Ethanol treatment improves the sensory quality of cherry tomatoes stored at room temperature

Quantified low voltage electrostatic field: The effects of intensity on cherry tomato preservation and mechanism

Low voltage electrostatic field (LVEF), a novel non-thermal processing technology, shows promise for food preservation. However, the absence of clear definition and quantification of the core concept "low voltage" obstructs the effective application of LVEF. This study assessed the efficiency of various LVEF intensities (100, 200, 300 V) on cherry tomato preservation, revealing significant differences in preservation efficiency. Compared to the control, samples treated with different intensities showed varied reductions in weight loss (6.26-25.45 %), firmness changes (5.17-28.91 %), and decay incidence (47.91-70.89 %). Quantitative analysis elucidated that the differential preservation efficiency may arise from a dose-response relationship between electric field strength and hydrogen peroxide (H2O2) content， identifying an optimal H2O2 content range of 21.18-27.01 mmol kg-1 for the effective preservation of cherry tomatoes under LVEF. These findings highlight the importance of precise LVEF intensity control for effective food preservation and offer insights for developing optimal LVEF treatment intensities for diverse produce.

Preparation and Efficacy of Microemulsion Carvacrol-Based Fruit and Vegetable Cleaner and Its Application on Cherry Tomatoes

Carvacrol, a natural plant compound with antibacterial, antioxidant, and various biological activities, serves as the basis for developing a micro-emulsion fruit and vegetable cleaner. The study found that carvacrol demonstrated a minimum inhibitory concentration (MIC) ranging between 0.25 and 0.5 mg/mL against four foodborne pathogenic bacteria and three spoilage fungi. The formulated cleaner, containing 67 mg/mL of carvacrol, demonstrated superior characteristics (a particle size of 228 nm, an absolute zeta potential of 21.4 mv, and a stability coefficient of 91.2%). Remarkably, the cleaner remained stable when stored at room temperature for at least 3 months. Its efficacy against pesticides ranged from 76% to 91%. The cleaning effectively inhibited microbial colonies and the decay rate of cherry tomatoes during storage at 4 °C. Furthermore, the cleaning treatment was found to minimize changes in color and hardness. Overall, this study provides evidence that a fruit and vegetable cleaner based on carvacrol enhances the safety of the food industry effectively.

AmiRNA Technology Enhances Tomato Disease Resistance by Suppressing Plant-Pathogen Interaction Pathways through Inhibiting TYLCV Replication

Tomato yellow leaf curl virus disease has seriously threatened the quality and yield of tomatoes. In this study, we investigated the role of amiRNA technology in disease resistance in tomatoes (cherry tomato and large-fruited tomato) and analyzed the physiological and molecular mechanisms of disease resistance in transgenic plants. TYLCV contains six functional genes, of which the C1, C2, and V1 genes have more phosphorylation sites and glycosylation sites, and the protein structure is more complex. The virus replication was inhibited, the peroxidation of membrane lipids was reduced, and disease resistance was enhanced in all transgenic cherry tomato (J6) plants in which the C1, C2, and V1 genes were silenced, respectively. Similarly, silencing of the C1 gene enhanced disease resistance in large-fruited tomatoes. In conclusion, amiRNA technology hinders viral replication, leading to reduced activity of the tomato plant-pathogen interaction pathway and weakening tomato-virus interactions, thereby improving disease resistance.

Enzymatic treatment to improve permeability and quality of cherry tomatoes for production of dried products

BACKGROUND

Cherry tomatoes are nutritious and favored by consumers. Processing them into dried cherry tomatoes can prolong their storage life and improve their flavor. The pretreatment of tomato pericarp is crucial for the subsequent processing. However, the traditional physical and chemical treatments of tomato pericarp generally cause nutrient loss and environmental pollution.

RESULTS

In this study, a novel enzymatic method for cherry tomatoes was performed using mixed enzymes containing cutinase, cellulase and pectinase. Results showed that the pericarp permeability of cherry tomatoes was effectively improved due to enzymatic treatment. Changes in the microscopic structure and composition of the cuticle were revealed. After treatment with different concentrations of enzymes, cherry tomatoes exhibited higher pericarp permeability and sensory quality to varying degrees. The lycopene content and total polyphenol content significantly increased 2.4- and 1.45-fold, respectively. In addition, the satisfactory effect of the six-time reuse of enzymes on cherry tomatoes could still reach the same level as the initial effect, which effectively reduced the cost of production.

CONCLUSIONS

This study revealed for the first time that a mixed enzymatic treatment consisting of cutinase, pectinase and cellulase could effectively degrade the cuticle, enhance the pericarp permeability and improve the quality of cherry tomatoes, with the advantages of being mildly controllable and environmentally friendly, providing a new strategy for the processing of dried cherry tomatoes. © 2023 Society of Chemical Industry.

Responses of animals and plants to physiological doses of ethanol: a molecular messenger of hypoxia?

Our viewpoint is that ethanol could act as a molecular messenger in animal and plant organisms under conditions of hypoxia or other stresses and could elicit physiological responses to such conditions. There is evidence that both animal and plant organisms have endogenous levels of ethanol, but reports on the changes induced by this alcohol at physiological levels are sparse. Studies have shown that ethanol has different effects on cell metabolism at low and high concentrations, resembling a hormetic response. Further studies have addressed the potential cellular and molecular mechanisms used by organisms to sense changes in physiological concentrations of ethanol. This article summarizes the possible mechanisms by which ethanol may be sensed, particularly at the cell membrane level. Our analysis shows that current knowledge on this subject is limited. More research is required on the effects of ethanol at very low doses, in plants and animals at both molecular and physiological levels. We believe that further research on this topic could lead to new discoveries in physiology and may even help us understand metabolic adjustments related to climate change. As temperatures rise more frequently, dissolved oxygen levels drop, leading to hypoxic conditions and consequently, an increase in cellular ethanol levels.

Identification and confirmation of key compounds causing cooked off-flavor in heat-treated tomato juice

Cooked off-flavor produced by heat treatment greatly limited the acceptability of commercial tomato juice. To screen and identify the cooked off-flavor compounds, gas chromatography-mass spectrometry-olfactometry (GC-MS-O), aroma extract dilution analysis (AEDA), gas chromatography-mass spectrometry (GC-MS), and odor activity value (OAV) calculation were applied simultaneously. The results showed that there were 17 aroma-active compounds in tomato juice samples. Among them, three newly formed sulfur-containing compounds (dimethyl sulfide, dimethyl trisulfide, and methional) and 1-octen-3-one, which exhibited cooked corn/potato, onion, and mushroom odor, were proved to be responsible for the cooked off-flavor in heat-treated tomato juice (HTJ) by omission experiments and electronic nose analysis. The three newly formed sulfur-containing compounds were further confirmed to be the key compounds responsible for the cooked off-flavor in four different tomato cultivars that were commonly consumed in the market. PRACTICAL APPLICATION: Tomato is one of the most popular vegetables in the world and tomato juice is an important part of the tomato industry. However, the cooked off-flavor of tomato juice after sterilization severely restricts its industrial development. This study analyzed and compared the changes of aroma compounds before and after sterilization, and identified and confirmed the major off-flavor components. This work could provide fundamental information for the prevention of cooked off-flavor.

Effects of Different Treatments on Physicochemical Characteristics of ‘Kyoho’ Grapes during Storage at Low Temperature

Low temperature storage is widely used to maintain the postharvest quality of table grape. However, grape clusters easily undergo deterioration without treatment during the storage time. The main goal of this study was to evaluate the effect of postharvest 1-methylcyclopropene (1-MCP), calcium chloride (1%) and ethanol (16%), and the combination of 1-MCP with calcium chloride and ethanol treatments on maintenance of quality of table grapes ‘Kyoho’ (Vitis vinifera × Vitis labrusca) under 5 °C and 0 °C storage. Changes in decay incidence, weight loss, rachis browning and quality indexes of grape clusters were investigated. The results were as follows: all treatments significantly reduced the decay incidence, weight loss, rachis browning at both low temperatures storage; 1-MCP had positive effect for reducing the decay incidence in early stage, but no effect in late stage; there are no significant variations of taste and color quality indexes under two low temperatures storage, regardless of the treatments. Overall findings suggested that the combination of 1-MCP with calcium chloride and ethanol treatment is suitable for short-term 0 °C storage, while for long-term 0 °C storage, calcium chloride (1%) and ethanol (16%) treatment should be selected.

Rosmarinic Acid Delays Tomato Fruit Ripening by Regulating Ripening-Associated Traits

Fruits are excellent sources of essential vitamins and health-boosting minerals. Recently, regulation of fruit ripening by both internal and external cues for the improvement of fruit quality and shelf life has received considerable attention. Rosmarinic acid (RA) is a kind of natural plant-derived polyphenol, widely used in the drug therapy and food industry due to its distinct physiological functions. However, the role of RA in plant growth and development, especially at the postharvest period of fruits, remains largely unknown. Here, we demonstrated that postharvest RA treatment delayed the ripening in tomato fruits. Exogenous application of RA decreased ripening-associated ethylene production and inhibited the fruit color change from green to red based on the decline in lycopene accumulation. We also found that the degradation of sucrose and malic acid during ripening was significantly suppressed in RA-treated tomato fruits. The results of metabolite profiling showed that RA application promoted the accumulation of multiple amino acids in tomato fruits, such as aspartic acid, serine, tyrosine, and proline. Meanwhile, RA application also strengthened the antioxidant system by increasing both the activity of antioxidant enzymes and the contents of reduced forms of antioxidants. These findings not only unveiled a novel function of RA in fruit ripening, but also indicated an attractive strategy to manage and improve shelf life, flavor, and sensory evolution of tomato fruits.

Biodegradable Food Packaging Materials and Prospects of the Fourth Industrial Revolution for Tomato Fruit and Product Handling

The environment and food safety are major areas of concern influencing the development of biodegradable packaging for partial replacement of petrochemical-based polymers. This review is aimed at updating the recent advances in biodegradable packaging material and the role of virtual technology and nanotechnology in the tomato supply chain. Some of the common biodegradable materials are gelatin, starch, chitosan, cellulose, and polylactic acid. The tensile strength, tear resistance, permeability, degradability, and solubility are some of the properties defining the selection and utilization of food packaging materials. Biodegradable films can be degraded in soil by microbial enzymatic actions and bioassimilation. Nanoparticles are incorporated into blended films to improve the performance of packaging materials. The prospects of the fourth industrial revolution can be realized with the use of virtual platforms such as sensor systems in authentification and traceability of food and packaging products. There is a research gap on the development of a hybrid sensor system unit that can integrate sampling headspace (SHS), detection unit, and data processing of big data for heterogeneous tomato-derived volatiles. Principal component analysis (PCA), linear discriminant analysis (LDA), and artificial neutral network (ANN) are some of the common mathematical models for data interpretation of sensor systems.

Ultrasound improves the decontamination effect of thyme essential oil nanoemulsions against Escherichia coli O157: H7 on cherry tomatoes

Development of novel and effective decontamination technologies to ensure the microbiological safety of fresh produce has gained considerable attention, mainly driven by numerous outbreaks. This work presented the first approach regarding to the application of the previously reported hurdle technologies on the sanitization of artificially contaminated cherry tomatoes. Thyme (Thymus daenensis) essential oil nanoemulsion (TEON, 8.28 nm in diameter with a narrow size distribution) was formulated via ultrasonic nanoemulsification, showing remarkably improved antimicrobial activity against Escherichia coli (E. coli) O157:H7, compared to the coarse emulsion. The antimicrobial effect of ultrasound (US), thyme essential oil nanoemulsion (TEON) and the combination of both treatments was assessed against E. coli O157:H7. The remarkable synergistic effects of the combined treatments were achieved, which decontaminated the E. coli populations by 4.49-6.72 log CFU/g on the surface of cherry tomatoes, and led to a reduction of 4.48-6.94 log CFU/sample of the total inactivation. TEON combined with US were effective in reducing the presence of bacteria in wastewater, which averted the potential detrimental effect of cross-contamination resulted from washing wastewater in fresh produce industry. Moreover, the treatments did not noticeably alter the surface color and firmness of cherry tomatoes. Therefore, ultrasound combined with TEON is a promising and feasible alternative for the reduction of microbiological contaminants, as well as retaining the quality characteristics of cherry tomatoes.

A Combination of Melatonin and Ethanol Treatment Improves Postharvest Quality in Bitter Melon Fruit

Central composite design (CCD), utilized with three independent variables, verified that the optimal treatment conditions in bitter melon fruit were melatonin (MT) concentration of 120 µmol L−1, ethanol concentration of 6%, and immersing time of 10 min. Under optimal conditions, the experimental values of firmness, chilling injury (CI) index, and weight loss were shown as 27.81 N, 65.625%, and 0.815%, respectively. Moreover, the combined effect of MT and ethanol on CI and physiological quality in postharvest bitter melon fruit stored at 4 °C was investigated. It was found that the combined treatment contributed to the reduced CI symptoms and inhibited ion leakage and malondialdehyde (MDA) accumulation. Moreover, higher levels of chlorophyll, total soluble solids (TSSs), soluble sugar, soluble protein, and ascorbic acid (AsA) were observed in comparison with the control group. Furthermore, the synthesis of total phenols and flavonoids in bitter melon was greatly promoted. Therefore, the combination of MT and ethanol could have the potential for alleviating CI and maintaining postharvest quality for the duration of cold storage.