Search Results (128)

This study developed antimicrobial composite coatings from gelatin (GL) and carboxymethyl chitosan (CMCS) functionalized with carvacrol (CA) as a natural alternative for the preservation of strawberries. Films incorporated with 0%, 1.5%, and 3% CA were characterized by their physical, mechanical, and structural properties. The addition of CA significantly improved opacity, tensile strength, elongation-at-break, and thickness, while reducing water vapor permeability, moisture content, and solubility (p < 0.05). Spectroscopy and microscopy also confirmed CA’s uniform dispersion within the matrix. During 14 days of storage at 4 °C, strawberries coated with GL/CMCS/CA-3% significantly reduced weight loss (50.91%) and fungal contamination, improved firmness (79.31%), and maintained color and pH. Conversely, uncoated strawberries showed rapid declines in soluble solids, acidity, phenolics, anthocyanins, vitamin C, and antioxidant activity (p < 0.05). Microbial growth was effectively suppressed in coated fruits, while sensory profiles were drastically impaired in uncoated samples at the end of storage (p < 0.05). These results demonstrate that GL/CMCS/CA coatings can effectively preserve strawberry quality and extend shelf life without synthetic preservatives. Full article

Exhausted olive oil pomace (EOP), Fucus spiralis, and Limnospira sp. extracts—rich in bioactives, polysaccharides, or proteins—were incorporated into alginate-based edible coatings and applied to strawberries to evaluate their effects on postharvest quality parameters, including decay, weight loss, color, antioxidant activity, and microbial growth. Among the tested formulations, the EOP-based coating (0.25% bioactive rich-extract) was the most effective, reducing weight loss to approximately 18% after 10 days at 10 °C, compared with higher losses in the control and other coatings, while also better preserving color through higher hue and chroma retention. Antioxidant activity, measured by ABTS and DPPH assays, was consistently higher in EOP-coated strawberries, despite a general decline in total phenolic content across treatments. Specifically, ABTS values decreased from 21.43 ± 0.90 (day 0) to 12.88 ± 0.39 (day 10) mmol TE/100 mg DW, while DPPH values declined from 10.23 ± 1.39 (day 0) to 5.96 ± 1.03 (day 10) mmol TE/100 mg DW. Microbial analyses further showed that the EOP coating strongly inhibited spoilage fungi, yeasts, and bacteria, whereas coatings containing Fucus spiralis or Limnospira sp. extracts (0.25% bioactive rich-extract plus 0.5% polysaccharide- or protein-rich extract) offered only moderate protection and, in some cases, promoted microbial growth. Overall, the EOP coating demonstrated superior performance in maintaining freshness, delaying microbial spoilage, and extending the shelf life of strawberries, highlighting its potential as a sustainable and functional strategy for fruit preservation. Full article

This study aimed to evaluate the effects of controlled atmosphere (CA) treatment on the postharvest quality of strawberries harvested at different 50% and 80% maturity under export shipping conditions. The strawberries were subjected to CA and refrigerated container (Reefer) environments at 10 °C, and their quality attributes were then analyzed. Metabolomic profiling revealed significant variations in primary and secondary metabolites and volatile organic compounds (VOCs). A pathway analysis revealed that CA conditions altered metabolic pathways related to sugar, amino acid, and energy metabolism during storage. CA treatment effectively delayed the accumulation of anthocyanins and enhanced the levels of specific amino acids and VOCs essential for the flavor and aroma of strawberries. Bioluminescence imaging revealed that CA treatment effectively reduced lipid peroxidation. A correlation analysis showed that certain VOCs and secondary metabolites significantly correlated with lipid peroxidation, indicating their role in enhancing antioxidant activity and reducing oxidative stress. These results suggest that CA conditions are associated with significantly reduced weight loss, the maintenance of firmness, and lower respiration rates in strawberries, particularly in those harvested at 80% maturity, extending the shelf life and improving the sensory quality of strawberries. Therefore, CA treatment is an effective method for long-term export. Full article

Strawberries are highly perishable despite their popularity, as their limited shelf life compromises both freshness and market value. The study investigated the effects of 1-methylcyclopropene (1-MCP), modified atmosphere packaging (MAP), and their combined treatments on the quality and flavor of strawberries during cold storage and simulated shelf life. 1-MCP was applied by enclosing strawberry fruits in a hermetically sealed container and exposing them to 250 nL/L 1-MCP at 20 °C for 18 h. Three initial MAP gas compositions were tested: MAP1 (5% O₂, 15% CO₂, 80% N₂), MAP2 (10% O₂, 10% CO₂, 80% N₂), and MAP3 (15% O₂, 5% CO₂, 80% N₂), with MAP1 identified as optimal based on strawberry postharvest quality metrics. The results showed that all treatments could inhibit the deterioration of strawberry quality, and the 1-MCP + MAP treatment had the best fresh-keeping effect. Untargeted Gas Chromatography-Mass Spectrometry (GC-MS) analysis identified 85 volatile compounds, and sensory correlation analysis revealed that 1-MCP + MAP-treated strawberries maintained the highest consumer acceptability, with odor characteristics closely resembling those of pre-storage controls. Further studies demonstrated that the combined treatment uniquely suppressed the generation of fatty acid oxidation-derived volatiles while stabilizing critical aroma-active esters, thereby decelerating flavor degradation. Collectively, these findings highlight the potential of 1-MCP + MAP as a postharvest strategy to delay the postharvest senescence of strawberries and maintain their storage quality. GC-MS provided a scientific method for the flavor quality evaluation of this preservation technology. Full article

Strawberries are economically valuable but highly perishable fruits, mainly due to fungal spoilage, with no fungicides currently registered for postharvest use. This study aimed to develop a biobased postharvest treatment for strawberries focusing on fungal control and shelf-life extension. The antifungal activity of Eucalyptus staigeriana, Eucalyptus urograndis, and their binary mixture was evaluated in vitro against the spoilage fungus Colletotrichum acutatum. The effects on pathogen morphology, in vivo efficacy when incorporated into carboxymethylcellulose (CMC), and impacts on postharvest and sensory quality of strawberries were also assessed. E. staigeriana EO showed the highest antifungal activity in vitro. In vivo, the incorporation of E. staigeriana EO into CMC significantly reduced disease severity when applied curatively. Treated fruits exhibited less fungal decay during refrigerated storage, indicating improved preservation. However, sensory evaluation revealed changes mainly in the aroma of the fruit. These results suggest that E. staigeriana EO combined with CMC coating is a promising postharvest antifungal treatment for strawberries, though further research is needed to optimize the formulation and reduce sensory impacts. Full article

Carboxymethyl cellulose (CMC) films, derived from sugarcane bagasse agricultural waste (SCB) incorporated with Betalains-nitrogen-doped carbon dots (Betalains-N–CQDs), derived from beet root waste (BR), offer a sustainable, smart and naked-eye sensor for strawberry packaging due to their excellent fluorescent and shape memory properties. These CMC-Betalains-N–CQDs aim to enhance strawberry preservation and safety by enabling visual detection of common food contaminants such as bacteria, fungi and Pb(II). Crucially, the CMC-Betalains-N–CQD film also exhibits excellent shape memory properties, capable of fixing various shapes under alkaline conditions and recovering its original form in acidic environments, thereby offering enhanced physical protection for delicate produce like strawberries. Optical studies reveal the Betalains-N–CQDs’ pH-responsive fluorescence, with distinct emission patterns observed across various pH levels, highlighting their potential for sensing applications. Scanning Electron Microscopy (SEM) confirms the successful incorporation of Betalains-N–CQDs into the CMC matrix, revealing larger pores in the composite film that facilitate better interaction with analytes such as bacteria. Crucially, the CMC-Betalains-N–CQD film demonstrates significant antibacterial activity against common foodborne pathogens like Escherichia coli, Staphylococcus aureus, and Candida albicans, as evidenced by inhibition zones and supported by molecular docking simulations showing strong binding interactions with bacterial proteins. Furthermore, the film functions as a fluorescent sensor, exhibiting distinct color changes upon contact with different microorganisms and Pb(II) heavy metals, enabling rapid, naked-eye detection. The film also acts as a pH sensor, displaying color shifts (brown in alkaline, yellow in acidic) due to the betalains, useful for monitoring food spoilage. This research presents a promising, sustainable, and multifunctional intelligent packaging solution for enhanced food safety and extended shelf life. Full article

Potassium is the most abundant macronutrient in plants, participating in essential physiological processes such as turgor maintenance. A reduction in cell turgor is a hallmark of the ripening process associated with fruit softening. The dynamic of K⁺ fluxes in fleshy fruits is largely unknown; however, the reallocation of K⁺ into the apoplast has been proposed as a contributing factor to the decrease in fruit turgor, contributing to fruit softening. High-affinity K⁺ transporters belonging to the KUP/HT/HAK transporter family have been implicated in this process in some fruits. In this study, a comprehensive genome-wide analysis of the KUP/KT/HAK family of high-affinity K⁺ transporters in strawberry (Fragaria × ananassa Duch.) was conducted, identifying 60 putative transporter genes. The chromosomal distribution of the FaKUP gene family and phylogenetic relationship and structure of predicted proteins were thoroughly examined. Transcriptomic profiling revealed the expression of 19 FaKUP genes within the fruit receptacle, with a predominant downregulation observed during ripening, particularly in FaKUP14, 24 and 47. This pattern suggests their functional relevance in early fruit development and turgor maintenance. Mineral composition analyses confirmed that K⁺ is the most abundant macronutrient in strawberry fruits, exhibiting a slight decrease as ripening progressed. Membrane potential (E_m) and diffusion potentials (E_D) at increasing external K⁺ concentrations were measured by electrophysiology in parenchymal cells of green and white fruits. The results obtained suggest a significant diminution in cytosolic K⁺ levels in white compared to green fruits. Furthermore, the slope of change in E_D at increasing external K⁺ concentration indicated a lower K⁺ permeability of the plasma membrane in white fruits, aligning with transcriptomic data. This study provides critical insights into the regulatory mechanisms of K⁺ transport during strawberry ripening and identifies potential targets for genetic modifications aimed at enhancing fruit firmness and shelf life. Full article

Strawberries have a short shelf-life leading to food loss and waste when production unexpectedly exceeds demand. PGRs may have potential to delay production and reduce food loss and waste, but no PGRs are available for delaying strawberry production. The aim of this preliminary study was to investigate re-purposing a stomatal blocking film antitranspirant polymer as a PGR to temporarily delay production. Poly-1-p-menthene or water was applied during early fruit ripening in two glasshouse experiments, one on a June-bearer cultivar and one on an everbearer cultivar. Ripe strawberries were harvested during the next 23 days, the cumulative yield was recorded, and the production curves were fitted using polynomial regression in groups. The statistical analysis showed that cubic polynomial regression curves could be fitted separately to each treatment. Application of the blocker delayed the production of both cultivars by 1–2 days during the period of rapid berry production. The delay diminished and cumulative yield returned to the water-treated value by 13 and 18 days after application in the June-bearer and everbearer cultivars, respectively. At 23 days after application, the blocker gave 8% greater cumulative yield in the June-bearer, but not in the everbearer. It was concluded that, if a greater delay could be achieved, there may be potential to use stomatal blockers as PGRs in some cultivars of strawberry to delay production and reduce food loss and waste when unanticipated lower demand occurs. Full article

This study investigates the potential of bamboo-based sustainable packaging in combination with passive modified atmosphere (MA) and cold storage to enhance the shelf life of strawberries while preserving their physico-chemical properties, bioactive compounds, and antioxidant enzyme activity. The study monitored key parameters such as fruit weight loss, firmness, color, and the content of bioactive compounds as well as phenolics and flavonoids. Additionally, antioxidant enzyme activity, including catalase, ascorbate peroxidase, and superoxide dismutase, was assessed to evaluate oxidative stress during 9 days at 4 °C. The results show that strawberries packaged with bamboo materials in a passive MA retained their physico-chemical traits, exhibiting slower changes in firmness, color, and bioactive compound content compared to those in unpackaged samples. Furthermore, the antioxidant enzyme activity remained significantly higher, suggesting a lower oxidative stress in packaged fruit. This combination of bamboo-based packaging with passive MA is a valid, effective, and sustainable approach to prolonging the qualitative traits of strawberries during cold storage, offering both environmental and nutritional benefits. Full article

Chitosan coatings have been demonstrated to be a highly effective and safe approach to extending the shelf life of food. This study, for the first time, evaluates the effectiveness of bamboo-leaf flavonoids (BLFs) added to a chitosan coating to delay the spoilage of strawberries, blueberries, and bamboo shoots. The addition of BLFs improved the tensile strength of the coatings. Chitosan coating incorporated with 0.1% BLFs had the highest tensile strength (36.38 ± 2.69 MPa). BLFs conferred antioxidant properties to chitosan coatings as determined by DPPH radical scavenging activity. Key quality parameters were measured over the storage period of strawberries, blueberries, and bamboo shoots. The coating significantly affected the impact of storage time on some variables. Chitosan/BLF coatings were particularly effective in limiting changes over time in weight loss, spoilage percentage, and vitamin C content (strawberries and blueberries), as well as crude fiber content (bamboo shoots), although their effect on titratable acid, soluble solids, and soluble protein content was less pronounced. The chitosan/BLFs composite coating demonstrated superior efficacy over pure chitosan in delaying spoilage. In conclusion, the chitosan/BLF coating could be useful for maintaining the quality of strawberries, blueberries, and bamboo shoots. Full article

Berries are highly perishable due to their high water content, making them prone to rapid deterioration and spoilage. This study investigates the effects of osmotic dehydration and edible coatings, with and without bioactive compounds, on various quality attributes of blueberries, raspberries, and strawberries during storage. The berries were pretreated using osmotic dehydration with apple juice, followed by the application of edible coatings from Chlorella vulgaris protein, with or without the addition of aqueous rosemary extract as a source of bioactive compounds. The results indicated that the combination of the two methods significantly reduced weight loss in all berry types, with the incorporation of bioactive compounds further enhancing moisture retention up to approximately 3% for blueberries and raspberries and 5% for strawberries. Total phenolic content and antioxidant activity exhibited significantly increased stability in coated samples, with bioactive coatings contributing to improved antioxidant properties. The HPLC analysis proved that the bioactive profile was preserved after the treatments. Microbial analysis demonstrated that edible coatings, particularly those enriched with bioactive compounds, effectively inhibited microbial growth (TC approximately 4.5 log(CFU/g) with limit = 5 log(CFU/g) and YM approximately 3.5 log(CFU/g) with limit 4 log(CFU/g)), thereby extending the shelf life of the berries. These findings suggest that the synergistic application of osmotic dehydration and edible coatings, especially those containing bioactive compounds, significantly enhances the quality, shelf life, and potential health benefits of fresh berries during storage. Full article

This study investigated the combined antibacterial effects of PAW with natural antimicrobial agents and further examined the impact of this technology on postharvest strawberry preservation. The optimal PAW preparation condition was determined at 50 min at 400 W, although PAW alone showed limited efficacy against Staphylococcus aureus and Escherichia coli. Among the five selected natural antimicrobial agents, the 1% tannic acid–PAW combined treatment demonstrated optimal bactericidal performance, achieving reductions of 3.62 log CFU/mL for S. aureus in 20 min and 5.13 log CFU/mL for E. coli in 8 min. The results revealed membrane damage in both S. aureus and E. coli, with leakage of intracellular proteins and nucleic acids, decreased membrane protein content, and cellular shrinkage and collapse observed morphologically. Increased MDA content indicated membrane lipid peroxidation, while elevated intracellular H₂O₂ and ROS levels resulted from oxidative stress induced by PAW’s reactive species. Tannic acid reduced SOD and CAT enzyme activities, impairing bacterial antioxidant capacity, and PAW further exacerbated the decline in SOD and CAT activities, intensifying oxidative stress and disrupting bacterial physiological balance. In strawberry preservation applications, the combined treatment reduced surface microbial loads, decreased mold incidence and weight loss, slowed the deterioration of color, firmness, and edible quality, and enhanced antioxidant capacity. The results suggest that the tannic acid–PAW combined treatment offers a promising strategy for enhancing microbial safety and extending the shelf life of strawberries. Full article

The browning of fruit juices and nectars is a common issue in the beverage industry and is a particular problem in strawberry nectars, where it significantly reduces the shelf-life. Polyphenol oxidases (PPOs), which are multicopper enzymes responsible for the oxidation of a wide plethora of polyphenols in plants, have been widely assumed to be involved in the enzymatic browning of strawberry nectar. To investigate the possible involvement of PPOs, the substrate specificity of four recombinant PPOs and their gene expression pattern in 10 cultivars of Fragaria × ananassa at five ripening stages were determined. This allowed us to obtain adequate amounts of enzymes to study them independently and without interfering matrix effects. All four PPOs possess monophenolase activity, which was particularly high for PPO4. PPO3 did not show sufficient stability for the kinetic studies. The other three showed a high preference for the flavan 3-ol catechin with a 2-fold higher catalytic efficiency compared to dopamine for PPO1 and PPO2. At a neutral pH, they also showed activity with cyanidin but not with pelargonidin, which is the prevalent anthocyanidin type in strawberry. The enzymes showed a high affinity but only low turnover rates for the dihydrochalcone phloretin, resulting in an inhibitory effect that was strong enough to extend the shelf-life of the strawberry nectar by one week if phloretin was added in high concentrations (600 µM). PPO1 and PPO2 were prevalently expressed in all fruit stages. The gene expression of the four PPOs did not correlate with the color stability of the nectars of the 10 varieties and also showed a random expression pattern during fruit development. The limited activity in acidic conditions and the low substrate specificity for pelargonidin does not point to a crucial role for PPOs in the browning of strawberry nectar, but the high catalytic efficiency with catechin as a substrate could contribute to anthocyanin degradation via mechanisms such as copolymerization. Full article

Strawberries face marketing challenges due to their short post-harvest shelf-life, largely impacted by shrivelling, weight loss, fungal decay, and mechanical damage. Neem oil (NO) is known for its shelf-life extension benefits; however, encapsulation is needed to maintain its efficacy. This study aimed to stabilize and encapsulate NO in a polymeric and lipid material to preserve the quality of strawberries stored at 4 ± 1 °C, 80 ± 2% RH for seven days. After seven days, the nanoparticle-coated fruits showed a weight loss of around 5.9% with niosomes and 8.9% with starch nanoparticles, while the control had a significant 32.45% weight loss. Additionally, both nanoparticle coatings significantly (p < 0.05) preserved fruit colour compared to the untreated control. The findings suggest that nanoparticle coatings could serve as an active agent in preserving the quality of strawberries within the food supply chain. The study provides valuable insights into post-harvest management and fruit preservation, showcasing the effectiveness of these coatings as active packaging solutions. Full article

Background/Objectives: Strawberries (Fragaria × ananassa) are among the most commonly consumed fruits due to their taste and nutritional benefits. However, their high rate of spoilage poses a major problem during the period from harvest and transport to further processing or marketing. The aim of this study was, therefore, to investigate the effects of passive modified atmosphere packaging on the metabolome and shelf life of strawberries as a more sustainable alternative compared to standard market storage conditions. Methods: A total of 99 strawberry samples were analyzed for microbial viable counts, water content, and metabolomic changes using non-targeted low-resolution near-infrared spectroscopy, high-resolution mass spectrometry, and microbial culture-based methods. Results: Using near-infrared spectroscopy as a rapid screening method, the linear regression model indicated that strawberries stored under modified atmosphere packaging conditions had a longer shelf life. Furthermore, lipidomic analysis using mass spectrometry showed that the levels of spoilage biomarkers, such as oxidized phosphatidylcholines and lysophosphatidylcholines, were increased under common market storage conditions without a controlled atmosphere. In contrast, the levels of these metabolites were reduced when strawberries were stored in modified atmosphere packaging. Moreover, the strawberries stored under modified atmosphere packaging had a lower number of bacteria, yeasts, and molds as well as a lower water loss throughout the entire storage period. Conclusions: Overall, the study highlights the potential of passive modified atmosphere packaging films to extend the shelf life and thus maintain the edibility of strawberries over a longer period. Full article