Pattern of phenolic content, antioxidant activity and senescence-related enzymes in granulated vs non-granulated juice-sacs of ‘Kinnow’ mandarin (Citrus nobilis x C. deliciosa)

Abstract

'Kinnow' is a hybrid mandarin, developed at California (USA) but could not become successful there. However, it revolutionized citrus industry in India, Pakistan and Bangladesh. Recent reports indicate that like other citrus fruits, it also suffers from juice-sac granulation but exact cause of this malady is not known. Fully-mature 'Kinnow' fruits were harvested and observations on some physical and biochemical attributes were recorded and their relationship was established with occurrence of granulation. About 12.8 % 'Kinnow' fruits were affected by juice-sac granulation. Granulated fruits had higher average weight (178 ± 2.26 g), peel thickness (3.72 ± 0.23 mm), and less soluble solids concentrates (7.4 ± 0.21 %) than non-granulated fruits. Granulated fruits exhibited lower concentrations of total phenolics compounds (4.3 ± 0.56 mg 100(-1) g gallic acid equivalent fresh weigh) and antioxidants activity (1.78 ± 0.29 μmol Trolox g(-1) FW) but produced higher rates of carbon dioxide and ethylene, and exhibited higher activities of senescent-related enzymes such as lipoxygenase (LOX) (1.3 ± 0.31 μmoles min(-1) g(-1) FW) and pectin methylesterase (PME) (0.52 ± 0.12 μmol of NaOH g(-1) FW min(-1)) and had strong relationships with the occurrence of granulation. From this study, it can be concluded that total phenolics compounds, antioxidants and PAL enzyme activity have strongly negative co-relation; whereas, senescent-related enzymes such as LOX, and PME and rates of respiration or ethylene evolution have strongly positive relationships with the occurrence of granulation in 'Kinnow' mandarin.

Postharvest treatment of antioxidant reduces lenticel browning and improves cosmetic appeal of mango (Mangifera indica L.) fruits without impairing quality

“…For this, randomly ten fruits were randomly selected and their respiration rate was determined as per method suggested by Sharma et al (2015). For determination of ethylene evolution rate, Hewlett Packard (H.P.)…”

Nutritional Profile and Health Benefits of Kinnow: An Updated Review

“…Comparative analysis of flavonoids indicates the presence of their maximum amount in Ponkan peel extract (35.6 mg REQ/g) and minimum amount in Kinnow peel extract (11.7 mg REQ/g). Sharma et al (2016) studied pattern of phenolic compounds with antioxidant properties in granulated and nongranulated juicy sacs of Kinnow mandarin. The resulting output of their study indicate that granulated kinnow possess low amount of phenolic compounds (4.3 mg GAE/100 ml); ascorbic acid (16.2 mg/100 ml) with antioxidant capacity (1.78 μmol Trolox/g).…”

The Effects of Edible Coatings on the Postharvest Quality of Citrus Fruits as Affected by Granulation

“…For this purpose, cell wall thickening happens to prevent moisture loss [13]. Previous studies have also showed that polyphenol oxidase (PPO) activity and phenolic contents have a significant influence on granulation where the granulated fruits have lower PPO activity and phenolic content [27].…”

“…Granulation was reported to cause a significant reduction at the concentrations of SSC and TA [4]. Sharma et al [27] noted that the granulated "Kinnow" mandarin fruits exhibit lower antioxidants activity and ascorbic acid content. Fruit granulation also causes a reduction in the juice content of the citrus fruits resulting in colour change (lighter) of the juice sac [12,28,31].…”