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.

Ozone Gas for Low Cost and Environmentally Friendly Desulfurization of Mute Grape Must.

Ozone is widely used for storage and processing facilities and food sanitization. In this research, ozone was tested as an alternative to high temperature vacuum must desulfurization in order to make a more sustainable process. Bubbling ozone in highly sulfited red must (mute must) at two treatment temperatures, a significant reduction in total and free sulfites from around 1000 mg/L to 200 and 120 mg/L at 20 and 10 °C, respectively, was observed in 24 h, but already after 4 h the concentration was halved. Air flushing of the mute must did not reduce the SO2 content. To evaluate the potential ozone effect on polyphenol oxidation, we carried out the ozone treatment on a water solution with tannins, ascorbic acid, or potassium metabisulfite (MBK) as single and as mixture. In 1 h, 2/3 of sulfite disappeared with the treatment, but the reduction was greater with ascorbate and tannins; the same was observed for ascorbate, whereas tannins decreased to a lesser extent when combined with ascorbate and MBK. Taken together, the results indicate that ozone could be an environmentally friendly, low cost, treatment for desulfurization, especially for white must, and is also easy to use by small wineries.

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.

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.

Using UAV-based remote sensing to assess grapevine canopy damage due to fire smoke.

BACKGROUND: Bushfires are becoming an increasing issue for the wine sector due to grape and vine losses and smoke taint in wine. Smoke affects vine physiology and the smoke's volatile phenols are absorbed by plants and berries, contaminating the wine. Our hypothesis was that, for the first time, unmanned aerial vehicle (UAV)-based visible images can be used to study the physiology of smoke-affected vines and to assess compromised vines. RESULTS: Procanico vines were exposed to two smoke treatments, a week apart. Gas exchanges and leaf biochemical traits were measured in the short term (30 min after smoke exposure) and in the long term (24 h after smoke exposure). Canopy damage was assessed with conventional vegetation indices (VIs) and by an innovative index derived by UAV-based visible images, the Canopy Area Health Index (CAHI). Gas exchange showed a reduction after the first smoke exposure, but the vines recovered within 24 h. The second smoke exposure led to an irreversible reduction in functional parameters. The VIs exhibited significant differences and CAHI presented a damage gradient related to bushfire nearby. CONCLUSION: The vineyard damage assessment by UAV-based visible images may represent a tool to study the physiological activity of smoke-affected vines and to quantify the loss of destroyed or damaged vines. © 2020 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, ß-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.

Methyl jasmonate and ozone affect the antioxidant system and the quality of wine grape during postharvest partial dehydration.

Postharvest partial dehydration is a technique used in the production of important dry and sweet wines in Italy. An accurate management of the dehydration environmental parameters allows for the modulation of berry metabolism and the maintenance/improvement of the enochemical quality of grapes. As it is known that water loss induces oxidative processes in berries, our hypothesis was that methyl jasmonate (MeJA) and ozone (O3), as postharvest treatments before partial dehydration, might be beneficial for grape berry quality. Grape bunches were postharvest treated with 10 or 100 µM MeJA at 20 °C or with ozone gas at 10 °C, in 70% relative humidity (RH) and air flow, for 12 h; the control bunches were untreated and kept at 20 °C for 12 h. Subsequently, partial dehydration was performed at 10 °C until a 30% weight loss (w.l.) was reached. MeJA hastened grape berry water loss. Polyphenol and flavonoid contents at the end of the partial dehydration were lower in the MeJA-treated berries than in the control and ozone samples. Superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and guaiacol peroxidase (GPX) activity rates increased in the treated samples. In contrast, lipoxygenase (LOX) and polyphenoloxidase (PPO) had lower activities in the MeJA-treated samples than in the controls. It would seem that MeJA accelerates grape water loss but at the same time activates the antioxidant system. Ozone does not accelerate grape water loss but induces the antioxidant system and increases polyphenol content.