Giridhari Subedi1*, Sujan Subedi2 , Dipendra Ghimire2 , Ishwori Prasad Gautam2 and Sanjeeb Thapa3

1 National Potato Research Program, Khumaltar, Lalitpur, Nepal

2 Nationa Horticulture Research Centre, Khumaltar, Lalitpur, Nepal

3 Banaras Hindu University, Varanasi, Uttar Pradesh, India

* Corresponding Author’s E-mail: subedigiridharinarc@gmail.com

* Orcid ID: https://orcid.org/0000-0002-4425-8295

Abstract
Maturity indices of papaya fruits vary with variety and growing environment. During maturation, papaya varieties differ in terms of skin color, pulp color, fruit firmness, and Total Soluble Solid (TSS). Although Red Lady is the most popular papaya cultivar in Nepal, its maturity indices have yet to be investigated. Therefore an experiment was conducted at the farmer’s field of Kalika Municipality of Chitwan district to identify the maturity indices of the Red Lady variety of papaya. Both destructive and non-destructive methods were used for determining the maturity indices, among non-destructive methods; visual observations, and colorimeter reading were recorded. Based on visual observation, six maturity indices were identified as MS1, MS2, MS3, MS4, MS5, and MS6. Colorimeter readings of those six stages were recorded by using a digital colorimeter. The l* value which represents the brightness of fruits ranges from 30.7-53.1 in MS1 to MS6. Similarly, a* representing the degree of greenness ranges from -15.5 in MS1 to 4.6 in MS6. Likewise, b* indicating yellowness varies greatly with the minimum value in MS1 (15.0) and the maximum value (35.1) in MS6. In destructive methods, fruit firmness and TSS were measured by using a penetrometer and refractometer respectively. The fruit firmness of different stages of maturity gradually decreases from 11.2 kg/cm2 in MS1 to 1.1 kg/cm2 in MS6 while the TSS of different maturity stages greatly increases from 4.2°Brix in MS2 to 12.48°Brix in MS6.

Keywords: Colorimeter, Firmness, Maturity, and Stages