Evaluation of product quality of low-fat sausage containing lotus rhizome root powders as affected by cooking method during storage

Objective: This study investigated the antioxidant activities of lotus root, Nelumbo nucifera, by producing oven-dried lotus root powder (ODLRP) and powdered ethanolic extracts of the ODLRP produced using different concentrations of ethanol (25%, 50%, 75%, and 100%) for various times (0-8 h). The effect of ODLRP and an ethanolic extract powder produced by an extraction of ODLRP with 50% ethanol for 4 h (ODLRP_E50%) in low-fat boiled and smoked pork sausages were investigated. Methods: Antioxidant activities of the ODLRP and the ethanol extracts produced from the ODLRP under different extraction conditions were analyzed. Then, the ODLRP and ODLRP_E50% extract powder were added to pork sausages at concentrations of 1% and 0.1%, respectively, to determine their effects on the physicochemical properties, and antibacterial and antioxidant activities the sausages. Results: The ODLRP ethanol extract powder exhibited antioxidant activity, regardless of extraction time. The pH value of the boiled pork sausages containing 1% ODLRP was lower than that of the control sausages (CS). The color value demonstrated that the lightness of the boiled and smoked sausages decreased with the addition of 1% ODLRP or 0.1% ODLRP_E50% compared with the CS, but their redness and yellowness increased. The hardness and gumminess of smoked sausages with 0.1% ODLRP_E50% were lower than those of the CS (p<0.05). However, the springiness of the boiled sausages containing 0.1% ODLRP_E50% decreased. Boiled sausages treated with ODLRP and ODLRP_E50% had lower thiobarbituric acid reactive substances compared with the CS from day 14 of storage. Moreover, the boiled sausages containing 1% sausages containing 0.1% ODLRP_E50% extract powder exhibited an extended shelf-life compared with the CS. Conclusion: Ethanol extraction conditions of ODLRP and cooking methods of low-fat pork sausages are critical factors affecting the quality and shelf-life of sausages.