The objective of this study was to investigate the effects of neutral proteases from different sources on the textural properties and flavor compounds of high-protein fermented milk, so as to improve the taste, flavor, and drinking experience of high-protein fermented milk. In this study, two neutral proteases—ADMIL (AD) and Galaya smooth (GS)—were added at mass concentrations of 0.02% and 0.012%, respectively, to a high-protein yogurt base with a protein content of 6 g/100 g. After fermentation at 42 ℃, the final products were characterized for textural properties including viscosity, gel strength, hardness, friction coefficient, and water-holding capacity, while changes in flavor compounds induced by the two enzymes were also analyzed. Results showed that compared with the control sample without protease addition, the AD-treated and GS-treated samples exhibited decreases in viscosity by 8.9% and 5.3%, respectively, a 42.1% reduction in gel strength, and decreases in hardness by 33.3% and 41.7%, respectively. Particle size and friction coefficient were also reduced, while water-holding capacity slightly decreased with no significant difference (P>0.05). Sensory evaluation indicated that the addition of neutral proteases improved the drinking experience of high-protein fermented milk. Further analysis of volatile compounds revealed an increase in the content and variety of flavor compounds in both enzyme-treated samples. Among them, the concentrations of flavor compounds such as n-pentanoic acid, hydroxyacetone, butyric acid, 2-hydroxy-3-pentanone, sec-butanol, myristic acid, benzoic acid, 2,3-pentanedione, (+)-limonene, and 3-hydroxy-2-butanone were significantly increased in the AD-treated sample. In the GS-treated sample, the concentrations of n-pentanoic acid and butyric acid were significantly increased. The AD-treated sample showing a more pronounced flavor enhancement. In conclusion, neutral proteases effectively reduced the viscosity, particle size, and friction coefficient of high-protein fermented milk, significantly improved its flavor, and demonstrated substantial application potential.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |