The chemical composition, in vitro gas production and digestibility of pistachio by-products

Document Type : Scientific - Research Articles


1 Ferdowsi University of Mashhad

2 Ferdwosi University of Mashhad


To study the chemical composition and qualitative comparison of the pistachio by-products and the effect of pistachio hull
tannin on its digestibility and gas production, four experiments were carried out. In the first experiment, nutrient composition,
phenolic and tannin components of the Ohadi, Kaleghuchi and White varieties of pistachio by-product from dehulling
process were measured. Pistachio epicarp (hull) was the main part of this by-product. The Ohadi cultivar contained 9, 14, 8.7,
25.5 and 20.4% of ash, CP, EE, NDF and ADF, and 8.6 and 4.1% phenolic components and tannin, respectively. The
Kaleghuchi had lower CP than Ohadi and White varieties. The White variety had the lowest tannin level among them. In the
second experiment the ruminal disappearance of pistachio by-product constituents including hull, peduncle, leaf, mesocarp
and kernel until 24 h incubation were 0.77, 0.60, 0.66, 0.22 and 0.92 g/g, respectively; also the amount of soluble fraction of
these constituents were determined 0.52, 0.37, 0.36, 0.05 and 0.77 g/g, respectively. The third trial was consisted of
measuring in vitro dry matter and organic matter digestibility of different pistachio by-product varieties. The dry matter
digestibility of the Ohadi, Kaleghuchi, and White cultivars were 58, 68, and 64%, respectively and were significantly
different (P