Effects of magnesium potassium sulfate on Tibetan sheep quality and its volatile and non-volatile metabolic substances.

Abstract

Preliminary research has identified that potassium and magnesium may influence the quality of Tibetan sheep meat, although the underlying mechanisms remain unclear. This study investigated the effects of dietary supplementation with magnesium potassium sulfate (PMS) on carcass quality, meat quality, nutritional composition, and flavor metabolites of Tibetan sheep, and explored potential mechanisms using a metabolomics approach. Dietary inclusion of 0.3% PMS significantly enhanced carcass quality, as shown by increases in abdominal wall thickness and backfat thickness by 13.13% and 7.41%, respectively, compared with the control group ( p < 0.05). Supplementation with 0.25% PMS significantly elevated pH at 24 h, a, and intramuscular fat content, while reducing pH at 45 min and b ( p < 0.05). The 0.25% PMS group also exhibited significantly higher concentrations of linoleic acid, linolenic acid, EPA, and DHA than the control group ( p < 0.05). Volatile compound analysis showed that PMS was associated with the production of fruity and nutty compounds (e.g., methyl 3-methylpentanoate and methyl heptanoate) and with the suppression of malodorous substances such as 1-hydrazinopropan-2-ol. Non-volatile metabolomics revealed that PMS supplementation was associated with enhanced fatty acid biosynthesis, which correlated with the adipocyte cytokine signaling pathway. PMS supplementation was further associated with modulation of the sphingolipid signaling pathway, which correlated with synergistic regulation of meat quality and contributed to an improved flavor profile of Tibetan sheep meat.