Quantification of Free Short-Chain Fatty Acids in Raw Cow Milk by Gas Chromatography-Mass Spectrometry

Abstract

Free short-chain fatty acids (FSCFAs) are a momentous contributor to the flavor of the raw cow milk. Hence, the purpose of this research was to build an approach for the quantification of 10 FSCFAs in raw cow milk. Raw cow milk samples are acidified by hydrochloric acid ethanol (0.5%) solution pretreatment and then processed on the gas chromatography-mass spectrometry. With the exception of iso C5:0 and anteiso C5:0 co-flux, the remaining eight FSCFAs were effectively separated by chromatography. The methodological validation data revealed that the linear relationship satisfied the assay requirements (coefficient of determination >0.999), the limits of quantification were 0.167 to 1.250 μg mL−1, the recoveries ranged from 85.62% to 126.42%, the coefficients of variation were 1.40~12.15%, and no SCFAs in the triglyceride form were potential degradation, and the precision ranging from 0.56% to 9.09%. Our easy, fast, and robust method successfully determined three FSCFAs in raw cow milk without derivatization. Some characteristic features of FSCFAs have been discovered in raw cow milk such as its higher percentages of C4:0 and C6:0. Our research has provided a very valuable method for the future quality and safety control of raw milk and nutritional studies.

Content of orotic acid and selected bioactive compounds in ovine milk during lamb rearing

“…The presence of SCSFAs in sheep's milk contributes to its distinctive taste and smell, as well as improves fat digestibility (Miltko et al, 2016). High levels of SCSFAs increase the acidity of milk, and caproic acid (C6:0) is especially known for its cheese-like, rancid odour (Wu et al, 2023). Excessive SCSFAs content can alter the taste and texture of raw milk, making it unsuitable for consumption and processing (Wu et al, 2023).…”

“…High levels of SCSFAs increase the acidity of milk, and caproic acid (C6:0) is especially known for its cheese-like, rancid odour (Wu et al, 2023). Excessive SCSFAs content can alter the taste and texture of raw milk, making it unsuitable for consumption and processing (Wu et al, 2023). Ruminal microorganisms are responsible for the biosynthesis of SCSFAs, mainly acetates, propionates and butyrates (Takizawa et al, 2023).…”

The effect of Lactococcus lactis CICC 23610 fermentation on the physicochemical properties and flavor formation of oat beverage

“…Headspace solid‐phase microextraction (HS‐SPME) was performed following the method of Xufang Wu et al (2023), with slight modifications. In brief, 5 mL of the sample and 10 μL of internal standard material were added to a 20 mL injection vial, which was then sealed with a headspace‐sealed cap.…”