Effects of Rosemary (Rosmarinus officinalis L.) and Green Tea (Camellia sinensis L.) Extracts on Sensory Properties and Shelf-Life of Fresh Pork Sausage during Long-Term Frozen Storage and Subsequent Retail Display

The quality attributes of whole hog fresh pork sausages (28% fat) formulated with combinations of rosemary extract (R: 1500, 2000, 2500 ppm), green tea extract (G: 100, 200, 300 ppm), and synthetic antioxidants (approximately 0.02% BHA, BHT, and propyl gallate based on fat %) were evaluated after 0.5, 3, and 6 mo at –20°C followed by simulated retail display (3 ± 1°C) for up to 21 d. R and G delayed lipid oxidation across all frozen storage periods. The TBARS were reduced (P < 0.05) in treatments with higher amounts of R compared with the control (synthetic antioxidants only) after 6 mo of frozen storage. Volatile lipid oxidation products, including 2,4-decadienal were less abundant (P < 0.05) in sausages with higher concentrations of R following 3 mo of frozen storage. Greater concentrations of combined R and G extracts resulted in increased (P < 0.05) redness and yellowness and decreased (P < 0.05) lightness after 6 mo of storage. Higher concentrations of R enhanced (P < 0.05) chroma and slowed (P < 0.05) discoloration throughout 14 d of retail display after 3 and 6 mo of storage. Addition of R and G resulted in greater (P < 0.05) consumer acceptability than the control, which displayed spoilage and detectable rancidity by d 7 following 6 mo of storage in comparison to approximately 14 d for treatments with G and R. Pork, nutmeg, ginger, spice complex, and rosemary aromas were highest (P < 0.05) in sausages with increased concentrations of R following 0.5 and 3 mo of storage. Increasing green tea concentration reduced the intensities of ginger, copper-herbal, rancid, off-flavor and off-odor descriptors (P < 0.05). In conclusion, the addition of R and G enhanced the shelf-life of fresh pork sausages throughout 6 mo of frozen storage and helped maintain their quality during retail display for up to 14 d.