•A. vera (AV) and ascorbic acid (AA) have a synergistic effect on microbial control.•AV and AA combination preserve strawberry bioactive constituent and fruit quality.•AV+AA, specially higher AA ...concentrations, effectively delayed strawberry ripening.
Rapid loss of quality and decay causes economic loss of strawberries after harvest. The effects of an edible coating based on natural Aloe vera (AV) gel in combination with ascorbic acid (AA; 0, 1, 3 and 5% (w/v)) on postharvest quality of strawberries was studied. After treatment, fruit weight loss, firmness, titratable acidity, soluble solids content (SSC), pH value, concentrations of ascorbic acid, anthocyanin and total phenolics, total antioxidant activity, and microbial activity were evaluated at 0, 3, 6, 9, 12, 15 and 18 days of storage (1°C, 95% relative humidity). Compared with untreated fruit, AV+AA treatments delayed weight loss, had higher SSC, vitamin C concentrations and titratable acidity. The coatings reduced total aerobic mesophilic, yeasts and molds populations. AV+5% AA was the most effective in delaying changes in the ripening and reducing microbial populations among the treatments. These results demonstrate that AV and AA coatings have potential to maintain postharvest fruit quality of strawberry fruit.
Low temperature storage causes chilling injury in plum (
L.) fruits. Consequently, any treatments with beneficial effects against these symptoms would achieve attention. For this purpose, ...phenylalanine treatments were applied on 'Stanley' plum fruits. The main purpose of the present study is to investigate the influence of the exogenous application of phenylalanine on fruit quality, chilling tolerance, and antioxidant capacity of 'Stanley' plums during cold storage.
Phenylalanine at different concentrations was applied on 'Stanley' plums. Following phenylalanine application, plums were cold stored. Chilling injury, antioxidant capacity, electrolyte leakage, malondialdehyde, proline and internal contents of anthocyanin, flavonoids, phenols, ascorbic acid and some antioxidant enzymes were assessed.
Phenylalanine treatment significantly alleviated chilling injury in plum fruits by enhancing antioxidant capacity and increasing the activity of phenylalanine ammonia lyase enzyme (PAL). Phenylalanine-treated fruits had higher mass fractions of ascorbic acid, anthocyanins, flavonoids and phenols, as well as a higher total antioxidant activity than the control fruits during low temperature storage. Phenylalanine at 7.5 mM was the most effective treatment in enhancing the activity of PAL, the accumulation of phenolic compounds and in reducing the severity of chilling injury. Treatments delayed mass loss and maintained fruit firmness. In addition, the application of 7.5 mM phenylalanine improved the activities of antioxidant enzymes (superoxide dismutase, catalase and ascorbate peroxidase), decreased the accumulation of hydrogen peroxide, and increased the endogenous content of proline. Moreover, phenylalanine maintained membrane integrity, manifested by a reduced electrolyte leakage and malondialdehyde accumulation.
In the current study, chilling injury had a positive correlation with the activities of PAL and antioxidant enzymes. However, negative correlations were observed between the chilling injury and ascorbic acid mass fraction, and antioxidant capacity. Considering the results, phenylalanine treatment could be an encouraging approach to alleviate the severity of chilling injury and thus preserve nutritional quality of plums during low temperature storage.
Low temperature (1°C) storage causes internal browning (IB) in plum (Prunus domestica L.) fruit. Consequently, any treatment with beneficial effect on decreasing these symptoms would achieve ...promising attention. For this purpose, L‐cysteine (0.1, 0.2, and 0.5%) treatments were applied on “Stanley” plum, and investigated IB, antioxidant capacity, electrolyte leakage (EL), malondialdehyde (MDA), internal content of anthocyanin, flavonoids, phenols, and ascorbic acid and some antioxidant enzymes. The results showed that L‐cysteine at 0.5% concentration could significantly alleviate IB in plum fruit by enhancing antioxidant capacity and inhibiting polyphenol oxidase activities. In addition, 0.2 and 0.5% L‐cysteine improved the activity of antioxidant enzymes (i.e., superoxide dismutase, catalase, and ascorbate peroxidase) and decreased hydrogen peroxide content. Moreover, L‐cysteine maintained membrane integrity as manifested by reduced EL and MDA accumulation. L‐cysteine‐treated fruit showed higher ascorbic acid, anthocyanin, flavonoids, and phenol contents, and total antioxidant activity higher than the control fruit during low temperature storage. In conclusion, L‐cysteine postharvest treatment could act as promising and safe method for preserving nutritional quality of plum during low temperature storage.
Practical applications
Low temperature storage is considered as an effective way to slow down respiration and senescence processes and then extending the postharvest life of plum. However, low temperature storage results in chilling injury (e.g., IB) and causes requisite of complementary treatment(s) to reduce the injury. Considering the present results, L‐cysteine treatment could be spotted as an encouraging approach to reduce browning and preserve nutritional quality of plum during low temperature storage.
Pozadina istraživanja. Niske temperature tijekom skladištenja uzrokuju oštećenja ploda šljive (Prunus domestica L.), stoga je od interesa obraditi ih na način da se ublaže ti simptomi. Iz tog razloga ...smo šljive sorte „Stanley“ tretirali fenilalaninom. Glavna je svrha ovog istraživanja bila ispitati utjecaj vanjske primjene fenilalanina na kakvoću ploda, toleranciju na niske temperature i antioksidacijski kapacitet šljive sorte „Stanley“ tijekom skladištenja pri niskim temperaturama. Rezultati i zaključci. Obrada fenilalaninom povećala je antioksidacijski kapacitet i aktivnost enzima fenilalanin-amonij-lijaza (PAL), što je znatno ublažilo oštećenja ploda šljive pri niskim temperaturama. Voće tretirano fenilalaninom imalo je veće masene udjele askorbinske kiseline, antocijanina, flavonoida i fenola, te veću antioksidacijsku aktivnost od kontrolnih uzoraka tijekom skladištenja pri niskim temperaturama. Fenilalanin pri koncentraciji od 7,5 mM je u najvećoj mjeri povećao aktivnost PAL i akumulaciju fenolnih spojeva, te umanjio oštećenja ploda pri niskim temperaturama. Obradom fenilalaninom usporen je gubitak mase i održana čvrstoća ploda. Osim toga, povećala se aktivnost antioksidacijskih enzima (superoksid dismutaze, katalaze i askorbat peroksidaze), smanjila akumulacija vodikovog peroksida, te povećao udjel prolina. Uz to, fenilalanin je očuvao integritet stanične stijenke, što se očitovalo u smanjenju gubitka elektrolita i akumulacije malondialdehida. Novina i znanstveni doprinos. U ovom je radu utvrđena pozitivna korelacija između oštećenja pri niskim temperaturama i aktivnosti PAL i antioksidacijskih enzima. Međutim, opažena je negativna korelacija između oštećenja pri niskim temperaturama i masenog udjela askorbinske kiseline te antioksidacijskog kapaciteta. S obzirom na dobivene rezultate, možemo zaključiti da obrada fenilalaninom može ublažiti oštećenja plodova i očuvati kakvoću šljiva tijekom skladištenja pri niskim temperaturama.
Fresh cut apples have a short shelf-life due to their high rate of deterioration, water loss and cut-surface browning that can rapidly reduce fruit quality. In this study the effects of carboxymethyl ...cellulose (CMC) coatings in combination with CaCl2 and ascorbic acid (AA) has been studied. Apple slices were dipped for 5 min in distilled water (uncoated), CMC (1% w/v) + CaCl2 (0.5%), or CMC (1%) + CaCl2 (0.5%) + AA (2%), and then stored at 4 °C, 90–95% (RH). The treatments suppressed browning, retained flesh firmness, and reduced soluble solid content, titratable acidity and pH changes of the slices. Browning incidence with CMC in combination with AA was lower than that of CMC solely. Vitamin C and antioxidant capacity in treatments was higher than that of uncoated. Coating treatments generally reduced total phenolic and flavonoid concentrations and polyphenol oxidase and peroxidase activity changes of slices during storage. These findings suggest that the combination use of CMC + AA may be useful for maintaining quality and reducing surface browning of fresh cut apples.
•CMC and AA seemed to have a synergistic effect for control of surface browning of fresh-cut apple.•PPO and POX enzyme activity in fresh-cut apple affected by AA treatment.•Combination of CMC and AA maintained total antioxidant, vitamin C and fruit quality attributes during storage.
A rapid decline of quality causes economic loss of strawberries after harvest. Treatments based on nano-ZnO at different concentrations (0.03%, 0.07% and 0.5%) were used to prolong the shelf-life of ...strawberry fruit in cold storage. After treatments microbial growth, weight loss, firmness, titratable acidity, soluble solid content, pH value, vitamin C, anthocyanin and total phenolics and antioxidant activity were evaluated at 0, 3, 6, 9, 12, 15 and 18days of storage. Furthermore, the levels of zinc and the sensory attributes of treated strawberries were evaluated three days after treatment. Nano-ZnO treatments decreased the microbial load during fruit storage (total mesophilic bacteria in control and 0.5% nano-ZnO treated strawberries were 4.35 and 3.67LogCFUg−1, respectively). Treatments delayed weight loss, retained fruit firmness and maintained anthocyanin, vitamin C, phenol content and antioxidant activity at higher concentration than those of untreated fruit. Fruit sweetness and aftertaste attributes were not affected by treatments but the 0.5% ZnO treated fruit was less luminous (1.6) compared to control (5.6). 0.5% nano-ZnO was the most effective in delaying changes in the ripening and reducing microbial populations among the treatments. These findings indicated that the nano-ZnO might provide an alternative to maintain quality and control decay of fresh strawberries during extended storage.
Strawberries are a highly perishable fruit and postharvest life is limited to 4days or even shorter at room temperature or 2weeks at cold storage, therefore finding a method to extend the shelf life of strawberries is important. Modified atmosphere packaging is a useful method but control of spoilage microorganisms is still a problem. Fruit coating has great potential to extend fruit postharvest life and maintain nutritional quality. Nano-ZnO may be an effective alternative.
•The bioactive compounds of strawberries decreased during storage.•Nano-ZnO coatings controlled aerobic mesophilic bacteria and yeast and mold populations on strawberries during storage.•The inhibitory effect of nano-ZnO against total aerobic bacteria was greater than yeasts and molds during storage.•Nano-ZnO coatings, specially higher concentrations (0.07 and 0.5%), maintained bioactive constituents and fruit quality.
The shelf-life of fresh-cut apples is limited because of their high water loss, deterioration rate, and surface browning. In this research, the effects of ultrasonic, ultrasonic + carboxymethyl ...cellulose (CMC) 1% coatings, ultrasonic + ascorbic acid (AA) 2%, and combination of ultrasonic + AA 2% and CMC 1% on fresh-cut apples were studied. Physicochemical, antioxidant properties, and microbial stability of ready to eat treated fresh-cut apple was investigated during storage at 4 °C for 12 days. Results showed that the treated fresh-cut had less changes of L*, flesh firmness, soluble solid content, and titratable acidity than that of untreated. Vitamin C, total phenol, total flavonoid, antioxidant capacity, and superoxide dismutase activity were greater in treated fresh-cut apple than that of untreated ones. Ultrasonic application mostly declined polyphenol oxidase and peroxidase activity changes. The combined treatment of ultrasonic + AA 2% + CMC 1% had the greatest impact on reducing microbial load among the treatments. These results revealed that the simultaneous application of ultrasonic and AA followed by CMC coating might have the potential to be used in minimally processed industry.
Research background. Low temperature storage causes chilling injury in plum (Prunus domestica L.) fruits. Consequently, any treatments with beneficial effects on these symptoms would achieve ...attention. For this purpose, phenylalanine treatments were applied on ‘Stanley’ plum fruits. The main purpose of the present study was to investigate the influence of the exogenous application of phenylalanine on fruit quality, chilling tolerance, and antioxidant capacity of ‘Stanley’ plums during cold storage.
Experimental approach. Phenylalanine at different concentrations were applied on ‘Stanley’ plums. Following phenylalanine application, plums were cold stored. Chilling injury, antioxidant capacity, electrolyte leakage, malondialdehyde, proline, and internal contents of anthocyanin, flavonoids, phenols, ascorbic acid, and some antioxidant enzymes were assessed.
Results and conclusions. Phenylalanine treatment significantly alleviated chilling injury in plum fruits by enhancing antioxidant capacity and increasing the activity of phenylalanine ammonia lyase enzyme (PAL). Phenylalanine-treated fruits had higher levels of ascorbic acid, anthocyanin, flavonoids, and phenols, as well as a higher total antioxidant activity, than the control fruits during low temperature storage. Phenylalanine at 7.5 mM was the most effective treatment in enhancing the activity of PAL and the accumulation of phenolic compounds and in reducing the severity of chilling injury. Treatments delayed mass loss and maintained fruit firmness. In addition, the application of 7.5 mM phenylalanine improved the activities of antioxidant enzymes (superoxide dismutase, catalase, and ascorbate peroxidase), decreased the accumulation of hydrogen peroxide, and increased the endogenous content of proline. Moreover, phenylalanine maintained membrane integrity, manifested by a reduced electrolyte leakage and malondialdehyde accumulation.
Novelty and scientific contribution. In the current study, chilling injury had a positive correlation with the activities of PAL and antioxidant enzymes. However, negative correlations were observed between chilling injury and ascorbic acid content and antioxidant capacity. Considering the results, phenylalanine treatment could be spotted as an encouraging approach to alleviate the severity of chilling injury and thus preserve nutritional quality of plums during low temperature storage.
PDF
