Chemical Composition and Nutritional Quality of Commercial Tahini

Abstract

Thanks to its valuable nutritional value and captivating flavour, tahini, an oily paste made from sesame seeds, has recently become popular outside of Middle Eastern cuisine. However, alongside valuable and balanced levels of lipids, proteins, sterols, and minerals, this product may contain various contaminants, including toxic and potentially toxic elements. The aim of this study was therefore to evaluate the quality and safety of seven brands of commercial tahini. To this end, the proximate composition and the fatty acid and sterol profiles were determined. Moreover, the atherogenicity index (AI) and thrombogenicity index (TI) were also assessed. The elemental composition was screened, and the uptake percentage of each element was evaluated. The percentages of saturated (SFAs), mono- (MUFAs), and poly- (PUFAs) fatty acids fell within the following ranges, respectively: 15.44–17.14%, 37.93–43.36%, and 38.51–45.14%. The order of abundance of macro-elements for most samples was P > K > Ca > Mg > Na. Significant concentrations of essential trace elements were found in the tahini samples, including Zn, Fe, Mn, Cu and Se. As regards toxic elements, only one brand appears to exceed the maximum limits for Cd and Pb specified in the European Regulation. However, a low intake of most inorganic elements was obtained from the consumption of 1 g of tahini per day.

1. Introduction

The growing demand among consumers for plant-based foods, such as tahini, is part of a broader trend of seeking answers to specific issues related to well-being, environmental sustainability and particular dietary requirements, such as vegetarianism, veganism and gluten-free diets [1]. Tahini is a thick, beige-coloured paste made from the mechanically hulled, roasted and ground seeds of the plant Sesamum indicum L., which mainly grows in tropical and temperate climates in Africa, Asia and Europe [2,3]. It is used as a condiment in many regions of the Middle East [4,5], mainly in the Levant countries such as Syria, Lebanon, Palestine, and Jordan, but its use is now widespread in various areas of Southeast Asia and Africa, where it is appreciated for its nutritional qualities [6]. It has always been used to prepare famous Middle Eastern dishes such as hummus and babaghanoush [7], and more recently it has gained popularity for its use in vegetarian recipes [8].

In recent years, there has been a significant increase in global tahini production, establishing it as a popular food beyond the Middle East. Geographically, the main market for tahini is the Middle East and Africa, which is estimated to account for between 36% and 63% of the market. This dominance is linked to the region’s important and well-established culinary tradition, in which tahini is a key ingredient in many dishes, particularly in countries such as Lebanon, Turkey, Israel and Egypt. However, the European market is also growing. In 2024, it was valued at around $230 million, and growth is forecast to reach approximately $340 million by 2032, representing a CAGR of 3.9% [9]. In 2024, the global tahini market was valued at around $1.77 billion, and is projected to reach $2.29 billion by 2030, supported by a compound annual growth rate (CAGR) of 5.3%. The growing popularity of Arabic cuisine in developed countries and greater awareness of the nutritional benefits of tahini are key factors driving this market’s growth, thanks to the ever-increasing demand for sesame-based products [10]. This market growth opportunity is supported by the increase in supply and the product’s easy availability, facilitated by the expansion of e-commerce, which makes tahini accessible to a wide and diverse audience.

The growing popularity of tahini is undoubtedly due to its nutritional benefits, which stem from its chemical composition (proteins, bioactive components, fatty acids, minerals and vitamins) [11]. The chemical profile of tahini generally depends on the variety of sesame used and the technological processes employed during production, such as husking, roasting and grinding [11].

Its nutritional profile is like that of sesame. Lipids are the most abundant class, accounting for 57–85% of the total and are characterised by a high proportion of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) [12]. The unfortunate truth about tahini is that it is low in omega-3 fatty acids. However, there is a bright side: it contains no cholesterol [13]. The protein content varies between 23% and 27%, which is rich in methionine, cysteine, and tryptophan [11]. In general, tahini is an excellent source of calcium, followed by potassium, magnesium and phosphorus [14]. These elements are essential for maintaining healthy bones, muscles and a healthy cardiovascular system. Although they are present in lower concentrations, other micronutrients such as iron, zinc, copper, and selenium are still important for completing the nutritional picture [15,16]. Tahini is a good source of B vitamins, including niacin (B3), folic acid, thiamine (B1), pyridoxine (B6) and riboflavin (B2) [17]. These micronutrients play a key role in energy metabolism, nucleic acid synthesis and proper nervous system function. Conversely, the product contains low levels of vitamins C, B12, retinol (vitamin A), D2, D3 and K, which is typical of oilseeds [18]. Furthermore, the presence of phenolic compounds gives tahini antioxidant properties, which help to prevent the oxidation of various biological molecules [11]. Another important class of compounds found in tahini is lignans, particularly sesamin. Numerous studies have highlighted the role of these compounds in regulating fatty acid metabolism and inhibiting cholesterol absorption and biosynthesis [14]. They also have a powerful antioxidant and vitamin E-saving effect. These compounds also have hypotensive, anti-ageing and liver function support properties [14].

Thanks to its nutritional, preventive and curative properties, tahini is an important resource in both the culinary and medical fields [14]. However, scientific evidence regarding tahini consumption and its potential health benefits is still limited [13]. Nevertheless, despite the small number of studies, the preliminary results are promising and support the beneficial effects of tahini on oxidative stress and improvements in certain cardiovascular parameters, as observed in both healthy subjects and diabetic patients [19]. In this regard, integrating tahini and tahini-based products into our daily diet is an ideal way to promote healthy and balanced eating patterns, providing an alternative to other frequently consumed snacks.

Although tahini contains many beneficial compounds, it is also important to consider possible xenobiotics that may be present, such as toxic or potentially toxic inorganic elements, due to cross-contamination or inadequate processing methods [20]. The main inorganic pollutants found in tahini are lead and cadmium. As tahini is plant-based, the presence of these elements is directly related to either the product’s environmental origin (soil and air) or the packaging used [20].

However, the available literature contains very little information on the safety and quality of tahini. This lack of data is a significant barrier to a full understanding of this food, which is becoming increasingly widespread on international markets. Most studies only focus on determining its proximal and fatty acid compositions and the presence of certain essential macro- and micronutrients. However, there is no research focused on the sterol profile of tahini or screening for a larger number of inorganic elements, including toxic and potentially toxic ones. Consequently, there are also no studies assessing potential exposure to these contaminants following the ingestion of certain amounts of tahini, nor any research into consumer safety. This highlights the need for further research to ensure more rigorous control and thorough evaluation of the safety and quality of tahini.

Therefore, this study aims to expand upon existing knowledge of the tahini matrix by providing new information, particularly concerning bioactive compounds and contaminants that have been less extensively explored in the previous literature. To this end, this study will conduct a comprehensive assessment of the quality and safety of commercial tahini products available on the Italian market, produced by companies in various geographical regions. In this regard, the proximate composition, mineral profile (including essential, toxic and potentially toxic elements) and lipid fraction were determined. In addition to evaluating the total lipid content and fatty acid composition, the phytosterol content was determined for the latter. The ultimate goal of this research was to provide a reliable picture of the nutritional profile and commercial safety of the analysed samples, while also providing consumers with useful information about the versatility of tahini and its beneficial effects on human health.

2. Materials and Methods

2.1. Samples

This study considered samples of tahini produced by different companies and, consequently, from different geographical origin (

Table 1. Description of the analysed tahini samples.

Sample Code	Sample	Tahini Composition	Geographical Origin
T-1	Organic tahini hulled seed sesame	100% Sesame Seeds	Turkey
T-2	Tahini sesame seed paste	Toasted Hulled Sesame Seeds	Israel
T-3	Light tahini sesame cream	100% Hulled Sesame Seed. This product may contain traces of nuts, lupin beans, milk and peanuts	Germany
T-4	Hulled original tahini	Sesame Seeds	Non-UE
T-5	Tahini 100% organic	Sesame Seeds	Lebanon
T-6	Whole tahini sesame cream	Whole toasted sesame seeds. This product may contain soia, nuts, and peanuts	Non-UE
T-7	Tahini sesame paste	100% Ground Sesame Seeds	Greece

). These products were purchased online in 2025. Once in the laboratory, the samples were logged and stored at 4 °C prior to analysis. Per every tahini sample, n = 3 analytical replicates were performed.

2.2. Standard and Reagents

Merck (Darmstadt, Germany) supplied all the analytical-grade reagents and chemicals that were used for the analysis of the samples’ proximate composition. Carlo Erba (Milan, Italy) supplied the Kjeldahl catalyst for the protein determination.

The reference fatty acid methyl esters (FAME, C4–C24) used for fatty acid analysis were sourced from Sigma-Aldrich (Steinheim, Germany) and Supelco (Bellefonte, PA, USA), while the analytical grade reagents were sourced from Merck (Darmstadt, Germany).

The solvents used for sterol analysis (ethyl ether, n-heptane and n-hexane) were supplied by J.T. Baker (Milan, Italy). The derivatising agents bis-trimethylsilyl-trifluoroacetamide and trimethylchlorosilane (BSTFA:TMCS 99:1), as well as the analytical standards of the individual sterols (cholesterol, β-sitosterol, campesterol, stigmasterol, clerosterol, Δ-5-avenasterol, Δ-5,24-stigmastadienol, Δ-7-stigmastenol, and Δ-7-avenasterol, ≥98% purity each), were supplied by Supelco (Bellefonte, PA, USA) and Sigma-Aldrich (Steinheim, Germany).

All the chemicals needed for the analysis were very pure and were supplied by J.T. Baker (Milan, Italy). The procurement of single-element standard solutions of Mg, Ca, P, Mn, Fe, Co, Cu, Zn, Cd, Cr, Li, Be, Na, Ni, Mo, K, Pb, As, Se, Sn, Sb and V (1000 mg/L in 2% HNO₃) was completed for the purposes of ICP-MS and ICP-OES analyses from Fluka (Milan, Italy).

Merck (Darmstadt, Germany) supplied a Hg solution (1000 mg/L in 3% HCl).

2.3. Proximate Composition

The proximal composition of each tahini sample (fibre, crude protein, ash and moisture content) was determined in triplicate, in accordance with the official AOAC analytical protocols [21,22].

The quantity of dietary fibre was ascertained by means of the Megazyme test kit (International Ireland Ltd., Wicklow, Ireland) in accordance with the official AOAC method guideline 991.43. Two 1 g samples were analysed at the same time. First, α-amylase was used to treat them at 80 °C, and then they were digested with protease and amyglucosidase at 60 °C. The solutions were subsequently chilled to approximately 40 °C prior to being combined with ethanol, leading to the formation of the fibres. Next, the fibre residues were filtered, washed with organic solvents and dried. The mean weight was subsequently calculated. At this stage, there was a difference in the processing of the two residues. The first residue was then subjected to an incubation process at a temperature of 500 °C, continuing until it had reached a constant weight, a process that took approximately 12 h. Following this, the ash content was determined using AOAC method 972.15. The second residue was analysed for crude protein. This was performed according to the official AOAC method 976.05. The digestion of the residue was carried out using H₂SO₄, CuSeO₃·2H₂O and K₂SO₄, with the use of a SpeedDigester K-439 mineraliser (Büchi, Switzerland). Treatment of the resulting solution with NaOH led to the production of NH₃. The nitrogen content was then measured using a titration with HCl. Crude protein content was then calculated by multiplying nitrogen content by a conversion factor of 6.25. The dietary fibre content was calculated by determining the average weight of the dried residue and subtracting the weights of the protein and ash.

2.4. Total Lipids

The lipid component was analysed using a method based on the Folch method [23] and reported by Nava et al. (2023) [24], with some modifications. Four grams of sample were mixed with 40 mL of a 2:1 chloroform-methanol solution and then 10 mL of 0.73% NaCl to facilitate separation of the aqueous and organic phases. The mixture was treated with ultrasound for 15 min and then centrifuged for 10 min at 4000 rpm to separate the two phases. The chloroform extract was filtered with anhydrous Na₂SO₄ and filter paper in a volumetric flask to remove any traces of water. The filtrate was then transferred to a rotary evaporator and dried. The lipid content (g/100 g) was determined gravimetrically.

2.5. Fatty Acid (FA) Analysis

To evaluate the fatty acid profile, the extracted lipids were converted into fatty acid methyl esters (FAMEs) via cold transesterification. Specifically, 2 mL of heptane and 0.2 mL of methanolic potassium hydroxide were added to each 0.1 g sample [25]. The samples were analysed using a gas chromatograph equipped with a flame ionisation detector (GC-FID, Dani Master GC, Dani Instrument, Milan, Italy). The operating conditions were identical to those reported by Litrenta et al. (2025) [26]. The retention times of FAMEs of nutritional interest were compared with those of reference compounds present in the Supelco 37-component FAME Mix to identify them. Triplicate analyses were performed for each sample, along with analytical blanks.

The atherogenicity index (AI) and the thrombogenicity index (TI) were used to assess the health and nutritional potential of the lipids in the tahini samples. The AI is the amount of the main saturated fatty acids added together compared to the amount of the main classes of unsaturated fatty acids, using this formula [24]:

AI = [C12:0 + (4 × C14:0) + C16:0]/[Σ n-6 PUFA + Σ MUFA + Σ n-3 PUFA]

Instead, TI indicates the propensity to form blood clots and is determined by calculating the ratio of pro-thrombogenic (SFA) to anti-thrombogenic (MUFA, n-6 PUFA and n-3 PUFA) fatty acids [24]:

TI = [C14:0 + C16:0 + C18:0]/[0.5 × Σ n-6 PUFA + 0.5 × Σ MUFA + 3 × Σ n-3 PUFA +
(n-3 PUFA/n-6 PUFA)]

2.6. Phytosterols Analysis

The sterol content was determined using our previous method [27], which is in accordance with the provisions of European Regulation No. 1348/2013 [28]. In summary, 1 mL of α-cholestanol (2.33 mg/mL) was added to each lipid extract (0.1 g) and used as an internal standard. Saponification was achieved using a solution of 2 M methanol and potassium hydroxide. The unsaponifiable fraction was then extracted using ethyl ether. Then, thin-layer chromatography was used to separate the sterols from the unsaponifiable fraction. Each ethyl ether solution was loaded onto 20 × 20 cm² glass plates coated with basic silica gel that had been heated to 110 °C for 90 min. Elution took place over 45 min using 100 mL of an n-hexane–ethyl ether solution (65:35, v/v) in a glass developing chamber. Each plate was then sprayed with 2,7-dichlorofluorescein in ethanol (0.2% w/v) and examined under a UV source at 366 nm to identify the different bands. The scraping of the sterol band from the gel and the extraction of it with 10 mL of hot ethyl acetate was the next step. The resulting residue was dried under vacuum and subsequently derivatised with 0.1 mL of BSTFA-TMCS (99:1, v/v) for 30 min at room temperature. The trimethylsilyl ether derivatives were then analysed using gas chromatography coupled with flame ionisation detection (GC-FID) with a capillary column (SPB-1, 15 m × 0.20 mm ID × 0.20 μm df, Supelco). The oven temperature was increased from 240 °C (held for 5 min) to 290 °C (held for 5 min) at a rate of 2 °C per minute. The injector and detector temperatures were set to 280 and 290 °C, respectively, and the helium gas flow rate was held constant at 30 cm/s. Each sample was injected at a volume of 1 μL with a split ratio of 1:50. Phytosterols were identified by comparing the retention times of commercial standards, and their quantification using appropriate external calibration curves was normalised by the internal standard. Triplicate analyses were performed for each sample, along with analytical blanks.

2.7. Inorganic Elements Analysis

The tahini samples were mineralised using an ETHOS 1 microwave mineraliser (Milestone, Bergamo, Italy) in accordance with the method proposed by Nava et al. (2025) [29]. Each sample was treated with 1 mL of 30% H₂O₂ and 7 mL of 69% HNO₃. The acid digestion process involved three steps: heating from 0 °C to 200 °C over 10 min, holding at 200 °C for 20 min, and cooling for a further 20 min. Finally, the samples were diluted with ultrapure water and filtered through a 0.45-micrometre filter using a syringe. The blank solution and the certified matrix (NIST SRM 1570a-Spinach Leaves, Merck (Darmstadt, Germany)) were prepared under the same conditions as the samples.

The elements Mg, Ca, P, Mn, Fe, Co, Cu, Zn, Cd, Cr, Li, Be, Na, Ni, Mo, K, Pb, As, Se, Sn, Sb and V were analysed. ICP-OES ULTIMA 2 (HORIBA, Kyoto, Japan) was used to determine the content of Ca, Fe, K, Mg, Na and Zn, while inductively coupled plasma mass spectrometry (iCAP-Q ICP-MS, Thermo Scientific, Waltham, MA, USA) was used to determine the content of the other elements. The operating parameters of the ICP-OES instrument were set according to those reported by Di Bella et al. (2015) [30]. The analytical wavelengths for the analytes were as follows: Ca (393.366 nm), Fe (259.940 nm), K (766.490 nm), Mg (279.553 nm), Na (588.995 nm), Zn (213.856 nm) and P (213.618 nm).

The operational conditions of the ICP-MS were consistent with those previously documented by Nava et al. (2025) [29]. The isotopes monitored were ⁷Li, ⁹Be, ⁵¹V, ⁵²Cr, ⁵⁵Mn, ⁵⁹Co, ⁶⁰Ni, ⁶³Cu, ⁷⁵As, ⁸⁰Se, ⁹⁸Mo, ¹¹¹Cd, ¹²⁰Sn, ¹²¹Sb, ²⁰⁸Pb. The construction of seven-point calibration curves was carried out for each element with a concentration ranging from 0.5 to 50 µg/L. The analysis of all samples was conducted in batches, with the inclusion of blank samples and known standards. Each analysis was carried out three times.

2.8. Mercury Analysis

A direct mercury analyser (DMA-80, Milestone, Bergamo, Italy) was used to evaluate the levels of mercury present, according to a method previously optimised by Ben Amar et al. [31]. One hundred milligrams of each sample were subjected to an initial drying phase at 280 °C for four minutes. The second phase involved thermal decomposition at 650 °C for four minutes. After thermal decomposition, the mercury content was determined using atomic absorption spectroscopy (TDA-AAS) at a wavelength of 253.7 nm. A seven-point calibration curve was constructed before the analysis (1–100 µg/L).

2.9. Element Uptake

One of the aims of this study was to calculate the absorption percentage of inorganic elements following the consumption of the analysed tahini samples.

The RDAs reported by the European Commission [32,33,34] were used as a reference for essential macronutrients and micronutrients: Ca (800 mg/day), Cr (0.040 mg/day), Cu (1 mg/day), Fe (14 mg/day), K (2000 mg/day), Li (1 mg/day) Na (1500 mg/day), Mg (375 mg/day), Mn (2 mg/day), Mo (0.050 mg/day), P (700 mg/day), Se (0.055 mg/day) and Zn (10 mg/day).

Instead, the references TDI, TWI and BMDL01 were used to calculate the percentage of absorption of toxic and potentially toxic elements [35,36,37,38,39,40]: As (0.3 μg/kg_b.w./day), Hg (4 μg/kg_b.w./day), Ni (22 μg/kg_b.w./day) and Pb (0.5 μg/kg_b.w./day), and Cd (2.5 μg/kg_b.w./week). The absorption percentage was calculated using an average weight of 70 kg. As it was not possible to determine the precise average global consumption of tahini, the average daily intake of 1 g/day reported by FAOSTAT for sesame seeds was used instead [41]. Daily exposure (mg/day) was then calculated by multiplying the average concentrations (mg/kg) in the samples by the amount consumed (kg/seed/day).

2.10. Statistical Analysis

The statistical analysis was performed using the SPSS 19.0 software package (SPSS Inc., Chicago, IL, USA). Experimental data were always reported as mean ± standard deviation of n = 3 analytical replicates conducted per every tahini sample. One-way analysis of variance (ANOVA) was applied to evaluate statistically significant differences between tahini samples based on brand and, consequently, geographical origin. The level of statistical significance was set at p < 0.05. Analytes that were not quantified in at least 50% of the samples were excluded from the statistical analysis. On the other hand, concentrations below the LOQ in only a few samples were assigned a value of LOD/2.

3. Results and Discussions

Given the evident gaps in the current scientific literature, a new study on the safety and quality of tahini is particularly important. Available research offers an incomplete and often limited picture, failing to provide a comprehensive overview of this product. In this context, this study is a valuable addition to the existing literature, improving consumer knowledge of the nutritional characteristics and safety of tahini.

In this regard, the main nutritional parameters of the tahini samples under study were determined. In particular, the above methods made it possible to evaluate the moisture, protein, lipid, fatty acid, sterol and mineral content. Where possible, the experimental data were compared with the values reported by the various manufacturers on the labels. Additionally, an ANOVA analysis was performed to observe purely statistical differences that have no nutritional or toxicological significance. The aim of this statistical analysis was to distinguish tahini samples based on brand and, consequently, their geographic origin. Furthermore, although multivariate analyses were considered, they were deemed inappropriate due to the size of the dataset.

3.1. Proximate Composition

The results relating to the protein, moisture, fibre and ash contents of the tahini samples can be found in

Table 2. Proximate composition of tahini samples and comparison with labelled values. Bold p-values are statistically significant according to the one way-ANOVA (p < 0.05).

Sample	Moisture (%)		Proteins (%)		Fibres (%)		Ash (%)
	Experimental	Declared	Experimental	Declared	Experimental	Declared	Experimental	Declared
T-1	5.0 ± 0.10	-	22.4 ± 0.20	22.3	9.4 ± 0.10	9.78	4.5 ± 0.06	-
T-2	3.0 ± 0.06	-	24.1 ± 0.18	24.0	7.2 ± 0.08	-	5.1 ± 0.05	-
T-3	3.5 ± 0.05	-	25.2 ± 0.08	25.0	7.6 ± 0.06	8.1	3.8 ± 0.04	-
T-4	4.0 ± 0.05	-	27.0 ± 0.13	27.0	8.0 ± 0.11	-	5.3 ± 0.06	-
T-5	4.5 ± 0.03	-	26.0 ± 0.14	27.0	6.5 ± 0.06	-	5.9 ± 0.07	-
T-6	4.0 ± 0.04	-	24.0 ± 0.19	26.0	11.0 ± 0.15	10.0	6.3 ± 0.05	-
T-7	3.5 ± 0.05	-	24.0 ± 0.22	25.0	8.0 ± 0.08	-	4.5 ± 0.07	-
p-value	<0.05	-	<0.05	-	<0.05	-	<0.05	-

. Where possible, these results were compared with those stated on the label.

It is important to understand that the amounts of nutrients in food do not always match the figures on labels. This can be due to natural variations and production and storage processes [25]. However, the actual nutritional content of food must not deviate significantly from the amounts indicated on the label; otherwise, consumers could be misled. Consequently, the European Commission has developed guidelines for defining the tolerance for each nutrient in collaboration with EU Member States [42]. These guidelines establish the acceptable difference between the nutritional value declared on the label and that determined through laboratory testing.

Specifically, for proteins, the guidelines state that for contents between 10 and 40 g/100 g, the permissible tolerance for food products is ±20%. Conversely, for fibres, given that our content was less than 10 g/100 g, the permissible tolerance is ±2 g [42].

In general, the percentages of moisture, proteins, fibres, and ashes varied in relation to the brand of tahini analysed. This result has also been showed by the p-values obtained after the one way-ANOVA test, always less than 0.05.

The moisture content analysis showed values between 3.0 ± 0.06% and 5.0 ± 0.10% (see Table 2). Overall, the humidity of the tahini remains within a narrow, constant range that is compatible with the product’s stability and shelf life. Furthermore, the results were found to align with those reported in the literature for tahini and sesame seeds [14,43]. It was not possible to make a comparison between the labels because the water content was not reported for any of the samples (Table 2).

The values obtained through experimentation guarantee good correspondence with the protein values declared on the label. Samples T-2, T-3 and T-4 were perfectly aligned, while samples T-1, T-5, T-6 and T-7 showed slight differences, with experimental values slightly lower or higher than the certified ones. This could be due to the natural variability of the seeds, their different geographical origins, or the processing methods used. However, any discrepancies observed were always within European tolerance limits. The obtained data confirm that tahini is a high-quality source of protein among plant-based foods, with an average content of between 22.4 ± 0.20 and 27.0 ± 0.13 g per 100 g (Table 2). This protein composition makes it particularly suitable for increasing protein intake in vegetarian and vegan diets, enhancing the nutritional value of the product. Overall, the protein content of our samples was similar to that reported in the literature on both tahini and sesame seed (range: 17–28%) [11,12,14]. However, our results were slightly higher than those reported by Bradley Morris et al. (2021), who found an average protein percentage of 18.08% in eight sesame (Sesamum indicum L.) genotypes [44]. This demonstrates the influence that variety, geographic origin, environment, climate and genetics can have on the protein content of sesame seeds and, consequently, tahini [43,44].

The tahini samples examined contained a moderate amount of fibre. Sample T-6 had the highest content (11.0 ± 0.15%), while sample T-5 had the lowest (6.5 ± 0.06%) (Table 2). Overall, however, our results were similar to those of Sumaina et al. (2021) and Labban et al. (2021) [13,14]. Furthermore, the fibre percentage obtained for samples T-1, T-3 and T-6 could be compared with the percentage reported on the label. The results showed slight discrepancies: samples T-1 and T-3 had a slightly lower fibre percentage than reported on the label (9.4 ± 0.10% vs. 9.78% for T-1; 7.6 ± 0.06% vs. 8.1% for T-3). However, the difference between the percentage of experimental fibres and the figure reported on the label did not exceed European tolerance limits. Conversely, sample T-6 had slightly higher experimental values than those on the label (11.0 ± 0.15% vs. 10.0%) (Table 2).

Finally, the tahini samples showed variable ash percentage content. In fact, the percentages ranged from 3.8 ± 0.04% in T-3 to 6.3 ± 0.05% in T-6 (Table 2). Some of our results were comparable with those reported by Beshaw et al. (2022) in sesame seeds (Sesamum indicum L.) from Ethiopian markets (range: 3.10 ± 0.55%–4.75 ± 1.23%) [45], while others were slightly higher. This is probably due to the different environmental influences on the plants as they grow and absorb elements through their roots [46]. Furthermore, as mentioned previously with regard to humidity, it was not possible to compare the experimental data with the information on the label for ash, given that this value was not reported for any tahini sample (Table 2).

3.2. Total Lipids

The results for the lipid fraction of the tahini samples are presented in

Table 3. Total lipid content of tahini samples and comparison with labelled values. Bold p-values are statistically significant according to the one way-ANOVA (p < 0.05).

Sample	Lipid Content (%)
	Experimental	Declared
T-1	61.0 ± 0.1	61
T-2	60.0 ± 0.1	60
T-3	62.0 ± 0.2	60
T-4	56.8 ± 0.2	58
T-5	59.5 ± 0.1	60
T-6	54.9 ± 0.2	57
T-7	58.8 ± 0.1	60
p-value	<0.05

, alongside the values indicated on the nutrition labels. The total lipid content varied depending on the brand analysed, as well as the ingredients used to prepare the tahini and the product’s geographical origin (p-value < 0.05, see Table 3).

The lipid content of all the tahini samples varied between 54.9 ± 0.2% (T-6) and 62.0 ± 0.2% (T-3) (Table 3). Samples T-1 and T-2 exhibited a perfect correlation between the lipid values stated on the label and the values obtained through experimentation. In contrast, samples T-4, T-5, T-6 and T-7 showed a slight underestimation of the lipid content measured experimentally compared to that declared by the manufacturers. Of all the samples tested, only T-3 showed a slightly higher percentage than that reported on the label. This is probably due to factors such as the natural variability of the raw material or discrepancies between production batches. Overall, these results confirm the reliability of the nutritional information provided for the analysed samples and enable us to gain a precise understanding of their lipid composition. However, although there were some discrepancies between the labelled and experimental values, these did not exceed the tolerability limits set by the European Commission. In fact, for foods with a total lipid content of more than 40 g/100 g, the permissible tolerance is ±8 g [42].

Furthermore, the experimental values of total lipids were found to be higher than those reported by Seid et al. (2022) and Asghar et al. (2013) [47,48]. Seid et al. obtained a mean percentage of total lipids in Ethiopian sesame seed samples equal to 49.86 ± 1.43%, while Asghar et al. obtained a range of percentages of total lipids between 49.5 ± 0.53% and 53.9 ± 0.12% for different varieties of Pakistan sesame seed oils [47,48]. This difference in total fat content may be due to the various steps and processing conditions involved in producing tahini, such as heating [49], as well as the different environmental conditions in which sesame seeds are grown [50].

3.3. FA Composition

The fatty acid composition of the tahini samples is presented in

Table 4. Fatty acid composition (g/100 g lipid extract) of the tahini samples. The results are expressed as the mean ± standard deviation of three replicates. Bold p-values are statistically significant according to the one way-ANOVA (p < 0.05).

	T-1	T-2	T-3	T-4	T-5	T-6	T-7	p-Value
C12:0	0.01 ± 0.01	0.01 ± 0.00	0.01 ± 0.01	0.01 ± 0.01	0.01 ± 0.01	0.01 ± 0.01	0.02 ± 0.00	<0.05
C14:0	0.09 ± 0.01	0.07 ± 0.01	0.03 ± 0.00	0.06 ± 0.01	0.06 ± 0.01	0.04 ± 0.00	0.03 ± 0.00	<0.05
C15:0	0.02 ± 0.01	0.01 ± 0.01	0.01 ± 0.01	0.01 ± 0.00	0.01 ± 0.01	0.02 ± 0.00	0.03 ± 0.00	<0.05
C16:0	9.59 ± 0.83	10.78 ± 0.95	10.04 ± 0.91	10.27 ± 0.75	10.09 ± 0.78	10.07 ± 0.87	9.92 ± 0.89	>0.05
C17:0	0.05 ± 0.01	0.06 ± 0.01	0.06 ± 0.01	0.06 ± 0.01	0.05 ± 0.01	0.06 ± 0.00	0.07 ± 0.01	<0.05
C18:0	5.40 ± 0.46	5.53 ± 0.49	4.69 ± 0.32	6.08 ± 0.56	4.91 ± 0.36	5.96 ± 0.50	6.14 ± 0.78	<0.05
C20:0	0.48 ± 0.03	0.41 ± 0.03	0.47 ± 0.02	0.54 ± 0.02	0.45 ± 0.02	0.29 ± 0.01	0.31 ± 0.02	<0.05
C22:0	0.11 ± 0.01	0.11 ± 0.01	0.13 ± 0.01	0.08 ± 0.00	0.13 ± 0.01	0.15 ± 0.01	0.11 ± 0.01	<0.05
C24:0	0.02 ± 0.00	0.01 ± 0.00	0.01 ± 0.00	0.04 ± 0.01	0.02 ± 0.01	0.03 ± 0.00	0.04 ± 0.00	<0.05
∑ SFA	15.76 ± 0.41	16.97 ± 0.47	15.44 ± 0.57	17.14 ± 0.57	15.71 ± 1.16	16.64 ± 1.38	16.66 ± 0.11
C16:1 n-9	0.04 ± 0.01	0.04 ± 0.01	0.03 ± 0.01	0.05 ± 0.01	0.03 ± 0.00	0.10 ± 0.01	0.06 ± 0.01	<0.05
C16:1 n-7	0.14 ± 0.01	0.15 ± 0.01	0.15 ± 0.01	0.16 ± 0.01	0.13 ± 0.01	0.14 ± 0.01	0.15 ± 0.00	<0.05
C17:1	0.02 ± 0.01	0.02 ± 0.01	0.03 ± 0.00	0.02 ± 0.01	0.02 ± 0.00	0.04 ± 0.01	0.03 ± 0.00	<0.05
C18:1 n-9	38.81 ± 2.14	37.17 ± 1.53	36.57 ± 1.65	41.13 ± 2.78	36.45 ± 1.72	37.00 ± 1.66	41.24 ± 2.08	<0.05
C18:1 n-7	0.97 ± 0.08	0.96 ± 0.07	1.01 ± 0.08	0.91 ± 0.06	1.39 ± 0.11	1.26 ± 0.11	1.73 ± 0.11	<0.05
C20:1 n-9	0.15 ± 0.01	0.14 ± 0.01	0.15 ± 0.01	0.15 ± 0.01	0.15 ± 0.00	0.11 ± 0.00	0.15 ± 0.00	<0.05
∑ MUFA	40.13 ± 2.07	38.49 ± 1.60	37.93 ± 1.60	42.42 ± 2.71	38.17 ± 1.67	38.64 ± 1.76	43.36 ± 1.97
C18:2 n-6	42.47 ± 2.35	43.18 ± 2.23	44.82 ± 2.70	39.17 ± 2.03	43.94 ± 2.82	43.39 ± 1.58	38.18 ± 1.86	<0.05
C18:3 n-6	0.01 ± 0.01	0.01 ± 0.01	0.05 ± 0.01	0.01 ± 0.00	0.06 ± 0.00	0.11 ± 0.01	0.04 ± 0.00	<0.05
C18:3 n-3	0.38 ± 0.03	0.37 ± 0.02	0.27 ± 0.01	0.31 ± 0.02	0.28 ± 0.01	0.35 ± 0.01	0.29 ± 0.01	<0.05
∑ PUFA	42.86 ± 2.34	43.56 ± 2.22	45.14 ± 2.71	39.49 ± 2.05	44.27 ± 2.81	43.84 ± 1.57	38.51 ± 1.86
SFA/UFA	0.19	0.21	0.19	0.21	0.19	0.20	0.20
O/L	0.91	0.86	0.82	1.05	0.83	0.85	1.08
AI	0.12	0.13	0.12	0.13	0.13	0.12	0.12
TI	0.36	0.39	0.35	0.39	0.36	0.38	0.39

. The content varied depending on the brand of tahini analysed. In fact, the p-values were almost always less than 0.05, except for C16:0 (Table 4).

The fatty acids found in the highest concentrations in all the tahini samples were C16:0, C18:0, C18:1 n-9 and C18:2 n-6.

Among saturated fatty acids, palmitic acid (C16:0) is predominant, with values ranging from 9.59 to 10.78 g/100 g, followed by stearic acid (C18:0), which varies between 4.69 and 6.14 g/100 g. Rajagukguk et al. (2022) observed the same trend on sesame oil and derived products [51]. The other SFAs (C12:0, C14:0, C15:0, C17:0, C20:0, C22:0, C24:0) are present in very small quantities (<1 g/100 g). The total saturated fatty acid content ranged from 15.44 to 17.14 g per 100 g. Sample T-4 had the highest saturated fatty acid (SFA) content (17.14 ± 0.57 g per 100 g), and sample T-3 had the lowest (15.44 ± 0.57 g per 100 g).

The monounsaturated fraction of tahini is dominated by oleic acid (C18:1 n-9), with values ranging from 36.45 (T-5) to 41.24 (T-7) g/100 g (Table 4).

The other MUFAs, including C16:1 n-7, C16:1 n-9, C18:1 n-7, C17:1, and C20:1 n-9, are present in smaller quantities. The total MUFA content varies between 37.93 (T-3) and 43.36 (T-7) g/100 g (Table 4). The oleic acid (C18:1 n-9) content of the analysed tahini samples was similar to the levels reported by Ahmed et al. (2022) for sesame seed provided from different locations (range: 35.88 ± 1.42–44.54 ± 1.74%) and by Shaltout et al. (2014) for sesame oil (range: 35.83–48.70%) [43,52].

Linoleic acid (C18:2 n-6) is the predominant PUFA, with values ranging from 38.18 (T-7) to 44.82 (T-3) g/100 g (Table 4). Other polyunsaturated fatty acids, such as C18:3 n-6 and C18:3 n-3, are present in smaller quantities. This is consistent with findings from those reported by Rajagukguk et al. (2022) (range: 35.81–44.62%) and by Shaltout et al. (2014) (range: 20.60–45.68%) [51,52]. Total PUFA content varies from 38.51 to 45.14 g/100 g, with sample T-3 having the highest value and sample T-7 having the lowest (Table 4).

Overall, our results were comparable with those reported in the literature. The small variations in the percentage of individual fatty acids could be due to environmental factors, genetics, or different harvest periods for sesame seeds [43]. As mentioned above, the total lipid and, consequently, fatty acid content can vary also depending on the stages and conditions that the sesame seeds undergo during tahini production and the plant’s cultivation requirements [49,50].

Moreover, the data confirm that the analysed tahini has a balanced lipid profile, which is consistent with the manufacturers’ claims. It is characterised by a moderate saturated fatty acid (SFA) content and a predominance of unsaturated fatty acids (MUFA and PUFA). The fatty acid composition of tahini enhances its nutritional quality, particularly thanks to the predominance of MUFA and PUFA, which are known to provide health benefits, such as improving cardiovascular health [53].

Determining certain fatty acid composition indices, such as the average saturated fatty acid (SFA)/unsaturated fatty acid (UFA) ratio and the average oleic/linoleic acid (O/L) ratio, enables us to evaluate resistance to oxidative stress and, consequently, lipid oxidation (Table 4). Specifically, greater resistance is indicated by higher SFA/UFA and O/L values. Similar values were observed for the SFA/UFA ratio, ranging between 0.19 and 0.21 (Table 4). Furthermore, the O/L ratio enables us to assess product quality, as it correlates with the development of unpleasant flavours over time [27]. The values for this ratio were not too different between the tahini samples, ranging from 0.82 for the T-3 sample to 1.08 for the T-7 sample (Table 4). This indicates that all the tahini samples exhibited the same oxidative stability and, consequently, a comparable shelf life.

Table 4 also reports the atherogenicity and thrombogenicity index values. Higher AI and TI values indicate a greater likelihood of platelet aggregation and thrombus formation [54]. Conversely, values below one are considered low and beneficial to human health [24]. This study found that all samples had AI and TI values lower than 1 (see Table 4), indicating no risk to consumers.

3.4. Sterols

As little information on the sterol content of tahini is available in the literature, one of the aims of this study was to determine the sterol profile of the analysed samples. However, the results could be compared with data on sesame seeds, which have been the focus of many studies determining phytosterol content.

The sterol percentage of the various tahini samples is shown in

Table 5. Sterol composition (g/100 g of lipid extract) of the tahini samples. The results are expressed as the mean ± standard deviation of three replicates. Bold p-values are statistically significant according to the one way-ANOVA (p < 0.05).

Sterol	T-1	T-2	T-3	T-4	T-5	T-6	T-7	p-Value
Campesterol	16.20 ± 0.55	17.66 ± 0.03	17.72 ± 0.06	16.96 ± 0.36	16.23 ± 0.17	18.10 ± 0.03	16.05 ± 0.03	<0.05
Stigmasterol	6.86 ± 0.19	7.22 ± 0.08	6.48 ± 0.02	8.41 ± 0.24	7.64 ± 0.03	8.30 ± 0.02	7.09 ± 0.04	<0.05
Clerosterol	1.64 ± 0.07	1.65 ± 0.01	2.10 ± 0.09	0.61 ± 0.05	1.43 ± 0.10	0.86 ± 0.05	1.97 ± 0.06	<0.05
β-Sitosterol	56.06 ± 1.33	56.23 ± 0.19	61.23 ± 0.28	54.26 ± 1.16	53.43 ± 0.10	55.92 ± 0.13	57.89 ± 0.29	<0.05
Δ-5-avenasterol	14.37 ± 0.37	12.38 ± 0.04	7.59 ± 0.09	16.71 ± 0.34	12.86 ± 0.03	12.90 ± 0.01	9.38 ± 0.02	<0.05
Δ-5,24-stigmastadienol	3.57 ± 0.11	3.50 ± 0.04	3.38 ± 0.05	1.94 ± 0.12	3.42 ± 0.03	1.59 ± 0.06	3.12 ± 0.06	<0.05
Δ-7-stigmastenol	0.57 ± 0.04	0.62 ± 0.01	0.75 ± 0.04	0.36 ± 0.02	3.22 ± 0.03	0.65 ± 0.02	0.85 ± 0.08	<0.05
Δ-7-avenasterol	0.74 ± 0.01	0.73 ± 0.01	0.76 ± 0.00	0.76 ± 0.06	1.78 ± 0.04	1.68 ± 0.02	3.66 ± 0.07	<0.05
Total sterols (mg/kg)	4591.51 ± 73.75	4418.22 ± 47.59	4005.11 ± 42.78	4136.07 ± 109.79	2982.49 ± 19.15	3012.27 ± 26.13	3753.66 ± 43.10

. In general, this study showed that our tahini samples contain high levels of certain phytosterols, and their sterol profile varied depending on the tahini brand and its geographical origin of the sample (p-value < 0.05 for each sterol).

As previously mentioned, tahini does not contain cholesterol [13]. Our analyses also confirmed this, as they did not detect the presence of this sterol.

Of all the samples analysed, β-sitosterol was found to be the most abundant, followed by campesterol and Δ5-avenasterol (Table 5). Although the absorption of phytosterols in the human body is generally lower than that of cholesterol, they can still reduce LDL cholesterol levels in the blood and the risk of cardiovascular disease [27,55].

The prevalence of β-sitosterol is consistent with the findings of Vecka et al. (2019) regarding sesame seed samples [56]. In our study, the β-sitosterol content ranged from 53.43% ± 0.10% (T-5) to 61.23% ± 0.28% (T-3) (see Table 5). This is an expected result, given that β-sitosterol is the most abundant and widely distributed phytosterol found in lipid-rich plant foods, such as vegetables, nuts, seeds, cereals, and olive oil [57,58]. Furthermore, this result is very important considering that this sterol exhibits notable pharmacological properties, including significant antitumour activity [57,59]. Furthermore, Vecka et al. (2019) [56] found average β-sitosterol percentages of 73.0 ± 2.4%, which are slightly higher than ours. It is likely that a small amount of this phytosterol was lost during the processing of sesame seeds and the preparation of tahini.

The other most abundant phytosterols were campesterol and Δ5-avenasterol. The former ranged from 16.05% ± 0.03% (T-7) to 18.10% ± 0.03% (T-6) and the latter from 7.59% ± 0.09% (T-3) to 16.71% ± 0.34% (T-4).

Stigmasterol was detected at concentrations greater than 6% in all tahini samples (range: 6.48% ± 0.02% (T-3) to 8.41% ± 0.24% (T-4).

However, the content of campesterol and stigmasterol must be considered. The fundamental role of these two sterols has been highlighted by many studies. Stigmasterol, for example, has different health benefits: anticancer, anti-osteoarthritis, anti-inflammatory, immunomodulatory, antibacterial, antifungal, antioxidant, anti-diabetic, and antiviral [60]. Campesterol is a natural phytosterol found in plant cell membranes. Due to its strong biological activities, such as antioxidant, anti-inflammatory and antitumour properties, it is used in nutraceutical and pharmaceutical applications [61]. However, there are conflicting opinions regarding their intake. While some authors hypothesised that high intake of these sterols can lead to colorectal cancer [62], numerous studies mention phytosterols as protective substances in the development of this type of cancer [63]. Furthermore, our results for stigmasterol and campesterol were comparable and higher, respectively, than those reported by Vecka et al. (2019) in sesame seeds (8.0 ± 1.6% and 8.1 ± 0.8%, respectively) [56]. These differences may be due to the fact that changes in phytosterol levels in plants are caused by biotic and abiotic factors [64].

The concentrations of all other phytosterols (clerosterol, Δ5,24-stigmastadienol, Δ7-stigmastenol and Δ7-avenasterol) were consistently below 5%.

3.5. Inorganic Elements

The three methods (ICP-MS, ICP-OES and DMA-80) used to determine the inorganic components have been validated in terms of their linearity, sensitivity, accuracy and precision. All the results obtained are shown in Table S1.

For the first parameter, seven-point calibration curves were constructed using multi-element standard solutions. The linearity of these curves was verified using correlation coefficients (R²). The standard concentration ranges are reported in paragraphs 2.7 and 2.8. The methods demonstrated excellent linearity for all the analysed elements, with R² values consistently exceeding 0.9990 (Table S1).

To assess analytical sensitivity, the limits of detection (LOD) and quantification (LOQ) were determined for each element. These were obtained using the following formulas, respectively: 3.3σ/S and 10σ/S, where σ is the standard deviation of the mean value obtained from analysing ten blank samples, and S is the slope of the corresponding calibration curve. The lowest LOD and LOQ values were obtained for Cr, Mo, Cd, Pb, As, Hg and Ni (0.003 and 0.010 mg/kg, respectively), whereas the highest values were obtained for K (0.720 and 2.376 mg/kg, respectively).

Using the certified matrix (spinach leaves, NIST1570A), with six replicates, allowed us to determine the accuracy of the methods. The latter was obtained by subtracting the experimental value from the reference value and expressing the result as a percentage recovery. Furthermore, if one of the analytes being sought was missing from the reference material, it was supplemented with known concentrations of the missing elements (5 mg/kg for Fe; 2 mg/kg for Cr, Mo, Be, Li, Sn and Sb; see Table S1). Specifically, the highest average recovery was obtained for cadmium (Cd) (100.75%), while the lowest was obtained for potassium (K) (91.15%) (see Table S1).

Finally, the precision of the methods was determined. Specifically, intraday precision (analysing the certified matrix and the spiked samples on the same day) and interday precision (evaluated over a longer period of one week) were assessed. The results, expressed as relative standard deviation (RSD%), were found to be less than 1.2% and 1.3%, respectively (see Table S1).

The inorganic elements content (macro-, trace, toxic and potentially toxic elements) is reported in

Table 6. Macro-, trace, toxic and potentially toxic elements content (mg/kg) in tahini samples. Bold p-values are statistically significant according to the one way-ANOVA (p < 0.05).

	T-1	T-2	T-3	T-4	T-5	T-6	T-7	p-Value
Macro-Elements
Ca	2929.37 ± 78.38	1299.89 ± 50.77	5105.53 ± 39.50	3250.48 ± 115.86	4387.88 ± 28.65	3380.50 ± 24.69	3796.11 ± 17.31	<0.05
K	5191.27 ± 84.55	4699.85 ± 51.28	4159.36 ± 80.91	5069.67 ± 48.07	4473.71 ± 48.34	5095.87 ± 28.98	4939.51 ± 25.81	<0.05
Na	1986.47 ± 23.73	381.98 ± 27.80	672.14 ± 14.48	30.95 ± 2.35	763.35 ± 7.50	433.18 ± 11.62	160.52 ± 2.18	<0.05
Mg	2495.54 ± 0.83	2401.14 ± 55.56	2925.25 ± 40.49	2094.11 ± 32.89	2338.20 ± 62.98	2784.51 ± 64.30	2285.88 ± 592.20	<0.05
P	9434.88 ± 14.99	8538.09 ± 46.25	8666.49 ± 45.63	9077.47 ± 85.41	9155.90 ± 61.75	8186.24 ± 44.02	7951.51 ± 66.26	<0.05
Trace Elements
Fe	62.98 ± 1.93	56.17 ± 1.03	47.40 ± 1.14	53.81 ± 1.17	83.13 ± 1.10	66.62 ± 0.93	72.10 ± 1.58	<0.05
Zn	72.83 ± 2.29	61.45 ± 2.49	68.25 ± 2.82	86.80 ± 1.17	67.45 ± 1.80	54.75 ± 1.80	60.17 ± 1.11	<0.05
Cu	9.80 ± 0.47	10.71 ± 0.21	13.20 ± 0.57	11.10 ± 0.13	13.63 ± 0.47	9.59 ± 0.36	15.00 ± 0.12	<0.05
Se	1.11 ± 0.03	0.91 ± 0.03	0.76 ± 0.03	0.93 ± 0.02	0.88 ± 0.03	1.04 ± 0.02	0.72 ± 0.03	<0.05
Mn	18.56 ± 0.42	15.83 ± 0.68	21.03 ± 0.34	14.29 ± 0.28	16.19 ± 0.63	17.81 ± 0.41	13.51 ± 0.34	<0.05
Cr	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	-
Mo	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	-
Toxic and potentially toxic elements
Cd	0.35 ± 0.02	0.01 ± 0.00	<LOQ	<LOQ	0.02 ± 0.00	<LOQ	0.01 ± 0.00	<0.05
Pb	0.50 ± 0.02	0.01 ± 0.00	<LOQ	<LOQ	0.01 ± 0.00	<LOQ	<LOQ	-
As	0.20 ± 0.02	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	-
Hg	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	-
Be	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	-
Li	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	-
Ni	0.05 ± 0.01	0.10 ± 0.01	0.03 ± 0.00	0.04 ± 0.01	0.08 ± 0.02	0.04 ± 0.01	0.02 ± 0.00	<0.05
Sn	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	-
Sb	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	<LOQ	-

. The analyses focused on the presence of various elements, including macro-elements such as Ca, K, Na, Mg and P, as well as microelements including Fe, Zn, Cu, Se, Mn, Cr, Mo, Ni, Li, Sn, Sb and Be. Additionally, the presence of toxic elements such as Cd, Pb, As and Hg was examined for the first time. All values are expressed in milligrams per kilogram (Table 6).

Overall, the analyses performed revealed significant differences in the mineral composition of the various tahini samples analysed, with p-values lower than 0.05 for all quantified elements in at least 50% of the samples (Table 6).

In terms of macro-elements, phosphorus was the most abundant element in all of the tahini samples analysed (Table 6). For most samples, the order of abundance was P > K > Ca > Mg > Na. However, there were exceptions. This demonstrates how the geographical origin of the sesame seeds used to prepare the tahini can influence the macro-element composition of these samples.

The Ca content varies greatly. The highest value, 5105.53 ± 39.50 mg/kg, is found in sample T-3, while the lowest value, 1299.89 ± 50.77 mg/kg, is found in sample T-2 (Table 6). This difference could be due to the quality of the sesame seeds used in production, or to whether they have been hulled. This is because the outer husk is the main source of this mineral and removing it results in a significant loss [65]. Furthermore, Ca determined in our samples was comparable to that reported by Attiyah (2023) in tahini samples purchased in the Saudi market [16]. Overall, good calcium concentrations were obtained in the tahini samples. This is a significant result, given the numerous beneficial effects of calcium on the human body. For example, calcium is an important component of bone tissue, a fundamental element in various biochemical reactions and physiological processes, and essential for blood clotting and the functioning of the nervous system [66].

The presence of K, Mg and P in all samples is uniform and dominant among samples (Table 6), confirming the important role of tahini as a source of these essential elements in regulating nerve impulses, muscle health and blood pressure [67]. Specifically, sample T-1 exhibited the highest K and P content (5191.27 ± 84.55 mg/kg and 9434.88 ± 14.99 mg/kg, respectively). Sample T-3 had the highest Mg content (2925.25 ± 40.49 mg/kg). Overall, our K and P results were higher than those reported by Attiyah (2023) (K: ~4000 mg/kg; P: ~7200 mg/kg), while our Mg content was lower (Mg: ~3600 mg/kg) [16]. Overall, good concentrations of Mg, K and P were therefore obtained. This is important given the beneficial properties of these macronutrients for the human body: Mg acts as a cofactor for over 300 enzymes, regulating fundamental processes (muscle contraction, neuromuscular conduction, glycaemic control, myocardial contraction and blood pressure) and playing a vital role in energy production, active transmembrane transport of other ions, synthesis of nuclear materials and bone development [68]; potassium plays a number of important roles in the human body. For example, some studies show that a potassium-rich diet can have a beneficial effect on cardiovascular disease [69]; phosphorus is an essential element for the human body, required for diverse processes such as ATP synthesis, signal transduction and bone mineralization [70].

The Na content varies depending on whether NaCl is added during processing [71]. In fact, sample T-1 has a sodium content of 1986.47 ± 23.73 mg/kg, whereas sample T-4 contains just 30.95 ± 2.35 mg/kg (Table 6).

Of the trace elements, Fe and Zn are present in greater quantities (Table 6). Sample T-5 has a high Fe content (83.13 ± 1.10 mg/kg), while sample T-4 has a high Zn content (86.80 ± 1.17 mg/kg). These results are comparable to those obtained by El-Adawy et al. (2000) [71] for tahini samples prepared using heat-treated sesame seeds and by Hu et al. (2019) for six sesame seed varieties [72] and by Attiyah (2023) [16]. These values reinforce the idea that tahini is a functional food that can help to prevent nutritional deficiencies and support immune system and cellular metabolism function.

The Cu content ranges from 9.59 to 15 mg/kg, with the highest values found in samples T-7 and T-3 (Table 6). The Cu concentrations in our samples were slightly lower than those reported by Kurt et al. (2018) in sesame seeds (range: 17.16–40.14 mg/kg) [73]. The tahini production process is likely to have resulted in a decrease in the content of this element in the final product [11]. However, in some cases, our results were slightly higher than those reported by Attiyah (2023) (mean: ~9 mg/kg) [16].

The various samples had similar concentrations of Se (0.72–1.11 mg/kg) (Table 6). However, the slight variations in Se content across our samples could be attributed to the sesame seeds’ different geographical origins and the soil type (whether rich or poor in selenium) in which they were grown [74].

The concentration range of Mn was 13.51 ± 0.34 (T-7)–21.03 ± 0.34 (T-3) mg/kg (Table 6). These important Mn concentrations confirm the possible contribution of tahini to bone metabolism and enzyme function [75]. Furthermore, our Mn levels were consistent with those reported by Attiyah (2023) (mean: ~17 mg/kg) [16].

Finally, Cr and Mo levels were always below the limit of quantification (LOQ).

For the first time, toxic elements were assessed in tahini samples. Traces of these inorganic contaminants were found in some samples (Table 6). Sample T-1 showed the highest content of Cd (0.35 ± 0.02 mg/kg), Pb (0.50 ± 0.02 mg/kg) and As (0.20 ± 0.02 mg/kg). Traces of these elements were found also in T-2 (Cd: 0.01 ± 0.00 mg/kg, Pb: 0.01 ± 0.00 mg/kg), T-5 (Cd: 0.02 ± 0.00 mg/kg, Pb: 0.01 ± 0.00 mg/kg), and T-7 (Cd: 0.01 ± 0.00 mg/kg).

There is currently no regulatory limit set for toxic elements in tahini. However, Regulation (EU) No 2023/915 sets a maximum limit of 0.1 mg/kg for Cd in oilseeds [76]. Consequently, sample T-1 was the only one with a Cd concentration higher than the reference level. Regarding Pb, since tahini is a high-lipid food, it can be categorised as a ‘fat and oil’, for which EU Regulation No. 2023/915 sets a maximum limit of 0.10 mg/kg [77]. Consequently, the T-1 sample is the only one with a concentration of this toxic element that is five times higher than the regulatory limit.

Of the potentially toxic elements, only nickel was quantified in all the analysed samples, with concentrations ranging from 0.02 ± 0.00 mg/kg (T-7) to 0.10 ± 0.01 mg/kg (T-2). The element’s presence in the final product is probably influenced by the different use of metal materials during the tahini production phase.

The concentrations of all other elements (Be, Li, Sn and Sb) were below the limit of quantification in all tahini samples (Table 6).

Overall, tahini remains an important source of essential minerals. Discrepancies between brands are related to the production process, the origin of the sesame seeds and the possible addition of ingredients during processing [77].

While the presence of toxic metals is generally low, it should be monitored to ensure food safety.

The present study aimed to determine the intake of inorganic elements following the ingestion of a specific amount of tahini. As there is no reported average daily consumption for tahini, the value indicated by FAOSTAT for sesame seeds was used as a hypothetical reference: 1 g per day [41]. The results obtained are reported in

Table 7. Uptake percentage (%) of mineral elements from the consumption of 1 g/day of tahini samples.

	T-1	T-2	T-3	T-4	T-5	T-6	T-7
Macro-Elements
Ca	<1	<1	1	<1	<1	<1	<1
K	<1	<1	<1	<1	<1	<1	<1
Na	<1	<1	<1	<1	<1	<1	<1
Mg	1	1	1	1	1	1	1
P	1	1	1	1	1	1	1
Trace Elements
Fe	<1	<1	<1	1	<1	<1	<1
Zn	<1	1	1	1	1	<1	1
Cu	1	1	1	1	1	1	1
Se	2	2	1	2	2	2	1
Mn	1	1	1	1	1	1	1
Toxic and potentially toxic elements
Cd	1	<1	-	-	<1	-	<1
Pb	1	<1	-	-	<1	-	-
As	1	-	-	-	-	-	-
Ni	<1	<1	<1	<1	<1	<1	<1

. Concentrations of elements for which the concentrations were consistently lower than the LOQ are not reported in the table.

The results showed that the consumption of 1 g of tahini per day resulted in a generally low intake of inorganic elements, especially for macro-elements. In fact, the uptake percentages of most of this class of inorganic elements (Ca, Na and K) were lower than 1%, while Mg and P were always equal to 1%. A low contribution was obtained even for trace elements, with selenium (Se) showing the highest percentage (2%) and iron (Fe) the lowest (<1%). Fortunately, the absorption of toxic and potentially toxic elements was also low, at almost always less than 1%. Consequently, given the low risk associated with the intake of toxic and potentially toxic elements, it may be desirable to increase daily consumption of this matrix to improve absorption of the essential elements. However, the limitation of this study is that it focuses on the intake of sesame seeds rather than tahini. This is because tahini is a paste/cream and the amount consumed could exceed one gram of sesame seeds per day. For this reason, it would be helpful if international organisations also reported a specific intake amount for the tahini matrix. This would enable them to provide consumers with a more accurate indication of the safety level of the analysed samples.

3.6. Study Limitations

The main limitation of this study is the small sample size, which restricts the representativeness of the results and makes it more challenging to generalise the conclusions to the entire market. Furthermore, using an incorrect dose of sesame seeds to estimate consumer exposure introduces a methodological error that may lead to the actual intake of contaminants or nutrients through tahini consumption being over- or underestimated. To improve the reliability of the evidence, future studies should include a larger number of samples from diverse geographical areas and use more accurate data on quantities to assess exposure to toxic elements following tahini ingestion. While this research already provides useful information for consumers and industry professionals, overcoming these limitations would provide a fuller picture of the nutritional characteristics of tahini and its potential benefits and risks.

4. Conclusions

The following study provided important information on the quality and safety of commercial tahini samples. Specifically, the research determined the samples’ proximate composition, fatty acid content, sterol content and inorganic components.

This food has a lipid profile characterised by low saturated fat content and high levels of monounsaturated and polyunsaturated fatty acids, which may benefit cardiovascular health.

It also contains a good amount of proteins, which helps to maintain muscle mass, energy metabolism and enzyme and hormone synthesis. This makes tahini suitable for vegetarian and vegan diets, where essential amino acid intake can often be limited.

A comparison of the values listed on the label with those obtained experimentally showed a good correlation, with slight discrepancies attributable solely to variability in the sesame seeds used or differences between production batches. This further supports the accuracy of the nutritional information provided by manufacturers, guaranteeing transparency, and quality for consumers when purchasing and consuming the product.

Tahini samples had beneficial amounts of minor lipophilic compounds with bioactive properties, especially β-sitosterol. Moreover, there was no cholesterol present.

A good elemental profile was detected in the tahini samples analysed. In fact, significant concentration of Ca, K, Mg, P, Fe and Zn—minerals that are essential for bone health, energy metabolism and immune system function—was detected.

However, regarding elemental intakes, the hypothetical consumption of 1 g of tahini per day resulted in a low intake of most inorganic elements, especially macro-elements. Moreover, the intake of toxic and potentially toxic elements was well within the acceptable limits. This demonstrates that the analysed samples are safe to consume and supports the idea of increasing daily tahini consumption.

Finally, this research provides useful information for consumers and professionals in the sector, supporting the idea that tahini is a versatile and healthy food, particularly when included in a varied and balanced diet.

However, given the limited number of tahini samples analysed, further studies on the quality and safety of this product are needed. These studies should involve a larger number of samples, and where possible, the sesame seeds used in their production should also be analysed. This data would also provide additional information on product traceability and the potential beneficial and detrimental effects on consumers.