Search Results (47)

The market for fresh-cut fruits and vegetables is gradually expanding and is popular among consumers, but fresh-cut fruits and vegetables are highly susceptible to browning, causing a decrease in their quality and nutrition. Although anti-browning reagents and cryopreservation methods are often used for fresh-cut fruits and vegetables, the effects are not satisfactory. In this paper, hydrogen sulfide (H₂S) donor NaHS solution was used for fumigation of fresh-cut potatoes to explore the mechanism of H₂S signaling on the browning of fresh-cut potatoes at the biochemical level. Fresh-cut potatoes were fumigated with H₂S and it was found that H₂S treatment maintained better color compared with the browning of water control. Then, total phenolic content, reactive oxygen species-related metabolites hydrogen peroxide (H₂O₂) and superoxide anion (·O₂⁻), along with malondialdehyde (MDA), the activities of antioxidant enzymes, and the browning-related enzymes polyphenol oxidase (PPO), catalase (CAT), peroxidase (POD), and phenylalanine amine lyase (PAL) were determined. The results of both principal component analysis (PCA) and correlation analyses consistently indicated that CAT activity showed a strong positive correlation with the browning degree of fresh-cut potatoes. The data indicated that H₂S reduced the degree of browning, increased the total phenolic content, inhibited the accumulation of reactive oxygen species (ROS) content, inhibited POD, PPO, and PAL activities, and increased CAT activity. Full article

Tea plants (Camellia sinensis) are among the world’s most significant economic tree species. Tissue culture serves as a crucial method in commercial breeding by facilitating the rapid propagation of valuable genotypes and the generation of disease-free clones. However, callus browning represents a prevalent challenge in tea plant tissue culture, and may adversely affect explant growth and development. Our research demonstrates that although anti-browning agents can effectively suppress browning, they induce distinct color changes in the callus. These color variations could significantly influence callus induction and subsequent growth patterns. In this study, callus tissues from C. sinensis var. Assamica cv. Mengku were employed as experimental materials and treated with three commonly used anti-browning agents: ascorbic acid (VC), activated carbon (AC), and polyvinylpyrrolidone (PVP). The results demonstrated that while these three reagents effectively inhibited browning, they also induced distinct color changes in the explants, which appeared red, green, and white, respectively. Furthermore, this study investigated the molecular mechanisms underlying callus color changes using transcriptomic and metabolomic approaches. Based on transcriptome analysis, it was revealed that photosynthesis and flavonoid biosynthesis pathways were significantly enriched. Metabolome analysis identified 14 phenolic acids, which exhibited significant variation in accumulation across calluses of different colors. The differential expression of genes involved in flavonoid biosynthesis pathways, coupled with the distinct accumulation patterns of metabolites, can effectively alleviate photooxidative damage and enhance the resistance of callus to browning. AC activates the photosynthesis of callus by regulating carbon source allocation and upregulating the expression of key genes in the psa, psb, and pet families within the photosynthetic system. This process promotes chlorophyll biosynthesis, thereby enabling the callus to grow green, while VC activates the expression of key genes such as CHS, F3H, C4H, CYP75B1, and ANR in the flavonoid pathway, which are involved in the regulation of pigment synthesis in red callus. This study elucidated the molecular mechanisms underlying the effects of anti-browning agents on color variations in C. sinensis callus, thereby providing a robust theoretical foundation for optimization, the establishment of tea plant tissue culture systems, and enhancing cultivar quality. Full article

Enzymatic browning poses a formidable obstacle to the commercial sustainability of fresh-cut potatoes. Although the synergistic effects of bio-inductive technologies with natural compounds in anti-browning strategies have been observed, their full potential remains underexplored. To fulfill the demand for synergistic approaches in real-world applications, this research elucidates the complementary effects of short-term high-oxygen (HO, 80%) treatment of whole tubers in conjunction with cod peptides (CP, 0.1%) applied to fresh-cut potato slices in mitigating browning. The results demonstrated that the combined treatment (HO + CP) showed superior anti-browning efficacy compared to single treatments (HO or CP) and the untreated group (control). Specifically, peroxidase (POD) and polyphenol oxidase (PPO) activities were suppressed by 55.7% and 35.1%, respectively, under the synergistic treatment compared with the control after 8 days of storage. Meanwhile, increases in the activities of catalase (CAT), superoxide dismutase (SOD), and phenylalanine ammonia-lyase (PAL), along with an approximately 117% increase in total phenolic content, were noted with synergistic treatment. Furthermore, the combined treatment reduced malondialdehyde (MDA) accumulation by 17.5% on day 8. This effect may be attributed to enhanced antioxidant capacity and the preservation of membrane integrity. In summary, this novel strategy provides a practical synergistic solution for the control of enzymatic browning in fresh-cut potatoes. Full article

Moringa oleifera (MO) leaf infusion has gained attention for its potential therapeutic effects, particularly in metabolic health, due to its rich content of bioactive compounds, including polyphenols. The study evaluates the antioxidant properties and metabolic effects of the prophylactic administration of MO infusion in a high-fat diet (HFD)-induced murine model. First, polyphenol content (0.45 mg/g) and antioxidant activity (45.39%) were determined using Folin-Ciocalteu, DPPH, phosphomolybdenum, ferrocyanide, and anti-browning assays. In the in vivo phase, BALB/c mice were divided into three groups: a balanced diet group, a negative control group, and an HFD group supplemented with MO infusion. Over eight months, biochemical analyses, psychomotor tests, glucose tolerance assessments, and liver histopathology were conducted. MO infusion significantly reduced food intake, weight gain, lipid profiles, and liver inflammation compared to the negative control group, while promoting a metabolic profile similar to that of the balanced diet group. Additionally, it positively influenced psychomotor performance, reinforcing its neuroactive potential. These findings suggest that MO leaf infusion may serve as a functional beverage with protective effects against metabolic disorders, offering a promising natural strategy for managing obesity-related health issues. Full article

Macrocybe gigantea is a rare high-temperature edible fungus known for its resistance to browning. Previous studies suggested that the anti-browning property of the SCAU4 strain might be associated with low expression levels of the TYR7523 gene. In this study, an overexpression vector for the TYR7523 gene was constructed and introduced into SCAU4 mycelium using an Agrobacterium-mediated transformation method. After three rounds of hygromycin resistance screening, successful transformants were identified through PCR amplification and validated by qRT-PCR analysis, confirming a 3.47-fold upregulation of TYR7523 expression. The overexpression strain OE7523 was compared with the wild-type SCAU4 strain in terms of growth rate, browning degree, and tyrosinase activity. Although there was no significant difference in growth rate on the mother culture medium, OE7523 showed faster growth on the stock culture and mycelium culture medium. In the late storage period, OE7523 exhibited a higher browning degree and tyrosinase activity than SCAU4, suggesting a potential role of TYR7523 in fruiting body browning. Physiological analyses indicated that low TYR7523 expression may contribute to storage tolerance, while high expression influenced postharvest browning and preservation duration. The results provide data support for further study on the function of TYR7523 gene of Macrocybe gigantea. Full article

The growing demand for fresh foods, as well as the rise in ready-to-eat foods, is leading the food industry to study edible coatings to maintain the quality of fresh-cut fruit. The objective of this work was, first, to determine the antimicrobial activity of a commercial anti-browning solution (A), chitosan (CH), and nanochitosan (NCH) both in vitro and in vivo and, secondly, to assess the effects of those coatings on the quality of fresh-cut nectarines. Antimicrobial activity was studied against Listeria monocytogenes and Saccharomyces cerevisiae, which were used as models of a foodborne pathogen and a spoilage microorganism, respectively. After evaluating their effect against both microorganisms, including in nectarines (Prunus persica L. cv Nectagala), the fruit was treated with commercial anti-browning alone (A), anti-browning with chitosan (A + CH), and anti-browning with nanochitosan (A + NCH). The slices were then sealed in polyethylene plastic trays and stored at 5 °C for 6 days. pH, titratable acidity, soluble solids content, firmness, color, visual acceptance, and microbiological evolution were assessed. Total color difference (TCD) results demonstrated higher value in the fresh-cut fruit without coating. The chitosan coating controlled microbial growth during cold storage without causing significant alterations to the fruit’s quality, while it had the highest overall visual acceptance of the final product. Chitosan demonstrated clear advantages as an edible biocoating for fresh-cut nectarines, whereas nanochitosan did not perform as effectively as expected, indicating the need for further optimization to realize its potential benefits. The combination of chitosan and anti-browning agents presents a sustainable method for enhancing the quality and safety of fresh-cut nectarines, which may contribute to the extension of their shelf life Full article

Fresh-cutting fruits is a common practice in markets and households, but their short shelf life is a challenge. Active packaging is a prominent strategy for extending food shelf life. A systematic review was conducted following the PRISMA guidelines to explore the performance and materials used in biodegradable active packaging for fresh-cut fruits. Sixteen studies were included from a search performed in July 2024 on Scopus and Web of Science databases. Only research articles in English on biodegradable active films tested on cut fruits were selected. Polysaccharides were the most employed polymer in film matrices (87.5%). Antioxidant and anti-browning activities were the active film properties that were most developed (62.5%), while plant extracts and essential oils were the most employed active agents (56.3%), and fresh-cut apples were the most commonly tested fruit (56.3%). Appropriate antioxidant, antibacterial, and barrier properties for fresh-cut fruit packaging were determined. Furthermore, there is a wide range of experimental designs to evaluate shelf-life improvements. In each case, shelf life was successfully extended. The findings show that different storage conditions, fruits, and material configurations can lead to different shelf-life extension performances. Thus, biodegradable active packaging for fresh-cut fruits has a strong potential for growth in innovative, sustainable, and functional ways. Full article

The increasing demand for fresh and convenient foods has led to the production of Minimally Processed Products (MPPs), which are suitable for culinary and industrial uses. However, cutting potatoes can trigger browning, negatively impacting their sensory and nutritional quality. This study aimed to evaluate different anti-browning methods on Colombian potato varieties (Diacol Capiro, Pastusa, Nevada, and Sabanera) as raw materials for the development of MPPs. The physicochemical properties evaluated included moisture, pH, acidity, enzymatic activity, total phenolic content, vitamin C, and browning index. The anti-browning treatments involved immersing the potatoes in citric acid, ascorbic acid, and garlic extract. Evaluations were carried out over a 15-day storage period in refrigerated conditions. The results indicated that the Sabanera variety had the highest browning index, followed by Nevada, while Diacol Capiro and Pastusa showed lower browning indices, even without the use of technological coadjuvants. Among the treatments, citric acid proved to be the most effective across all varieties, with Diacol Capiro exhibiting the least browning after 15 days. Garlic extract was the least effective against browning. The sensory analysis indicated that an acidic descriptor was noted for both treated (with citric acid) and untreated (control) Diacol Capiro potatoes at similar intensities, suggesting that citric acid did not negatively affect the sensory quality and/or was masked during cooking, enhancing overall quality. In conclusion, the Diacol Capiro variety treated with 1% citric acid is the most appropriate choice for use as a raw material for MPPs without compromising sensory quality. Full article

Fresh-cut salads are highly appreciated by consumers due to their healthy and convenient nature. Fresh-cut (FC) lettuce is one of the best-selling FC products due to its freshness and low preparation time for salads. However, FC lettuce is very perishable and, in addition, has been recently associated with severe foodborne illness alerts. Alternative natural sanitizing treatments to conventional sodium hypochlorite are needed. The antimicrobial activity of vinegar has been well-known since ancient times. In addition, bioactive compounds from plant byproducts are widely recognized for their antioxidant properties. This work aimed to evaluate the use of a novel and encapsulated vinegar powder enriched with bioactive compounds from fruit byproducts with high antimicrobial and antioxidant properties to preserve the physicochemical (titratable acidity, total soluble solids, weight loss, and color), microbial (psychrophiles, enterobacteria, lactic-acid bacteria, molds, and yeasts), and sensory quality of FC lettuce at 4 °C for up to 10 days. Small to no differences were observed in terms of physicochemical quality (≈0.1% titratable acidity; 2.3–3.3% total soluble solids; <1% weight loss) in comparison to control samples through storage. Vinegar treatments reduced by 2–4 log CFU g⁻¹ the microbial loads after 10 days. In addition, a synergistic sensory antibrowning effect (greener and less yellowish appearance, showing −a* and −b*) between organic acids and the released polyphenols from the encapsulated plant byproduct extracts was observed. Hence, the enriched encapsulated vinegar represents an effective green alternative to conventional sanitizers to maintain the quality of FC lettuce through storage time. Full article

The global demand for sustainable and non-toxic alternatives across various industries is driving the exploration of naturally derived solutions. Hydrosols, also known as hydrolates, represent a promising yet underutilised byproduct of the extraction process of essential oils (EOs). These aqueous solutions contain a complex mixture of EO traces and water-soluble compounds and exhibit significant biological activity. To fully use these new solutions, it is necessary to understand how factors, such as distillation time and plant-to-water ratio, affect their chemical composition and biological activity. Such insights are crucial for the standardisation and quality control of hydrosols. Hydrosols have demonstrated noteworthy properties as natural antimicrobials, capable of preventing biofilm formation, and as antioxidants, mitigating oxidative stress. These characteristics position hydrosols as versatile ingredients for various applications, including biopesticides, preservatives, food additives, anti-browning agents, pharmaceutical antibiotics, cosmetic bioactives, and even anti-tumour agents in medical treatments. Understanding the underlying mechanisms of these activities is also essential for advancing their use. In this context, this review compiles and analyses the current literature on hydrosols’ chemical and biological properties, highlighting their potential applications and envisioning future research directions. These developments are consistent with a circular bio-based economy, where an industrial byproduct derived from biological sources is repurposed for new applications. Full article

Enzymatic browning, occurring on the cut surfaces of many popular fresh-cut fruit and vegetables due to wounding and the activity of endogenous polyphenyloxidase enzymes, is considered as the main reason for their rejection by consumers. In this study, water extracts were obtained from seeds of cabbage, sinapis, and wild rocket at 10 and 20% w/w seed:water ratios (SWE) and analyzed for total phenolic compounds (TPC) and antioxidant capacity (AC). The extract was then applied on cut surfaces of mid rib segments of lettuce leaves for 1 or 3 min. The segments were stored at 7 °C for 14 days. The SWE’s inhibitory capacity on enzymatic browning were measured by CIELAB color coordinates L* a* and b* and expressed as second derivatives, their % inhibition and different indices. An additional visual acceptance measurement and calculation of shelf life was also performed. The seed extracts of cabbage at 10–20% and wild rocket at 20% showed the highest anti-browning efficacy (comparable to 25 mM potassium metabisulfite control) along with TPC and AC. A high % of seed:water extract and increased exposure time led to a considerable increase in shelf life, visual score, % inhibition of browning or whitening index of the extracts of all seed sources. Chromatometric outcome data clearly showed that the visual data were more accurate than the chromatometric procedure (L*, a*, b* values, their derives ΔE, h°, C, Δh° and ΔC or calculated indices), although the latter could detect the differing degrees of browning development or its inhibition in treated and control segments during storage. Full article

A potential strain, Paenibacillus sp. JNUCC32, was isolated and subjected to whole-genome sequencing. Genome functional annotation revealed its active metabolic capabilities. This study aimed to investigate the pivotal secondary metabolites in the biological system. Fermentation and extraction were performed, resulting in the isolation of seven known compounds: tryptophol (1), 3-(4-hydroxyphenyl)propionic acid (2), ferulic acid (3), maculosin (4), brevianamide F (5), indole-3-acetic acid (6), and butyric acid (7). Tryptophol exhibited favorable pharmacokinetic properties and demonstrated certain tyrosinase inhibitory activity (IC₅₀ = 999 μM). For further analysis of its inhibition mechanism through molecular docking and molecular dynamics (MD) simulation, tryptophol formed three hydrogen bonds and a pro-Michaelis complex with tyrosinase (binding energy = −5.3 kcal/mol). The MD simulation indicated favorable stability for the tryptophol–mushroom tyrosinase complex, primarily governed by hydrogen bond interactions. The crucial residues VAL-283 and HIS-263 in the docking were also validated. This study suggests tryptophol as a potential candidate for antibrowning agents and dermatological research. Full article

The commercialisation of fresh-cut artichokes with optimal quality and appearance and a maximum shelf-life is a great challenge for the artichoke market. The use of different anti-browning agents has been previously studied; however, their effect is still limited. Therefore, the objective of this study is the evaluation of the effect of L-cysteine and, in combination with a mixture of essential oils components (eugenol, thymol and carvacrol) on browning, quality and bioactive compounds of fresh-cut artichokes stored for 9 days at 2 °C. Four different treatments were applied to ‘Blanca de Tudela’ fresh-cut artichokes: cysteine and cysteine with 75, 150 and 300 µL of the essential oils components (EOs) mixture. After 2, 4 and 9 days of storage, physicochemical parameters (weight loss, colour, respiration rate) and functional (total phenolic content, antioxidant activity) were studied. A descriptive sensorial analysis was also carried out to evaluate sensory attributes. Results showed that the application of cysteine and 150 µL of EOs displayed the lowest browning and highest antioxidant properties, as well as the best quality and sensory parameters. The use of this post-harvest treatment on fresh-cut artichokes would result in a natural and eco-friendly solution to improve artichoke quality and shelf-life. Full article

Ten 2-mercaptobenzimidazole (2-MBI) analogs were synthesized as potential tyrosinase inhibitors because mercapto-containing compounds can bind to copper ions at the active site of tyrosinase to inhibit enzyme activity. Nine 2-MBI analogs showed sub-micromolar IC₅₀ values for mushroom tyrosinase monophenolase activity; analog 4 was 280-fold more potent than kojic acid, and in diphenolase activity, 6 was 970-fold more potent than kojic acid. The inhibition mode of the 2-MBI analogs was investigated using kinetic studies supported by docking simulations. Benzimidazoles without the 2-mercapto substituent of the 2-MBI analogs lost their tyrosinase inhibitory activity, implying that the 2-mercapto substituent plays an important role in tyrosinase inhibition. The 2-MBI analogs exerted potent antioxidant effects against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and reactive oxygen species (ROS). The results obtained from apple slices and human embryonic kidney cells (HEK-293) suggest that most 2-MBI analogs are sufficiently safe candidates to delay the browning of apple slices effectively. Thus, these results support the potential use of 2-MBI analogs as anti-browning agents in foods such as mushrooms, vegetables, and fruits. Full article

In order to develop a new type of antioxidants with high efficiency, a series of β-ionone thiazolylhydrazone derivatives were designed and synthesized from β-ionone, and their structures were characterized by ¹H-NMR, ¹³C-NMR, FT-IR, and HR-MS. The antioxidant test in vitro indicated that most of the target compounds had high biological activity. Among them, compound 1k exhibited very strong DPPH (1,1-diphenyl-2-picrylhydrazyl radical)-scavenging activity with a half-maximal effective concentration (IC₅₀) of 86.525 μM. Furthermore, in the ABTS (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt)-scavenging experiment, compound 1m exhibited excellent activity with an IC₅₀ of 65.408 μM. Their biological activities were significantly better than those of the positive control Trolox. These two compounds, which have good free-radical-scavenging activity in vitro, were used as representative compounds in the anti-browning experiment of fresh-cut potatoes. The results showed that 1k and 1m had the same anti-browning ability as kojic acid, and they were effective browning inhibitors. In addition, it is well known that microbial infection is one of the reasons for food oxidation. Therefore, we investigated the antifungal activity of 25 target compounds against eight plant fungi at a concentration of 125 mg/L. The results indicated that these compounds all have some antifungal activity and may become new potential fungicides. Notably, compound 1u showed the best inhibitory effect against Poria vaporaria, with an inhibition rate as high as 77.71%; it is expected to become the dominant structure for the development of new antifungal agents. Full article