Journal of Biology, Agriculture and Healthcare www.iiste.org ISSN 2224-3208 (Paper) ISSN 2225-093X (Online) Vol.8, No.24, 2018 24 The Effect of Different Waxing Technologies on Shelf Life of ‘Apple’ Mango Fruits Stored Under Different Storage Conditions Benson Maina 1* Jane Ambuko 1 Margaret Hutchinson 1 Willis Owino 2 1.Department of Plant Science and Crop Protection, Faculty of Agriculture, University of Nairobi, 29053-00625 2.Department of Food Science and Technology, Faculty of Agriculture, Jomo Kenyatta University of Agriculture and Technology, 62000-00200 Abstract Beneficial effect of Shellac and Mango wax of different formulations was studied on shelf life of apple mango fruits which were harvested at mature green stage and stored in various storage conditions including ambient (25 º C) and simulated commercial cold storage (12 º C). Mango wax (one mixed with a fungicide and another without) was obtained from United Phosphorous Limited, while Shellac wax was purchased from a commercial trader in flakes form and dissolved in 0.1N Sodium hydroxide to make two concentrations (3% and 5%). The two waxes were applied by dipping the fruits in a bowl of wax and placing them on wire mesh for air drying using fans. Upon drying the fruits were packed in open cotton boxes and stored in ambient (25 º C) and cold storage (12 º C). Three fruits from each treatment and different storage conditions were sampled after every 3 and 7 days (ambient and cold storage respectively) for measurement of attributes associated with ripening including weight loss, respiration rate, peel firmness and pulp hue angle. Results indicated that waxing whether with Shellac or Mango wax was effective in extending shelf life of mango fruits for 4 and 6 more days in ambient and cold storage respectively. At the end of observation period, un waxed fruits in ambient and cold storage had lost 12.4% (day10) and 5.5% (day 22) compared to an average of 7.6% (day14) and 3.7% (day 28) for the waxed fruits respectively. Waxed fruits exhibited low respiration peak of 49.39 and 30.38 ml/kg/hr compared to un waxed fruits that had a high peak of 85.09 and 43.15 ml/kg/hr for ambient and cold storage respectively signifying high respiratory activity in the un waxed fruits. Other ripening related parameters had a positive correlation to respiration and water loss. This study shows that coating of mango fruit with wax is effective in delaying ripening thereby extending its postharvest life. Keywords: Mango wax, Shellac wax, Shelf life, Mango, Postharvest technologies, Storage 1. Introduction Mango (Mangifera indica L.) is regarded as the king of all fruits, but with a short shelf life depending on harvest maturity and storage conditions (Slaughter, 2009). The perishability leads to high postharvest losses that limits its commercial potential. The major contributors of losses in mango include water loss, respiration and postharvest diseases (Zheng et al., 2012). Loss of water from perishable commodities such as mango is the major cause of deterioration as it results in both qualitative and quantitative losses. Qualitative losses include the loss of firmness due to softening, loss in gloss due to shriveling and loss in nutritional value such as loss of vitamins. Quantitative losses include loss of salable weight due to transpiration losses and discount selling due poor looking fruits. Various postharvest technologies have been employed to manage the factors that predispose mango fruit to deterioration including low temperature storage (Nair and Singh, 2003), edible coatings (Dhall, 2013), Controlled Atmosphere Storage (CAS) (Meyer et al., 2011), Modified Atmospheric Packaging (MAP) (Githiga et al., 2012), Evaporative coolers (Dvizama et al., 2000), among others. However, most of these are coupled with challenges such as gas injury (Thompson, 2001)), chilling injury (Nair et al., 2004), environmental pollution (MAP bags), among others and are also limited to resource constrained small holder farmers in developing countries. This has led to exploration of alternative technologies that are easy to access, use and affordable. Use of surface coating can be a simple and versatile postharvest technology to prolonging shelf life of perishables such as mangos. Edible coatings have been found to be effective as other materials such as fungicides can be added in the polymer matrix (Dhall, 2013). The efficacy of waxing to extend shelf life is based on the modification of the internal atmospheric condition of the fruit in storage. The coating is applied by either spraying or dipping the fruits into the solution. The coating is then allowed to dry on the surface forming a thin layer which creates a modified environment around the fruit (Hoa et al., 2001). The modified atmosphere is achieved by limiting water vapor loss to the environment by blocking the lenticels, leading to a water saturated internal environment and by regulating gaseous exchange in and out of the fruit (Hagenmaier and Baker, 1993). The low O 2 condition created with waxing affects physiological processes such as respiration. Furthermore, the modified condition created (elevated CO 2 and reduced O 2 ) also interferes with several enzymatic processes such as the ethylene biosynthesis pathway by limiting the activities of 1-Aminocyclopropane-1-Carboxylic acid (ACC) oxidase (Hoffman et al., 1994) the enzyme that catalyses the conversion of ACC to ethylene, reduced activity of enzymes involved in the cell wall degradation such as pectin methylestearse (PME), polygalacturonase (PG), endo-B-1,4-glucanase brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by International Institute for Science, Technology and Education (IISTE): E-Journals