The 2012 ASHS Annual Conference

Pear fruits are popular among consumers due to their sweetness, crispness, characteristic fragrance and slight aroma. However, 25% to 30% of total fruit yields are practically applied to produce pear juice and pear flesh is throwing away as a waste although it is consisted of nutritious dietary fiber, accounting for 35% to 40% of whole fruit weight. In this study, we analyzed the pear dietary fiber content of five major Asian pear cultivars and determined optimal enzymatic hydrolysis condition of pear fleshes. Furthermore, we functionally characterized enzyme treated pear fleshes with respect to antioxidant activity, anti-lipid peroxidation, and anti-diabetic effect. Five pear cultivars showed the 11.63% to 30.15% amount of total fiber, occupied for 0.85% to 2.23% of soluble dietary fiber contents. Their dietary fibers were consisted of cellulose (15–113 mg/g), hemicellulose(93–171 mg/g), pectin (0.43–6.33 mg/g), and lignin (4.4–10.0mg/g). Fruit fleshes from five varieties pears were prepared by grinding, removing juice out and frozen-drying. Pear fleshes powder (1% to 50%) were enzymatically hydrolyzed for 3–12 h at 28–60 °C using four commercial enzymes including pectinase, cellulase, hemicelluase, or/and b-glucanse. Fleshes powder showed above 50% solubilization efficiency by the combination of pectinase (0.1 unit/mL) and cellulose (0.1–1 unit/mL) with a 10% flesh powder at 37 °C for 3–6 h. Solubilized fleshes showed higher antioxidant activity (62 mM vit C eq.) and anti-diabetic effect (23%), compared to those of pear juice with 2.9 mM vit C eq. and 22%, respectively. Those results indicated that it could be applicable to increase the yield of pear juice and produce nutritional and functional pear juice in food industry. This study was financially supported by Rural Development Administration (Project No. PJ 907072)