The quantification and prediction of green husk and hard shell by-products in walnut (Juglans regia) production

Walnuts (Juglans regia) have small fruits consisting of a juicy fleshy, inedible mesocarp, woody endocarp, and oil and protein-rich seed portions. Kernels considered the seed of walnut fruits are consumed as human food. During the walnut production process, hard shells and green husks are produced as by-products. There are not many statistics results and measurements on by-products and residue/waste of walnut production. In this thesis, suitable to the walnut production pattern of Türkiye, biomass amounts of different fruit parts in Chandler, Fernette, Fernor, Franquette, and Kaman-1 cultivars were determined. The ratios between fresh and dry biomass values of different fruit parts were also calculated for estimation. Correlations between the green husk and hard shell biomass of walnut fruit parts were examined and Simple Linear Regression equations were obtained for the prediction of by-products. Fresh and dry biomass values of the cultivars were found significantly different. Fresh Green Husk Biomass values can be easily predicted from Fresh Whole Walnut Fruit Biomass values with r2 predicted values above 90% by using measured biomass data. Dry Hard Shell Biomass values are more advantageous than Dry Green Husk Biomass values in predictability. DGHB values were found not predictable by Simple Regression Equations in all cultivars. However, DHSB values can be predicted with higher r2 predicted values in most cultivars, especially from Dry In-Shell Biomass and Dry Kernel Biomass values. Keywords: Walnut, by-product, biomass, green husk, hard shell, Chandler