Abbas Rajaei Rad; Mohsen Sari; Mohammad javad Zamiri; Morteza Chaji; Somayeh Salari
Volume 18, Issue 3 , October 2016, , Pages 431-445
Abstract
Palm date leaves were processed with lime in a processing reactor in a factorial arrangement of treatments (3 × 3) with 3 levels of temperatures (40, 80 and 100°C) and time periods (80, 160, and 240 minutes) in a completely randomized design. Fermentation parameters measured using gas production ...
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Palm date leaves were processed with lime in a processing reactor in a factorial arrangement of treatments (3 × 3) with 3 levels of temperatures (40, 80 and 100°C) and time periods (80, 160, and 240 minutes) in a completely randomized design. Fermentation parameters measured using gas production technique. With increasing pretreatment time and temperature lignin content reduced from 13.0 percent in untreated leaves to 6.0 percent in leaves treated in 100°C for 240 min. Increasing time and temperature of the processing decreased ash content (P<0.01). Calcium concentration was increased from 0.58 percent in untreated leaves to 0.94 in the processed biomass at a temperature of 40°C for 80 min (P<0.01). Interaction was significant among pretreatment time and temperature on cell wall, dry matter loss, gas production from fermentable fraction and gas production (P<0.01). Gas production at the end of 72 h incubation increased from 76.2 ml per gram of dry matter in untreated samples to 189.8 ml per gram of dry matter in the treatment of 100°C for 240 min. Organic matter digestibility increased with increasing severity of pretreatment from 26.5 percent in the treatment of 40°C for 80 min to 36.4 percent in the treatment of 100°C for 240 min. The images of scanning electron microscopy showed more pores and holes in pretreated samples with increasing temperature and processing time compared to untreated sample. Results indicated that lime pretreatment with heat can remove lignin and improve in vitro digestibility of date leaves.