Effects of gaseous ozone treatment on the mite pest control and qualitative properties during ripening storage of pecorino cheese

BACKGROUND

Ripened cheeses, such as pecorino, are susceptible to mites and molds contamination on the crust area that must be removed before the product can be marketed. This study investigates the effectiveness of gaseous ozone treatment in the control of microbiological and mite growth without negatively affecting product quality.

RESULTS

Cheese samples were treated with gaseous ozone at 200 and 300 ppb for 8 h per day (overnight) for 150 days in storage rooms under controlled conditions (12 °C and 85% relative humidity). The results showed that ozone at 200 ppb limits the growth of mites starting from 25 days of storage and significantly reduced bacteria, molds, and yeasts counts starting from 75 days of storage. Concerning the physicochemical and qualitative parameters evaluated during ripening (weight loss, moisture content, dry weight, ash, fat, protein, total nitrogen, color, non-destructive firmness), no significant differences were shown between the control samples and ozone treatment at 200 ppb. Sensory analysis (consumer test) also showed no specific defects with the ozone-treated samples. It was observed that the ozone treatment at 300 ppb had limited microbiological growth and no alteration of sensory aspects but did not have the same positive impact on some aspects of overall quality, compared with ozone treatment at 200 ppb.

CONCLUSION

The use of gaseous ozone treatments during ripening of pecorino cheese can potentially offer an excellent solution for the control of mite growth, while preserving the quality and sensory characteristics of the product. For this reason, this technique could be very useful for commercial purposes. © 2022 Society of Chemical Industry.

The Use of Ozone Technology: An Eco-Friendly Method for the Sanitization of the Dairy Supply Chain

The dairy field has considerable economic relevance in the agri-food system, but also has the need to develop new 'green' supply chain actions to ensure that sustainable products are in line with consumer requirements. In recent years, the dairy farming industry has generally improved in terms of equipment and product performance, but innovation must be linked to traditional product specifications. During cheese ripening, the storage areas and the direct contact of the cheese with the wood must be carefully managed because the proliferation of contaminating microorganisms, parasites, and insects increases significantly and product quality quickly declines, notably from a sensory level. The use of ozone (as gas or as ozonated water) can be effective for sanitizing air, water, and surfaces in contact with food, and its use can also be extended to the treatment of waste and process water. Ozone is easily generated and is eco-sustainable as it tends to disappear in a short time, leaving no residues of ozone. However, its oxidation potential can lead to the peroxidation of cheese polyunsaturated fatty acids. In this review we intend to investigate the use of ozone in the dairy sector, selecting the studies that have been most relevant over the last years.

Post-Harvest Quality Evaluation of “Soreli” Kiwifruit at Two Ripening °Brix Values from Vineyards of Different Age under Hail Nets

The application of anti-hail nets is a practice that has been employed for a long time on different fruit and vegetable cultivations and in different fields of the world. In this work, we checked the effects of shading with white anti-hail nets on the post-harvest quality of “Soreli” kiwifruit collected at two different °Brix (7–8 and 8–9) from vineyards of two different ages (8 and 9 years) and stored at 1 °C for 90 days. It was observed that during the storage, the firmness and color parameters (L*, a*, b*, and Chroma) and the SSC content were generally higher in kiwifruit samples harvested in open field than in those under the nets. Regarding the bioactive compounds, the open field samples showed higher values in total flavonoids content during storage, and the content of carotenoids and chlorophylls in fruits grown in open fields was higher from 30–45 days up to the end of the storage. In contrast, the polyphenols and ascorbic acid values of fruits in open fields and under the nets showed a similar evolution of the values from 45 to 60 days. In general, the early and late harvest time based on the °Brix values and the different ages of the kiwifruit plants under the nets did not affect the quality parameters.

A Review into the Effectiveness of Ozone Technology for Improving the Safety and Preserving the Quality of Fresh-Cut Fruits and Vegetables

In recent years, consumers have become increasingly aware of the nutritional benefits brought by the regular consumption of fresh fruits and vegetables, which reduces the risk of health problems and disease. High-quality raw materials are essential since minimally processed produce is highly perishable and susceptible to quality deterioration. The cutting, peeling, cleaning and packaging processes as well as the biochemical, sensorial and microbial changes that occur on plant tissue surfaces may accelerate produce deterioration. In this regard, biological contamination can be primary, which occurs when the infectious organisms directly contaminate raw materials, and/or by cross-contamination, which occurs during food preparation processes such as washing. Among the many technologies available to extend the shelf life of fresh-cut products, ozone technology has proven to be a highly effective sterilization technique. In this paper, we examine the main studies that have focused on the effects of gaseous ozone and ozonated water treatments on microbial growth and quality retention of fresh-cut fruit and vegetables. The purpose of this scientific literature review is to broaden our knowledge of eco-friendly technologies, such as ozone technology, which extends the shelf life and maintains the quality of fresh produce without emitting hazardous chemicals that negatively affect plant material and the environment.

Time of Postharvest Ethylene Treatments Affects Phenols, Anthocyanins, and Volatile Compounds of Cesanese Red Wine Grape

Red Cesanese wine grapes, picked at around 22–23 °Brix, were treated with gas ethylene (500 mg L⁻¹) for 15, 24, and 36 h, or air at 20 °C and 95–100% relative humidity (R.H.), then analysed for titratable acidity, sugar content, pH, total phenols, total and specific anthocyanins, and volatile compounds. Ethylene treatments increased the polyphenol content from 412 to 505 and 488 mg L⁻¹ (about +23 and +19%) for 15 and 24 h samples, respectively. Anthocyanins were increased by ethylene, mainly for 15 h treatment (about +17%). The 36 h ethylene treatment induced a loss anthocyanins (−14%), while phenols practically returned to the initial content. A high content of ethanol, acetic acid, and ethyl acetate were detected in 36 h ethylene-treated grapes, together with higher isoamyl acetate content, compared to air and other ethylene treatments. C6 compounds, markers of lipids peroxidation, were slightly higher in 36 h ethylene-treated samples than in control. Shorter ethylene treatments did not significantly modify the aroma profile compared to air treatment.

Response of antioxidant system to postharvest ozone treatment in 'Soreli' kiwifruit

BACKGROUND

Among the challenges for postharvest researchers is that of understanding the physiological and biochemical pathways associated with postharvest fruit decay. Fruit senescence directly affects sensorial and nutritional quality during postharvest life. It has been clarified that reactive oxygen species and oxidative damage are responsible for fruit senescence. Some cultivars of yellow-fleshed kiwifruit can be stored for a short period compared with green-fleshed kiwifruit. Postharvest performance is affected by the physiological state of the fruit at harvest, associated with its postharvest management. Among several postharvest applications, ozone treatment is considered as a cost-effective and eco-friendly food-processing technology to preserve the fruits' quality during cold storage. In this study, we investigated the influence of ozone, after gradual cooling treatment, on the antioxidant defense system in Actinidia chinensis, 'Soreli'.

RESULTS

Bioactive compound content decreased during cold storage, and ozone treatment enhanced the activities of superoxide dismutase and catalase during cold storage. This treatment preserved membrane integrity by inhibiting lipoxygenase activity and malondialdehyde accumulation. A multivariate statistical approach, using principal component analysis, provided the global response to the effect of ozone postharvest treatment during cold storage in kiwifruit 'Soreli'.

CONCLUSION

Ozone treatment improves the efficiency of antioxidative system and storability of 'Soreli' kiwifruits. © 2019 Society of Chemical Industry.

Ozone gas as a storage treatment to control Gnomoniopsis castanea, preserving chestnut quality

BACKGROUND

Chestnuts are gluten-free, low-fat, cholesterol-free products. Postharvest decay reduces chestnut shelf life and can cause severe economic losses. In this study we investigated the effect of ozone (O₃ ) gaseous treatment on chestnut rot caused by Gnomoniopsis castanea and the quality parameters of chestnuts.

RESULTS

The results showed that ozone treatment (150 ppb during the day, and 300 ppb during the night) reduced the decay of chestnuts and had a fungistatic effect on isolates of G. castanea. The exposure of chestnuts to ozone did not alter weight losses, sugar content and titratable acidity. The concentration of total phenolics decreased during the storage period, both for treated and untreated nuts. However, after 150 days of treatment the polyphenol content of the chestnuts exposed to ozone was significantly higher than in control nuts.

CONCLUSIONS

Our results suggested that ozone is an appropriate and economical tool to maximize the quality of chestnut shelf life, enabling it to be stored for long periods. © 2019 Society of Chemical Industry.

Effects of ozone postharvest treatment on physicochemical and qualitative traits of Actinidia chinensis 'Soreli' during cold storage

BACKGROUND

Ozone has been used for improving the postharvest life of fruits and vegetables. Ozonation, an alternative decontamination method, can be applied effectively to perishable commodities immediately after harvest. Kiwifruit is a subtropical climacteric fruit that is less able to acclimate and is susceptible to low temperatures. In this study, we investigated the influence of ozone and different storage temperatures on the physico-chemical and qualitative features in Actinidia chinensis 'Soreli'. The fruits were treated with a continuous flow of ozone in air (300 ppb), stored at 2 and 4 °C for 60 days, and sampled every 15 days.

RESULTS

It was found that ozone treatment induced the ripening process; this was evident at the end of the storage, with higher soluble solids content for ozone-treated fruits at 2 and 4 °C. Storage temperatures and gaseous ozone treatment influenced in a different manner the bioactive compounds, such as polyphenols, flavonoids, ascorbic acid, and carotenoids. Additionally, under gaseous ozone storage, microbial growth was delayed, improving the microbial quality index when the fruits were stored at the lowest storage temperature (2 °C). Principal component analysis highlighted that the effects of storage temperature on physico-chemical and bioactive compounds were greater than the postharvest treatment.

CONCLUSION

Storage temperature influenced the postharvest life of 'Soreli'. Storage at 2 °C and under 300 ppb gaseous ozone improved the yellow-fleshed fruit storage life. However, storage at 4 °C under 300 ppb gaseous ozone did not show advantages in preserving the fruit quality. © 2019 Society of Chemical Industry.

Alternating temperature in postharvest cooling treatment of 'Fiano' and 'Falanghina' grapes affects cell wall enzyme rate, berry softening and polyphenols

BACKGROUND

In wine production, temperature control is important and cooling techniques are frequently used to cool down grape must. Grape compound extraction is facilitated by enzymatic cell wall disassembly. Accordingly, our hypothesis is that the use of an alternating temperature could favor enzyme activity and thus berry compound extraction.

RESULTS

White wine grapes (cvs 'Falanghina' and 'Fiano') were kept at 4 °C or at an alternating temperature (4 and 20 °C with a 6-h interval) for 24 h. During the cooling treatment, berry skin resistance, berry firmness and native enzymes from the cell wall were analyzed; sugars, total acidity, malic acid and polyphenols were also measured. In 'Falanghina', α-d-glucosidase, β-d-galactosidase and pectinmethylesterase increased in grape berry kept at an alternating temperature, and the berry firmness decreased and the polyphenol content was greater than in the other sample. In 'Fiano', polygalacturonase and pectinmethylesterase were responsable for berry softening and, overall, with an alternating temperature, the activity was higher and, consequently, sugars and polyphenol contents were higher.

CONCLUSION

Instead of just cooling wine grape, a 24-h cycle of low and high temperature on wine grape after harvest could be used to increase cell wall enzyme activity and, consequently, decrease the berry firmness, favouring an increase in sugars and polyphenol contents. © 2018 Society of Chemical Industry.

Postharvest gaseous ozone treatment enhances quality parameters and delays softening in cantaloupe melon during storage at 6 °C

BACKGROUND

A trial was conducted to evaluate the effect of postharvest gaseous ozone (O₃ ) treatment on quality parameters and cell wall enzymes of cantaloupe melon cv. Caldeo during storage at 6 °C for 13 days. Fruits were kept in cold storage and treated with 0.15 ppm gaseous O₃ during the day and 0.3 ppm overnight; control fruits (CK) were stored in normal atmosphere.

RESULTS

Firmness was higher and ethylene concentration significantly lower in O₃ fruits compared with CK fruits. During storage, microbial counts were lower in both O₃ and CK fruits; from day 9, O₃ fruits showed a significant decrease in mesophilic aerobes. Additionally, total carotenoids had a tendency to be higher, with no significant differences between CK and O₃ fruits. The same trend was observed for ascorbic acid, colour, total soluble solids content and acidity. Finally, O₃ treatment reduced the activities of cell wall enzymes α-arabinopyranosidase, β-galactopyranosidase and polygalacturonase starting from day 3 of storage. Pectin methyl esterase activity did not seem to be affected by O₃ treatment.

CONCLUSION

Gaseous O₃ treatment during cold storage was effective in decreasing ethylene production and delaying fruit softening in cantaloupe melon by extending quality maintenance. © 2017 Society of Chemical Industry.

A comparative study on the effectiveness of ozonated water and peracetic acid in the storability of packaged fresh-cut melon

Ozonated water and peracetic acid were tested as sanitizers to enhance the storability of fresh-cut melon cubes. Sanitizers were also combined with suitable packaging materials (polypropylene and polylactic acid based plastic films). Fresh-cut melon cubes were stored at 4 °C for up to 7 days. Ozonated water and peracetic acid treatments were given by dipping cubes into 0.8 ppm O3 and 100 ppm Tsunami 100™ solutions, respectively, for 3 min. Both sanitizers exhibited efficiency in reducing the total microbial counts on melon cubes (< 2 log CFU g(-1)). Respiratory activity and ethylene production were both affected by the interaction between the sanitizer and the packaging used. Carbon dioxide and oxygen reached 9.89 kPa and 12.20 kPa partial pressures, respectively, using peracetic acid treatment in combination with polypropylene film packaging, consequently developing off-odors starting from day 3. Strong color changes were noted in cubes stored in polylactic acid packaging after 7 days of storage, affecting the sensory quality of the melon cubes. Sensory evaluation (overall visual quality) indicated loss in flavor in the polypropylene packaging. The overall visual quality started to decline on 3rd day because of the development of translucency.Overall, the use of ozone in combination with polypropylene packaging provided the best solution to maintain the quality of melon cubes for up to 5 days of storage at 4 °C.

Ozone fumigation for safety and quality of wine grapes in postharvest dehydration

This paper proposes postharvest ozone fumigation (as a method) to control microorganisms and evaluate the effect on polyphenols, anthocyanins, carotenoids and cell wall enzymes during the grape dehydration for wine production. Pignola grapes were ozone-treated (1.5 g/h) for 18 h (A=shock treatment), then dehydrated or ozone-treated (1.5 g/h) for 18 h and at 0.5 g/h for 4 h each day (B=long-term treatment) during dehydration. Treatment and dehydration were performed at 10 °C. No significant difference was found for total carotenoid, total phenolic and total anthocyanin contents after 18 h of O3 treatment. A significant decrease in phenolic and anthocyanin contents occurred during treatment B. Also carotenoids were affected by B ozone treatment. Pectin methylesterase (PME) and polygalacturonase (PG) activities were higher in A-treated grapes during dehydration. Finally, ozone reduced fungi and yeasts by 50%. Shock ozone fumigation (A treatment) before dehydration can be used to reduce the microbial count during dehydration without affecting polyphenol and carotenoid contents.

Simultaneous application of ethylene and 1-MCP affects banana ripening features during storage

BACKGROUND

In order to avoid the ripening blocking effect of 1-MCP (1-methylcyclopropene) on bananas when applied before ethylene commercial treatment, 1-MCP in combination with 'CD ethylene' (ethylene-cyclodextrin complex) was used in gas formulations: 300 nmol mol(-1) 1-MCP + 1200, 2400 or 4800 nmol mol(-1) ethylene (ETH). Control bananas received 1-MCP alone or 4800 nmol mol(-1) ethylene alone or no treatment. Treatments were done on overseas shipped bananas, at 14 °C, 90% relative humidity (RH), for 16 h; the bananas were stored under the same atmospheric conditions. After 4 or 12 days the bananas were commercially treated with 500 µmol mol(-1) ethylene.

RESULTS

A 300 nmol mol(-1) 1-MCP treatment significantly blocked banana ripening in terms of physiological and technological parameters, inhibiting ethylene production and respiration, despite the commercial ethylene treatment. The application of 300 nmol mol(-1) 1-MCP + 1200 or 2400 nmol mol(-1) ethylene delayed ripening but with a regular pattern. A 300 nmol mol(-1) 1-MCP + 4800 nmol mol(-1) ethylene application did not delay ripening as did 4800 nmol mol(-1) ethylene treatment. The development of black spots was closely associated with advanced ripening/senescence of fruits.

CONCLUSION

The combined 300 nmol mol(-1) 1-MCP + 1200 or 2400 nmol mol(-1) ethylene treatment appears to be a promising treatment to extend banana storage, following overseas shipping.

Temperature and water loss affect ADH activity and gene expression in grape berry during postharvest dehydration

Clusters of Aleatico wine grape were picked at 18°Brix and placed at 10, 20, or 30°C, 45% relative humidity (RH) and 1.5m/s of air flow to dehydrate the berries up to 40% of loss of initial fresh weight. Sampling was done at 0%, 10%, 20%, 30%, and 40% weight loss (wl). ADH (alcohol dehydrogenase) gene expression, enzyme activity, and related metabolites were analysed. At 10°C, acetaldehyde increased rapidly and then declined, while ethanol continued to rise. At 20°C, acetaldehyde and ethanol increased significantly with the same pattern and declined at 40%wl. At 30°C, acetaldehyde did not increase but ethanol increased rapidly already at 10%wl. At the latter temperature, a significant increase in acetic acid and ethyl acetate occurred, while at 10°C their values were low. At 30°C, the ADH activity (ethanol to acetaldehyde direction), increased rapidly but acetaldehyde did not rise because of its oxidation to acetic acid, which increased together with ethyl acetate. At 10°C, the ADH activity increased at 20%wl and continued to rise even at 40%wl, meaning that ethanol oxidation was delayed. At 20°C, the behaviour was intermediate to the other temperatures. The relative expression of the VvAdh2 gene was the highest at 10°C already at 10%wl in a synchrony with the ADH activity, indicating a rapid response likely due to low temperature. The expression subsequently declined. At 20 and 30°C, the expression was lower and increased slightly during dehydration in combination with the ADH activity. This imbalance between gene expression and ADH activity at 10°C, as well as the unexpected expression of the carotenoid cleavage dioxygenase 1 (CCD1) gene, opens the discussion on the stress sensitivity and transcription event during postharvest dehydration, and the importance of carefully monitoring temperature during dehydration.

Salicylic acid induces H2O2 production and endochitinase gene expression but not ethylene biosynthesis in Castanea sativa in vitro model system

Salicylic acid (SA), ethylene (ET), and wounding are all known to influence plant defense response. Experiments attempting to determine SA's relation to ET biosynthesis and defense gene expression have shown conflicting results. To confront this, we developed an in vitro model system to investigate how SA affects ET biosynthesis, hydrogen peroxide (H(2)O(2)) production and endochitinase gene expression in the European chestnut. ET measurements of in vitro shoots indicated a critical time point for SA exogenous application, enabling us to study its effects independent of ET. In addition, ET measurements demonstrated that its own increased biosynthesis was a response to wounding but not to SA treatment. Application of the ET biosynthesis inhibitor, aminoethoxyvinylglycine (AVG), on wounded and SA-treated shoots blocked wounding-induced ET production. Interestingly, SA inhibited ET production, but to a lesser extent than AVG. Additionally, SA also induced the accumulation of endochitinase transcript level. Likewise, a sensitive tissue-print assay showed that SA further increased the level of H(2)O(2). Yet, SA-induced endochitinase gene expression and SA-enhanced H(2)O(2) production levels were independent of ET. The cumulative results indicate that SA acts as an inducer of endochitinase PR gene expression and of H(2)O(2) oxidative burst. This suggests that SA is a component of the signal transduction pathway leading to defense against pathogens in chestnut. Further, the model system developed for this experiment should facilitate the deciphering of defense signaling pathways and their cross-talk. Moreover, it should also benefit the study of trees of long generation time that are known to be recalcitrant to in vitro studies.

Metabolic changes of Malvasia grapes for wine production during postharvest drying

Malvasia (Vitis vinifera L.) grapes were harvested at 17.8% of soluble solids content (SSC) and placed inside an innovative dehydration room where temperature, relative humidity, and air flow were maintained, respectively, at 15 degrees C, 40%, and 1-1.5 m s(-1). Weight loss of bunches reached approximately 33% in 29 days. SSC increased inversely proportionally with the weight decrease, reaching at the end of experiment 23%. Abscisic acid (ABA) increased rapidly from around 29 to 80 microg g(-1) of dry weight at 11.7% of bunch weight loss and then declined gradually. Lipoxygenase (LOX) showed the same behavior as ABA, whereas alcohol dehydrogenase (ADH), read in the way of ethanol oxidation, increased continuously when the weight loss reached approximately 19.5%. In parallel with the activity of LOX, C6 compound [hexanal, hex-1-enol, (E)-hex-2-enal] concentrations reached a peak at 11.7% of weight loss, whereas ethanol and acetaldehyde increased with the increase of ADH and successively decrease and ethyl acetate increased. Proline increased initially as ABA and successively with the increase of ADH, 5.3-fold increase versus 4.2-fold increase of proteins. Postharvest dehydration of Malvasia grapes shows a biphasic pattern: a first metabolic stress response up to 11.7% of bunch weight loss and a second stress response beyond 19.5% of weight loss. The metabolic mechanism of these postharvest water stress responses is discussed.

Effects of exogenous propylene on softening, glycosidase, and pectinmethylesterase activity during postharvest ripening of apricots

Apricots (Prunus armeniaca L. cv. Boccuccia spinosa) picked at the commercial ripening stage [soluble solids content (SSC) 12.6%] were left to reach full ripening in continuously humidified air at 20 degrees C. Changes in the rate of ethylene production, firmness, soluble solids concentration, and titratable acidity were measured. The alpha-D- and beta-D-glucosidases, alpha-L-arabinofuranosidase, alpha-D- and beta-D-galactosidases, beta-D-xylosidase, and alpha-D-mannosidase activities were assayed. To evaluate the influence of ethylene on glycosidase activity, propylene (500 microL x L(-1)) was applied to apricots for 24 and 48 h. In apricots ripened in air, ethylene production increased on the first day and exhibited a typical climacteric pattern. Good edible quality was reached in 5 days when SSC was at least 14% and acidity was between 1.1 and 1.2% (% malic acid). During postharvest ripening, alpha-L-arabinofuranosidase activity increased from 1.9 to 11.6 nkat until day 7. alpha-D-Galactosidase, alpha-D-mannosidase, and beta-D-galactosidase activity increased continuously but at a lower rate. beta-D-Xylosidase activity also increased, but the level of activity was lower than the other glycosidases assayed. Pectinmethylesterase (PME) decreased during the postharvest ripening, and propylene enhanced this pattern, by stimulating ethylene production. Even the activities of alpha-L-arabinofuranosidase, beta-D-xylosidase, alpha-D-mannosidase, and beta-D-galactosidase were greatly stimulated by the propylene treatment, which consequently induced rapid softening of the fruits.