Effect of Postharvest Putrescine Application and Chitosan Coating on Maintaining Quality of Table Grape Cv. “Shahroudi” During Long-Term Storage

Abstract

The role of postharvest application of putrescine (PUT) alone or in combination with chitosan (CH) on maintaining quality of fresh table grapes (Vitis vinifera) cultivar “Shahroudi” was investigated. The clusters were dipped in an aqueous solution containing different concentrations of PUT (0, 1 and 2 mM). Following PUT treatments, some fruits were coated with 1% w/v CH. After treatment, fruits were stored at 0 ± 1C and 90 ± 5% relative humidity for 60 days and 5 additional days in evaluation room. The general appearance of rachis and berries and some physiological characters were estimated. The combination of 1 mM PUT and 1% CH reduced the weight loss, decay incidence, browning, and berry shattering and cracking. Postharvest PUT‐treated berries (1 and 2 mM) exhibited higher total phenolic content, catechin, total quercetin and antioxidant activity and the lower quercetin 3‐galactoside as compared with other treatments. PRACTICAL APPLICATIONS Table grape is a nonclimacteric fruit with a low physiological activity, but is subject to serious physiological disorders, water loss and fungal deterioration during postharvest handling. Stem browning and gray mold infection caused by the fungus Botrytis cinerea are the two main factors which reduce table grape postharvest quality. Recently, biologically active natural products have started to become an effective alternative to synthetic fungicides in maintaining fruit quality during storage. Chitosan coating has been reported to enhance disease resistance against many fungal diseases, when applied as either a preharvest or postharvest treatment. Polyamines (PAs) are also biological compounds with low molecular weight that are ubiquitous in living organisms. PAs have been reported as anti‐senescence agents, the main effects in fruits being retarded color changes, increased fruit firmness, delayed ethylene and respiration rate emissions, induced mechanical resistance.

Shelf life extension of fresh fruit and vegetables by chitosan treatment

“…Similarly, the combination of chitosan with potassium metabisulfite was tested in litchi fruit. Both chitosan and the combination of chitosan and potassium metabisulfite decreased postharvest decay of these litchi fruit (Sivakumar et al, 2005a).…”

Pre and postharvest practices for quality improvement of table grapes (Vitis vinifera L.)

“…However, if harvested at the correct maturity and packed (selected bunches which are free from any visible damages) in ventilated CFB boxes of 4 kg capacity, lined with LDPE containing one sheet of grape guard and stored at low temperature (0 -2 o C, 90 -95 % RH), the grapes can be kept for up to 45 -50 days with acceptable market quality (Mahajan et al, 2011), which can gain premium prices at the end of the season. Shiri et al (2012) have reported that a combination of 1 mM putrescine (a diamine) dip treatment followed by coating with 1 % chitosan reduced the rate of weight loss, decay incidence, rachis browning and berry shattering in grape cv. Shahroudi stored at 0 ± 1 o C, 90 -95 % RH for up to 60 days.…”

Postharvest putrescine and ultrasound treatments to improve quality and postharvest life of table grapes (Vitis vinifera L.) cv. Michele Palieri

“…The relatively higher content of phenolic in ultrasound treated alone and combined with Put was observed. Similarly, previous studies showed that Put treatments had significant positive effect on phenolic compound of fruits (Shiri et al, 2012;Davarynejad et al, 2013). At the end of the storage, the highest total phenolic content was found in Put 2+ultrasound treatment (340.9 mg*100 g .…”

“…Flame Seedless for up to 60 days in cold storage. Further, postharvest Put-treated berries (1 and 2 mM) exhibited higher total phenolic content, catechin, total quercetin and antioxidant activity (Shiri et al, 2012).…”