FOOD SCIENCE ›› 2020, Vol. 41 ›› Issue (15): 15-21.doi: 10.7506/spkx1002-6630-20190620-236

• Basic Research • Previous Articles     Next Articles

Comparison of Antioxidant Properties between Yak Milk and Holstein Cow Milk Hard Cheese

YANG Jing, LIANG Qi, SONG Xuemei, ZHANG Yan   

  1. (Functional Dairy Product Engineering Laboratory of Gansu Province, College of Food Science and Engineering, Gansu Agricultural University, Lanzhou 730070, China)
  • Online:2020-08-15 Published:2020-08-19

Abstract: Objective: To explore the pattern of milk fat oxidation during cheese ripening and improve the theory of milk fat oxidation in hard cheese by comparing the relationship between milk fat content and oxidation rate of hard cheese made from yak milk and Holstein cow milk. Methods: The acidity value (ADV), carbonyl value (CV), peroxide value (POV), reflecting the degree of primary oxidation, and thiobarbituric acid (TBA) value, reflecting the degree of secondary oxidation, were measured after 0, 1, 2, 3, 4, 5 and 6 months of ripening at 4 ℃. Results: 1) The ADV and CV of both cheeses increased continuously during the ripening process; for yak milk and Holstein cow milk cheese, the total increment in ADV was respectively (263.94 ± 13.88)% and (363.91 ± 11.71)%, and the average rate of increase in CV were respectively (0.140 0 ± 0.017 7) and (0.138 5 ± 0.015 1) meq/(kg·month). 2) POV first increased and then decreased during the maturation period for both cheeses, and there was no significant difference in POV between the two cheeses at all ripening periods (P > 0.05) except for 3 months (P < 0.05). 3) TBA value showed an upward trend during the maturation process, increasing by (330.48 ± 72.64)% and (335.89 ± 36.41)% and at an average rate of (0.035 4 ± 0.002 9) and (0.033 6 ± 0.002 0) mg/(kg·month) in yak milk and Holstein cow milk cheese, respectively. 4) The regression equations of first- and second-order oxidation rate for yak milk hard cheese were fitted as follows: Y = –0.001 7x5 + 0.038 2x4 - 0.336 6x3 + 1.347 7x2 – 2.146 7x + 1.496 9 (r2 = 0.993 2) and Y = 0.034 3x + 0.024 4 (r2 = 0.968 8), respectively. Conclusion: During the ripening process, yak milk hard cheese exhibited a lower oxidation rate despite its higher milk fat, indicating that the antioxidant factor in yak milk cheese is higher than that in Holstein cow milk cheese and plays an important role in the late stage of ripening, thereby inhibiting the oxidation rate.

Key words: hard cheese, lipid oxidation, oxidation indices, average growth rate

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