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Effects of Ascorbic Acid and Melatonin Treatments on Antioxidant System in Fresh-Cut Avocado Fruits During Cold Storage

DOI:10.1007/s11947-022-02892-3
Authors:
Anna Magri at Università degli Studi della Campania "Luigi Vanvitelli
Anna Magri
Danilo Cice at Council for Agricultural Research and Agricultural Economy Analysis
Danilo Cice
Giuseppe Capriolo at Council for Agricultural Research and Agricultural Economy Analysis
Giuseppe Capriolo
Milena Petriccione at Council for Agricultural Research and Agricultural Economy Analysis
Milena Petriccione
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Abstract and Figures

Fresh-cut fruits have a limited postharvest life compared to fresh intact fruits; they have gained considerable market share. In this study, we investigated the effectiveness of melatonin (1 mM) and ascorbic acid (20 mM) treatments, alone or in combination, on qualitative traits and antioxidant systems of fresh-cut avocado fruits during 14 days of cold storage (4 ± 0.5 °C and RH 95 ± 0.5%). The results showed that the combined melatonin and ascorbic acid treatment delayed colour changes, thereby retarding the ripening process and weight loss compared with separate melatonin and ascorbic acid treatments. Furthermore, melatonin and ascorbic acid treatment showed a synergistic effect on fresh-cut avocado, improving the enzymatic and non-enzymatic antioxidant system during cold storage. Compared with the control, the total polyphenol and flavonoid contents in the treated avocado were increased, and a higher antioxidant activity was observed. The combined treatment improved catalase, ascorbate peroxidase, and superoxide dismutase activities; decreased polyphenol oxidase and guaiacol peroxidase activities; and effectively reduced membrane damage by influencing lipoxygenase activity. These results indicate that the combination of melatonin and ascorbic acid could be a useful, reliable, and eco-friendly postharvest treatment to maintain physicochemical and nutraceutical features, reduce oxidative stress and enzymatic browning, and extend the shelf life of fresh-cut avocado.
Evolution of the total polyphenols (A), flavonoids (B), ascorbic acid (C) content, and antioxidant activity (D) of control (C) and treated (M, melatonin; A, ascorbic acid; MA, melatonin-ascorbic acid) ‘Hass’ avocado after 0 (T0), 7 (T1), and 14 days (T2) of cold storage at 4 °C ± 0.5. Error bars indicate standard deviation. Means followed by the same letter do not differ significantly at P = 0.05 (Tukey’s test)
Evolution of the total polyphenols (A), flavonoids (B), ascorbic acid (C) content, and antioxidant activity (D) of control (C) and treated (M, melatonin; A, ascorbic acid; MA, melatonin-ascorbic acid) ‘Hass’ avocado after 0 (T0), 7 (T1), and 14 days (T2) of cold storage at 4 °C ± 0.5. Error bars indicate standard deviation. Means followed by the same letter do not differ significantly at P = 0.05 (Tukey’s test)
… 
Superoxide dismutase (A), catalase (B), ascorbate peroxidase (C) activity, and hydrogen peroxide content (D) of control (C) and treated (M, melatonin; A, ascorbic acid; MA, melatonin-ascorbic acid) ‘Hass’ avocado after 0 (T0), 7 (T1), and 14 days (T2) of cold storage at 4 °C ± 0.5. Error bars indicate standard deviation. Means followed by the same letter do not differ significantly at P = 0.05 (Tukey’s test)
Superoxide dismutase (A), catalase (B), ascorbate peroxidase (C) activity, and hydrogen peroxide content (D) of control (C) and treated (M, melatonin; A, ascorbic acid; MA, melatonin-ascorbic acid) ‘Hass’ avocado after 0 (T0), 7 (T1), and 14 days (T2) of cold storage at 4 °C ± 0.5. Error bars indicate standard deviation. Means followed by the same letter do not differ significantly at P = 0.05 (Tukey’s test)
… 
Guaiacol peroxidase (A), polyphenol oxidase (B), lipoxygenase (C) activity, and malondialdehyde content (D) of control (C) and treated (M, melatonin; A, ascorbic acid; MA, melatonin-ascorbic acid) ‘Hass’ avocado after 0 (T0), 7 (T1), and 14 days (T2) of cold storage at 4 °C ± 0.5. Error bars indicate standard deviation. Means followed by the same letter do not differ significantly at P = 0.05 (Tukey’s test)
Guaiacol peroxidase (A), polyphenol oxidase (B), lipoxygenase (C) activity, and malondialdehyde content (D) of control (C) and treated (M, melatonin; A, ascorbic acid; MA, melatonin-ascorbic acid) ‘Hass’ avocado after 0 (T0), 7 (T1), and 14 days (T2) of cold storage at 4 °C ± 0.5. Error bars indicate standard deviation. Means followed by the same letter do not differ significantly at P = 0.05 (Tukey’s test)
… 
Two-dimensional principal component analysis plot of all analyzed traits of control (C) and treated (M, melatonin; A, ascorbic acid; MA, melatonin-ascorbic acid) ‘Hass’ avocado after 0 (T0), 7 (T1), and 14 days (T2) of cold storage at 4 °C ± 0.5 (WL, weight loss; TSS, total soluble solid content; TA, total titratable acidity; pH; TPC, polyphenol content; TF, flavonoid content; AA, ascorbic acid content; AOX, antioxidant activity; CAT, catalase; APX, ascorbate peroxidase; SOD, superoxide dismutase; GPX, guaiacol peroxidase; LOX, lipoxygenase; PPO, polyphenol oxidase; MDA, malondialdehyde content; H2O2, hydrogen peroxide content; L*, a*, b*, chromaticity coordinates; ΔE, colour variation)
Two-dimensional principal component analysis plot of all analyzed traits of control (C) and treated (M, melatonin; A, ascorbic acid; MA, melatonin-ascorbic acid) ‘Hass’ avocado after 0 (T0), 7 (T1), and 14 days (T2) of cold storage at 4 °C ± 0.5 (WL, weight loss; TSS, total soluble solid content; TA, total titratable acidity; pH; TPC, polyphenol content; TF, flavonoid content; AA, ascorbic acid content; AOX, antioxidant activity; CAT, catalase; APX, ascorbate peroxidase; SOD, superoxide dismutase; GPX, guaiacol peroxidase; LOX, lipoxygenase; PPO, polyphenol oxidase; MDA, malondialdehyde content; H2O2, hydrogen peroxide content; L*, a*, b*, chromaticity coordinates; ΔE, colour variation)
… 
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Food and Bioprocess Technology (2022) 15:2468–2482
https://doi.org/10.1007/s11947-022-02892-3
RESEARCH
Effects ofAscorbic Acid andMelatonin Treatments onAntioxidant
System inFresh‑Cut Avocado Fruits During Cold Storage
AnnaMagri1,2· DaniloCice1· GiuseppeCapriolo1· MilenaPetriccione1
Received: 13 June 2022 / Accepted: 8 August 2022
© The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2022
Abstract
Fresh-cut fruits have a limited postharvest life compared to fresh intact fruits; they have gained considerable market share.
In this study, we investigated the effectiveness of melatonin (1mM) and ascorbic acid (20mM) treatments, alone or in com-
bination, on qualitative traits and antioxidant systems of fresh-cut avocado fruits during 14days of cold storage (4 ± 0.5°C
and RH 95 ± 0.5%). The results showed that the combined melatonin and ascorbic acid treatment delayed colour changes,
thereby retarding the ripening process and weight loss compared with separate melatonin and ascorbic acid treatments. Fur-
thermore, melatonin and ascorbic acid treatment showed a synergistic effect on fresh-cut avocado, improving the enzymatic
and non-enzymatic antioxidant system during cold storage. Compared with the control, the total polyphenol and flavonoid
contents in the treated avocado were increased, and a higher antioxidant activity was observed. The combined treatment
improved catalase, ascorbate peroxidase, and superoxide dismutase activities; decreased polyphenol oxidase and guaiacol
peroxidase activities; and effectively reduced membrane damage by influencing lipoxygenase activity. These results indicate
that the combination of melatonin and ascorbic acid could be a useful, reliable, and eco-friendly postharvest treatment to
maintain physicochemical and nutraceutical features, reduce oxidative stress and enzymatic browning, and extend the shelf
life of fresh-cut avocado.
Keywords Postharvest· Tropical fruit· Antioxidant systems· Quality· Nutraceutical traits· Principal component analysis
Introduction
Avocado (Persea americana Mill.) is a tree species belong-
ing to Lauraceae family. These fruits originated in Mexico
and Central America (Jimenez etal., 2020), and their world-
wide production was approximately 7.0 million tonnes in
2019 (FAO, 2019). Avocado is a climacteric fruit and is
highly perishable owing to its high content of lipids that eas-
ily undergo lipoperoxidation reactions (Chen etal., 2017).
Currently, avocado is highly consumed as a fresh product,
but also processed as oil, avocado puree, guacamole, slices,
ready-to-eat products, and dehydrated or dried avocado
(Jimenez etal., 2020). The consumption of these fruits is
beneficial to human health because they contain phyto-
chemicals, such as monounsaturated fatty acids, tocophe-
rols, sterols, and folate (Lu etal., 2009), and the avocado
flesh is made up of 30% proteins and lipids (Vanini etal.,
2010). Several studies have reported that avocado acts
against oxidative stress (Melgar etal., 2018), inflammatory
states (Tremocoldi etal., 2018), cancer cells (Bonilla-Porras
etal., 2014), and gastric ulcer (Athaydes etal., 2019) and
regulates lipid and carbohydrate metabolism (Pahua-Ramos
etal., 2012). However, it is highly perishable, and several
studies have been conducted to improve the postharvest life
of avocado fruits using the following methods—application
of 1-methylcyclopropene (Defilippi etal., 2018; Hershkovitz
etal., 2005), chitosan alone (Obianom etal., 2019) or com-
bined with carboxyl methylcellulose and moringa plant
extracts (Tesfay & Magwaza, 2017) or methyl cellulose
alone (Maftoonazad & Ramaswamy, 2005), modified atmos-
phere alone (Burdon etal., 2017) or in conjunction with heat
treatment (Escribano & Mitcham, 2014), nanoemulsions
* Milena Petriccione
milena.petriccione@crea.gov.it
1 Council forAgricultural Research andEconomics - Research
Centre forOlive, Fruit andCitrus Crops, Via Torrino, 3,
81100Caserta, Italy
2 Department ofEnvironmental, Biological
andPharmaceutical Sciences andTechnologies - DiSTABiF,
University ofCampania “Luigi Vanvitelli”, Via Vivaldi 43,
81100Caserta, Italy
/ Published online: 15 August 2022
1 3
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... The anthocyanin content (ANT) was assessed as described by Magri et al. [63] and expressed as mg of cyanidin-3-glucoside equivalent (C3G) per 100 g −1 FW. The antioxidant activity (AOX) was measured by 1.1-diphenyl-2-picryl-hydrazil (DPPH) according to Magri et al., [64]. ...
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Background Most of postharvest fruits are highly perishable, which limits greatly marketability and potential expansion. In recent years, significant progresses on understanding the role of melatonin in delaying senescence have been achieved while the melatonin as a postharvest alternative in maintaining quality and extending shelf life of postharvest fruit has been developed. Scope and approach This paper reviews the recent progresses in the multiple functions of melatonin, summaries the detection, content and synthesis of endogenous melatonin in postharvest fruit, discusses the possible mechanisms of melatonin in maintaining quality and extending shelf life of postharvest fruit, emphasizes the beneficial effects of the melatonin-related handling and provides the future research direction for postharvest alternative. Key findings and conclusions The amount of melatonin in postharvest fruit is relatively low and affected greatly by many factors. The major precursors and genes of melatonin biosynthetic pathway have been identified in various fruits. Exogenous melatonin treatment not only delayed ripening, senescence and quality deterioration, but also enhanced disease resistance and chilling tolerance of postharvest fruit. The multiple biological functions of melatonin in postharvest fruit were attributed to the induction and interaction with reactive oxygen species and nitric oxide and coordination with plant hormones and other signaling molecules, which enhanced antioxidant and defense systems, reduced oxidative damage, and maintained energy of postharvest fruit.