Abstract:

【Objective】The objective of this study was to research the function of thinned young kiwifruit discarded in “Blossom and Fruit Thinning” in goat meat cold storage and to provide useful information for lengthening the shelf life of refrigerated goat meat, maintaining goat meat quality and delaying the oxidation of goat meat. 【Method】The goat meat was sprayed with 1 mg·mL ^-1 polyphenols from thinned young kiwifruit, epicatechin and potassium sorbate solution, control group was treated with distilled water, then preserved at 4℃ refrigerator in ziplock bags. The microstructure, texture characteristics, pH, fatty acid content, thiobarbituric acid reactive substance assay (TBARS) and volatile base nitrogen (TVB-N) of goat meat were measured during 8 d refrigeration. 【Result】As time went on, the goat meat microstructure of the four groups became tender and muscle fibers were gradually loosened and relaxed. During the cold storage period, the hardness of goat meat in four groups showed a decreasing trend. In the first 3 days, the hardness values were ranked as follows: potassium sorbate group> epicatechin group> blank group> thinned kiwifruit polyphenol group. After 5 days, the hardness values of the groups became similar. At the end of cold storage, the hardness of the thinned kiwifruit polyphenol group, epicatechin group, potassium sorbate group and blank group decreased by 50.52%, 41.73%, 39.63% and 51.56%, respectively. The springing of goat meat in four groups was first increased and then remained stable. In the first 3 days, the springing value of the polyphenols group was lower than that of the other three groups. At the end of cold storage, the springing values of the thinned kiwifruit polyphenol group, epicatechin group, potassium sorbate group and blank group were reduced by 45.23%, 33.34%, 44.64% and 41.31%, respectively; the chewiness of goat meat in four groups showed a downward trend as a whole, and the chewiness of the thinned kiwifruit polyphenol group, epicatechin group, potassium sorbate group and blank group decreased by 72.06%, 61.46%, 62.00% and 67.37%, respectively. The cohesiveness and resilience of the thinned kiwifruit polyphenol group were relatively stable, and the cohesiveness of the potassium sorbate group was in the same trend. With the prolongation of time, the content of polyunsaturated fatty acids (PUFA) in the thinned kiwifruit polyphenol group was remained stable, and the PUFA content of epicatechin and potassium sorbate groups was peaked at 6 d, while the content of blank group showed a downward trend. At the end, the PUFA content of thinned kiwifruit polyphenol group was 1.11, 1.40 and 1.86 times of the epicatechin, potassium sorbate and blank groups, respectively. The content of monounsaturated fatty acid (MUFA) in the thinned kiwifruit polyphenol group was increased first and then decreased. The highest value of MUFA content in the thinned kiwifruit polyphenol group was reached in 4 d, while other groups showed a downward trend. At the end of cold storage, the MUFA content of thinned kiwifruit polyphenol group was 1.10, 1.17 and 1.21 times of the epicatechin, potassium sorbate and blank groups, respectively. The content of the saturated fatty acids (SFA) and total fatty acids (TFA) in the thinned kiwifruit polyphenol, epicatechin and blank groups was decreased, while the content of potassium sorbate group decreased first and then stabilized. The TFA content of thinned kiwifruit polyphenol group was higher than that of the other three groups in 2-4 days. The TFA content of the thinned kiwifruit polyphenol and epicatechin groups was higher than that of the other two groups in 4-8 days. The TBARS values of goat meat in four groups decreased firstly after storage, and after 3 days, their values were ranked as follows: thinned kiwifruit polyphenol group < epicatechin group < blank group < potassium sorbate group. At the end of cold storage, the TBARS values of thinned kiwifruit polyphenol group were 90.84%, 56.83% and 59.45% of the epicatechin, potassium sorbate and blank groups, respectively. With the prolongation of time, the TVB-N value of goat meat gradually increased while the pH increased first and then stabilized. Compared with the epicatechin, potassium sorbate and blank groups, the chilled time of goat meat in the thinned kiwifruit polyphenol group was extended by 0.48, 1.13 and 1.61 d, respectively. 【Conclusion】Thinned young kiwifruit polyphenols could prolong the shelf life of meat and improve meat quality by delaying the rise of goat meat pH, inhibiting lipid oxidation, slowing down PUFA oxidation, and helping maintain cohesiveness and resilience stability.

Key words: goat meat, kiwi fruit thinning, polyphenol, refrigerated storage, quality, oxidation