Phytochemical Composition and Antioxidant Activity of Trichoderma reesei Degraded Date (Phoenix dactylifera L.) Pits

Abstract

Background: Date palm (Phoenix dactylifera L.) is a dominant fruit crop in most of the Arabian countries. Date pits, as a major byproduct which remained after consumption of date flesh proved to be valuable source of energy. Methods: Solid State Degradation (SSD) system was used for the preparation of degraded date pits. Date pits degraded with Trichoderma reesei were evaluated for their proximate, chemical composition and antioxidant activity. Results: The crude fiber content of degraded date pits was found to be 20.8 %, ash (2.09%), crude fat (7.2%), protein (5.56%), and total carbohydrate (87.2%). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) was found to be 74.6% and 45.7%, respectively. Monosaccharide composition of fiber showed that the degradation with T. reesei significantly (P<0.05) enhanced the glucose and mannose content of cellulose, hemicellulose and lignin. Pectin, total carbohydrate and mannan oligosaccharide content were also increased in degraded date pits in which galactose and mannose were the major neutral sugars. Among the studied minerals, potassium, calcium, magnesium, sulphur and phosphorus were predominant. The phenolic and flavonoid contents of degraded date pits significantly (P<0.05) increased to 14.230 g Gallic equivalent/100g DW and 11.68 g Rutin equivalent /100g DW. Degraded date pits also showed significant antioxidant activity as evidenced by the results of 2,2-diphenyl-1- picrylhydrazyl(DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline 6 sulphonicacid) (ABTS) and Ferric Reducing Antioxidant Power (FRAP) assays. Conclusion: Biological degradation with T. reesei significantly (P<0.05) improved the nutritional effect of date pits and thereby its potential usage in food industry was greatly improved.