2.5. Fruit Quality Assessment

Fruit development (weight, size, and sphericity) and quality (color and soluble solids) were assessed according to Chonhenchob et al. [24]. Size and sphericity were measured at the widest position using a Vernier caliper and expressed by the following equations:

where a = width, b = length, c = depth, and d = circumference.

Peel color was determined with a CR-300 Chromometer (Minolta Inc., Osaka, Japan) using the CIE system. Data were expressed as L* a* b* values, where: L* indicates the lightness (0 = black and 100 = white); a* represents the green and red color (+a* = green and −a* = red); and b* indicates the yellow and blue (+b* = yellow and −b* = blue). The hue angle (°) and chroma were estimated using the following equations:

Internal flesh color development stages were estimated according to the procedure described in the Mango Maturity and Ripeness Guide provided by the National Mango Board in the USA (NMB 2010), which describes five stages (1 to 5) defined by the appearance and progression of yellow to orange color, from 0 to 100% of the flesh in 20% increments starting near the pit and progressing outward. Soluble solids or sugar content was measured using a HI-96801 Refractometer (Hanna Instruments Ltd., Leighton Buzzard, UK), expressed as ºBrix.