storage

Lettuce is one of the major fresh-cut products in the market. However, browning is the main cause of quality loss in fresh-cut lettuce during storage. Here, the effects of different hormones on the browning control in fresh-cut lettuce were investigated. Results showed that 6-Benzylaminopurine (6-BA) was the optimal hormone to delay the fresh-cut lettuce browning. Metabolome profiling showed that 392 metabolites were detected in fresh-cut lettuce, including 250 primary metabolites and 92 secondary metabolites. Five phenolic-related metabolites, including chrysin O-malonylhexoside, calycosin-7-O-glucoside, chrysoeriol 7-O-rutinoside, glycitin, and scopoletin, increased with browning but reduced by 6-BA treatment. Transcriptome profiling revealed that phenolic-related metabolites pathways, especially the scopoletin, were enriched by differentially expressed genes, supporting that 6-BA reduced the fresh-cut lettuce browning through transcriptional regulation of phenolic-related metabolites biosynthesis, and scopoletin could serve as a marker compound for browning prediction. These results suggest that 6-BA is a promising anti-browning agent for fresh-cut lettuce.

High-pressure carbon dioxide treatment alleviates browning development by regulating membrane lipid metabolism in fresh-cut lettuce

The influence of high-pressure carbon dioxide (HPCD) treatment on the browning of fresh-cut lettuce was investigated during storage at 4 °C. The browning degree, color, weight loss, browning-related enzymes, and components related to membrane lipid metabolism of fresh-cut lettuce were assessed during storage. The results showed that HPCD treatment slowed down the browning of fresh-cut lettuce. Polyphenol oxidase activity and total phenolic content of HPCD-treated group were reduced by 53.50% and 74.63%, respectively. In addition, HPCD treatment inhibited lipoxygenase activity and delayed membrane lipid peroxidation, thus decreasing PAL's stimulation by membrane lipid peroxidation products and further reducing the synthesis of phenolic. On the other hand, HPCD treatment maintained the structural integrity of the cell membrane and prevented the cell membrane compartmentalization from being broken due to cell membrane breakage by inhibiting phospholipase D activity, which avoided the contact between enzyme and phenol and delayed the oxidative browning.

Untargeted metabolomics to explain browning of fresh-cut lettuce

Untargeted metabolomics to explain browning of fresh-cut lettuce

Browning of fresh-cut lettuce as affected by preprocessing storage and heat treatments

Browning of fresh-cut lettuce as affected by preprocessing storage and heat treatments

A novel technique using ozone micro bubbles to control microbial contamination and browning of fresh-cut lettuce

A novel technique using ozone micro bubbles to control microbial contamination and browning of fresh-cut lettuce

Effect of Grape Leaf Extract on Phenolic Profile and Browning of Fresh-Cut Lettuce (Lactuca sativa)

This study aimed to investigate the effects of grape leaf extract (GLE) on the inhibition of lettuce polyphenol oxidase (PPO) and on the loss of phenolic compounds in fresh-cut lettuce during storage. The addition of GLE that had been heated at 100C for 15 min exhibited a higher inhibitory effect on the lettuce PPO activity than that of the fresh extract. It was found that heat-treated GLE inhibited the lettuce PPO noncompetitively. The addition of GLE prevented loss of lightness in lettuce monitored during storage. Loss of phenolic compounds was measured during the enzymatic browning process by high-performance liquid chromatography. Protocatechuic acid, chlorogenic acid, ferulic acid, coumaric acid and caffeic acid were identified in lettuce. Degradation of phenolics followed the first-order kinetic pattern during storage. Synergistic effects of GLE, in combination with ascorbic acid or citric acid, were also tested for the protection of phenolics. Practical Applications Fresh-cut produce, especially lettuce, deteriorates faster than intact produce because of internal and external browning of the cut surface. The addition of chemicals, pH adjustment, refrigeration, thermal treatments and exclusion of oxygen are among the most effective methods for the inhibition of browning. Several authors have stated the necessity to evaluate the inhibitory effect of natural and nontoxic compounds on polyphenol oxidase (PPO) activity and its potential applicability to the food industry. The result of the present study revealed that grape leaf extract (GLE) had an inhibitory effect on PPO and effectively prevented enzymatic browning in fresh-cut lettuce. Our results suggest that GLE could potentially be used as a natural inhibitor of PPO, and its utilization is possible because of its wide occurrence, low cost and nontoxicity, but further feasibility studies are needed to increase its effect as an anti-browning agent in its application in the food industry.

Effect of whey protein concentrate on phenolic profile and browning of fresh-cut lettuce ( Lactuca Sativa)

The in vitro kinetics of lettuce PPO with respect to dissolved oxygen using catechin, chlorogenic acid, caffeic acid and gallic acid has been examined. In-vitro lettuce polyphenol oxidase (PPO) activity was determined by measuring the consumption of oxygen during the oxidation reaction. The effect of whey protein concentrate (WPC) was tested on the inhibition of lettuce PPO comparing with ascorbic acid (AA) and cysteine. A competitive model that considered inhibitors was the most appropriate model to explain reaction kinetics. Browning of lettuce was also monitored during storage for 24 h. Addition of WPC prevented loss of lightness in lettuce. Loss of identified phenolic compounds in lettuce was measured during the enzymatic browning process by high-performance liquid chromatography. Degradation of identified phenolic compounds followed first order kinetics during storage. Combination of WPC with cysteine was proposed for the protection of phenolics compounds against PPO-catalysed oxidation.