Here in California kiwi’s (or better kiwi fruit) is often graded by dry matter. Generally the better the sunlight available for each kiwi, the higher the dry matter. That dry material is the structure of the kiwi fruit, whereas often the size and weight of a kiwi is more directly related to water content. It makes sense that a low-light, and therefore low dry matter, fruit would break down more quickly because it lacks the structural integrity of a better quality piece of fruit. Considering that pectin is a polysaccharide there will certainly be less pectin in a fruit grown with less internal sugars.