Sesame meal and lemon zest – enriched mayonnaise: Proximal analysis and toxicological studies in animals

Abstract

Considering the high global consumption of mayonnaise and modern concerns about the health value of food products, the recipe for mayonnaise sauces is constantly evolving. In this study, we present the proximal analysis and toxicological evaluation of a new mayonnaise, which was patented. Starch was replaced with sesame meal, and lemon zest was added as an antioxidant. Compared to a mayonnaise prepared using a traditional recipe as control, the enriched mayonnaise had higher protein and lower fat content, suggesting a potentially healthier product. Aditionally, peroxide and anisidine values were lower in the new mayonnaise, indicating higher resistance to oxidative damage. Toxicological studies of the enriched mayonnaise, including oral moderate-to-lethal dose (acute oral toxicity), cumulative (subacute) action, irritating effect on mucous membranes, and sensitizing properties, which were conducted on laboratory animals following required regulatory standards, are shown in this work. The patented sesame meal and lemon zest-enriched mayonnaise proved to be safe in all performed studies, meeting safety requirements regarding toxicological parameters. Furthermore, the enriched mayonnaise is affordable, with a production cost similar to that of control mayonnaise.

Graphical abstract

Highlights

• •Potentially healthier mayonnaise where starch and antioxidants were replaced with sesame meal and lemon zest was developed.
• •New mayonnaise has a higher protein and lesser fat amount than control, what may indicate a potentially healthier product.
• •AV and PV were lower in new mayonnaise than in control, which may indicate a higher resistance to oxidative damage.
• •No toxicological effects of the new mayonnaise were found.

1. Introduction

Mayonnaise has been considered one of the most consumed sauces in the world for the past 100 years [1]. Although it was initially made of vegetable oil, lime juice, eggs, salt, and pepper, its recipe has undergone significant modifications due to increased awareness of healthy food consumption. Several scientific institutions, such as the Tashkent Institute of Chemical Technology in Uzbekistan [2], the Key Laboratory of Food Science and Safety in China, and “Southern Yangtze University” in China [3], as well as regulatory and metrology agencies like Gosudarstvennyy standart (GOST) [4], and industry research and development (R&D) departments, have been actively involved in improving the mayonnaise recipe [2,5,6].

Mayonnaise is an oil-in-water emulsion, meaning that oil droplets are dispersed in a continuous water phase [5]. Due to its composition, mayonnaise is highly susceptible to quality deterioration, as lipid oxidation can lead to a decrease in its quality and shelf life [7]. This oxidation occurs when unsaturated fatty acids in the oil component of mayonnaise react with oxygen, particularly in the presence of light, heat, or metal ions [5]. Without a stabilizer, the oil droplets may coalesce and separate from the water phase, causing the emulsion to break [[8], [9], [10]]. Lipid oxidation results in the formation of volatile compounds, contributing to off-flavors and odors in mayonnaise, along with changes in color and texture [7]. Moreover, undesirable changes in pH and acidity can facilitate microbial deterioration of mayonnaise [5].

Modifications to mayonnaise recipes, such as replacing fats, egg yolks, and synthetic antioxidants with ingredients like starch, inulin, microcrystalline cellulose, carrageenan, propylene glycol alginate, or guar gum, have been undertaken in response to health-related concerns [3,[11], [12], [13]]. However, it is crucial to note that some of the alternative ingredients used in lieu of those in the original formula may also have potential negative effects on human health. For instance, although starch has been widely employed as both a fat replacement in low-fat mayonnaises and a stabilizer to prevent emulsion breakdown, it may contribute to issues such as elevated glucose levels, impaired glucose tolerance, and an increased risk of cardiovascular disease [14,15]. Similarly, synthetic antioxidants, commonly utilized to reduce lipid oxidation and control microbial growth, may pose potential harm to human health [16,17].

In the Food Products Technology Department of the Tashkent Institute of Chemical Technology (TICT), Uzbekistan, endeavors have been undertaken to enhance the mayonnaise recipe using ingredients that are readily available and widely consumed in our country, aiming to offer potential additional benefits to human health. As part of this effort, a mayonnaise incorporating sesame meal and lemon zest has been developed. Sesame meal replaces corn starch and partially substitutes vegetable oil. Concurrently, lemon zest is incorporated for its antioxidant properties, as it has demonstrated successful use in mayonnaise as a source of phenolic compounds with antioxidant and antimicrobial activity [18].

Sesame seeds are among the most widely used oilseeds in Uzbekistan, serving both as a culinary product and as a source of oil, which is akin to olive oil [14]. Apart from their exceptional sensory properties, sesame seeds also contain compounds that may boost human health, including sesamin, sesamol, sesaminol, sesamolin, and sesamolinol, lignans which are known for their antioxidant potential. Additionally, sesame seeds contain nutrients such as vitamins, calcium, and zinc, among others, which could aid in addressing issues like osteoporosis and cardiovascular disorders [19,20]. Moreover, the fatty acid profile of sesame seed oil causes it to be regarded as one of the best edible oils [21,22]. Following the cold pressing of sesame seeds to extract oil, the residual meal contains about 20–40 % protein and 8–30 % fat, alongside dietary fiber, pectin, vitamins (B1, B2, F, PP, C), and minerals (Ca, K, Zn, Mg, Na, Fe, Cu) [2,23,24]. Furthermore, this meal boasts a high content of phenolic compounds with antioxidant activity [24,25]. A growing body of studies suggests that the diverse phenolic compounds found in food may exert an anti-oxidant effect, potentially reducing the prevalence of health problems [26,27]. Given the widespread availability of sesame in Uzbekistan and its potential as a functional food for improving human health, it was chosen as an ingredient.

An article published in 2021 detailed the recipe and the process for obtaining sesame meal and lemon zest-enriched mayonnaises developed at the Food Products Technology Department of the Tashkent Institute of Chemical Technology (TICT). Additionally, the article included studies on oxidation, shelf-life, and sensory evaluation of the enriched mayonnaises [2]. Despite the high acceptance of the enriched mayonnaise, as indicated by the published results [2], ongoing work on the mayonnaise development at TICT continued, and the final recipe was officially patented in 2023 under the registry number IAP 07339 [28]. Subsequently, a mandatory toxicological assessment was conducted on the patented mayonnaise to comply with Uzbek laws, which require such assessments before commercialization of the product in our country [29].

In this work, we present additional data complementing the information already published [2]. This includes proximate analysis and physical appearance of mayonnaise formulations that were evaluated before the patenting process. Furthermore, we provide details on the toxicological assessment performed according to regulatory standards on the patented mayonnaise, as mandated by the Law of the Republic of Uzbekistan. To obtain the toxicological passport, various tests were conducted on laboratory animals, including oral moderate to lethal dose, cumulative (subacute) action, irritating effect on the mucous membranes, and sensitizing properties. In addition to the toxicological assessment, we also present an evaluation of the cost of production for the new mayonnaise. Our primary objective is to share the patented formula of the sesame meal and lemon zest-enriched mayonnaise developed at the TICT, along with evidence supporting its non-toxic nature.

2. Materials and methods

2.1. Materials

The following materials were purchased from local sources in Tashkent City, Uzbekistan.

• •Pure soybean oil.
• •Pure corn oil.
• •Pure sunflower oil.
• •Sugar.
• •Salt.
• •Egg powder.
• •Lemon.
• •Sesame seeds.
• •Water.

The following materials were obtained after further processing of previously described items.

• •Lemon zest was obtained by zesting lemons with a microplane zester (Microplane, USA).
• •Sesame meal was obtained by screw-pressing sesame seeds in a pilot plant screw press, as described in Ref. [30].

The following materials were sourced as indicated.

• •Potassium sorbate. Purchased from Moonshine Ingredients (Moonshine, China).
• •Sodium benzoate. Purchased from FOODS IMPEX GROUP LLC (FOODS IMPEX GROUP LLC, Uzbekistan).
• •Citric acid. Purchased from FOODS IMPEX GROUP LLC (FOODS IMPEX GROUP LLC, Uzbekistan).
• •Corn starch. Purchased from FOODS IMPEX GROUP LLC (FOODS IMPEX GROUP LLC, Uzbekistan).
• •Acetic acid (70%). Purchased from XIMIK (XIMIK, Uzbekistan).

2.2. Formula development before patenting. Proximal analyzes

In the article published in 2021 on sesame meal and lemon zest–enriched mayonnaise developed at the TICT, taste, mouthfeel, peroxide value, and other parameters showed an increase and better shelf life (after 90 days of storage) in the mayonnaise with a 10% sesame meal when compared to other formulations (2). The research endeavors continued, leading to ongoing formula refinements. Table 1 outlines five different formulations of sesame meal and lemon zest-enriched mayonnaises, alongside control, which is mayonnaise prepared according to a traditional recipe with some modifications, where starch is used as a stabilizer [31].

Table 1.

Recipes of sesame meal and lemon zest enriched mayonnaises prepared while investigating the formula to be patented. *Mixture of oils: Soybean: 70%, corn: 20%, sunflower: 10%. ** Water: 34.14%, sugar: 1.1%, salt: 1.2%, potassium sorbate: 0.03%, citric acid: 0.2%, acetic acid (70%): 0.3%, egg powder: 3%, lemon zest: 3%.

Mayonnaise composition and recipe
Amount of component, %	Control	SMM-1	SMM-2	SMM-3	SMM-4	SMM-5
Sesame meal	0	5	8	10	11	12
Mixture of oils*	50	50	47	45	44	43
Corn starch	5	–	–	–	–	–
Water and other components**	45	45	45	45	45	45

Pictures were taken after the preparation of all the mayonnaises shown in Table 1. Proximal analyses, including pH, acidity, peroxide value, anisidine value, moisture, protein content, fat content, and carbohydrate content, were conducted on the sesame meal and lemon zest–enriched mayonnaises, as well as on the control mayonnaise, prepared as detailed in Table 1. Peroxide and Anisidine Values analyses were performed after 180 days of storage at 30 °C. The following specific tests were performed.

2.2.1. pH

The pH was determined by adding 90 g of water to 10 g of sample, weighed using a Kern (Balingen, Germany) analytical balance, model ABJ-4NM, and mixing until the emulsion became stable. Subsequently, the electrode of a Mettler-Toledo (Columbus, Ohio, USA) calibrated pH/Ion bench meter, model SC S220–B, was immersed into the emulsion.

2.2.2. Acidity

The acidity, calculated as a percentage of acetic acid, was performed through titration using potassium hydroxide 0.1 M and phenolphthalein as an indicator, on a mixture comprising of 2 g of the sample, weighed on a Kern (Balingen, Germany) analytical balance, model ABJ-4NM, which was combined with 50 mL of distilled water and 1% of ethanol. The procedure followed the guidelines outlined in ISO 660:2009 [32].

2.2.3. Peroxide value (PV)

The Peroxide Value (PV) was performed in accordance with ISO 3960:2017 [33]. Initially, an aliquot of mayonnaise was centrifuged on a Hettich (Tuttlingen, Germany) centrifuge, model EBA 200. Subsequently, 10 g of the aqueous phase, weighed on a Kern (Balingen, Germany) analytical balance, model ABJ-4NM, were transferred to a a 100 mL flask. To this, 5 mL of distilled water were added and mixed, followed by the addition of 10 mL of ethanol, and the mixture was thoroughly mixed again. Finally, 30 mL of chloroform were added, and the mixture was allowed to stand for 20 min. Afterward, the organic layer was recovered, potassium iodine was added, and the PV was determined through titration with sodium thiosulfate.

2.2.4. Anisidine value

The Anisidine Value (AV) was performed in accordance with ISO 6885:2016 [34]. Initially, an aliquot of mayonnaise was centrifuged at a Hettich (Tuttlingen, Germany) centrifuge, model EBA 200, where fat was separated. Subsequently, 0.4 g of the separated fat were taken and weighed using a Kern (Balingen, Germany) analytical balance, model ABJ-4NM, then diluted with 25 mL of isooctane, and read at 350 nm using a quartz cuvette on a Mettler-Toledo (Columbus, Ohio, USA) UV–Vis spectrophotometer, model Uv5.

2.2.5. Moisture

The analysis of moisture and volatile substances was performed in accordance with ISO 7700–2:2011 [35]. Moisture was analyzed on an aliquot of mayonnaise on a Kern (Balingen, Germany) moisture analyzer, model DBS60-3.

2.2.6. Protein content

The determination of protein content was performed in accordance with ISO 1871:2009 [36]. 1 g of mayonnaise, weighed on a Kern (Balingen, Germany) analytical balance, model ABJ-4NM, was mixed with 12 mL of sulfuric acid 26 N and digested at 420 °C for 1.5 h. Subsequently, 50 mL of distilled water and 40 mL of NaOH 40% were added, and ammonia was distilled on a Beger (Radomlje, Slovenia) steam distillation unit, model SDU 100. The distillate was mixed with 50 mL boric acid at 2% and methyl red as an indicator, and titrated with sulfuric acid 0.1 N. A multiplication factor was used to obtain crude protein content.

2.2.7. Fat content

The analysis of fat content was performed in accordance with ISO 17189:2003 [37]. 5 g of mayonnaise, weighed using a Kern (Balingen, Germany) analytical balance, model ABJ-4NM, were placed in an oil separator. To this, 1 mL of isooctane and 20 mL of sulfuric acid were added, and the mixture was heated at 67 °C. Subsequently, the mixture was separated using a Hettich (Tuttlingen, Germany) centrifuge, model EBA 200, and then placed in a Memmer (Schwabach, Germany) oven, model 30–160, for 5 min. The percentage of fat was determined according to the formula specified in the method.

2.2.8. Carbohydrate content

Carbohydrate content was determined by substracting the percentages of moisture, fat, ash, and protein from 100%.

2.3. Formula of patented mayonnaise

The exact formula for the sesame meal and lemon peel-enriched mayonnaise developed at the TICT, patented under document IAP 07339 [28], is displayed in Table 2. Additional notes regarding preparation can be consulted in the article published in 2021 by personnel of the Food Products Technology department of the TICT, where the mayonnaise was developed [2].

Table 2.

Sesame meal and lemon zest–enriched mayonnaise developed in the TICT as patented under document IAP 07339. * Vegetable oil: Soybean: 70%, corn: 20%, sunflower: 10%.

Compound	Amount (%)
Vegetable oil*	45
Sugar	1.1
Salt	1.2
Potassium sorbate	0.03
Sodium benzoate	0.03
Citric acid	0.2
Acetic acid (70%)	0.3
Egg powder	5
Lemon peel	3
Sesame meal	10
Water	34.14

2.4. Toxicological assessment

The patented sesame meal and lemon zest–enriched mayonnaise, as detailed in Table 2, underwent a toxicological assessment in animals in accordance with local regulations and standards, where it is also specified that control samples should consist of distilled water. The product's toxicological analysis result is the toxicological passport, where the toxicity or non-toxicity of the evaluated product is affirmed.

Animal research tests, including oral moderate to lethal dose, cumulative action, irritating effect on the mucous membrane, and sensitizing properties, were conducted at the Department of Sanitary and Epidemiological Surveillance General Directorate of Medicine Under the Administration of The President of The Republic of Uzbekistan. This research laboratory is certified by SSEBiOZ RUz (Certificate No. 24 of 04/27/2022) and holds a Certificate of Accreditation by the Uzbek Center for Accreditation: No O’ZAK. SL.0183 dated April 06, 2022. This work was performed under the contract No. 1/04–2131.

Experimental tests were conducted in accordance with the rules adopted by the European Convention for the Protection of Vertebrate Animals for Experiments or Other Scientific Purposes (ETS No. 123. Strasbourg, March 18, 1986). Small laboratory animals, including white rats, mice, and guinea pigs, were utilized based on the requisites of each specific experiment.

On each of the tests for the toxicological assessment of the sesame meal and lemon zest–enriched mayonnaise developed at the TICT and patented under document IAP 07339 [33], this mayonnaise is regarded as “sample,” while distilled water is considered as “control”. The following tests were performed and carried out in accordance with the indicated regulatory standards.

2.4.1. Oral moderate to lethal dose

GOST 32644: Test methods for the effects of chemical products on the human body. Acute oral toxicity is a method for determining the acute toxicity class [38].

The acute toxicity of the sample was evaluated under experimental conditions using two types of laboratory animals: white outbred rats and mice. In each case 6 individuals of each species received a single intragastric dose of 2000, 4000, and 6000 mg/kg of body weight of the sample, or control, in each instance. The test lasted 14 days, and animals were fed 3 h after the dose. Throughout the experiment, animals were observed to identify possible signs of intoxication. This observation provided information for risk assessment and classification.

2.4.2. Cumulative (subacute) action

Methodological Recommendations МР № 012–3/0244: Procedure and methodology of pre-registration toxicological and hygienic examination of food additives [39].

For this test, a subchronic experiment was conducted on male mongrel white rats, using 5 individuals per group, with an initial body weight of 110–120 g. Experiments lasted 28 days. The animals were divided into two groups: control and experimental. The control group received a standard diet and intragastric administration of distilled water, while the experimental group received the same diet with intragastric administration of the sample. The sample dosage was gradually increased every 4 days by 1.5 times, starting from 1/10 of the maximum tolerated dose established in the acute experiment (0.6 g/kg; data in Table 5). Daily records were maintained regarding the amount of food consumed, water intake, and excrement excreted.

Table 5.

Lethal effects on laboratory animals after intragastric administration of sesame meal and lemon zest-enriched mayonnaise.

Dose mg/kg	Number of animals in the group/Number of dead animals	LD50
2000	6/0	not reached
4000	6/0	not reached
6000	6/0	not reached

Observations encompassed the daily monitoring of mortality and paralysis throughout the entire experimental period of 28 days. Body weight was recorded before drug administration and every three days until the conclusion of the experiment. Clinical signs were monitored four times, at 1, 2, 3, and 4 h after administration of the initial dose on the first day, and subsequently, daily throughout the remaining observation period. All deviations were recorded.

Biochemical blood tests were conducted using a semi-automatic biochemical analyzer, “CYANSmart,” equipped with software from Cypress Diagnostics, Belgium. Standard methods were used to determine AsT, AlT, ALP, and total protein, using sets of reagents also sourced from Cypress Diagnostics, Belgium. Hematocrit was determined using a hematocrit centrifuge from Cypress Diagnostics, Belgium. A comprehensive analysis of peripheral blood was determined using Goryaev's cell.

Pathomorphological studies were conducted the day after the last administration of the mayonnaise enriched with sesame meal and lemon zest. At the conclusion of the experimental period, all of the animals from both the experimental and control groups were euthanized using ether as anesthesia. During autopsy, their internal organs were visually assessed. Since no pronounced pathological changes were observed in either group, histological examination of randomly selected tissue samples from three rats in each group was performed. The tissue samples were fixed with neutral formalin, passed through increasing alcohol concentrations, and then paraffin was poured. Paraffin sections were prepared, stained with hematoxylin-eosin, and examined under an optical microscope. Studies were performed on skin, mammary glands, lymph nodes, submandibular glands, thymus, trachea, lungs, heart, thyroid gland, parathyroid gland, tongue, esophagus, stomach, duodenum, small intestine, large intestine, liver, pancreas, spleen, kidneys, adrenal glands, and bladder.

2.4.3. Irritating effect on the mucous membranes

MU No. 2102: Assessment of the effects of harmful chemical compounds on the skin and justification of the maximum permissible levels of skin pollution [40].

For this test, guinea pigs, with 3 animals per experiment, were used. The test duration was 24 h. A single inoculation of 0.05 mL (equivalent to 2 drops of an aqueous suspension) of the sample was administered into the conjunctival sac of the right eye of a guinea pig. The left eye served as a control in the group of 3 individuals.

2.5. Sensitizing properties

GOST 32375.

Test methods for the effects of chemical products on the human body. Tests for the assessment of skin sensitization [41].

Rats, with 5 individuals per group, were used for this test, which spanned 11 days. The scarification method was used, involving the application of a drop (with a weight between 0.8 g and 1 g) of the substance of study, either sample or control, on the lateral surface of the animal body, followed by an incision with a scarifier through the drop, creating a scar 1–1.5 cm long. The detection of sensitization was carried out by analyzing the reaction on the skin at the site of scarification after 4, 24, and 48 h, followed by a further period of observation, according to the following scale (Table 3).

Table 3.

Scale for classification of skin reaction at the site of scarification.

Type of reaction	Designation of the reaction	Description of the reaction
Negative	–	Incision sizes are the same as in animals of the control group.
Doubtful	±	Hyperemia at the site of scarification
Weakly positive	+	Hyperemia at the site of scarification and a small nodule
Moderately positive	++	Blister up to 5 mm, clearly visible and surrounded by hyperemia.
Sharply positive	+++	Hyperemia, blister up to 10 mm, lichenification.

2.6. Statistic analyses

The obtained results were statistically processed using a standard program (MS Excel), assessing the significance of indicators (M ± m) and differences according to the Student's t-test [42]. Differences between groups were considered significant at a 95% confidence level (p < 0.05). Two-tailed ANOVA, unequal variances, and Welch's test two-tailed ANOVA, unequal variances (one tailed were also explored), were performed in Minitab 21.64 (Minitab LLC, USA). Tukey's honestly significant difference (HSD) tests were performed on astatsa.com by Navendu Vasavada (last accessed, November 20, 2023).

3. Results

3.1. Formula development before patenting. Proximal analyzes

A visual representation of mayonnaises prepared as indicated in Table 1, while investigating the sesame meal and lemon zest–enriched mayonnaise formula to be patented, is depicted in Fig. 1. The results of their proximal analyzes are presented in Table 4.

Fig. 1.

Visual appearance of sesame meal and lemon zest-enriched mayonnaises prepared while formulating the formula to be patented, plus control mayonnaise.

Table 4.

Proximal analyzes of sesame meal and lemon zest-enriched mayonnaises prepared while investigating the formula to be patented, plus control mayonnaise.

Parameter	Mayonnaise sample
	Control	SMM-1	SMM-2	SMM-3	SMM-4	SMM-5
pH	3.9	3.8	3.8	3.8	3.8	3.8
Acidity, calculated as acetic acid (%)	0.32	0.32	0.32	0.32	0.33	0.33
Peroxide Value (PV) (mmol. active oxygen)	11.4	10.3	10.2	8.0	7.5	7.5
Anisidine Value (AV)	22.6	20.6	18.8	17.0	16.4	16.4
Moisture and volatile substances (%)	34.9	35.1	35.3	35.8	35.8	36.1
Protein (%)	2.65	5.71	5.74	5.76	5.77	5.77
Carbohydrates (%)	5.05	7.95	8.15	8.28	8.31	8.33
Total fat (%)	50.5	51.2	48.6	47.3	46.5	45.8

Due to color specifications outlined in GОSТ 31761–2012: Mayonnaises and mayonnaise sauces. General specifications (2012) [4], which state that mayonnaises should range from white to light ivory, SMM-4 and SMM-5 were not selected. Additionally, their organoleptic properties did not meet the desired criteria. Based on the previously published results [2], formulations SMM-1 and SMM-2 were also discarded. Therefore, SMM-3 was chosen as the preferred mayonnaise formulation for submission to the Center for Intellectual Property, a State Institution Under The Ministry of Justice of The Republic of Uzbekistan, where patent IAP78326 was issued [28].

It is noteworthy that the results in Table 4 indicate that SMM-3 mayonnaise has a higher amount of protein and a lower fat content. Therefore, its nutritional properties may represent an improvement over control. Additionally, its PV and AV are also lower than control, which may be an indicator of a higher resistance to oxidative damage.

3.2. Animal studies for toxicological assessment

As described in Section 2.4, in each of the tests for the toxicological assessment of the sesame meal and lemon zest–enriched mayonnaise developed at the TICT and patented under document IAP 07339 [33], this mayonnaise is referred to as “sample,” while distilled water is considered as “control”.

3.2.1. Oral moderate to lethal dose (acute toxicity)

Throughout the experiment, no deaths of experimental animals were observed. The animals exhibited a normal response to external stimuli, maintaining satisfactory overall conditions and behavior. All animals were active and willing to eat, with their fur and visible mucous membranes showing no noticeable changes. Consequently, the average lethal dose of the sample was not reached in the tested animals, and there were no significant differences in sensitivity regarding species or gender (data not shown). Furthermore, no lethal effects were observed when the product was administered intragastrically to the laboratory animals (Table 5).

Therefore, based on the observational data on experimental animals, it can be concluded that, as a result of toxicology testing after potential acute poisoning, sesame meal and lemon zest–enriched mayonnaise developed at the TICT and patented under document IAP 07339 [33] may be classified as a low-hazard substance (IV hazard class according to GOST 12.1.007) [43].

3.2.2. Cumulative (subacute) action (subchronic experiment)

Throughout the experiment, no deaths of experimental animals were observed, and no clinical signs of intoxication were observed during the experimental period after administering the sample. Furthermore, the general condition and behavior of both the control and experimental groups were satisfactory. All animals remained active and willing to eat, with their fur and visible mucous membranes showing no noticeable changes. The body weight of the animals after exposure to a potentially toxic product may be regarded as a simple and quite sensitive indicator of the possible adverse effects of that product on the body. However, there were no significant differences between the control and experimental groups (Fig. 2).

Fig. 2.

Gain of body weight in animals during the observation period (Data is in percentage of initial weight).

In the study of hematological parameters in the peripheral blood of experimental animals (Table 6), no significant changes were observed in any of the parameters studied. The hematocrit, hemoglobin content, thrombocritis (the ratio of platelets to the total blood volume), and the content of leukocytes and erythrocytes in all experimental animals did not show any statistically significant difference from the control group. p-values were >0.05 in all cases, except for hemoglobin, where p < 0.05, thus, a Tukey's HSD test was conducted, and it was determined that p-values lower than 0.05 could be attributed only to the Control/Before treatment group (Data not shown).

Table 6.

Average indicators of the morphological composition of the blood of rats with subchronic exposure to the sample.

Group	Observation period	Hematological indicators
		Hematocrit, %	Hemoglobin, g/l	Thrombocrit, %	Leukocytes, 109/l	Erythrocytes, 1012/l
Control: distilled water	Before treatment	31	132	0.460	15	8
		36	130	0.459	16	6
		32	131	0.455	14	7
		34	135	0.464	13	4
		33	128	0.458	15	9
		33.2 ± 1.72	131.8 ± 4.2	0.459 ± 0.04	14.6 ± 1.02	6.80 ± 1.72
	After treatment	33	141	0.444	14	5
		36	144	0.61	18	7
		34	146	0.458	11	8
		36	142	0.442	13	9
		35	138	0.451	16	4
		34.8 ± 1.17	142.2 ± 2.71	0.450 ± 0.01	14.40 ± 2.42	6.60 ± 1.85
Sample: Sesame meal and lemon zest- enriched mayonnaise	Before treatment	37	132	0.460	10	7
		36	136	0.418	19	6
		33	141	0.501	16	8
		38	142	0.383	13	5
		40	131	0.428	15	8
		36.8 ± 2.32	136.40 ± 4.5	0.438 ± 0.04	14.60 ± 3.01	6.80 ± 1.17
	After treatment	35	138	0.500	12	7
		40	136	0.467	17	4
		37	135	0.438	11	6
		32	143	0.476	20	8
		42	137	0.442	12	9
		37.2 ± 3.54	137.80 ± 2.8	0.465 ± 0.02	14.40 ± 3.5	6.67 ± 1.72

It is known that the consumption of any substance, including food products, multiple times in short intervals, may cause its accumulation in the body, leading to biochemical disturbances. Changes in enzyme activity may occur before morphological cell disorders in various organs can be observed. The levels of hepatic transferase enzymes in blood serum are an indicator of liver activity and may reveal a liver pathology. Therefore, methods for studying cellular enzymes and total protein content are valuable in assessing the potential adverse effects of the sample on liver function. The results of the study on the biochemical parameters of the blood serum of experimental and control animals (Table 7) showed that the activity of transaminase enzymes (AsT, AlT) and alkaline phosphatase (ALP) did not significantly differ between the experimental and control groups. Additionally, the total protein content (TP) of both groups was also found to be significantly the same. p-values were >0.05 in all cases (data not shown).

Table 7.

Biochemical parameters of the blood of white rats with subchronic exposure to the sample.

Group	Observation period, weeks	Biochemical parameters
		AlT, U/l	АSТ, U/l	ALP, U/l	TP, g/l
Control: distilled water	1	51	111	31	66
		58	118	42	65
		52	121	36	67
		56	115	38	61
		54	116	34	72
		54.2 ± 2.56	116.2 ± 3.31	36.20 ± 7.5	66.2 ± 3.54
	4	58	115	33	63
		56	100	30	68
		51	131	36	71
		62	114	41	66
		54	112	28	62
		56.2 ± 3.71	114.4 ± 9.9	33.6 ± 4.59	66.0 ± 3.29
Sample: Sesame meal and lemon zest- enriched mayonnaise	1	48	112	30	58
		52	108	35	64
		50	133	32	66
		45	98	34	60
		56	114	32	62
		50.2 ± 3.70	112.4 ± 11.07	32.6 ± 1.74	62.0 ± 2.83
	4	52	110	31	61
		53	122	43	72
		57	115	36	65
		54	99	32	67
		55	134	39	66
		54.2 ± 1.72	116.0 ± 11.71	36.20 ± 4.45	66.2 ± 3.54

After pathomorphological studies were conducted, observations showed no differences between the experimental and control groups. The rats exhibited a healthy physique and satisfactory nutrition, and no discharge from natural holes was detected during external inspection. Their furs were shiny and neat, and no hair loss was observed. Their teeth were intact, and the visible mucous membranes were pale and shiny. The females' mammary glands had no nodules, and there was no discharge from their nipples. The males' genitals were correctly developed, and the limbs showed no deformation or swelling.

The macroscopic and microscopic post-mortem examination of the studied organs and the determination of their relative mass coefficients showed no differences between the experimental and control groups. This study showed that daily intragastric administration of the sample for 28 days at an increasing dose did not cause lethal effects, changes in general condition, hematological parameters, biochemical parameters, or dystrophic or destructive changes in organs (skin, mammary glands, lymph nodes, submandibular glands, thymus, trachea, lungs, heart, thyroid gland, parathyroid gland, tongue, esophagus, stomach, duodenum, small intestine, large intestine, liver, pancreas, spleen, kidneys, adrenal glands, and bladder) after macroscopic and histological examination. Additionally, it was not accompanied by any irritation of the mucous membranes. Therefore, it may be concluded that, according to the integral indicators of subchronic toxicity, the sesame meal and lemon-zest enriched mayonnaise does not accumulate, and it is non-toxic.

3.2.3. Irritating effect on the mucous membranes

The average total score of mucosal irritation severity (I_ir) after the end of contact with the sample, was 0 points for all the samples in the group (Table 8). Mild hyperemia was observed under the influence of mayonnaise, which disappeared within a minute. No tearing or abnormal contraction of the eyelid occurred.

Table 8.

Results of the evaluation of the product's impact on the mucous membranes of the eyes (points).

Conjunctival hyperemia	Edema of the eyelids	Ptosis or blepharospasm	Eye discharge	Iir
0	0	0	0	0

Therefore, the research data obtained showed that the sesame meal and lemon zest - enriched mayonnaise did not cause any irritation to the eye's mucous membrane (I_ir = 0 points).

3.2.4. Sensitizing properties

After conducting the scarification test for the sample, the results showed that in all of the animals of the experimental group, the reaction was negative (according to the evaluation scale: "-"). Consequently, the sensitization index (Is) was 0 points in all cases (Table 9).

Table 9.

Results of the sensitizing effect assessment. Where: “-”: evaluation according to Table 1; and “/6”: the number of animals where the evaluation occurred.

Group	Hyperemia	Hyperemia and compaction	Blister up to 5 mm, hyperemia around	Blister up to 10 mm, lichenification	Is, Points
Control (Distilled water)	−/6	−/6	−/6	−/6	0
Mayonnaise enriched with sesame cake and lemon zest	−/6	−/6	−/6	−/6	0

Therefore, the sesame meal and lemon zest-enriched mayonnaise does not have a sensitizing effect (Is = 0 points) and does not provoke the development of allergies.

3.3. Cost evaluation

To evaluate whether our patented mayonnaise was cost-effective when compared to both control and some locally commercially available mayonnaises, we performed a cost evaluation. Individual prices of ingredients for mayonnaise elaboration (either control or sesame meal and lemon zest-enriched recipes) in Tashkent, Uzbekistan, as of February 2024, are shown in Table 10 (Table 10). It is important to mention that sesame seeds are priced at about лв 20000 UZS (Uzbek Soms)/Kg; after screw pressing, yield of oil is about 0.4 L/kg, and sesame oil is sold at about лв 110000 UZS/L (if high-quality cold pressing), thus it is the main product sought after in processing plants. In local screw presses, however, sesame meal is either discarded and/or used for forage, hence in many cases, it can be obtained at no cost. Considering that in this work we used sesame seeds, extracted the oil, and retained the meal for mayonnaise production, our cost of production of sesame meal was of about лв 33333 UZS/Kg if completely neglecting the value of the obtained oil. However, a local vendor, Гелиодор (Heliodor), LLC (Urgench, Uzbekistan), directly sells sesame meal for лв 12500 UZS/Kg, thus we are considering this value as the basis for our cost calculations. Regarding lemon zest, we considered the price of лв 22000 UZS/Kg of lemons in local markets, and a yield of 0.16 kg/kg of lemon zest, while also discarding the value of the rest of the lemon, thus the high price of this ingredient, which is the most expensive among all the ingredients. It is worth mentioning that the value of lemon juice is лв 37000 UZS/L so on a higher scale, where all byproducts were to be also commercialized, the production costs of our sesame meal and lemon zest enriched mayonnaise may be considerably lowered when compared to current evaluation.

Table 10.

Local prices of ingredients for preparation of Mayonnaise.

Item	Price (UZS/Kg)	Price (USD/Kg)
soybean oil	16250	1.30
corn oil	16750	1.34
sunflower oil	12800	1.03
Sugar	13500	1.08
Salt	1450	0.12
Potassium sorbate	48000	3.84
Sodium benzoate	30000	2.40
Citric acid	14500	1.16
Acetic acid (70%)	28000	2.24
Egg powder	63000	5.05
Lemon peel	137500	11.01
Water	500	0.04
Sesame meal	12500	1.00

Table 11, which is based on both Table 1, Table 10, displays the cost in UZS of the 5 recipes of sesame meal and lemon zest enriched mayonnaise, plus the control mayonnaise.

Table 11.

Cost of production (in UZS per Kg) of prepared mayonnaise. Total cost is also displayed in USD/Kg of mayonnaise. *Mixture of oils: Soybean: 70%, corn: 20%, sunflower: 10%. ** Water: 34.14%, sugar: 1.1%, salt: 1.2%, potassium sorbate: 0.03%, citric acid: 0.2%, acetic acid (70%): 0.3%, egg powder: 3%, lemon zest: 3%.

	Control	SMM-1	SMM-2	SMM-3	SMM-4	SMM-5
Sesame cake	0	625	1000	1250	1375	1500
Mixture of oils*	8002.5	8002.5	7522.35	7202.25	7042.2	6882.15
Corn starch	375	0	0	0	0	0
Water and other components**	7747.65	7747.65	7747.65	7747.65	7747.65	7747.65
Total (in UZS)	16125.15	16375.15	16270	16199.9	16164.85	16129.8
Total (in USD)	1.29	1.31	1.3	1.3	1.3	1.29

Regarding Tables 11 and it is important to mention that the cost of production is about half of the average cost of mayonnaises which may be purchased locally in Tashkent, Uzbekistan. For example, among the main brands commercialized locally, “Махеевъ” (Makheev), is лв 35000 UZS/L, “Milter” is лв 36000 UZS/L, and “Tanho” is лв 42000 UZS/L. Heinz mayonnaise is more expensive, at лв 80000 UZS/L. Therefore, even when considering that we are neglecting the value of sesame oil and lemon juice that may be obtained as additional products from the raw materials used for mayonnaise preparation, we can conclude that the sesame meal and lemon zest-enriched mayonnaise developed at the Food Products Technology Department of the TICT has a similar cost of production to the control mayonnaise prepared according to the traditional recipe.

4. Conclusion

The sesame meal and lemon zest-enriched mayonnaise developed at the TICT and patented under document IAP 07339 exhibits various favorable characteristics when compared to traditional mayonnaise with starch as a stabilizer (used as control). Notably, the enriched mayonnaise has a higher protein content, a lower fat content, and lower peroxide (PV) and anisidine (AV) values. These findings suggest that the enriched mayonnaise has potential health benefits, including improved nutritional properties and increased resistance to oxidative damage. Furthermore, it is also an economically viable option which may be prepared with widely available local ingredients.

The toxicological assessment conducted on the sesame meal and lemon zest-enriched mayonnaise developed at the TICT and patented under document IAP 07339 followed the standards and regulations outlined by the Law of the Republic of Uzbekistan. As indicated by Law, the specific studies of oral moderate-to-lethal dose (acute oral toxicity), cumulative (subacute) action, irritating effect on the mucous membranes, and sensitizing properties, were performed on laboratory animals. Following the conclusion of the studies, the toxicological passport No. 1/04–2131 was issued. According to this document, the evaluated mayonnaise belongs to IV Hazard Class, indicating its status as a low-toxicity substance, without cumulative, irritating, or sensitizing effects. As a result, it meets the safety requirements concerning toxicological parameters.

conflicts of interest

The authors declare that there was no conflict of interest in this study.

Data availability statement

The data that support the findings of this study are openly available in the following repository:

Calvo, Octavio (2023), “Mayonnaise enriched with sesame meal and lemon zest”, Mendeley Data, V1, https://doi.org/10.17632/53cgwr36gw.1.

CRediT authorship contribution statement

Shakhnozakhon Gaipova: Writing – original draft, Methodology, Investigation, Data curation, Conceptualization. Akbarali Ruzibayev: Project administration, Conceptualization. Shakhnozakhon Salijonova: Validation, Methodology, Investigation. Zulfiyakhon Khakimova: Visualization, Investigation. Octavio Calvo-Gomez: Writing – original draft, Methodology, Investigation, Writing – review & editing, Writing – original draft, Data curation.

Declaration of generative AI and AI-assisted technologies in the writing process

During the preparation of this work, the author(s) used Chat GPT and translators (Google Translate and Microsoft Translation tool included in Word) in order to improve clarity and help in translation of documents originally in Russian and Uzbek language. After using this tool/service, the authors reviewed and edited the content as needed and take full responsibility for the content of the publication.

Declaration of competing interest

The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Shakhnozakhon Gaipova has patent #Mayonnaise enriched with Sesame Meal. Patent IAP 78326 issued to Gaipova S, Ruzibayev A, Salijanova S, Khakimova Z. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.