Comparative study of fatty acid and sterol profiles for the investigation of potential milk fat adulteration

Abstract

Milk fat adulteration is a common issue in Central Asia. To assess the current situation in the commercial milk market, 17 milk samples were checked for fatty acid (FA) and sterol profiles to detect potential adulteration using multivariate analysis. Analysis of FA and sterols was performed using gas chromatography with flame ionization detection and gas chromatography with mass-spectrometric detection, respectively. Cluster analysis of FA profiles revealed 3 types of milk samples: (1) samples containing a higher proportion of short-chain FA, (2) samples containing a higher proportion of long-chain FA, and (3) samples with significant amounts of C18 FA. Analysis of sterols showed that samples included (1) milk fat containing 100% cholesterol, sometimes with traces of phytosterols, (2) milk fat with high proportions of β-sitosterol and campesterol, and (3) milk fat containing high proportions of brassicasterol. We found significant relationships between FA profiles and sterol profiles. The profiles were compared with vegetable oil patterns reported in the literature. More than 50% of the samples appeared to be counterfeited. We conclude that identification of adulteration in milk can be based solely on determination of sterol patterns.

Prevalence of Milk Fraud in the Chinese Market and its Relationship with Fraud Vulnerabilities in the Chain

“…Various advanced techniques have been developed for milk authentication. For example, chromatographic methods combined with mass spectrometry (MS) have been used for detecting milk adulteration with nitrogen-rich compounds [14,15] and vegetable oils [16], digital imaging for milk protein determinations [17] and the detection of hydrogen peroxide in milk [18], proton transfer reaction mass spectroscopy (PTR-MS) and stable isotope ratio mass spectroscopy (IRMS) for the discrimination of organic milk [19,20] and nuclear magnetic resonance (NMR) for the nontargeted detection of multiple adulterants in milk powder [21]. Moreover, infrared spectroscopy-based techniques have become the most commonly used method for determining food authenticity, and they are considered as alternatives to reference methods [22].…”

Dairy Processing Affects the Gut Digestion and Microecology by Changing the Structure and Composition of Milk Fat Globules

“…Phospholipids were extracted twice with chloroform:methanol (2:1, v/v). The detection of FA and cholesterol (CHO) was adopted from the previous report by Nurseitova et al (2019). 19 FFA constituents were assessed by gas chromatography with an HP-88 chromatographic column (Agilent Technologies, Santa Clara, CA).…”

Peripartal Rumen-Protected L-Carnitine Manipulates the Productive and Blood Metabolic Responses in High-Producing Holstein Dairy Cows

“…On the other hand, any differences in the supply of fermentable carbohydrate lead to altered production of acetate in the rumen, as a precursor of mammary de novo fatty acid production. Therefore, it has been proposed that fatty acids with <16 C originated from de novo synthesis and those >16 C were preformed fatty acids taken up by the mammary gland, and 16:0 and 16:1 fatty acids come from both de novo and preformed sources (59,60). However, Dewhurst et al (61) showed that actual milk yields of C15:0 and C17:0 exceeded the duodenal flow of these fatty acids.…”