Effects of electron beam, NaOH and urea on chemical composition, phenolic compounds, in situ ruminal degradability and in vitro gas production kinetics of pistachio by-products

The current study evaluated the effects of electron beam (EB; 10, 20, 30 and 40 kGy), urea and NaOH treatments on chemical composition, phenolic compounds, in vitro gas production and in situ ruminal degradability of pistachio by-product (PB). The EB decreased (p < 0.01) neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) contents of PB. Treating PB by NaOH and urea increased cell wall constitute of PB (p < 0.01). Irradiation at doses of 30 and 40 kGy reduced tannin and increased total phenol content of PB (p < 0.01). NaOH and urea treatments decreased tannins, total phenolics and condensed tannins of PB compared to control (p < 0.01). In situ ruminal dry matter (DM) degradation data showed that irradiation increased (p < 0.01) and, urea and NaOH decreased (p < 0.01) rapidly fermentable fraction (a) of PB. NaOH decreased (p < 0.01) fraction b and total degradable fraction (a + b) of PB. Irradiation and polyethylene-glycol increased rate of gas production (k), metabolizable energy (ME) and short chain fatty acid concentrations (SCFA), while, NaOH decreased gas production potential (b), ME and SCFA (p < 0.01). Data showed that although NaOH was efficent in detannification of PB, howevr, it reduced gas production and in situ degradation of PB.

Effects of electron beam, NaOH and urea on chemical composition, phenolic compounds, in situ ruminal degradability and in vitro gas production kinetics of pistachio by-products Keywords:

Pistachio by-product , Beam electron , Tannin , Gas Production