Comparison of the effects of different processing methods on the quality of pear paste: Color, polyphenol compounds and antioxidant property

Pear paste, a traditional Chinese functional food, is known for its potential effectiveness in alleviating pharyngitis. This study systematically investigated the effects of different processing methods on the quality of pear paste, including pretreatment (blanching and enzymatic treatment), vacuum concentration, and boiling. Blanching retained phenolic and flavonoid compounds of pear paste with 7.11 mg GAE/g DW and 4.85 mg RE/g DW, and the highest concentration of chlorogenic acid at 1000.72 mu g/g DW. However, the blanching paste had an undesirable dull appearance, with color parameters L*, a*, b*, and C* of 32.38, 9.59, 9.6, and 13.57, respectively. Enzymatic pretreatment enhanced the solubility and accumulation of phenolic and flavonoid compounds of 8.30 mg GAE/g DW and 3.85 mg RE/g DW, with coumaric acid being the highest at 7611.66 mu g/g DW. The enzymatic paste exhibited a reddish and translucent appearance, with color parameters L*, a*, b*, and C* of 36.39, 17.1, 13.61, and 21.86, respectively. Vacuum concentration and boiling are the processes responsible for the deepening of the color and the enhancement of the antioxidant property of pear paste due to non- enzymatic browning. The pear paste obtained by boiling at 120 degrees C for 145 min exhibited the most intense appearance and the highest levels of active ingredients and antioxidant properties. The DPPH, ABTS, and FRAP values of the pear paste prepared by the combination of enzymatic pretreatment and boiling at 120 degrees C were 1.40, 8.22, and 6.90 mg VC/g DW, respectively. This study lays the foundation for the scientific production of pear paste.