Aqueous Ozone Treatment Research Articles

Green synthesis of starch/chitosan complex via ozone-mediated Schiff reaction: Structure, thermal behaviors and surface properties

Ozone was used as a green and environmentally friendly initiator to directly induce a Schiff base cross-linking reaction between chitosan and waxy rice starch (CS) in the present investigation. The effects of oxidation on the structure of chitosan/starch bio-based composite, along with the cross-linked structure formation via Schiff base reaction, were investigated and confirmed using FTIR, XRD, and XPS characterization techniques. The formation of new bonds (C=N) along with other attributes imparted by the cross-linking reaction were evaluated and characterized. Notably, the ozone-induced cross-linking reaction significantly altered the water retention capabilities of CS, especially in the case of aqueous ozone treatment, which significantly improved its swelling power, water holding capacities, and water adsorption. Additionally, aqueous ozone treatment facilitated the formation and stabilization of the gel network. Gaseous ozone in dry state proved more effective in promoting the formation of CN groups, leading to enhanced surface hydrophobicity, while aqueous ozone offered better oxidation uniformity for the coexistence system of chitosan and starch. This work provides a novel and environmentally friendly approach for fabricating the chitosan/starch chemically cross-linking materials through ozone-induced direct Schiff base reaction, which simplifies the preparation process of the complex and minimizing the utilization of solvents.

Aqueous ozone effects on wheat gluten: Yield, structure, and rheology.

This study investigates the impact of aqueous ozone (AO) on the yield, molecular structure, and rheological properties of wheat gluten separated using the batter procedure. Employing strong gluten flour (SGF) and weak gluten flour (WGF), we demonstrate that AO pretreatment significantly enhances the yield and purity of separated starch and gluten. Surface hydrophobicity, free sulfhydryl groups, Fourier transform infrared spectroscopy (FTIR), Raman, and size exclusion-high-performance liquid chromatography (SE-HPLC) analyses were used to evaluate the effects of AO on the molecular structure of gluten. Our analysis reveals that low concentrations of AO induce specific modifications in gluten proteins. AO treatment increases cross-linking in glutenin macropolymer (GMP), reduces surface hydrophobicity, and stabilizes secondary and tertiary structures. These changes include an increase in β-sheet content by approximately 9% and a corresponding decrease in β-turn structures, leading to enhanced viscoelastic properties of the gluten. The research highlights AO's potential as a sustainable and efficient agent in wheat flour processing, offering advancements in both product quality and eco-friendly processing techniques. Future research should optimize AO treatment parameters and explore its effects on different cereal types further to enhance its applicability and benefits in food processing. PRACTICAL APPLICATION: Our work substantially advances the existing knowledge on wheat flour processing by demonstrating the multifaceted benefits of AO pretreatment. We unveil significant improvements in the yield and purity of starch and gluten when compared to conventional separation methods. Moreover, our in-depth analysis of molecular changes induced by AO, including increased cross-linking, alterations in surface hydrophobicity, and modifications in glutenin macropolymer content, provides new insights into how AO affects the viscoelastic properties of gluten. This contribution is pivotal for the development of more efficient, sustainable, and eco-friendly wheat flour processing technologies.

Examining the response of Botrytis cinerea to aqueous ozone: inactivation kinetics, structure, physiology, and growth in different strawberries cultivars

ABSTRACT This work aimed to study the kinetics and mechanisms of Botrytis cinerea conidia inactivation by aqueous ozone treatments (2.5 ± 0.8 mg O3 L−1 and 4.2 ± 0.2 mg O3 L−1, 0.5–16 min), using conventional plate count technique, flow cytometry analysis (FCM), and transmission electron microscopy (TEM). The effect of treatments on the mold incidence on two artificially contaminated strawberries cultivars over refrigerated storage (6 ± 1 °C) was also investigated. The inactivation pattern of B. cinerea conidial suspensions depended on initial level of the microorganism, dissolved ozone concentration and treatment time. Non-linear survival curves were obtained and fitted successfully with the Weibullian model. FCM and TEM analysis revealed alterations in the physiological state and ultrastructure of ozonated conidia that depended on the ozone dose. Ozonation (4.4 mg O3L−1, 5–10 min) reduced B. cinerea incidence throughout storage in strawberries of cv. Fortuna, but no effect was found in cv. Aroma.

Innovative Frontiers: Advancing Technologies for Pesticide Elimination in Grape Seeds

Grape seeds, a valuable by-product of winemaking, are rich in bioactive compounds with significant economic potential. However, pesticide residues in grape seeds pose risks to human health and product quality. This study explores innovative technologies including cold plasma, ultrasound, aqueous ozone, and gaseous ozone to eliminate pesticide residues from grape seeds. Cold plasma treatment emerged as highly effective, completely eliminating certain pesticides like Triadimenol and Azoxystrobin. Ultrasound treatment also showed promising results, particularly in reducing Pyrimethanil residues. Aqueous ozone treatment achieved moderate reductions, while gaseous ozone exhibited the least efficacy. Factors influencing efficacy included pesticide type, treatment duration, and matrix characteristics. Future research should focus on optimizing parameters to enhance pesticide removal while minimizing impacts on product quality. These findings underscore the importance of tailored approaches for pesticide elimination, contributing to safer agricultural practices and consumer health

Effect of aqueous ozone treatment on the reduction of chlorpyrifos and physicochemical and microbial qualities of cucumber (Cucumis sativusL.): Process modeling and optimization

AbstractA study was conducted at different combinations of ozone concentration (50%–100%) and time (10–30 min) to study the effect of aqueous ozone treatment on chlorpyrifos degradation in cucumber. A process was developed and compared using ANN‐GA and RSM techniques. The optimum conditions obtained using RSM were ozone concentration of 95% and treatment time of 10 min. While the optimum conditions achieved by ANN‐GA were ozone concentration of 81% and treatment time of 14 min. However, chlorpyrifos degradation is more at the condition optimized by ANN compared to the condition optimized by RSM. At the optimum condition, the cucumber showed superior physicochemical and microbial qualities, including pesticide degradation (91.08%), color change (3.58), firmness (11.75 N), moisture content (97.49%), water activity (0.93), pH (6.18), titratable acidity (0.06%), total soluble solids (2.1 °Brix), total plate count (1.5 × 105 CFU/g), and yeast/mold count (3 × 105 CFU/g), respectively.Practical applicationsIncreased awareness of the health benefits associated with the consumption of fruits and vegetables has led to a rise in their consumption. These items are primarily consumed in their raw or fresh state and often feature in salads. However, the presence of pesticide residues on the surface of raw fruits and vegetables can pose significant health risks to consumers. Ozone treatment can be used for effectively removing pesticide residue in the fresh‐cut fruits and vegetables industry. Also, ozone treatment can reduce the microbial count on the surface of fruits and vegetables which enhances the shelf life of fruits and vegetables. Furthermore, it can prevent the natural ripening process of commodities, thereby increasing the consumer's acceptance. Ozone is considered a safe and eco‐friendly alternative to chemical disinfectants and preservatives. It leaves no chemical residue on the produce and breaks down into oxygen, leaving no harmful byproducts, thereby ensuring safe consumption of the commodity.

Effect of aqueous ozone treatment on some quality changes of vacuum-packed meagre (Argyrosomus regius) fillets

In this study, microbiological, sensory and color changes in vacuum-packed meagre fillets treated with aqueous ozone for different periods of time were investigated. Meagre fillets were treated with ozone for 15 (O-15) and 30 (O-30) minutes and vacuum-packed and stored at +2 °C for 12 days. Control group (C) was not treated with ozone and stored after vacuum packaging. For microbiological changes, Total Mesophilic Aerobic Bacteria (TMAB), Pseudomonas sp., Lactic Acid Bacteria (LAB) and Total Psychrophilic Aerobic Bacteria (TPAB) counts were analyzed. At the end of storage, the highest bacterial counts were found in group C (>7.00 log cfu/g). In ozone-treated samples, Pseudomonas sp. counts did not exceed 7.00 log cfu/g only in the O-30 group. In the sensory evaluation of the samples, it was determined that the total demerit points were 18 points for group C, 16.25 points for O-15 and 14.75 points for O-30 at the end of storage over 30. No significant change was found according to the color results of the samples, but at the end of storage, it was observed that the L value of the ozone-treated samples was higher and the samples had a lighter color. In the conclusion of the results, it was observed that ozone treatment prolonged the shelf life of vacuum-packed meagre fillets for 4 days for the O-30 group compared to control and O-15 group without causing the sensory and color loss.

Effects of aqueous ozone treatment on the nutritional attributes of mango (Mangifera indica L.) fruit juice

The global fruit juice market is expanding alongside the exponentially growing demand for a healthy lifestyle. Fruit juice is a preferred drink among all age groups as it contains numerous essential nutrients that benefit human health. The safety aspects of fruit juice are equally important as its healthy features. The conventional method of thermal pasteurisation has been known to produce fruit juice of inferior quality. Hence, ozone is being considered as an alternative, non-thermal form of pasteurisation. With its strong oxidation potential, ozone exhibits antimicrobial characteristics and produces no toxic by-products. However, for ozone to be successfully adopted by juice producers, the synergistic effects of the composition of fruit juice and ozone treatment must be adequately evaluated. Therefore, the present work subjected various concentrations of Chokanan mango juice (MJ), diluted with distilled water (DW) at 100MJ:0DW, 75MJ:25DW, and 50MJ:50DW to aqueous ozone treatment at different ozone doses. The effects of these treatments on the physicochemical and antioxidant properties of the MJ were evaluated. Ozone was found to be effective in decreasing the pectin methylesterase (PME) activity arising from the de-esterification of the pectin molecules, and increasing the DPPH activity, thereby increasing the juice quality. Significant effects on the total colour difference (ΔE) and total phenolic content (TPC) were observed in proportion to the increases in ozone dose. The colour of the treated MJ was found to be positively correlated with the TPC, while a kinetic study was performed to investigate the proportionality of the colour and TPC degradation. The first-order reaction model fitted well with the degradation patterns of L* and b*, as well as the ΔE of the MJ samples. A significant difference was observed between the degradation rate constant (k-value) for the MJ samples, which suggested that the k-value could have been affected by not only the ozone dose, but also the juice matrix. The present work demonstrated that the composition of fruit juice was an essential intrinsic parameter that must be assessed before adopting ozone as a form of non-thermal pasteurisation to produce fruit juice which is stable in quality, and safe for consumption.

Microbial Inactivation: Gaseous or Aqueous Ozonation?

For decades, ozone has been known to have antimicrobial properties when dissolved or generated in water and when utilized in its gaseous form on different substrates. This property (the ability to be used in air and water) makes it versatile and applicable to different industries. Although the medium of ozonation depends on the specific process requirements, some industries have the inherent flexibility of medium selection. Thus, it is important to evaluate the antimicrobial efficacy in both media at similar concentrations, an endeavor hardly reported in the literature. This study provides insights into ozone’s efficacy in air and water using two Gram-negative bacteria (Escherichia coli NTCC1290 and Pseudomonas aeruginosa NCTC10332), two Gram-positive bacteria (Staphylococcus aureus ATCC25923 and Streptococcus mutans), and two fungi (Candida albicans and Aspergillus fumigatus). For gaseous ozonation, we utilized a custom-made ozone chamber (equipped with ultraviolet lamps), whereas an electrolysis oxygen radical generator was applied for ozone generation in water. During gaseous ozonation, the contaminated substrates (fabric swatches inoculated with bacterial and fungal suspensions) were suspended in the chamber, whereas the swatches were immersed in ozonated water for aqueous ozone treatment. The stability of ozone nanobubbles and their resulting impact on the aqueous disinfection efficiency were studied via dynamic light scattering measurements. It was observed that ozone is more effective in air than in water on all tested organisms except Staphylococcus aureus. The presented findings allow for the adjustment of the treatment conditions (exposure time and concentration) for optimal decontamination, particularly when a certain medium is preferred for ozonation.

Effectiveness of Ozonated Water for Preserving Quality and Extending Storability of Star Ruby Grapefruit

The aim of this study was to explore the impact of aqueous ozone technology on maintaining grapefruit flavor and freshness by minimizing the occurrence of postharvest deterioration. During the 2018 and 2019 seasons, Star Ruby grapefruit fruits were treated with 0.3 and 0.6 ppm aqueous ozone for 5 and 10 min after harvest at water temperatures of 5 °C and 15 °C, respectively. The fruits were stored for 40 days at 8 ± 1 °C with 85–90% relative humidity. The results revealed that all the ozonated water treatments reduced physiological weight loss, disease infection, and decay, as well as providing long-term protection to the fruits throughout storage. The best treatment for preserving the postharvest quality was 0.6 ppm ozonated water at 5 °C for 5 min, which successfully delayed ripening while concurrently preserving the TSS/acid ratios, total phenolics, and antioxidant activity. Overall, aqueous ozone treatment is a promising example of a treatment that is beginning to be utilized on a commercial scale. In accordance with the findings of this study, it can be deduced that aqueous ozone can be used to maintain fruit quality, reduce postharvest diseases, and extend storage life.

Use of aqueous ozone rinsing to improve the disinfection efficacy and shorten the processing time of ultrasound-assisted washing of fresh produce

In minimal processing industry, chlorine is widely used in the disinfection process and ultrasound (US) increases the disinfection efficacy of chlorine and reduces the cross-contamination incidence during washing. Tap water (TW), which has no disinfection effect, is generally used to rinse off sanitizer residues on the surface of disinfected fresh-cut vegetables. In this study, aqueous ozone (AO), a low-cost and residue-free sanitizer, was used to replace TW rinsing in combination with US (28 kHz)–chlorine (free chlorine [FC] at 10 ppm, a concentration recommended for industrial use) for the disinfection of fresh-cut lettuce as a model. US–chlorine (40 s) + 2.0 ppm AO (60 s) treatment resulted in browning spots on lettuce surface at the end of storage. In contrast, US–chlorine (40 s) + 1.0 ppm AO (60 s) did not lead to deterioration of the sensory quality (sensory crispness, color, and flavor) and a change in total color difference, and the activities of browning-related enzymes were significantly lower. Moreover, US–chlorine (40 s) + 1.0 ppm of AO (60 s) treatment led to significantly lower counts of Escherichia coli O157:H7, Salmonella Typhimurium, aerobic mesophilic (AMC), and molds and yeasts (M&Y) on days 0–7 than US–chlorine (60 s) + TW (60 s) and single 1.0 ppm AO (120 s) treatments, suggesting that AO provided an additional disinfection effect over TW, while reducing the overall processing time by 20 s. Cell membrane permeability analysis (alkaline phosphatase, protein, nucleotide, and adenosine triphosphate leakage) showed that the combination with 1.0 ppm AO caused more severe cell membrane damage in E. coli O157:H7 and S. Typhimurium, explaining the higher disinfection efficacy. 16S rRNA sequencing revealed that following US–chlorine (40 s) + 1.0 ppm of AO (60 s) treatment, Massilia and Acinetobacter had higher relative abundances (RAs) on day 7 than after US–chlorine (60 s) + TW (60 s) treatment, whereas the RAs of Escherichia–Shigella was significantly lower, indicating that the former treatment has a superior capacity in maintaining a stable microbial composition. This explains from an ecological point of view why US–chlorine (40 s) + 1.0 ppm of AO (60 s) led to the lowest AMC and M&Y counts during storage. The study results provide evidence that AO has potential as an alternative to TW rinsing to increase the disinfection efficacy of US–chlorine.

Potential of low‐dose aqueous ozone treatment and packaging to extend quality and shelf‐life of green pea pods under cold storage

Appropriate packaging, low temperature and sanitization have immense potential in maintaining postharvest quality of whole green pea pods throughout the supply chain. Untreated green pea pods packed in perforated 38 µm LDPE, 25 µm PP and 25 µm HDPE films were stored at 5, 10, 15°C with 80% ± 5% RH for 12 days. Regular assessment of respiration rates, weight loss, firmness, color change, and biochemical attributes indicated significantly better quality in LDPE bags at 5 ± 1°C with 80% ± 5% RH. The synergistic effect of sanitization using sodium hypochlorite solution (100 ppm/2 min) and aqueous ozone (2 mg L−1/2 min) modified atmosphere packaging (O2:3%–5%, CO2:5%–10%) and low temperature (5°C) on microbial load, weight loss, respiration rate, and total color change was significant at 5% level with a slight change in biochemical attributes along with extended shelf-life of 16 days as compared to 12 days for tap-water washed samples. Novelty impact statement Green pea pods are prone to substantial losses during postharvest handling operations. Sanitization treatments and packaging materials have potential to slow down metabolic activity, reduce rates of respiration and transpiration, prevent induction of spoilage causing bacteria/microorganisms, stimulate the Phenylalanine Ammonia Lyase (PAL) activity, and effectively delay the decay and senescence of vegetables. The present study suggests ozone sanitization, packaging in polymeric pouches and storage under recommended low temperature conditions as promising interventions for retention of the postharvest quality of green pea pods with extended shelf life.

Effect of ozone application on the removal of pesticides from grapes and green bell peppers and changes in their nutraceutical quality

The present study evaluates the efficacy of ozonated water for the removal of pesticide residues in grapes and green bell peppers. Fruit fortified with pesticides (azoxystrobin, chlorothalonil, chlorpyrifos, cypermethrin, hexaconazole and methyl parathion) were subjected to 15 and 30 min aqueous ozone treatment. GC analysis of ozonated fruits showed a 48.67% to 96.95% decrease in pesticide residues of different pesticides. Methyl paraoxon, a toxic degradation product of methyl parathion, was detected in the ozonated water sample. To assess the effect of ozonation on the nutraceutical quality of fruits, the concentrations of eleven polyphenols and ascorbic acid were analyzed. The individual polyphenols showed different trend in 15 and 30 min treatment. Overall, there was an increase in the levels of all the polyphenols in grapes after 30 min ozonation treatment. In peppers, there was a net increase in quercetin, quercetin-3-O-glucoside, rutin and kaempferol in 30 min while other polyphenols were decreased. The ascorbic acid content of both the fruits was decreased by more than 70% upon ozonation. Thus, ozonation treatment was effective in pesticide removal. However, it changed the nutraceutical quality of grapes and green bell peppers.

In-Plant Validation of Novel On-Site Ozone Generation Technology (Bio-Safe) Compared to Lactic Acid Beef Carcasses and Trim Using Natural Microbiota and Salmonella and E. coli O157:H7 Surrogate Enumeration.

The purpose of this study was to evaluate the antimicrobial efficacy of an aqueous ozone (Bio-Safe) treatment and lactic acid solutions on natural microbiota and E. coli O157:H7 and Salmonella surrogates on beef carcasses and trim in a commercial beef processing plant. For every repetition, 40 carcass and 40 trim swabs (500 cm2) were collected. Samples were taken using EZ-ReachTM swabs, and plated into aerobic plate count (APC), coliform, and E. coli PetrifilmTM for enumeration. In addition, a five-strain cocktail (MP-26) of E. coli surrogates was inoculated onto trim. For every trim surrogate repetition, 30 trim pieces were sampled after attachment and after ozone intervention. Samples were diluted and counts were determined using the TEMPO® system for E. coli enumeration. Ozone and lactic acid interventions significantly reduced (p < 0.003) bacterial counts in carcasses and trim samples. Moreover, lactic acid further reduced APC and coliforms in trim samples compared to ozone intervention (p < 0.009). In the surrogate trials, ozone significantly reduced (p < 0.001) surrogate concentration. Historical data from the plant revealed a reduction (p < 0.001) of presumptive E. coli O157:H7 in trim after a full year of ozone intervention implementation. The novel technology for ozone generation and application as an antimicrobial can become an alternative option that may also act synergistically with existing interventions, minimizing the risk of pathogens such as Salmonella and E. coli O157:H7.

Evaluation of the toxicity and chemical alterations of deoxynivalenol degradation products under ozone treatment

Here, we studied the ozonolysis of deoxynivalenol (DON) in saturated aqueous ozone. We found that ozone can play an important role in the oxidation and degradation of DON. The reaction reached its peak within 5 min of treatment, and the degradation rate was approximately 70%. Toxicity analysis (CCK-8 analysis, ROS analysis, and apoptosis analysis) revealed that DON and saturated aqueous ozone treatments did not significantly change the toxicity of degradation products, and both could induce a decrease in the viability of A549 cells. The results of the metabolomics and cytotoxicity analysis were consistent. We used the Q Exactive Focus high-resolution liquid chromatography-mass spectrometry system to identify degradation products. Among the four identified degradation products, only the epoxy groups at the C12, C13 positions of C15H20O9 were opened. Because the epoxy groups at the C12, C13 positions in most degradation products were not opened based on the toxicity mechanism of DON, the toxicity of DON was not significantly reduced.

Effects of aqueous ozone treatment on microbial growth, quality, and pesticide residue of fresh-cut cabbage.

The influence of aqueous ozone (1.4 mg/L) treatment for 1, 5, and 10 min on the microbial growth and quality attributes of fresh‐cut cabbage during storage at 4°C for 12 days was evaluated. The pesticide residue removal effect of aqueous ozone treatment for 5 min was also determined. The results show that the growth rates of aerobic bacteria, coliforms, and yeasts were significantly inhibited (p < .05) by aqueous ozone treatment during storage; treatment for 10 min showed the greatest inactivation of bacteria, coliforms, and molds. Aqueous ozone stimulated initial respiratory metabolism compared with that of the control. Aqueous ozone treatments reduced ethylene production and improved the overall quality of fresh‐cut cabbage. In addition, the effect of aqueous ozone treatment for 5 min on the removal of trichlorfon, chlorpyrifos, methomyl, dichlorvos, and omethoate from fresh‐cut cabbage was greater (p < .05) than that of the control. These results indicate that aqueous ozone treatment for 5 min could be an economic and effective method to remove pesticide residues and enhance the storability of fresh‐cut cabbage.

Aqueous ozone treatment inhibited degradation of cellwall polysaccharides in fresh-cut apple during cold storage

The effects of aqueous ozone (AO) treatment on the firmness, cellwall polysaccharide content, enzymatic activity, and gene expression of cell wall-degrading enzymes were investigated in fresh-cut apple during cold storage. AO treatment (1.4 mg L−1 for 5 min) delayed degradation of cellwall polysaccharides to reduce softening of fresh-cut apple. Water-soluble pectin content increased more slowly, while protopectin content, 4% KOH-soluble fraction, and cellulose content decreased at a lower rate in AO-treated fresh-cut apple compared with the control. However, no significant influence was shown on the 24% KOH-soluble fraction. AO treatment promoted increased pectin methylesterase activity, and distinctly inhibited β-galactosidase and α-arabinofuranosidase activities during storage. Polygalacturonase activity was not affected by AO treatment. Meanwhile, AO maintained the intactness of cell walls through repression of Mdβ-Gal and Mdα-Af transcript levels, thereby preserving the textural quality of fresh-cut apple during cold storage.

Ozone washing decreases strawberry susceptibility to Botrytis cinerea while maintaining antioxidant, optical and sensory quality

This work aimed to evaluate the effect of ozone washing (maximum concentration 3.5 mgL-1- 5 and 15 min) on Botrytis cinerea decay, physicochemical parameters, bioactive compounds, in vitro and in vivo antioxidant activity, and sensory properties of strawberries cv. Albion throughout refrigerated storage at 5 ± 1 °C. A 5 min long ozonation delayed the onset of B. cinerea infection by 4 days, and significantly reduced its incidence as storage progressed (~17 % lesser than in control at day 8), without impairing physicochemical parameters or sensory quality. This treatment did not affect the antioxidant activity of strawberry extracts neither in in vitro (ORAC and ABTS assays) or in vivo assays using Caenorhabditis elegans as a model organism. Higher ozone doses did not achieve greater reduction of B. cinerea decay throughout the storage period. This study demonstrated that exposing strawberries to a 5 min long aqueous ozone treatment could extend their storability at 5 °C.

Sonozonation: Enhancing the antimicrobial efficiency of aqueous ozone washing techniques on cherry tomato.

Ultrasound requires high power and longer treatment times to inactivate microorganisms when compared to ultrasound combined with other technologies. Also, the antimicrobial efficiency of aqueous ozone increases with an increase in its concentration and exposure time, but with a detrimental effect on the quality of the treated food. In this study, the effect of aqueous ozone at low concentration, multi-mode frequency irradiation and their combination on microbial safety and nutritional quality of cherry tomato was investigated. Individual washing with aqueous ozone and mono-mode frequency irradiation resulted in <1 log CFU/g reduction in the spoilage microorganisms, while dual-mode frequency irradiation (DMFI) resulted in higher microbial reduction (1.3-2.6 1 log CFU/g). The combined system (20/40kHz+aqueous ozone) on the other hand, resulted in >3 log CFU/g microbial reduction. The application of DMFI enhanced the antimicrobial efficiency of aqueous ozone without any detrimental effect on the physicochemical properties (except the firmness), bioactive compounds, and antioxidants of the cherry tomato during 21days refrigerated storage. The result obtained indicates the promising substitute to the single washing technique for microbial safety as well as preserving the nutritional quality and enhancing the shelf life of cherry tomato.

Quality Analysis of Chili Treated with Aqueous Ozone Treatment and Improved Transportation and Handling Technology

The objective of this research is to study the reduction of chili postharvest losses (PHL) after implementation of aqueous ozone treatment, perforated packaging and refrigerated transportation in inter-city distribution. The completely randomized design method was used in the research, with five levels of combination treatments of chili: (i) aqueous ozone treatment; refrigerated transportation; (ii) no ozone treatment; refrigerated transportation; (iii) aqueous ozone treatment; non-refrigerated transportation; (iv) no ozone treatment; non-refrigerated transportation; and (v) existing handling practice as a control treatment. The study was conducted on a large scale in order to imitate the practice of local traders when distributing chili to other cities, with three repetitions. Each repetition used 850 kg of chili, which was transported from Magelang District, Central Java to Bogor, West Java (541.5 km), a journey of approximately 15-17 hours. Temperature and relative humidity in the vehicles were monitored and recorded. Quality analysis included decayed/damaged chili and chili with inappropriate harvest age, grouped into four types, namely physical/mechanical, physiological, microbiological, and green chili; color and texture. The quantity parameter was determined by measuring weight loss. It was concluded that the implementation of aqueous ozone treatment and improved transportation handling technology using refrigerated vehicles could reduce the postharvest losses of chili by 60.61%. Quantity loss was reduced from 2.16% to 1.82% and quality loss from 6.70% to 1.68%. Moreover, the color and texture (hardness) of the chili was maintained, showing a preserved freshness, which is an important parameter in chili marketing.

Quality of vacuum packaged beef as affected by aqueous ozone and sodium citrate treatment

ABSTRACT This study was targeted to investigate the effect of the combination of aqueous ozone (AO) and sodium citrate (SC) pretreatment on quality of vacuum packaged beef stored at chilling temperature. The steers were randomly divided into five treatment groups, containing the group C (steers without any treatment), DW (steers pretreated with distilled water), AO, SC and AO+SC. During processing, the parameters included total Viable Count (TVC), total Volatile Basic Nitrogen (TVB-N), pH, meat color, metmyoglobin (Met-Mb), thiobarbituric acid reactive substances (TBArs), Warner–Bratzler shear force (WBSF), and purge loss were measured and compared. Firstly, the TVC in beef steaks of group AO+SC was significantly lower than group AO and SC during the whole storage (P < .05). In addition, the TVB-N values in AO+ SC group were significantly decreased than AO group at the end of storage time. Furthermore, compared with the group only treated by AO, the group AO+SC displayed higher L* (lightness) value, lower a* (redness) value and lower Met-Mb. The values of WBSF and purge loss of group AO+SC was lower than group AO, as well as TBArs. The treatment methods and storage time had significant interactive effects on TVC, TVB-N, pH, L*, Met-Mb, and TBArs (P < .05). The combination treatment of AO and SC showed better effect on inhibiting the microbial growth and decreased the deteriorated effect of AO on beef quality including TBArs, WBSF, and purge loss.