关键词: 沙葱；膻味脂肪酸；脂质氧化；蛋白质氧化；货架期

Abstract: Objective: The objective of this study was to investigate the effects of dietary supplementation of Allium mongolicum Regel or its extracts on the flavor and odor fatty acid deposition and shelf life of lamb Longissimus?dorsi?muscle in order to provide useful information to reduce lamb odor, extend the shelf life of refrigerated lamb meat, and delay oxidation in lamb meat. Methods: Sixty three-month-old male small-tailed Han sheep were selected and randomly allocated into four groups of five animals each in triplicate in a randomized block design: 1) a basal diet served as control; 2) the basal diet supplemented with 10 g/d Allium mongolicum Regel powder as AMR; 3) the basal diet supplemented with 3.4 g/d of a water extract of Allicum mongolicum Regel as AWE; and 4) the basal diet supplemented with 2.8 g/d of an ethanol extract of Allicum mongolicum Regel as AFE. The experiment lasted for 75 days, including a 15-day adaptive period and a 60-day experimental feeding period. At the end of the experiment, two lambs from each replicate of each group were randomly selected and slaughtered, and Longissimus?dorsi?muscle was excised to detect odor fatty acids. Moreover, the degree of lipid and protein oxidation, antioxidant capacity, pH, color, juice loss and microbial load of Longissimus dorsi muscle packaged in air-permeable polystyrene bags were measured during nine days of storage at (4.0 ± 0.5) ℃. Results: 1) The deposition of three odor fatty acids was significantly inhibited by dietary supplementation of AMR, AFE or AWE compared with the control group (P < 0.001). 2) Dietary supplementation with Allium mongolicum Regel or its extracts decreased the acid value (AV), peroxide value (POV) and total volatile base nitrogen (TVB-N) content of Longissimus dorsi muscle (P < 0.001). 3) Dietary supplementation with Allium mongolicum Regel or its extracts increased the total antioxidant activity (T-AOC) (P < 0.001), total superoxide dismutase (T-SOD) activity (P < 0.001), and glutathione peroxidase (GSH-Px) activity (P < 0.05), and lowered the thiobarbituric acid reactive substances (TBARS) value. 4) Dietary supplementation with Allium mongolicum Regel or its extracts lowered hue angle (P < 0.01). Besides, the water extract significantly decreased the color parameter b* (yellowness/blueness) and juice loss percentage, whereas AMR powder significantly decreased only the juice loss percentage (P < 0.05). The pH, color and juice loss percentage varied in different manner depending on storage time. 5) Dietary supplementation with Allium mongolicum Regel or its extracts decreased the total bacterial count (P < 0.01). Conclusion: Overall, dietary supplementation with Allium mongolicum Regel or its extracts can contribute to improve the characteristic flavor and odor of lamb by decreasing odor fatty acid deposition, delaying fat and protein oxidation, improving the antioxidant capacity, maintaining the pH and color, reducing the juice loss percentage, and inhibiting the growth of bacteria.

Key words: Allium mongolicum Regel; flavor and odor fatty acids; lipid oxidation; protein oxidation; shelf life