Waseem Ahmed, Saeed Ahmed, Liaquat Ali, Imatiaz Hussan
Institute of Horticultural Sciences, University of Agriculture Faisalabad, Pakistan
Key words: Grape fruit, ray ruby, total phenolic compound, phytochemicals, chilling injury.
Grapefruit is an important fruit crop in the world as well as in Pakistan. The signalling molecules like salicylic acid (SA) and methyl jasmonate (MeJA) are endogenous plant growth substances which can play a key role in plant growth and development, and responses to environmental stresses. Phytochemicals in grapefruit are considered very important for human body due to their medicinal properties. Therefore it is important that Grapefruit should be stored proper temperature and consumed when it has maximum quantity of these chemicals. Phytochemical and postharvest losses are crucial issues for citriculture industry. Therefore it is also important to establish techniques or to adopt some measures that can reduce these losses. This study was carried out to investigate the effect Pre-harvest spray of SA and Me JA on the shelf life and quality of Ray Ruby. Preharvest sprays of SA @ 12mM and MeJA @ 5 mM showed higher biochemical parameters such as higher total phenolic compounds (166.29 and 165.76 mgGAE/100g), total antioxidants (72.63 and 71.37 %), Total carotenoids (16.40 and 16.32,18.09 and 18.03 mg/100g), total flavonoids contents (55.74 and 53.43 mgCEQ/100g) and total limonin contents (11.95 and 12.04 μg/mL) with minimum chilling injuries (1.57 and 1.42%) and fruit rots (4.23 and 3.90%) were also recorded in same fruits. On the basis of the result of this study, Pre-harvest sprays of SA @ 12mM and MeJA @ 5Mm and storage temperature of 8°C was found the best for maintaining phytonutrient quality of grapefruit after 90 day storage.