Evaluation of sterol composition in different formulations of cocoa milk as milk fat purity indicator

Abstract

Based on available national standards, the level of phytosterols in cocoa milk should not exceed 3% of sterol compounds. The aim of this study is to control the quality of the product and evaluate the sterol composition application as an indicator of cocoa milk fat authentic. Therefore, the first part of the present study aimed to examine the sterol composition of ingredients, including milk, cocoa powders. For this purpose, the level of phytosterols in products determined. After the preparation of samples, their sterol composition examined using gas chromatography. Results showed that the level of cholesterol and phytosterols in milk was 99.24 and 0.76, respectively. The examination of the sterol profile of cocoa powder revealed that the largest portion of sterol compounds belongs to beta-sitosterol, stigmasterol and campesterol have the highest level among sterol compounds, respectively. In the second part of this study, the effect of adding various amounts (2, 5, and 8%) cocoa powders was examined on the level of phytosterols in milk due to determine the optimal amount of these compounds to observe standard ranges. As expected, by increasing the percentage of cocoa powders in the formulation of cocoa milk, the level of phytosterols increased.

Simultaneous determination of cholesterol, stigmasterol, and β‐sitosterol contents in milk and dairy products

“…According to Zarabadipour et al. (2020), the sterol composition of milk consisted of cholesterol (99.24%) and phytosterols (0.76%). The chromatogram and 3D spectrum of the analysis of the milk sample with the spiked stigmasterol (50 µg) and β‐sitosterol (50 µg) are shown in Figure 1.…”

“…Adulteration in dairy products is performed by removal of some valuable substances, e.g., milk fat can be partially replaced with low‐prized vegetable oils such as palm, sunflower, or soya bean oil (Sadeghi et al., 2018). The useful tool for dairy products authentication could be thus the analysis of fatty acid composition or triacylglycerols (TAG); however, it has some drawbacks in the variations in animal feeding and different regional and seasonal conditions or the similarities between the profiles of fatty acids in some vegetable oils and milk (Sadeghi et al., 2018; Zarabadipour et al., 2020). Despite that, the methods based on the analysis of fatty acid composition and physicochemical properties such as refractive index, melting point, or iodine value are often time‐consuming and involve several manual operations (Khorsandmanesh et al., 2020).…”

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Authentication is defined as the determination of the origin and purity of foods based on their composition or genome, and it is an important matter on legal requirements, economic reasons, quality assurance, or usage of safe products (Zarabadipour et al, 2020). As milk and dairy products have high nutritional value, global production as well as consumption, it makes them a target of adulteration (Nascimento et al, 2017).

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“…also found a small amount of stigmasterol and β-sitosterol in Iranian milk samples, ranging from 1.1 to 5.0 mg/kg and 14 to 53 mg/kg , respectively. According toZarabadipour et al (2020), the sterol composition of milk consisted of cholesterol (99.24%) and phytosterols (0.76%). The chromatogram and 3D spectrum of the analysis of the milk sample with the spiked stigmasterol (50 µg) and β-sitosterol (50 µg) are shown in Figure1.…”

“…Despite that, the methods based on the analysis of fatty acid composition and physicochemical properties such as refractive index, melting point, or iodine value are often time-consuming and involve several manual operations (Khorsandmanesh et al, 2020). The determination of the sterol composition is the most suitable method to differentiate vegetable and animal fat as phytosterols, such as stigmasterol or β-sitosterol, are not detectable in animal fat, or present only at trace levels, respectively (Kamm et al, 2002;Zarabadipour et al, 2020).Sterols are tetracyclic lipid components found in animals, plants, and microorganisms. Cholesterol is the major sterol of animal's fats, while the most common sterols in plants are β-sitosterol, campesterol, and stigmasterol (Chen et al, 2015).…”