where does the sugar in fruit come from
Fructose
Sugar
fructose 
wiki:19674673
Sugar [SEP] Sources
The sugar contents of common fruits and vegetables are presented in Table 1. The fructose to fructose plus glucose ratio is calculated by including the fructose and glucose coming from the sucrose. In November 2019, scientists reported detecting, for the first time, sugar molecules, including ribose, in meteorites, suggesting that chemical processes on asteroids can produce some fundamentally essential bio-ingredients important to life, and supporting the notion of an RNA World prior to a DNA-based origin of life on Earth, and possibly, as well, the notion of panspermia.