Utilization of natural plant sources in a traditional dairy dessert, Muhallebi

Abstract

Traditional dairy desserts attract consumers’ attention and are consumed with admiration. Adding functional components, especially herbs and spices has been widely used recently to make these traditional products more functional regarding public health. The aim of this study was to examine the characteristics of a traditional dairy dessert called “Muhallebi” that was enriched with turmeric (Curcuma longa) powder and saffron (Crocus sativus) and stored for 7 days at 4°C. The titratable acidity, pH, dry matter, color parameters (L*, a*, b*, h_ab, C*_ab, ΔE*_ab), sensory characteristics, phenolic content, and antioxidant activity of Muhallebi samples were assessed on the 1st, 3rd, and 7th days of storage. In the primary outcomes, the inclusion of saffron and turmeric powder had a significant effect on all color parameters of the Muhallebi samples (p < 0.05). Muhallebi sample supplemented with 0.02% saffron and turmeric powder (D) showed the highest total antioxidant and phenolic activity content (11.96 mM TE and 1291.50 mg GAE/kg, respectively) on day 7 of the storage period compared to those of other treatments (p < 0.05). Furthermore, the Muhallebi sample supplemented with 0.02% saffron and turmeric powder received the highest scores in eight different sensory criteria in the sensory evaluation performed by experienced panelists (p < 0.05).

Keywords:

• Muhallebi
• saffron
• turmeric
• color
• sensory

1. Introduction

Turkish cuisine is considered to be one of the most ancient and diverse culinary traditions, along with French and Chinese cuisine (Sürücüoğlu & Özçelik, 2019). Sweets and desserts have always held a significant place in Turkish cuisine, which boasts a wide range of traditional fresh dairy desserts. Some of the famous Turkish dairy desserts include Muhallebi, Sütlaç, Mustafakemalpaşa, Güllaç, Kazandibi, Hoşmerim, and Tavukgöğsü (Akpınar Bayızıt et al., 2010; Akpinar-Bayizit et al., 2009; Bakan, 2021; Ozer, 2020; Sürücüoğlu, 2019; Yerasimos, 2015). Among these dairy desserts, especially Muhallebi is a popular Turkish dairy dessert with consistency, produced by applying heat treatment to a mixture of milk, corn starch, and sugar (Sürücüoğlu, 2019). Dairy desserts are vastly popular thanks to their nutritive and sensorial properties. There are both classic and innovative varieties of dairy desserts that have a substantial amount of dairy components, making up roughly 60–75% of the total ingredients (Akpinar-Bayizit et al., 2009; Bakan, 2021). Also, adding herbs and spices or their extracts makes these dishes a carrier for nutraceuticals. In order to provide consumers with more benefits, the dairy sector should explore innovative methods to improve the functionality of conventional dairy items, as this could have considerable implications for their overall wellbeing (El-Sayed & Youssef, 2019; Kaptan & Sivri, 2018; Oraon et al., 2017; Tajkarimi et al., 2010). For centuries, herbs and spices have been added to food to improve its taste and provide additional health benefits, as they can act as natural preservatives, flavorings, and medicinal substances. In addition, they have been adopted as additives to improve the organoleptic/sensory properties and prolong the shelf-life by diminishing or eliminating foodborne pathogenic microorganisms (Lai & Roy, 2004). Spices and herbs contain bioactive compounds that have the potential to mitigate or eradicate the risk of degenerative illnesses like cancer, diabetes, obesity, and cardiovascular diseases (El-Sayed & Youssef, 2019). Saffron (Crocus sativus) is an herb with a long history of medicinal use and is mainly cultivated in countries like Italy, Greece, Spain, Iran, and India. The dried stigmas of the Crocus sativus L. flower comprise the “saffron spice” (Altaf et al., 2019; Muzaffar et al., 2019). Saffron is an expensive crop; therefore, it is called “the red gold” (Cardone et al., 2020; Leone et al., 2018). Saffron, also known as Crocus sativus, is a source of bioactive compounds with various therapeutic properties. These compounds include antioxidants, antidepressants, anticarcinogens, anti-inflammatories, and antitumor agents, as noted by Moratalla-López et al. (2019). Saffron contains a range of therapeutic agents, such as crocetin, crocins, picrocrocin, safranal, minerals, carbohydrates, proteins, raw fiber, fats, essential oils, anthocyanins, carotenoids, and flavonoids. However, it has lower levels of vitamins B1 and B2, as highlighted by Mzabri et al. (2019) and Rahaman et al. (2021). Turmeric is a globally popular spice, food preservative, and coloring agent/material derived from the rhizomes of Curcuma longa, which belongs to the Zingiberaceae family (Gupta et al., 2012; Niranjan & Prakash, 2008; Serpa Guerra et al., 2020). Curcuma longa, or turmeric, has various beneficial properties such as anti-inflammatory, antioxidant, anticancer, antidiabetic, antiallergic, antiviral, antiprotozoal, and antifungal properties (Chattopadhyay et al., 2004; Hay et al., 2019). Curcuminoids, the active compounds in turmeric, exhibit potent antioxidant effects and have been shown to inhibit the early stages of tumor formation, thus potentially preventing cancer development. Additionally, they have been found to stimulate neuroprotective activity and contribute to the protection of the cardiovascular system (Hewlings & Kalman, 2017). Curcumin, dethoxycurcumin, and bisdemethoxycurcumin are the three main pigments responsible for the yellow color in turmeric. These three pigments possess high antioxidant activities (Maizura et al., 2011). The medicinal properties of spices, which include anti-inflammatory, anti-microbial, and antioxidant qualities, have attracted consumers to these types of foods. As a result, the food industry has been encouraged to include these herbs in dairy products such as milk, desserts, butter, yogurt, ice cream, and cheese (Alenisan et al., 2017; Ansari & Kumar, 2012; El-Sayed & Youssef, 2019; Embuscado, 2015; Oraon et al., 2017).

The aim of this study was to assess the impact of adding turmeric powder and saffron on the physicochemical properties, sensory attributes, phenolic content, and antioxidant activity of Muhallebi. As a traditional dairy dessert that holds a significant place in Turkish culinary culture, it was important to investigate how the addition of these ingredients might alter its overall composition. The addition of turmeric powder and saffron to the conventional dairy dessert, Muhallebi, was viewed as an innovation in the consumer market that aimed to satisfy the consumers’ need for a novel and more healthful product.

2. Materials and methods

2.1. Materials

The UHT cow’s milk utilized in this research was supplied by Pınar Süt Co., which is located in Izmir, Turkey. Turmeric (Curcuma longa) powder, saffron (Crocus sativus L.), sugar, corn starch, and disposable polyethylene terephthalate (PET) containers (Moderate storage temperature below 80°F/26.66°C, 150 ccs) were obtained from a local market in Zonguldak, TURKEY. The saffron was ground to a certain size in a mortar before use. ABTS (2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt), Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), and gallic acid were supplied by Acros (Morris Plains, NJ, USA). For this study, the Folin-Ciocalteu reagent was procured from Merck, which is located in Darmstadt, Germany. Potassium persulfate (K₂S₂O₈), sodium carbonate (Na₂CO₃), and ethanol (C₂H₅OH) were purchased from Sigma-Aldrich, which is situated in St. Louis, MO. All the reagents and chemicals used in this study were of analytical grade.

2.2. Dairy dessert (Muhallebi) production

The production process adopted for Muhallebi—with modifications—was according to Sıçramaz et al. (2016) and Bakan (2021). The Muhallebi was prepared using the following ingredients in the indicated ratios: 81.81% (v:v) commercial UHT milk, 10.90% (w:v) sucrose, 7.27% (w:v) corn starch, and 0.02% (w:v) spices (turmeric powder and saffron). Control Muhallebi sample was prepared similarly without adding turmeric powder and saffron. According to traditional production methods, sugar, corn starch, and spices are added to milk at approximately 30–32 °C and mixed with a hand blender for 5 minutes, and then the mixture is heat treated at 75 °C for 10 minutes until the characteristic gelation rate of the product. Visually, the changes in the structure and fluidity of the Muhallebi samples are followed. After achieving the desired consistency and cooling, Muhallebi samples were stored in PET containers at 4 °C for 7 days for analysis. A total of four Muhallebi samples were prepared: A: Control Muhallebi, B: Muhallebi supplemented with 0.02% saffron, C: Muhallebi supplemented with 0.02% turmeric powder, D: Muhallebi supplemented with 0.02% saffron and turmeric powder (Figure 1).

Figure 1. Muhallebi samples, A: Control Muhallebi, B: Muhallebi supplemented with 0.02% saffron, C: Muhallebi supplemented with 0.02% turmeric powder, D: Muhallebi supplemented with 0.02% saffron and turmeric powder.

2.3. Physicochemical methods

The total solids values of the samples were analyzed according to AOAC (1990) while the titratable acid values were determined according to Case et al. (1985). The titratable acidity of the samples was measured by titrating with 0.1 N NaOH to a pH of 8.1. The results are presented in percentile lactic acid. The pH levels of the samples were measured using a digital pH meter (Schott Instruments, Lab 860, Germany).

The reflected color of the Muhallebi samples was measured at 1, 3, and 7 days of storage to determine any changes in color. Color analysis was carried out in the present study using a CHN Spec. Spectral Colorimeter (Model CS-410, China) and the CIELab color scale with illuminant D65 and 10° viewing angle. The color parameters examined included luminosity (L*), red and green intensity (a*), and yellow and blue intensity (b*). The degree of color saturation was expressed as chroma (C*_ab), while hue (h_ab) was determined using values ranging from 0°/360° (pure red) to 90° (pure yellow), 180° (pure green), and 270° (pure blue), as noted by Zhao et al. (2023). Total color change (ΔE*_ab) was calculated using equations (1), (2), and (3) to assess the overall difference in color between the control and other samples, according to Chao et al. (2023). For each muhallebi sample, three measurements were obtained at each sampling time.

The value of C*_ab was calculated utilizing Equation (1):

1 ${{\mathrm{C}}^{\ast }}_{\mathrm{a}\mathrm{b}}={\left({\mathrm{a}}^{\ast 2}+{\mathrm{b}}^{\ast 2}\right)}^{1/2}$1

The h_ab value was obtained using Equation (2):

2 ${\mathrm{h}}_{\mathrm{a}\mathrm{b}}=\mathrm{t}\mathrm{a}{\mathrm{n}}^{-1}\left({\mathrm{b}}^{\ast }/{\mathrm{a}}^{\ast }\right)$2

The ΔE*_ab value was determined by applying Equation (3):

3 $\mathrm{\Delta }{{\mathrm{E}}^{\ast }}_{\mathrm{a}\mathrm{b}}={\left[{\left({{\mathrm{L}}^{\ast }}_0-{\mathrm{L}}^{\ast }\right)}^2+{\left({{\mathrm{a}}^{\ast }}_0-{\mathrm{a}}^{\ast }\right)}^2+{\left({{\mathrm{b}}^{\ast }}_0-{\mathrm{b}}^{\ast }\right)}^2\right]}^{1/2}$3

2.4. Total antioxidant activity

2.4.1. The ABTS-TEAC assay involved using 2,2’-azinobis(3-ethylbenzothiazoline)-6-sulfonic acid

To prepare the 2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS+) radical cation, a 7 mM ABTS+ stock solution was reacted with 2.45 mM potassium persulfate in the absence of light for 16 hours. The ABTS+ radical cation solution was diluted with PBS at pH 7.4 until the absorbance reached 0.70 (±0.02) at 734 nm, and then equilibrated at 30°C. Briefly, 20 µL of the sample (100 µL sample+900 µL PBS) was added to 2 mL of diluted solution (A734nm = 0.70 ± 0.02) and the absorbance reading was taken up to 6 min. Spectrophotometric measurement was performed to assess inhibition of Trolox (6-hydroxy-2, 5, 7, 8-tetramethylchroman-2-carboxylic acid) by ABTS+ compound. A spectrophotometer (Shimadzu Scientific Instruments, Inc., Tokyo, Japan) was used to measure the absorbance at 734 nm. The TEAC values of the samples were determined by calculating the Trolox equivalents (in μmol ml⁻¹ of the sample) using the Trolox standard curve (Re et al., 1999).

2.5. Total phenolic content analysis

The Folin-Ciocalteu method (Singleton & Rossi, 1965) was used to analyze the phenolic content in Muhallebi, with gallic acid serving as the standard solution. The absorbance of the sample was measured at 760 nm using a spectrophotometer (Shimadzu Scientific Instruments, Inc., Tokyo, Japan). The concentration of total phenolic content in the Muhallebi was determined in mg GAE/kg, utilizing the standard gallic acid curve to obtain the gallic acid equivalent (GAE) values. The results were presented in this unit.

2.6. Sensory analysis

Ten trained panelists (comprising of 4–5 males and 4–5 females) conducted a sensory evaluation of Muhallebi using scorecards that were specifically designed for this purpose. Trained panelists selected for the sensory evaluation of the product voluntarily consented to the sensory evaluation of the proposed product. Muhallebi has been evaluated in eight different categories. The sensory evaluation of Muhallebi samples was carried out for a duration of three days, with assessments conducted on the first, third, and seventh day of storage. The evaluation criteria included appearance, texture, homogeneous structure, color, taste, mouthfeel, odor, and overall acceptability, and were rated on a scale of 1 to 10. Trained panelists, consisting of 4 to 5 male and female evaluators, participated in the sensory evaluation process (Altuğ Onoğur & Elmacı, 2011; Lawless & Heymann, 1999).

2.7. Statistical analysis

All trials and analyses were carried out twice for the sake of accuracy during the experimental process. The obtained data was analyzed using SPSS software version 16.0 for Windows. A repeated measures one-way analysis of variance (ANOVA) was employed to perform the analysis, while Tukey’s test was utilized to evaluate the differences between the repeated measures (SPSS, 2017).

3. Results and discussion

3.1. Physicochemical parameters

Table 1 presents the physicochemical composition of the Muhallebi samples. The LA% values of the samples ranged from 0.06 ± 0.01 to 0.12 ± 0.01. The Muhallebi samples containing saffron and turmeric powder showed higher titratable acidity values compared to the control sample (A). This variation was especially significant between samples A and B (p < 0.05). As reported in the literature, it is thought that this effect is seen since the basic components in the structures of saffron and turmeric increase the titratable acidity values (Cardone et al., 2020; Sueth-Santiago et al., 2015). Titratable acidity values are increased during storage, and the change in storage was significant (p < 0.05). These results agree with those Prasad et al. (2018) and Kıratlı (2019) reported. The Muhallebi samples exhibited pH values within the range of 6.72 ± 0.00 to 6.82 ± 0.01. During the storage period, there were noticeable variations (p < 0.05) in pH values among the different formulations. These results are similar to those of Kıratlı (2019), who studied the dairy dessert (Zerde) supplemented with different turmeric, safflower, and saffron concentrations. The dry matter values determined in the Muhallebi samples ranged from 29.45%±0.20 to %33.64 ± 0.14. In comparison to the control group, the inclusion of saffron and turmeric powder in the samples caused a significant change in the dry matter content (p < 0.05). The outcomes are in line with the findings stated by Bandyopadhyay et al. (2007) and Prasad et al. (2018).

Table 1. The physicochemical composition of Muhallebi samples

Sample	Storage periods (day)	Titratable acidity (LA%)	pH	Dry matter (%)
A	1	0.06 ± 0.01^Aa	6.77 ± 0.01^Aa	30.35 ± 0.14^Aa
	3	0.08 ± 0.01^Aa	6.82 ± 0.00^Ab	29.71 ± 0.17^Aa
	7	0.11 ± 0.00^Ab	6.82 ± 0.00^Ab	30.18 ± 0.10^Aa
B	1	0.10 ± 0.01^ABa	6.80 ± 0.00^Ba	31.36 ± 0.15^Ba
	3	0.12 ± 0.01^Ba	6.79 ± 0.00^Ba	30.24 ± 0.08^Ab
	7	0.12 ± 0.01^Aa	6.72 ± 0.00^ABb	31.16 ± 0.08^Ba
C	1	0.08 ± 0.01^Aa	6.82 ± 0.01^Ba	32.35 ± 0.14^Ca
	3	0.12 ± 0.01^Bb	6.77 ± 0.01^Bb	29.57 ± 0.22^Ab
	7	0.11 ± 0.00^Ab	6.82 ± 0.00^Aa	33.64 ± 0.14^Cc
D	1	0.08 ± 0.01^Aa	6.74 ± 0.00^Ca	31.24 ± 0.07^Ba
	3	0.10 ± 0.01^ABab	6.79 ± 0.01^Bb	29.45 ± 0.20^ABb
	7	0.12 ± 0.01^Ab	6.73 ± 0.00^Ba	29.61 ± 0.22^Ab

A: Control Muhallebi, B: Muhallebi supplemented with 0.02% saffron, C: Muhallebi supplemented with 0.02% turmeric powder, D: Muhallebi supplemented with 0.02% saffron and turmeric powder.

^a—cDifferent lowercase superscripts depict the statistical difference within a row between time (p < 0.05).

^ABCDifferent uppercase superscripts depict the statistical difference between means for Muhallebi samples (p < 0.05).

Color is one of the most important food characteristics that affect taste perception, consumer preferences, and purchasing choices (Sukkwai et al., 2018). Color is of the most attractive properties of foodstuffs, which forms the base for evaluating food freshness and quality (Zulueta et al., 2007).

All color variables of Muhallebi samples were significantly affected by saffron and turmeric powder addition (Table 2) (p < 0.05). As saffron and turmeric powder are characterized by carotenoid contents that primarily confer a yellow color (Gaglio et al., 2018; M. Sharma et al., 2022), their addition to Muhallebi samples significantly enhanced the yellow tone (b*) and chroma (C*_ab), while decreasing redness (a*), hue angle (h_ab), and luminosity values (L*). All treatments, except for sample A, remained within the yellow color range (90°) for hue (h_ab), as shown in Table 2, according to the classification of Lee et al. (2013). The angular range of the yellow color was maintained during the evaluation. After assessing the ΔE*_ab value, which provides insight into the overall color alteration, it was found that the smallest color difference was 9.30 in the Muhallebi sample with saffron addition (B), whereas the largest color difference was 20.39 in the Muhallebi sample with turmeric addition (C). Upon performing statistical analysis of the ΔE*_ab data, it was observed that the color difference between the control group and all the other groups was statistically significant (p < 0.05). The changes within each sample during storage were found to be insignificant (p > 0.05) (Table 2). If the ΔE*_ab value is greater than 5, consumers can detect changes in product color (Britto et al., 2020; Castellar et al., 2006). The addition of turmeric and saffron to Muhallebi samples resulted in a positive change in ΔE*_ab values in terms of consumer acceptance compared to the control samples. Similar results were reported by Prasad et al. (2018), Kıratlı (2019), and M. Sharma et al. (2022) while working on dairy desserts supplemented with saffron and turmeric.

Table 2. The physical color parameters of Muhallebi samples

Sample	Storage periods (day)	L*	a*	b*	C*ab	hab	ΔE*ab
A	1	72.57 ± 1.26^Aa	−2.32 ± 0.08^Aa	8.14 ± 0.56^Aa	8.47 ± 0.56^Aa	106.00 ± 0.61^Aa	-
	3	71.75 ± 0.94^Aa	−1.54 ± 0.03^Aa	8.03 ± 0.21^Aa	8.19 ± 0.21^Aa	100.83 ± 0.43^Ab	1.14 ± 0.73^Dd
	7	71.46 ± 0.54^Aa	−1.91 ± 0.33^Aa	7.61 ± 0.24^Aa	7.86 ± 0.15^Aa	104.17 ± 2.74^Aab	1.30 ± 0.64^Dd
B	1	65.50 ± 1.21^Aa	−3.61 ± 0.16^Ba	14.05 ± 0.44^Ba	14.06 ± 0.45^Ba	92.47 ± 0.64^Ba	9.30 ± 0.18^Cc
	3	63.23 ± 0.81^Ba	−3.72 ± 0.03^Aa	14.82 ± 0.29^Ba	14.84 ± 0.29^Ba	92.78 ± 0.17^Ba	11.57 ± 0.32^Cc
	7	64.37 ± 0.66^Aa	−3.20 ± 0.09^Ba	13.21 ± 0.13^Ba	13.22 ± 0.13^Ba	90.85 ± 0.41^Ba	9.69 ± 0.47^Cc
C	1	63.29 ± 1.08^Aa	−6.11 ± 0.22^Ca	24.79 ± 0.33^Ca	25.54 ± 0.32^Ca	103.77 ± 0.52^Aa	19.44 ± 0.49^Aa
	3	66.80 ± 0.68^Bb	−6.63 ± 0.13^Bab	27.21 ± 0.68^Ca	28.01 ± 0.67^Ca	103.63 ± 0.35^Aa	20.39 ± 0.26^Aa
	7	66.41 ± 1.41^Aa	−5.64 ± 0.15^Ca	26.12 ± 1.30^Ca	26.72 ± 1.29^Ca	102.17 ± 0.38^Aa	19.29 ± 0.19^Aa
D	1	67.62 ± 1.30^Aa	−3.73 ± 0.06^Da	20.74 ± 0.43^Da	21.08 ± 0.42^Da	100.20 ± 0.25^ABa	13.61 ± 0.47^Bb
	3	66.39 ± 0.69^ABa	−3.09 ± 0.21^Ca	20.75 ± 0.20^Da	20.99 ± 0.16^Da	98.49 ± 0.64^ABa	14.07 ± 0.91^Bb
	7	65.51 ± 2.12^Aa	−2.64 ± 0.20^Aab	19.40 ± 0.55^Da	19.58 ± 0.56^Da	97.74 ± 0.40^ABa	13.29 ± 0.54^Bb

A: Control Muhallebi, B: Muhallebi supplemented with 0.02% saffron, C: Muhallebi supplemented with 0.02% turmeric powder, D: Muhallebi supplemented with 0.02% saffron and turmeric powder.

^a—dDifferent lowercase superscripts depict the statistical difference within a row between time (p < 0.05).

^ABCDDifferent uppercase superscripts depict the statistical difference between means for Muhallebi samples (p < 0.05).

3.2. Assessment of the overall antioxidant activity and phenolic content

Figure 2 shows the total antioxidant activity of Muhallebi samples during storage. On the 7th day of storage, the Muhallebi sample supplemented with 0.02% saffron and turmeric powder (D) exhibited the highest antioxidant level (11.96 mM TE) among all the treatments (p < 0.05). On the seventh day of storage, the total antioxidant activity value of the saffron and turmeric powder added to Muhallebi sample (D) (11.96 mM TE) increased approximately 2.5 times compared to the control sample (A) (4.96 mM TE) (p < 0.05). The outcomes are comparable to the findings reported by Bandyopadhyay et al. (2007) and Kıratlı (2019), who studied sweet dairy products supplemented with different spice concentrations. The antioxidant properties of plants are associated with the presence of phenolic hydroxyl groups in their composition. Polyphenols and carotenoids, which are natural antioxidants, exhibit a broad range of biological effects, including anti-carcinogenic, anti-inflammatory, anti-atherosclerotic, and anti-aging properties (Baiano & Del Nobile, 2016; Manach et al., 2004). Moreover, antioxidants play a crucial role in nutrition as they alleviate physiological stress in cells and organs (Li et al., 2014; Salomone et al., 2016). Saffron and turmeric plants are characterized by elevated levels of total phenolic compounds and antioxidant activity (Akter et al., 2019; Chichiricc’o et al., 2019; Menghini et al., 2018; Tanvir et al., 2017). In the current study, due to the plants’ high antioxidant and phenolic substance content as mentioned above, it was thought that the Muhallebi samples, in which saffron and turmeric powder were added, had higher antioxidant substance contents compared to the control group. Furthermore, Muhallebi samples showed an increase in antioxidant activity towards the end of the storage period. Due to the structural changes in polyphenols during storage, there may be increases in flavonoid contents as the storage period progresses. It is predicted that especially short-term and low-temperature heat treatment may increase the polyphenolic substances, increasing the antioxidant activity in some food matrices during storage (Horváthová et al., 2007; Nicoli et al., 1997).

Figure 2. The total antioxidant activity of Muhallebi samples over the storage period: A: Control Muhallebi, B: Muhallebi supplemented with 0.02% saffron, C: Muhallebi supplemented with 0.02% turmeric powder, D: Muhallebi supplemented with 0.02% saffron and turmeric powder.

Results of the total phenolic content of Muhallebi samples are presented in Figure 3. After seven days of storage, the Muhallebi sample supplemented with 0.02% saffron and turmeric powder (D) displayed the highest total phenolic content (1291.50 mg GAE/kg) among all the samples, according to the statistical analysis (p < 0.05). There was a significant difference (p < 0.05) in the total phenolic content values between formulations, particularly in samples A and D, on all storage days. These results were consistent with Kıratlı (2019) results, who examined the milk dessert with turmeric, safflower, and saffron added at different concentrations. Spices and herbs are the primary sources of various phenolic compounds, including phenolic acids, alcohols, flavonoids, tocopherols, stilbenes, tocotrienols, ascorbic acid, and carotenoids. These compounds are well-known for their remarkable antioxidant activity (Zheng & Wang, 2001). Consistent with the initial hypothesis, the inclusion of saffron and turmeric powder in the Muhallebi samples had a significant impact on the total phenolic content values, according to the findings of the present study (Figure 3) (p < 0.05).

Figure 3. The total phenolic content of Muhallebi samples over the storage period: A: Control Muhallebi, B: Muhallebi supplemented with 0.02% saffron, C: Muhallebi supplemented with 0.02% turmeric powder, D: Muhallebi supplemented with 0.02% saffron and turmeric powder.

3.3. Sensory evaluation

Figure 4 shows the sensory characteristics of the Muhallebi samples on the first day of storage. The Muhallebi sample containing 0.02% saffron and turmeric powder (D) was rated highest in all sensory attributes, including color, appearance, odor, homogeneous structure, mouthfeel, texture, taste, and overall acceptability, by trained panelists in the sensory evaluation conducted on the first day of storage (p < 0.05). Throughout the storage period, there was a notable variation (p < 0.05) in sensory attribute scores among the formulations. The results presented in Figure 5 for the overall acceptability scores of the Muhallebi samples throughout the storage period showed that the highest score was observed in treatment (D), which corresponds to Muhallebi enriched with 0.02% saffron and turmeric powder (p < 0.05). The results were supported by those reported by Bandyopadhyay et al. (2007); Rahim and Ova (2016); Prasad et al. (2018); Kıratlı (2019); P. Sharma et al. (2020) with the addition of spice in dairy desserts.

Figure 4. Sensory characteristics of the Muhallebi samples on the first day of storage: A: Control Muhallebi, B: Muhallebi supplemented with 0.02% saffron, C: Muhallebi supplemented with 0.02% turmeric powder, D: Muhallebi supplemented with 0.02% saffron and turmeric powder.

Figure 5. Overall acceptability of the Muhallebi samples throughout the storage period: A: Control Muhallebi, B: Muhallebi supplemented with 0.02% saffron, C: Muhallebi supplemented with 0.02% turmeric powder, D: Muhallebi supplemented with 0.02% saffron and turmeric powder.

The current study demonstrated that Muhallebi samples formulated with saffron and turmeric, which are commonly used as food colorants (P. Sharma et al., 2020), received higher scores than the control group in terms of color criteria during sensory evaluation (p < 0.05). The higher scores given by the panelists in all sensory criteria for the Muhallebi samples containing saffron and turmeric indicate that the use of these spices in dairy desserts could have a positive impact on consumer acceptance.

4. Conclusion

It is common practice to incorporate herbs and spices in food products to enhance their functional properties. With the increasing demand for healthy food options, functional foods that contain plant-based ingredients have become popular in the food industry. Consumers are increasingly interested in incorporating healthy options into their diets, and incorporating herbs and spices into food products provides an attractive solution to meet this demand. Our results showed that herbs and spices could be a good alternative to produce functional dairy products with good properties and potentially higher nutritional value. According to the results, adding the saffron and turmeric powder improved the physicochemical parameters and total antioxidant activity and phenolic contents, and sensory evaluation scores in the treatments compared to the control sample. The Muhallebi sample enriched with 0.02% saffron and turmeric powder (D) was deemed the most favorable product according to all sensory evaluation criteria. Additionally, it was determined to have the highest total antioxidant activity and phenolic content values. By incorporating herbs and spices with recognized health benefits, a conventional Turkish milk dessert (Muhallebi) has been updated, potentially enhancing its consumer appeal and taste. The product has been found to have high sensory scores and increased levels of antioxidant activity and phenolic content. Therefore, it is anticipated that this modified dessert will gain popularity among consumers.

Authors’ contributions

ODO conducted the literature review, designed and carried out the experiments, analyzed the data, and wrote the manuscript. This paper is the sole authorship of ODO.

Disclosure statement

No potential conflict of interest was reported by the author.

Data availability statement

The data collected or analyzed during the study are all available in this published article.

Additional information

Funding

No specific grants were received from public, commercial, or not-for-profit funding agencies for this study.tat

Notes on contributors

Özge Duygu Okur

Özge Duygu Okur (PhD) is an assistant professor of Food Technology at Zonguldak Bulent Ecevit University, Faculty of Engineering, Department of Food Engineering, Zonguldak, Turkey. Her key research activities and interests include production, quality, antioxidant and phenolic contents, sensorial and physicochemical composition of functional dairy products; identification of functional compounds of novel dairy products.