Variation in the physicochemical characteristics of cashew (Anacardium occidentale L.) apples with maturity

Purpose - The purpose of this paper is to determine the physicochemical characteristics of yellow and red apples cultivars of cashew. This is with a view to harnessing the quality attributes of the different cultivars of cashew. Parameters investigated include pH, refractive index, specific gravity, vitamin C content, juice astringency, chlorophyll and juice yield.Design methodology approach - The methods of the Association of Official Analytical Chemists (AOAC) are employed in assaying the physicochemical properties, while the astringency is determined spectrophotometrically according to standard methods.Findings - Results showed that percentage juice yield increases linearly with maturity for both cultivars. A maximum of 79.5 per cent is obtained for the yellow apple cultivars, while 74.1 per cent juice yield is obtained in the red apple cultivar. The pH ranged from 3.73-4.5 and 3.64-4.55 for red and yellow apple cultivars, respectively, with a marked fall between seven and eight weeks after pollination (WAPo). Specific gravity and refractive index are of the order 0.999-1.007 and 1.34-1.89 for both selected samples. Highest refractive index is obtained in red and yellow cultivars at seven and eight WAPo. The changes in ascorbic acid followed a linear pattern and the maximum values of 249.5 mg 100 ml and 185.5 mg 100 ml are obtained for yellow and red apple cultivars, respectively. Meanwhile, the juice astringency level decreased steadily with maturity and at the ninth WAPo, values obtained are 0.47 and 0.86 mg 100 ml tannin for yellow and red apple cultivars, respectively. Generally, pH, astringency, refractive index, juice content, ascorbic acid and chlorophyll contents showed marked variations between six and eight WAPo, confirming physiological maturity and ripening in the crop species.Originality value - Cashew farmers and industrialists will know the best time to harvest the crop when the quality is at its peak.