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; ۱۰, ۲۰, ۳۰ and ۴۰ 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 < ۰.۰۱) 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 < ۰.۰۱). Irradiation at doses of ۳۰ and ۴۰ kGy reduced tannin and increased total phenol content of PB (p < ۰.۰۱). NaOH and urea treatments decreased tannins, total phenolics and condensed tannins of PB compared to control (p < ۰.۰۱). In situ ruminal dry matter (DM) degradation data showed that irradiation increased (p < ۰.۰۱) and, urea and NaOH decreased (p < ۰.۰۱) rapidly fermentable fraction (a) of PB. NaOH decreased (p < ۰.۰۱) 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 < ۰.۰۱). Data showed that although NaOH was efficent in detannification of PB, howevr, it reduced gas production and in situ degradation of PB.

Keywords:

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