Impact of ripening stage and drying on selected quality attributes of apple mango cubes and leathers

Abstract

Apple mango is an improved cultivar that has been widely adopted by farmers in Kenya for use in the fresh market and processing. However, its production and consumption are adversely affected by high postharvest losses, which result from the perishable nature of the fruit, especially during glut periods. This is partly due to limited availability of information on alternative product use. The aim of this study was to evaluate the impact of ripening stage and drying on the physico-chemical quality and sensory acceptability of Apple mango fruit grown in the upper Athi River region of Kenya. Moisture, crude ash, crude fibre, titratable acidity, total soluble solids, colour, total carotenoids and ascorbic acid of the unripe and ripe fresh mangoes were determined. Subsequent experiments involved drying of ripe and unripe mango cubes (8mm) in a windy oven (at 60°C) and, in parallel, drying of ripe mango puree (mixed with sucrose-glucose solution, citric acid and pectin) in a windy oven at three different temperatures (50, 60 and 70°C) which resulted in mango leathers. Analysis of total carotenoids, ascorbic acid content and colour was done for all dried samples, followed by sensory evaluation using the nine-point hedonic scale. The moisture content, crude ash and total soluble solids increased significantly (P<0.05) with ripening while titratable acidity decreased significantly (P<0.05). Ascorbic acid content decreased from 98.03 to 86.45 mg/100g with ripening while total carotenoids content approximately doubled from 768 to 1436 μg/100g. Drying resulted in high retention of total carotenoids, whereas, ascorbic acid content decreased. The mango samples became darker and redder in all cases. Dried mango cubes and leathers derived from ripe mangoes had higher scores in the sensory analysis compared to those obtained from unripe mangoes. In conclusion, the stage of ripening and drying technique employed are critical in determining the nutritional and sensory characteristics of dried Apple mango cubes and leathers. Drying Apple mango leathers at 60°C is the best method that can be adopted.

Keywords: Apple Mango, Drying, Ripening, Fruit Leather, Fruit Cubes, Physico-chemical, Sensory