Virtual Conference
Nutrition 2022

N.M. Bitange

University of Nairobi, Kenya

Title: Effects of mode and timing of calcium chloride application on tissue calcium and acceptability of mango fruits

Abstract

Mango (Mangifera indica L) production in Kenya supports about 200,000 farmers directly and many other beneficiaries. Despite this, its production faces post-harvest losses due to the fruits’ short shelf life in ambient conditions. Calcium maintains cell integrity, strengthens cell wall and membrane structure hence increasing shelf life. An experiment was set to compare the effect of spraying and immersion of mango fruits in calcium chloride at different concentrations and times on the fruit ripening rate and organoleptic acceptance. Completely randomized block design with a split plot arrangement was used. ‘Van Dyke’ mango fruits were sprayed or immersed in calcium chloride (0.5%, 1% 1.5% or 0%) at maturity or 15 days later. Fruit changes in peel firmness (N), total soluble solids (0Brix), fruit colour (Ho), beta carotene (mg/100ml) and carbon dioxide evolution (ml/kg/hr)  were investigated at time 0 and every 2 days up to 8 days of storage in ambient conditions. Organoleptic attributes, flesh firmness, calcium concentration (?g/mg) and their relationships were also determined. Fruits immersed in calcium chloride at maturity had a higher retained peel firmness (10.6 N, 10.3 N), flesh color (37.45, 36.78), lower total soluble solids (14, 13.8), in seasons I and II respectively, reduced carbon dioxide evolution (30.7 ml/kg/hr) higher beta carotene and flesh calcium concentration than other treatments. Fruits sprayed at maturity exhibited better results in the studied parameters than those sprayed 15 days later. Flesh calcium content reported a positive correlation with flesh firmness (r= 0.913, r= 0.852), peel color (r= 0.828, r= 0.841), fruit aroma (r=0.8199, r=0.841) and a negative relationship with skin shriveling (r=-0.778, r= -0.806) and fruit flavor (r=-0.811, r=-0.829). Flesh firmness exhibited negative correlation with skin shriveling (r=-0.868, r=-0.788) and fruit flavor (r=-0.8869, r=-0.821) and a positive correlation with peel color (r=0.9115, r=0.856) and aroma (r=0.907, r=0.848). Skin shriveling reported a negative relation with peel color (r=-0.944, r=-0.93) and aroma (r=-0.944, r=-0.938) and a positive relation with fruit flavor (r=0.933, r=0.947). Peel color exhibited positive and negative correlations with aroma (r=0.979, r=0.977) and fruit flavor (r=-0.962, r=-0.950) respectively. Despite the effectiveness of post-harvest immersion in calcium chloride in enhancing fruit shelf life, optimal use is recommended to avoid deteriorated pulp flavor and increased shriveling.  Further research needs to be done on how best calcium chloride can be available to the fruit while still attached onto the tree.

Biography

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