A novel combined approach for peel and pulp color classification in guava (Psidium guajava L.)

Guava (Psidium guajava L.) fruit color varies extensively due to the presence of pigments such as anthocyanins and carotenoids. The development of a standardized color classification system and a quantitative assessment of the peel and pulp color could aid in efficient grading and classification of the guava progenies and genetic resources. Thus, the intervarietal progenies derived from the cross Purple local × Arka Poorna were used for classification based on peel and pulp pigments and also for correlation study with International Commission on Illumination (CIELAB) color values (L*, a*, b*, C*, and h°). The results revealed that the integrated method of CIELAB and Munsell color system categorized 167 intervarietal progenies of guava into four and seven groups for peel and pulp color, respectively. Additionally, strong positive correlations were observed between a* and the total anthocyanins (r = 0.522), total carotenoids (r = 0.608), and lycopene (r = 0.586) pigments. The color value C* also recorded a positive correlation with the pigments. The linear equation derived from the significant correlation of a* and pigments indicated that the a* values may be more helpful as an indirect indicator of the pigment levels in guava pulp. The combined method of color classification and pigment estimation through correlation study provided a quicker and less costly way to simplify the color classification system and pigment estimation. Thus, this approach could be used in breeding program to define color and helps in developing a color-based grading system which is required in the food industry.