Blood oranges maintain bioactive compounds and nutritional quality by postharvest treatments with γ-minobutyric acid, methyl jasmonate or methyl salicylate during cold storage

The effects of postharvest treatments with γ-aminobutyric acid (GABA), methyl jasmonate (MeJA) or methyl salicylate (MeSA) on antioxidant systems and sensory quality of blood oranges during cold storage were evaluated (150 days at 3 °C plus 2 days at 20 °C, shelf life). Fruit firmness, titratable acidity (TA), total antioxidant activity (TAA) and ascorbic acid (AA) decreased during cold storage, all these changes being delayed in treated fruit, with the greatest differences observed with the 50 μmol L−1 MeJA and 100 μmol L−1 MeSA treatments. Total phenolic content (TPC), total anthocyanin content (TAC) and the major individual anthocyanins, cyanidin 3-glucoside and cyanidin 3-(6″-malonylglucoside), were found at higher concentration in treated fruit than in control during the whole cold storage period. Overall, 100 μmol L−1 MeSA was the most effective for maintaining fruit quality and maintained higher anthocyanin concentration due to higher phenylalanine ammonialyase (PAL) and lower polyphenol oxidase (PPO) activities

In vitro activity of some essential oils against Penicillium digitatum

Natural plant essential oils (EOs) can be used instead of synthetic fungicides because of human health concerns and environmental protection. In this study, the in vitro activity of some plants EOs against Penicillium digitatum, the cause of citrus green mold was evaluated during 8 days of incubation at 25°C. The EOs extracted from sweet orange (Citrus sinensis), lemon (Citrus limon), lime (Citrus aurantifolia), and sour orange (Citrus aurantium) fruit peel (500, 1000 and 2000 µl l-1 concentrations), cinnamon (Cinnamomum cassia) bark and summer savory (Satureja hortensis) aerial parts (400, 500 and 600 µl l-1 concentrations) were used on Penicillium digitatum mycelium. None of the EOs extracted from tested citrus in this study could inhibit mycelial growth completely even at concentration of 2000 µl l-1. The best results were obtained with cinnamon and summer savory EOs at concentration of 500 and 600 µl l-1. So, based on the results, cinnamon and summer savory EOs can be ideal candidates to replace the synthetic fungicides to control postharvest green mold of citrus fruit. GC-MS analysis showed that the most abundant of all constituents in EO extracts were carvacrol and γ-terpinene in summer savory and (E)-cinnamaldehyde in cinnamon

Postharvest nitric oxide treatment of persimmon (

Introduction. The effects of nitric oxide (NO) on postharvest ripening of persimmon were investigated. Materials and methods. Fruit were dipped for 30 min in 1.0 and 1.5 mM sodium nitroprusside (SNP), a nitric oxide donor, and stored at 1 °C and 90% relative humidity for 56 days. Changes in total antioxidant activity, total phenol compounds, color, firmness, soluble tannins and weight loss were evaluated. Results and discussion. The results showed that fruit ripening was significantly delayed by SNP. Application of 1.0 and 1.5 mM SNP delayed weight loss and retained greater total antioxidant activity, total phenolic compounds and firmness compared to the control treatments. No significant differences were observed between the two concentrations of SNP. Conclusion. These results demonstrated that postharvest NO application has potential to delay ripening and maintain quality of harvested persimmon fruit

Fortification of Chlorella vulgaris with citrus peel amino acid for improvement biomass and protein quality

The amino acid extract (protein hydrolysate) from various citrus peels was employed as an organic nutrition source for the culture of Chlorella to investigate their effects on the biomass and protein quality of the microalgae. The major amino acids in citrus peels included proline, asparagine, aspartate, alanine, serine, and arginine. The most plentiful amino acids in the Chlorella were alanine, glutamic acid, aspartic acid, glycine, serine, threonine, leucine, proline, lysine, and arginine. Adding the citrus peel amino acid extracts to the Chlorella medium enhanced overall microalgal biomass (more than two folds p  0.05). The present research shows that citrus peels have good nutritional quality and could be used for the inexpensive cultivation of Chlorella biomass with potential utility for food application

A combination of modified atmosphere packaging and two chemical disinfectants: Effects on microbial, sensory, and physicochemical properties of raw ready-to-eat leek

In the present study, the effect of modified atmosphere packaging (MAP) on microbial (total aerobic count, yeasts and molds, Enterobacteriaceae, psychrotrophic bacteria, and lactic acid bacteria), physicochemical (pH, moisture content, and color), and sensory properties of raw ready-to-eat leek was investigated after disinfection using Percidin–Nanosil disinfectants. There were six different treatments, of which four samples were packaged as MAP (T1 to T4) and two samples were packaged as non-MAP (T5 and T6). The highest and the lowest reduction in the number of microorganisms after disinfection was observed in psychrotrophic bacteria and total aerobic count, respectively. The count of microbial variables in T2 sample (87% N2, 3% CO2, and 10% O2) was lower than in other treatments. No significant difference was observed in the physcochemical properties (moisture and pH) of treated samples except for the color of T6 sample (cling film) compared to other treatments (p < .05). It is noteworthy that the panelists did not recognize differences among T1, T2, and T5 samples. However, T2 treatment was effective in maintaining microbial, physicochemical, and sensory properties of leek compared to the other treatments. Also, T6 sample showed the lowest quality in all parameters. Disinfection combined with MAP was able to maintain the physicochemical, microbial, and sensory properties of raw ready-to-eat leek during storage

Potential Role of Foliar Application of Azotobacter on Growth, Nutritional Value and Quality of Lettuce under Different Nitrogen Levels

Vegetables can be treated with biofertilizers as an alternative to chemical fertilizers because of their low toxicity. We investigated the effects of foliar spraying of Azotobacter under different levels of nitrogen (100, 150 and 200 mg/L in nutrient solution) on the growth, nutritional value, nitrate accumulation and antioxidant enzyme activities of hydroponically grown lettuce. The experiment was laid out in a completely randomized design with four replicates in a factorial combination. Plants treated with Azotobacter and 200 mg/L nitrogen had greater leaf area and photosynthetic pigments than plants treated with 200 mg/L nitrogen without spraying with Azotobacter. Increasing nitrogen levels increased leaf number, fresh and dry weights, leaf area and nitrate accumulation in lettuce plants. Peroxidase (POD) activity increased by 95.4% at a nitrogen level of 200 mg/L compared to a nitrogen level of 100 mg/L. Ascorbate peroxidase (APX) activity and leaf phosphorous (P) and potassium (K) concentrations were the highest in plants treated with a nitrogen source of 100 mg/L without foliar application of Azotobacter. As nitrogen levels increased in all treatments, nitrate reductase (NR) activity decreased and reached a minimum at the 200 mg/L nitrogen level. In general, foliar application of Azotobacter sp. can be used to promote plant growth and reduce nitrate accumulation in lettuce

Postharvest treatments with γ

BACKGROUND: Blood orange is sensitive to chilling injury (CI) depending on cultivar and storage temperature. Postharvest treatments with -aminobutyric acid (GABA), methyl jasmonate (MeJA), or methyl salicylate (MeSA) are known to alleviate CI. -Aminobutyric acid aqueous solution, applied at 20 and 40mM, was vacuum-infiltrated at 30 kPa for 8min at 20 ∘C. Methyl jasmonate orMeSA vapor treatmentswere applied separately at 50 and 100 Mby putting the fruit in 20 L plastic containers for 18 h at 20 ∘C. There have been no reports about postharvest treatments of GABA, MeJA, orMeSA on enhancing the tolerance of ‘Moro’ blood orange to chilling during long-term cold storage at 3 ∘C for 150 days, which was the subject of this study. RESULTS: All treatments significantly alleviated CI symptoms of blood orange manifested by lower electrolyte leakage (EL), malondialdehyde (MDA), hydrogen peroxide (H2O2) concentrations, and higher proline content in flavedo during storage. The largest effects were obtained with 100, 50 M, and 40mM for MeSA, MeJA, and GABA, respectively, which enhanced the activity of the antioxidant enzymes catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD), and phenylalanine ammonia-lyase (PAL).On the other hand, these treatments suppressed peroxidase (POD) and polyphenol oxidase (PPO) activities. CONCLUSION: The mechanisms involved in enhancing the tolerance of ‘Moro’ blood orange to chilling could involve scavenging H2O2 by increasing the activity of antioxidant enzymes, higher PAL/PPO activity ratio, and osmoregulation by increasing proline content. These changes led to themaintenance of the epidermis structure. Thiswas confirmed by scanning electron microscopy (SEM)micrograph

Improving Formaldehyde Removal from Water and Wastewater by Fenton, Photo-Fenton and Ozonation/Fenton Processes through Optimization and Modeling

This study aimed to assess, optimize and model the efficiencies of Fenton, photo-Fenton and ozonation/Fenton processes in formaldehyde elimination from water and wastewater using the response surface methodology (RSM) and artificial neural network (ANN). A sensitivity analysis was used to determine the importance of the independent variables. The influences of different variables, including H2O2 concentration, initial formaldehyde concentration, Fe dosage, pH, contact time, UV and ozonation, on formaldehyde removal efficiency were studied. The optimized Fenton process demonstrated 75% formaldehyde removal from water. The best performance with 80% formaldehyde removal from wastewater was achieved using the combined ozonation/Fenton process. The developed ANN model demonstrated better adequacy and goodness of fit with a R2 of 0.9454 than the RSM model with a R2 of 0. 9186. The sensitivity analysis showed pH as the most important factor (31%) affecting the Fenton process, followed by the H2O2 concentration (23%), Fe dosage (21%), contact time (14%) and formaldehyde concentration (12%). The findings demonstrated that these treatment processes and models are important tools for formaldehyde elimination from wastewater

The ameliorative effects of spermidine and calcium chloride on chilling injury in pomegranate fruits after long-term storage

Introduction. Pomegranate fruits (Punica granatum L.) are chilling-sensitive crops. Materials and methods. Pomegranate fruits were treated with calcium chloride and spermidine, alone or in combination, by normal dip and vacuum infiltration methods. The treated fruits were stored at 2 °C for 4 months. At the end of the storage period, samples were held for 3 days at 20 °C, then the qualitative constituents were evaluated. Results and discussion. Treated fruits exhibited less weight loss and higher juice content than control fruits. Non-treated fruits developed chilling injury manifested as an increase in K+ leakage and polyphenol oxidase activity. Calcium chloride and spermidine treatments resulted in lower soluble solid content, but some fruits showed higher titratable acidity. All treatments significantly increased ascorbic acid content. The pH of aril juice in treated fruits was lower than that of non-treated fruits, probably due to higher titratable acidity. Total antioxidant activity and total phenolic content increased in treated fruits. In our study, a correlation was observed between total phenolic content and total antioxidant activity. Conclusion. The treatments applied in our experiments maintained overall quality of pomegranate fruits during long-term storage. Postharvest application of calcium and spermidine either alone or in combination could ameliorate adverse effects of low temperature on pomegranate fruit quality during cold storage. Vacuum infiltration was as effective as the normal dip method. However, normal dip is a simpler and faster treatment method