Utilization of Date Powder as a Natural Sweetener in Milk Chocolate: Impacts on Production Process and Quality Attributes

Abstract

This study explored the utilization of date powder produced from non-marketable Sukkari and surplus dates as a natural sugar substitute in milk chocolate, with the dual objectives of improving product quality and reducing Saudi Arabia’s reliance on imported sugar. Molding chocolates were formulated with 10%, 20%, and 30% sugar substitution, while coating chocolates contained 20%, 40%, and 60%. Physical, chemical, and sensory properties were assessed immediately after production and following six months of refrigerated storage. Increasing substitution levels led to higher viscosity, with peak values observed at 30% in molding chocolate and 60% in coating chocolate. Ash and moisture contents also rose with substitution, whereas fat, protein, and carbohydrate levels remained largely unaffected. Energy content declined as substitution increased, and no significant differences were detected in peroxide or acid values between control and treated samples throughout storage. Sensory evaluations confirmed that molding chocolate with up to 20% substitution and coating chocolate with up to 40% substitution maintained comparable acceptability to control samples both initially and after storage. Overall, the findings recommend sugar replacement with date powder at 20% in molding chocolate and 40% in coating chocolate to achieve high-quality, nutritionally enhanced products with stable sensory and storage characteristics.

1. Introduction

Date palm (Phoenix dactylifera L.) has been deeply integrated into Middle Eastern culture for centuries, particularly in Saudi Arabia, due to its nutritional value and adaptability to the region’s arid climate. As one of the oldest cultivated trees, its fruit dates provide a rich source of carbohydrates, fiber, minerals like potassium and magnesium, and essential vitamins, including vitamin B. This nutritional profile, coupled with growing consumer interest in healthier foods, has positioned dates as a promising ingredient in innovative food products aimed at reducing the reliance on refined sugars and offering health benefits. However, despite their abundance, 20–30% of dates are wasted annually in Saudi Arabia due to overproduction and unsold stock [1], underscoring the need for more efficient utilization.

Saudi Arabia’s Vision 2030 prioritizes sustainability within the date palm sector, and the Kingdom became the world’s top exporter of dates in 2025 [2]. With surplus dates readily available, their natural sweetness and nutrient density make them ideal for transforming into value-added products, such as confections. By incorporating surplus dates into food products like chocolate, Saudi Arabia can address both sustainability and economic diversification while reducing waste and promoting local resources [3]. Dates contain high levels of glucose and fructose but are low in protein and fats, making them a valuable sugar substitute [4]. Beyond their nutritional content, research suggests that consuming dates can regulate blood sugar and lipid levels in diabetic people, reduce heart disease risks, and provide antioxidant and antimutagenic benefits [1,5]. Their transformation into date powder enhances their versatility, as it can be stored long-term and used in various food applications [6]. This aligns with global dietary recommendations, such as those from the World Health Organization (WHO), which advises limiting added sugars to less than 10% of total caloric intake, and the American Heart Association, which suggests daily limits of 100 calories for women and 150 calories for men. Products like date syrup or paste have already been successfully used as sugar alternatives in items like cakes, yogurt, and bread, though some sensory attributes may vary [7].

Chocolate, a globally cherished confection, is produced using cocoa, sugar, milk solids, and emulsifiers, with sugar comprising 34–40% of its formulation [8]. Milk chocolate, for example, must meet U.S. FDA standards, including specific levels of milk fat, milk solids, and chocolate liquor, while dark chocolate often excludes milk solids but may contain small amounts of milk fat [9]. The texture, gloss, and melting behavior of chocolate are heavily influenced by the composition of cocoa butter, making it a key determinant of quality and consumer appeal [10]. Emulsifiers like lecithin further enhance the mixing of sugar and fats, improving the consistency of chocolate, with FDA guidelines allowing up to 1% emulsifiers by weight [11]. The production of chocolate involves precise steps, including conching, where ingredients are mixed at specific temperatures, and tempering, which stabilizes fat crystals for the desired texture. Factors such as fat content, particle size distribution, and moisture levels affect the rheological properties of chocolate, which in turn determine its mouthfeel and stability [12,13]. Sensory attributes like texture, appearance, and flavor are critical for consumer acceptance, with evaluations often conducted by trained panels. Studies have shown that storage duration can significantly impact the sensory properties of chocolate, such as gloss and texture, emphasizing the importance of careful formulation and production techniques [14].

In response to rising costs of sugar and cocoa butter, there is increasing interest in sustainable alternatives. This study explores the use of surplus Sukkari dates, a variety commonly found in Saudi Arabia’s Qassim region, which are often unsuitable for packaging or marketing due to quality issues. These dates were processed into date powder, a natural sweetener, and used as a sugar substitute in two types of milk chocolate: molded chocolate and wafer biscuit coatings. The higher proportion of date powder used in the wafer biscuit coating was determined by its specific functional requirements. Wafer coatings require greater viscosity and stronger sweetness to ensure good adhesion and flavor balance when applied to biscuit surfaces. Unlike molded chocolate, which depends mainly on its solid texture, coatings need smoother flow and spreadability. The hygroscopic nature and natural sugars of date powder help achieve these properties while enhancing color and flavor. The aim was to reduce waste, create healthier confectionery products, and support Saudi Arabia’s economic diversification and sustainability goals. By leveraging surplus dates, this approach demonstrates the potential for producing cost-effective, nutritious, and appealing chocolate products, aligning with modern trends in health-conscious and sustainable consumption.

2. Materials and Methods

2.1. Materials

a. 

Non-marketable dry Sukkari dates: Non-marketable dry dates were obtained from a date factory in Buraydah, Qassim.

b. 

Raw materials used in chocolate production: The raw materials for chocolate production (cocoa powder, skimmed milk powder, powdered sugar, lecithin, vanilla, and packaging materials) were purchased from the local market in Qassim, Saudi Arabia. Turkish cocoa butter was imported from Sade Koy Company and stored under refrigeration until manufacturing.

c. 

Chemicals: All chemicals used in the research for chemical analyses were of high purity and were obtained from Sigma, Jeddah, Saudi Arabia.

2.2. Methods

2.2.1. Preparation of Dry Sukkari Date Powder

The Sukkari date powder was prepared from non-marketable dry dates following a standardized procedure. First, the dates were thoroughly sorted to remove any impurities, including fruits damaged by birds, insects, or mold. Next, the dates were cleaned using rollers equipped with soft brushes, while a gentle air stream was applied to remove residual dust and debris. The cleaned dates were then crushed, and the pits were separated using a mechanical crushing machine. The date flesh was subsequently ground in a cooled milling system to prevent clumping and ensure uniform particle consistency. After grinding, the powder was sieved to remove coarse particles and achieve a fine particle size suitable for incorporation into Wafer biscuit coatings; the final particle size was 200 µm. Finally, the date powder was packaged in moisture-proof polyethylene bags and stored under ambient conditions until use.

2.2.2. Preparation of Chocolate Mixes

Chocolate samples, including molded bars and wafer coatings, were prepared following a standardized process. Raw materials were weighed according to the proportions shown in

Table 1. Replacement ratios of sugar with Sukkari date powder in milk chocolate production.

The Components, %	Molding Milk Chocolate
	Control Sample	Replacing Sugar with Sukkari Date Powder, %
		10%	20%	30%
Cocoa butter, 40	400	400	400	400
Cocoa powder, 7	70	70	70	70
Sugar powder, 40	400	360	320	280
Sukkari date powder,	0	40	80	120
Skimmed milk powder, 12	120	120	120	120
Lecithin, 0.7	7	7	7	7
Vanilla powder, 0.3	3	3	3	3
Total, 100 (g)	1000	1000	1000	1000
	Coating milk chocolate
	Control Sample	Replacing sugar with Sukkari date powder, %
	60%	20%	40%	60%
Cocoa butter, 50	500	500	500	500
Cocoa powder, 6	60	60	60	60
Sugar powder, 34	340	272	204	136
Sukkari date powder,	0	68	136	204
Skimmed milk powder, 9	90	90	90	90
Lecithin, 0.7	7	7	7	7
Vanilla powder, 0.3	3	3	3	3
Total, 100 (g)	1000	1000	1000	1000

, including cocoa butter, lecithin, skimmed milk powder, cocoa powder, powdered vanilla, powdered sugar, and date powder. All ingredients were first mixed manually in a stainless-steel bowl at room temperature, then heated and stirred using an electric mixer in a water bath at 50 °C for one hour to complete the conching process. The liquid chocolate mass was then tempered by transferring it to an incubator at 31 °C for one hour with gentle stirring every 10–15 min to ensure proper crystallization. After tempering, the chocolate was either poured into plastic molds or used to coat wafer fingers. The molds measured 15 × 30 cm and were divided into cells of 3 × 3 cm and 1.5 cm in height; they were gently tapped to remove air bubbles. For coating, wafer fingers were placed on a stainless-steel mesh above a collection tray, and tempered chocolate was poured over them while applying a gentle air stream to ensure even coverage. The molded and coated samples were cooled at 10–15 °C for one hour to allow complete solidification, then released from the molds or racks and manually wrapped in aluminum foil without direct hand contact. All wrapped samples were stored at 15 °C for six months for sensory evaluation and quality analysis during storage.

2.2.3. Chemical Composition and Caloric Content for Date Powder and Chocolate Samples Produced

The chemical composition (moisture, ash, total protein, fat and carbohydrates) of the date powder and chocolate samples were analyzed following [15] methods.

Protein content was measured using the Kjeldahl method, with a conversion factor of 5.70 for wheat flour and 6.25 for both date powder and biscuits. Fat content was determined using a Soxhlet apparatus. Total carbohydrates, including fiber content, were calculated using Equation (1).

Carbohydrates (%) = 100 − (% protein + % fat + % ash)

(1)

Caloric content was estimated based on the energy values of protein (4 kcal/g), carbohydrate (4 kcal/g), and fat (9 kcal/g). Thus, the total calories were estimated using Equation (2).

Total calories = N. of grams × kcal/g

(2)

2.2.4. Estimation of Acid Number and Peroxide Value for Chocolate

Both the acid number and peroxide value of the resulting chocolate samples and during the storage period under refrigeration (15 °C) for 0, 2, 4, and 6 months were estimated according to the methods outlined by AOAC [16].

2.2.5. Quantitative Estimation of Sugars

The sugar content of date powder and chocolate samples was determined using the method outlined by [15].

2.2.6. Viscosity Measurement

The viscosity of the chocolate samples was measured at a temperature of 40 ± 1 °C and 100 rpm using spindle number 6 with a Brookfield Viscometer. Viscosity was expressed in centipoise (Pa·s) according to the method described by [12].

2.2.7. Sensory Evaluation of the Resulting Chocolate

Chocolate Sensory quality was determined according to the method described by [17]. Ten selected trained panelists from the Food Science and Human Nutrition Department, College of Agriculture and Food, Qassim University, were asked to judge chocolate samples in conformity with the given score sheets below (

Table 2. Score sheet for the resulting Molding chocolate.

Molding Milk Chocolate
Characteristics	Maximum score
Color	10
Surface appearance	10
Texture	15
Break (Snab)	15
Taste	30
Aroma	20
Overall Acceptability	100
Coating milk chocolate
Characteristics	Maximum score
Color	10
Surface appearance	40
Taste	40
Aroma	10
Overall Acceptability	100

).

2.2.8. Statistical Analysis

Statistical analysis was conducted using ANOVA followed by Duncan’s Multiple Range Test (p ≤ 0.05) using SAS [18] software v. 9.3. Results were expressed as mean values with three replicates for most analyses, except sensory evaluation (10 replicates).

3. Results

3.1. Physical Properties of the Resulting Chocolate (Viscosity)

The viscosity values in

Table 3. Viscosity of Molding and coating milk chocolate samples after manufacturing.

Molding Milk Chocolate	Viscosity (Pa./s)	Coating Milk Chocolate	Viscosity (Pa./s)
CS	2545 ± 7.61 a	CS	606 ± 3.71 b
C10%dp	1228 ± 4.51 d	C20%dp	380 ± 2.71 d
C20%dp	1650 ± 4.02 c	C40%dp	540 ± 3.01 c
C30%dp	1810 ± 4.02 b	C60%dp	750± 3.92 a

CS = Control sample, C10%dp = Chocolate, 10% date powder, C20%dp = Chocolate, 20% date powder, C30%dp = Chocolate, 30% date powder, C40%dp = Chocolate, 40% date powder, and C60%dp = Chocolate, 60% date powder. Data are mean ± standard error, number of replicates = 3, Data followed by the same letter within the same column have no significant difference (p ≤ 0.05).

show a noticeable increase in the viscosity of the molding chocolate mixtures compared to the viscosity values of the coating chocolate mixtures. This increase in viscosity for the molding chocolate is due to the lower proportion of the fat (liquid) phase in these mixtures (40%) compared to the coating chocolate mixtures, where the fat phase represents 50% of the mixture. Since the thickness of the chocolate layer used in coating various products depend on the viscosity of the chocolate liquid, it is naturally lower to facilitate spreading on the surface of these products. This explains the higher proportion of cocoa butter (50%) in the coating chocolate mixtures compared to the molding chocolate mixtures, which contain only 40%. Based on the above, the viscosity values of the control sample for the molding chocolate are higher, followed by the molding chocolate sample containing 30% date powder as a sugar substitute, recording values of 2545 and 1810 Pascal/s, respectively. For the coating chocolate samples, the sample containing 20% date powder as a sugar substitute had the lowest viscosity, with a value of 380 Pascal/s, compared to the control sample of the coating mixtures, which recorded 606 Pascal/s. This difference in viscosity values, whether in the molding chocolate or coating chocolate samples, is due to the thermal behavior of the fat phase in these mixtures and its proportion in the mixture, as well as the particle size of the solid phase in the mixtures, represented by sugar, cocoa powder, and non-fat milk powder. This solid phase increases in the molding chocolate due to the higher proportion of dried milk (12%) compared to the coating chocolate, which contains only 9%.

3.2. Chemical Analysis of Chocolate

The results of the chemical analysis of both molding and coating chocolate samples depend on the proportions of raw materials used in the formulations.

Table 4. Chemical analysis (%) and total energy (kcal/100 g) of the resulting chocolate samples.

Sample	Ash	Fat	Moisture	Protein	Carbohydrates	Total Energy (kcal/100 g)
SDP	3.72	0.20	9.37	3.02	83.69	351.44
Molding milk chocolate
CS	1.94 ± 0.14 b	41.80 ± 1.21 a	1.90 ± 0.36 a	5.50 ± 0.28 a	48.86 ± 163 a	593.64 ± 2.83 a
C10%dp	1.78 ± 0.13 b	41.84 ± 1.42 a	1.62 ± 0.16 ab	6.06 ± 0.22 a	48.70 ± 1.54 a	595.24 ± 3.16 a
C20%dp	2.42 ± 0.12 ab	41.93 ± 1.23 a	1.29 ± 0.15 ab	6.64 ± 0.26 a	47.82 ± 1.77 ab	594.81 ± 3.41 a
C30%dp	3.54 ± 0.18 a	41.95 ± 1.32 a	1.15 ± 0.15 b	6.60 ± 0.27 a	46.7 ± 1.536 b	590.99 ± 2.64 b
Coating milk chocolate
CS	1.30 ± 0.13 b	50.31 ± 0.33 a	3.42 ± 0.17 a	4.99 ± 0.18 b	39.98 ± 1.28 a	6.36.67 ± 3.29 a
C20%dp	2.96 ± 0.14 ab	50.34 ± 0.32 a	2.95 ± 0.12 ab	5.08 ± 0.32 ab	38.67 ± 1.13 a	628.06 ± 2.81 c
C40%dp	3.77 ± 0.18 a	50.37 ± 0.37 a	2.75 ± 0.13 ab	5.15 ± 0.34 a	37.96 ± 1.13 ab	625.77 ± 2.54 c
C60%dp	4.97 ± 0.22 a	50.51 ± 0.37 a	2.35 ± 0.13 b	5.20 ± 0.36 a	36.97 ± 1.13 b	623.27 ± 3.73 b

SDP = Sukkari date powder, CS = Control sample, C10%dp = Chocolate, 10% date powder, C20%dp = Chocolate, 20% date powder, C30%dp = Chocolate, 30% date powder, C40%dp = Chocolate, 40% date powder, and C60%dp = Chocolate, 60% date powder. Data are mean ± standard error, number of replicates = 3, Data followed by the same letter within the same column have no significant difference (p ≤ 0.05).

presents the chemical analysis results for both types of chocolate.

3.2.1. Ash Content

The ash content in molding chocolate samples increased significantly with higher substitution rates of sugar with date powder due to the higher mineral content in dates. The ash percentage in molding chocolate samples ranged from 1.78% in the sample containing 10% date powder to 3.54% in the sample with 30% date powder. In coating chocolate samples, the ash percentage ranged from 1.30% in the control sample to 4.97% in the sample containing 60% date powder. This variation is attributed to differences in the composition of the two types of formulations.

3.2.2. Fat Content

The average fat percentage in all samples was 41.88% for molding chocolate and 50.38% for coating chocolate. The higher fat content in coating chocolate samples is due to the increased cocoa butter proportion (50%) in its formulations compared to molding chocolate formulations, which contain only 40%. The higher fat content in coating chocolate affects the rheological behavior of the resulting chocolate mixtures, particularly their viscosity. Additionally, there were no significant differences in fat content among the different molding chocolate formulations, and the same was observed for coating chocolate samples.

3.2.3. Moisture Content

Moisture content values for molding chocolate samples after production ranged from 1.15% in the sample containing 30% date powder to 2.90% in the control sample. In coating chocolate samples, moisture content ranged from 2.35% in the sample with 60% date powder to 3.42% in the control sample. These significant differences in moisture content can be attributed to the nature of the ingredients, particularly the date powder, and its moisture retention capacity in the chocolate formulations.

3.2.4. Protein Content

No significant differences were observed in the protein content of molding and coating chocolate samples containing date powder. Overall, the protein percentage in molding chocolate was higher than in coating chocolate. This is due to the higher proportion of dried milk powder (12%) in the molding chocolate formulations compared to 9% in the coating chocolate formulations. Milk is a richer source of protein compared to other ingredients, which ultimately results in higher overall protein content in molding chocolate compared to coating chocolate.

3.2.5. Total Carbohydrates

Total carbohydrates, encompassing monosaccharides, disaccharides, and polysaccharides, showed an average value of 48.03% in molding chocolate formulations, while this average decreased to 38.40% in coating chocolate formulations. This reduction is due to the higher fat phase proportion (50%) in coating chocolate formulations, leaving only 50% for other components, including carbohydrates. In contrast, in molding chocolate, the fat phase proportion is 40%, increasing the proportion of other components, including carbohydrates, to 60%, resulting in higher carbohydrate content in molding chocolate.

3.2.6. Total Energy

The average total energy for all molding chocolate samples was 593.75 kcal/100 g, while for coating chocolate samples, it was 628.44 kcal/100 g. The higher energy content in coating chocolate is primarily due to its higher fat content, the main source of energy in these samples, alongside sugar. Additionally, total energy decreased as the sugar substitution with date powder increased in chocolate samples. For molding chocolate, the control sample recorded 593.64 kcal/100 g, which decreased to 590.99 kcal/100 g in the sample with 30% date powder. A similar trend was observed in coating chocolate samples, where total energy significantly decreased from 636.67 kcal/100 g in the control sample to 623.27 kcal/100 g in the sample with 60% date powder substitution from sugar.

This reduction in total energy in chocolate samples containing date powder, while slight in molding chocolate and significant in coating chocolate, is a positive indicator for health. It highlights the potential use of date powder as a sugar substitute in producing health-enhancing chocolate, whether as molded pieces or coating chocolate for food products [1].

3.2.7. Quantification of Reducing and Non-Reducing Sugars in Date Powder and Resulting Chocolate

It is well-known that dates contain a high percentage of sugars, which varies depending on the type of date. Results shown in

Table 5. Quantification of reducing and non-reducing sugars in date powder and resulting chocolate (g/100 g dry weight).

Sample	Reducing Sugars	Non-Reducing Sugars	Total Sugars
SDP	14.61	60.69	75.30
Molding milk chocolate
CS	5.19 ± 0.21 b	44.29 ± 1.23 a	49.44 ± 1.25 b
C10%dp	5.45 ± 0.24 ab	39.53 ± 1.02 b	45.07 b ± 1.32 c
C20%dp	5.58 ± 0.27 ab	38.46 ± 1.72 b	44.45 ± 1.62 c
C30%dp	6.44 ± 0.41 a	37.89 ± 1.62 b	44.33 ± 1.62 c
Coating milk chocolate
CS	3.69 ± 0.13 c	28.23 ± 0.72 d	38.92 ± 0.62 d
C20%dp	5.74 ± 0.12 ab	32.58 ± 1.01 c	38.33 ± 1.62 d
C40%dp	5.48 ± 0.15 ab	31.66 ± 1.01 c	37.15 ± 1.15 d
C60%dp	5.33 ± 0.19 b	31.58 ± 1.02 c	36.91 ± 1.01 e

SDP = Sukkari date powder, CS = Control sample, C10%dp = Chocolate, 10% date powder, C20%dp = Chocolate, 20% date powder, C30%dp = Chocolate, 30% date powder, C40%dp = Chocolate, 40% date powder, and C60%dp = Chocolate, 60% date powder. Data are mean ± standard error, number of replicates = 3, Data followed by the same letter within the same column have no significant difference (p ≤ 0.05).

indicate that the total sugar content in date powder was 75.33%, of which 14.61% were reducing sugars and 60.69% were non-reducing sugars. These results align with the findings on Sukkari dates [19].

From the table, it is evident that reducing sugars in molding chocolate increase as the substitution level of date powder rises, with no significant differences between samples containing 10% and 20% date powder, recording values of 5.54% and 5.58%, respectively. The control sample had the lowest value of reducing sugars (5.19%) compared to the samples containing date powder. Furthermore, the total and non-reducing sugars decreased as the substitution level increased in both molding and coating chocolates, with no significant differences among the samples, which can be attributed to the mixing ratios.

3.3. Preservation Quality of Molding and Coating Chocolate During Storage

The reason for keeping chocolate at refrigerator temperature was based on maintaining its physicochemical stability and preventing quality deterioration during the experimental period. Chocolate is highly sensitive to both temperature and humidity fluctuations, which can cause fat bloom, sugar bloom, or texture changes. According to previous studies, the optimal storage range for chocolate is typically between 14 °C and 18 °C with relative humidity below 50%, as this range minimizes fat migration and surface whitening [20].

The preservation quality of molding and coating chocolate samples after production and during refrigerated storage at 15 °C for six months was assessed based on sensory evaluation and changes in the fat phase (oxidation or hydrolysis). These were measured by peroxide and acid values, which reflect the quality of the fat phase in the chocolate mixtures, along with moisture content, which influences the hydrolytic breakdown of the fat phase (where most changes occur compared to other components in the chocolate formulations).

3.3.1. Moisture Content of Molding and Coating Chocolate During Refrigerated Storage

Results recorded in

Table 6. Moisture (%) in produced chocolate after processing and Cold storage at 15 °C.

Sample	Storage Period (Month)
	0	2	4	6
Molding milk chocolate
CS	1.90 ± 0.36 a	3.16 ± 0.15 a	3.38 ± 0.13 a	3.97 ± 0.14 a
C10%dp	1.62 ± 0.16 ab	2.24 ± 0.12 ab	2.45 ± 0.12 ab	3.40 ± 0.17 ab
C20%dp	1.29 ± 0.15 ab	1.90 ± 0.12 b	2.28 ± 0.11 b	3.10 ± 0.16 ab
C30%dp	1.15 ± 0.15 b	1.65 ± 0.11 c	1.96 ± 0.13 c	2.94 ± 0.12 b
Coating milk chocolate
CS	3.42 ± 0.17 a	3.70 ± 0.14 a	3.87 ± 0.15 a	4.35 ± 0.15 a
C20%dp	2.95 ± 0.12 ab	3.26 ± 0.13 ab	3.45 ± 0.13 ab	3.85 ± 0.14 ab
C40%dp	2.75 ± 0.13 ab	3.10 ± 0.12 ab	2.84 ± 0.12 b	3.23 ± 0.13 b
C60%dp	2.35 ± 0.13 b	2.65 ± 0.10 b	3.36 ± 0.14 ab	3.52 ± 0.13 ab

CS = Control sample, C10%dp = Chocolate, 10% date powder, C20%dp = Chocolate, 20% date powder, C30%dp = Chocolate, 30% date powder, C40%dp = Chocolate, 40% date powder, and C60%dp = Chocolate, 60% date powder. Data are mean ± standard error, number of replicates = 3, Data followed by the same letter within the same column have no significant difference (p ≤ 0.05).

show that the moisture content of the samples increased with prolonged refrigerated storage compared to their initial values. The moisture content in the molding chocolate sample with 30% date powder was 1.15%, 1.65%, 1.96%, and 2.94% after 0, 2, 4, and 6 months of storage, respectively. The control sample recorded the highest moisture values compared to the other treatments, reaching 1.90%, 3.16%, 3.38%, and 3.97% over the same storage periods, respectively.

The moisture percentage in coating chocolate samples over six months ranged from 2.65% in the sample with 60% date powder (after 2 months) to 4.35% in the control sample (after 6 months). Overall, the moisture content increased with extended storage time in all samples. Notably, the control sample of coating chocolate consistently recorded the highest moisture values: 3.42%, 3.70%, 3.87%, and 4.35% after 0, 2, 4, and 6 months, respectively. The observed increase in moisture content during storage can be attributed to the hygroscopic nature of date powder. Natural sugars such as glucose and fructose, along with other hygroscopic components present in date powder, have a strong tendency to attract and retain moisture from the surrounding environment. Consequently, chocolate samples containing higher levels of date powder may absorb and hold more water during storage than those formulated without it, leading to a slight but consistent increase in overall moisture content. These findings align with the general trend observed in the study by [21].

3.3.2. Peroxide Value of Molding and Coating Chocolate After Production and During Refrigerated Storage

The peroxide value was measured in the chocolate samples (both molding and coating) before the start of refrigerated storage at 15 °C and after 2, 4, and 6 months (results not tabulated). A decrease in peroxide values was observed for all samples, with no significant differences between the results at any storage stage or between the two types of chocolate.

The initial peroxide value for molding chocolate samples, including the control and those containing various levels of date powder, was 0.52 meq O₂/kg fat. This value slightly increased during storage, reaching 1.15 meq O₂/kg fat at the end of the six-month storage period. Such values are within acceptable limits and do not affect the chocolate’s edibility.

A similar trend was observed in coating chocolate samples. The peroxide value for all samples, including the control, was 0.68 meq O₂/kg fat at the beginning of storage, increasing slightly to 1.34 meq O₂/kg fat at the end of six months. These peroxide values for both molding and coating chocolates are within the permissible range for peroxide values in food, remaining below 10 meq/kg. This confirms the safety and quality of the chocolate during its storage period.

3.3.3. Acid Value of Molding and Coating Chocolate After Production and During Refrigerated Storage

Acid value measurements (results not tabulated) for molding chocolate after production and during storage showed a decrease in acid values immediately after production for all samples containing 10%, 20%, and 30% date powder as a sugar substitute, recording 0.64% as oleic acid. The control sample showed almost similar value of 0.65% with no significant differences.

In coating chocolate, the acid value directly after production ranged between 0.81% and 0.82% as oleic acid for samples containing various levels of date powder, with no significant differences compared to the control sample, which recorded 0.80%.

During storage, acid values increased for all samples, reaching 3.35% for molding chocolate and 3.95% for coating chocolate at the end of the six-month storage period, with no significant differences between samples. The slight and non-significant increase in acid values can be attributed to the fat phase, particularly the cocoa butter content, which represents 50% of the coating chocolate formulation.

All acid values for both molding and coating chocolates fall within the permissible range for acid values in food, indicating the safety and quality of the chocolate for consumption during its storage period.

3.4. Sensory Evaluation of the Produced Chocolate After Manufacturing and During Refrigerated Storage

3.4.1. Sensory Evaluation of Molding Chocolate

It was observed from the results recorded in

Table 7. Sensory evaluation of milk chocolate samples with date powder after manufacturing and during cold storage at 15 °C.

Sample	Odor (20)	Taste (30)	Snap (15)	Texture (15)	Surface Appearance (10)	Color (10)
After manufacturing (before cold storage)
CS	19.13 ± 0.36 a	28.20 ± 0.45 a	14.20 ± 0.26 a	14.13 ± 0.36 a	9.53 ± 0.19 a	9.60 ± 0.14 a
C10%dp	19.20 ± 0.36 a	27.27 ± 0.73 b	14.27 ± 0.28 a	14.27 ± 0.36 a	9.60 ± 0.16 a	9.47 ± 0.17 a
C20%dp	19.13 ± 0.36 a	28.40 ± 0.52 a	14.13 ± 0.29 a	14.13 ± 0.36 a	9.47 ± 0.27 a	9.30 ± 0.27 a
C30%dp	19.17 ± 0.39 a	27.27 ± 0.51 b	13.90 ± 0.21 b	13.47 ± 0.35 b	9.53 ± 0.19 a	9.33 ± 0.21 a
After 2 months of cold storage
CS	18.47 ± 0.72 a	26.60 ± 1.09 a	13.53 ± 0.40 b	14.07 ± 0.38 a	9.67 ± 0.21 a	9.40 ± 0.24 ab
C10%dp	18.40 ± 0.72 a	26.67 ± 1.65 a	14.27 ± 0.48 a	13.53 ± 0.54 b	9.60 ± 0.16 a	9.20 ± 0.24 b
C20%dp	17.93 ± 0.90 ab	25.80 ± 1.41 a	13.93 ± 0.36 ab	13.73 ± 0.45 ab	9.06 ± 0.16 b	9.63 ± 0.12 a
C30%dp	18.47 ± 0.72 a	24.53 ± 1.87 b	14.00 ± 0.35 a	13.80 ± 0.37 ab	9.60 ± 0.16 a	9.26 ± 0.21 ab
After 4 months of cold storage
CS	18.00 ± 0.34 ab	27.00 ± 0.45 ab	13.80 ± 0.34 a	14.10 ± 0.31 a	9.27 ± 0.31 a	9.43 ± 0.39 a
C10%dp	18.53 ± 0.45 a	27.73 ± 0.47 a	13.43 ± 0.43 ab	13.10 ± 0.54 ab	8.83 ± 0.32 b	9.20 ± 0.23 a
C20%dp	17.93 ± 0.73 b	27.40 ± 0.77 a	12.97 ± 0.50 b	13.13 ± 0.56 ab	9.17 ± 0.19 a	9.33 ± 0.24 a
C30%dp	18.27 ± 0.50 a	25.60 ± 0.42 b	13.70 ± 0.37 ab	13.30 ± 0.56 b	8.87 ± 0.35 b	9.70 ± 0.15 a
After 6 months of cold storage
CS	18.07 ± 0.45 a	27.50 ± 0.57 a	13.00 ± 0.49 a	13.13 ± 0.36 a	9.27 ± 0.19 a	9.33 ± 0.24 a
C10%dp	18.00 ± 0.34 a	27.07 ± 0.45 a	13.07 ± 0.44 a	13.00 ± 0.21 a	9.19 ± 0.17 a	9.00 ± 0.29 ab
C20%dp	18.00 ± 0.20 a	26.63 ± 0.46 b	12.83 ± 0.34 ab	12.60 ± 0.21 ab	8.93 ± 0.14 b	8.60 ± 0.22 b
C30%dp	17.93 ± 0.43 b	26.10 ± 0.47 c	11.97 ± 0.50 b	11.63 ± 0.36 b	8.04 ± 0.19 c	8.33 ± 0.34 c

CS = Control sample, C10%dp = Chocolate, 10% date powder, C20%dp = Chocolate, 20% date powder, and C30%dp = Chocolate, 30% date powder. Data are mean ± standard error, number of replicates = 10, Data followed by the same letter within the same column have no significant difference (p ≤ 0.05).

that there were no significant differences in all sensory attribute values between the samples with 10% and 20% sugar replacement with date powder and the control sample after manufacturing and before starting refrigerated storage. However, significant differences were noted in the attributes of taste, snap, and texture between the control sample and the one with 30% sugar replacement. These three attributes represent 60% of the overall acceptability. Consequently, the sample with 30% date powder recorded the lowest overall sensory attribute score, at 93.17%.

Taking a general look at the sensory evaluation results of the samples after 2, 4, and 6 months of refrigerated storage at 15 °C in the same table, some observations related to sensory attributes that significantly influence the overall acceptability of the samples can be noted as follows:

Color

There were no significant differences in color values between the control sample and the samples in which sugar was replaced with date powder at varying percentages (10%, 20%, and 30%). This is likely due to the chocolate’s brown color, which comes from the cocoa powder added to all samples in a consistent percentage (7%). Although manufacturing processes and sugar replacement with date powder may have some impact on color, the effect was not significant throughout the storage period up to four months. However, when storage was extended to six months, a significant difference in color value was observed between the control (9.33/10) and the sample with 30% date powder replacement (8.33/10).

Surface Appearance

No significant differences were found in the general surface appearance of chocolate pieces, especially after 4 and 6 months of storage, between the control sample and the other chocolate samples, except for the one with 30% sugar replacement with date powder. The importance of surface appearance lies in its reflection of the uniformity of the fat matrix in the chocolate and the effectiveness of the tempering process. Proper tempering ensures that no fat bloom appears on the surface, which would diminish its shine and light reflection.

Texture

Examining the texture values recorded during the three evaluation periods (after 2, 4, and 6 months), the sample with 30% date powder consistently recorded the lowest texture scores. No significant differences in texture were observed between the other samples and the control. This decrease in texture quality in the 30% date powder sample may be attributed to the nature of date powder and the composition of its sugars, which are not entirely sucrose and may include a proportion of fibers.

Snap

Since the snap attribute of chocolate pieces is linked to texture, the same ranking, observations, and explanations for texture were also noted for snap, particularly at the end of the storage period after six months.

Taste and Aroma

Taste and aroma, which represent 50% of the overall acceptability score and are thus decisive factors for the overall acceptability of the samples, showed a consistent trend in the sensory evaluations conducted after 2, 4, and 6 months. The same ranking and pattern observed immediately after manufacturing continued. A significant decrease in the taste and aroma values was noted in the sample with 30% date powder compared to the other samples, including the control. This trend, initially observed in the sensory evaluations conducted immediately after manufacturing, persisted throughout the six months of storage.

The overall acceptability of the chocolate pieces during the six-month refrigerated storage period is evaluated as the sum of the values of all six sensory attributes listed in Table 7. This serves as the final judgment for determining whether the samples are sensory acceptable to consumers or not.

It was observed that the overall acceptability of the chocolate pieces decreased after manufacturing and before storage as the percentage of sugar replaced with date powder increased. However, no significant differences were noted between the control sample and the samples with sugar replaced by date powder up to a replacement level of 20%. A significant difference, however, was observed when the sugar replacement level increased to 30%, as shown in Figure 1.

With continued sensory evaluation every two months during the storage period of the samples, the same general trend in the results was observed, with the differences between the control sample and the other samples persisting at the beginning of the storage. These differences became statistically significant by the end of the storage period after 6 months. Based on the previous results, it is recommended that sugar used in the production of molded chocolate can be replaced with date powder up to a 20% replacement level without significantly affecting the overall acceptability of the product by consumers or tasters. This result is considered positive from an economic standpoint, as it provides a 20% saving in sugar import costs and maximizes the utilization of locally produced date resources.

3.4.2. Sensory Evaluation of Wafer Biscuits Coated with Chocolate

The Sensory evaluation characteristics of wafer biscuits coated with chocolate made with sugar or those in which part of the sugar was replaced with 20%, 40%, or 60% date powder, either immediately after production or during the refrigerated storage period, are shown in

Table 8. Sensory evaluation of Wafer Biscuits Coated with Chocolate after manufacturing and during cold storage at 15 °C.

Treatments	Odor (10)	Taste (40)	Surface Appearance (40)	Color (10)
After manufacturing (before cold storage)
CS	9.40 ± 0.19 a	38.47 ± 0.52 ab	38.40 ± 0.53 a	9.47± 0.19 a
C20%dp	9.33 ± 0.21 b	38.93 ± 0.38 a	37.98 ± 0.86 ab	9.40 ± 0.24 ab
C40%dp	9.30 ± 0.21 ab	37.90 ± 0.484 b	37.93 ± 0.86 b	9.40 ± 0.24 ab
C60%dp	8.53 ± 0.30 b	35.33 ± 0.67 c	37.27 ± 0.78 b	9.47 ± 0.22 a
After 2 months of cold storage
CS	9.70 ± 0.12 a	36.91 ± 1.17 a	38.07 ± 0.91 a	9.57 ± 0.18 a
C20%dp	9.70 ± 0.12 a	35.93 ± 1.17 ab	38.07 ± 0.91 ab	9.50 ± 0.18 a
C40%dp	9.67 ± 0.12 a	38.10 ± 1.01 a	35.02 ± 1.27 b	8.98 ± 0.33 a
C60%dp	9.00 ± 0.17 a	35.86 ± 1.39 b	33.43 ± 1.28 c	8.80 ± 0.38 b
After 4 months of cold storage
CS	9.67 ± 0.12 a	38.10 ± 1.01 ab	34.97 ± 1.27 ab	8.98 ± 0.33 a
C20%dp	8.87 ± 0.30 ab	38.60 ± 1.76 a	35.47 ± 1.15 a	8.90 ± 0.26 a
C40%dp	8.83 ± 0.57 b	36.40 ± 1.98 b	34.73 ± 1.65 b	9.13 ± 0.95 ab
C60%dp	7.80 ± 0.19 c	34.07 ± 1.46 c	32.43 ± 1.33 c	8.60 ± 0.39 b
After 6 months of cold storage
CS	9.77 ± 0.15 a	36.60 ± 1.76 ab	35.47 ± 1.15 ab	9.27 ± 0.28 a
C20%dp	9.70 ± 0.66 a	37.47 ± 1.67 a	34.93 ± 1.80 a	8.10 ± 0.38 b
C40%dp	9.10 ± 0.36 ab	37.33 ± 1.77 a	32.07 ± 1.37 b	7.87 ± 0.47 c
C60%dp	6.57 ± 0.24 b	32.83 ± 1.58 c	31.30 ± 1.60 c	8.57 ± 0.70 b

CS = Control sample, C20%dp = Chocolate, 20% date powder, C40%dp = Chocolate, 40% date powder, and C60%dp = Chocolate, 60% date powder. Data are mean ± standard error, number of replicates = 10, Data followed by the same letter within the same column have no significant difference (p ≤ 0.05).

. Looking at the results immediately after production and before storage, we find that there are no significant differences between the control sample and those with sugar replaced by date powder up to 60% regarding the color and surface appearance, which represent 50% of the overall acceptability value of the samples. As for the taste and aroma, which represent the other 50% of the overall acceptability value of the samples, the lowest values were recorded for the chocolate sample in which 60% of the sugar was replaced with date powder. The other chocolate samples, with 20% and 40% date powder added, were acceptable when compared to the control sample.

After two months of storage, no significant differences were observed between the samples containing 20% and 40% date powder and the control sample regarding the color and surface appearance. This means that no fat bloom defect appeared on the surface of the samples. However, significant differences were noted between the control sample (9.57 & 38.07) and the sample containing 60% date powder (8.60 & 35.13) for the color and surface appearance values, respectively.

As the storage period increased to four months, and referring to the same table, we observe the same general trend that was noted in the values of color and surface appearance. This was also observed in the taste results, which represent 40% of the overall acceptability of the product. However, no significant difference was found between the control sample and the chocolate samples containing date powder at all replacement levels up to 60% regarding aroma. Therefore, we can conclude that the aroma of these samples (those with added date powder) is acceptable compared to the control sample, as the aroma source is the same in all samples in equal proportions (vanilla, cocoa powder, and cocoa butter).

The general trend of the results obtained when evaluating these samples either immediately after production or after 2 or 4 months of refrigerated storage was also maintained when evaluated after 6 months.

Since the overall acceptability of the product is the final determinant for whether a food product is accepted or rejected by the consumer, a closer look at the overall acceptability, as shown in Figure 2, reveals that the coating chocolate samples made with date powder as a substitute for sugar at levels up to 40% are acceptable compared to the control. This allows for the recommendation of using date powder in the production of coating chocolate up to a 40% sugar replacement, which can enhance health compared to regular sugar, due to the high nutritional value of dates, which are rich in minerals and antioxidant compounds [1].

4. Discussion

The aim of this study was to investigate the potential of substituting refined sugar with date powder produced from non-marketable Sukkari dates in milk chocolate and to evaluate its impact on physicochemical properties, Sensory evaluation, and storage stability. This approach aligns with current global trends in developing functional and sustainable food products by utilizing local agricultural by-products. The findings demonstrated that moderate substitution levels (20% in molding chocolate and 40% in coating chocolate) maintained comparable sensory acceptability and product stability, suggesting that date powder can serve as a promising natural sweetener alternative.

Date powder is a nutrient-dense natural product composed primarily of glucose and fructose, accompanied by substantial levels of minerals, phenolic compounds, and dietary fiber [22]. These components impart both sweetness and functional benefits, allowing date powder to act as a healthier substitute for refined sucrose. The observed increase in ash content in the current study with higher substitution levels reflects the mineral richness of date fruits, particularly in potassium, calcium, and magnesium. A similar trend was reported by [23], who found elevated ash content in bakery products formulated with date by-products. Such mineral enrichment not only enhances nutritional quality but also contributes to the functionality of food matrices through ionic interactions with proteins and polysaccharides, potentially affecting textural stability.

The moisture content of the chocolate samples also increased with the incorporation of date powder, owing to its hygroscopic nature and the presence of soluble fiber fractions that readily bind water [24]. Moisture retention is an important parameter because excessive water may affect the rheological behavior of chocolate, leading to undesirable viscosity changes. In this study, viscosity increased proportionally with the amount of date powder, particularly in molding chocolate where the fat phase was lower. These results are consistent with [25], who demonstrated that replacing sucrose with natural sweeteners or fruit powders increased chocolate viscosity due to the higher solid particle content and water-binding ability of these ingredients. Also, who reported that plant-based confectionery systems enriched with fruit powders exhibited higher apparent viscosity, confirming that fine natural particles can influence the dispersion and flow characteristics of the cocoa matrix.

Fat content remained statistically unchanged across treatments, indicating that date powder substitution did not disrupt the lipid structure of the chocolate matrix. This observation agrees with the results of [26], who emphasized that moderate incorporation of non-fat sweeteners in cocoa-based products does not significantly alter fat crystallization or texture. In this context, the proper tempering process and the relatively low moisture content of the formulations prevented the formation of fat bloom, a common defect during chocolate storage. Moreover, the stable peroxide and acid values recorded throughout the six-month refrigerated storage period reflect the oxidative stability of the fat phase. The antioxidant constituents naturally present in dates, including flavonoids and phenolic acids, likely contributed to retarding lipid oxidation. Comparable antioxidant protection was observed by [27] in cocoa products fortified with plant-derived antioxidants and by [28], who demonstrated that natural extracts effectively enhance the oxidative stability of chocolate without compromising flavor.

From a nutritional perspective, the total energy content of chocolate samples decreased as sugar substitution levels increased. Since fats and sugars are the major caloric contributors in chocolate, replacing part of the sucrose with date powder, which contains lower energy density and additional fiber, results in reduced caloric values. This result supports earlier reports by [29], who found that date-based sweeteners produce confections with a lower glycemic response and improved nutritional balance. Benucci and his colleagues [30] confirmed that partial replacement of sugar with natural sweeteners in chocolate reduced total energy without adversely affecting acceptability, highlighting the feasibility of formulating “better-for-you” chocolates using local natural resources. The sugar profile analysis revealed that date powder contributed both reducing and non-reducing sugars, primarily glucose and fructose, which influence caramelization, color development, and sweetness perception. These natural sugars tend to create a mild caramel flavor and darker hue, especially at higher replacement levels. While these attributes can enhance the sensory complexity of chocolate, excessive substitution may result in slight bitterness or a gritty mouthfeel due to incomplete particle dispersion. Similar sensory patterns were documented by, who reported that chocolate fortified with date paste up to 30% maintained high consumer acceptance, but higher inclusion levels led to perceptible textural changes.

Sensory evaluation across six months of refrigerated storage showed that the color, aroma, and texture of chocolate samples with moderate date powder substitution remained stable and comparable to the control. The absence of visible fat bloom or flavor deterioration indicates that date powder did not negatively affect cocoa butter crystallization or volatile stability. The slow increase in moisture and acid values during storage was within acceptable limits, suggesting good shelf stability. These results align with [31], who noted that controlled storage temperature and low moisture uptake are key factors for maintaining chocolate quality. In this study, the sensory scores of samples containing up to 20% date powder for molding chocolate and 40% for coating chocolate were statistically indistinguishable from those of the control. The higher proportion of date powder for coating chocolate was selected to achieve the desired sweetness and texture while maintaining nutritional benefits. Since date powder has lower sweetness intensity than sucrose and contains fiber and minerals, a slightly higher amount was needed to match the sensory balance and coating consistency [24]. In addition, the chocolate coating in this study served mainly as a flavoring and protective layer, rather than molding chocolate; thus, melting behavior and fine mouthfeel were less critical. The Wafer biscuits coated with chocolate themselves contain larger particle sizes than standard chocolate, which reduces the effect of particle fineness. This was confirmed by sensory evaluation, as no significant differences were observed between the sample containing 40% date powder and the control sample, reinforcing the suitability of these substitution levels for industrial production.

From a sustainability standpoint, utilizing non-marketable Sukkari data provides an eco-friendly strategy for reducing agricultural waste and promoting value-added processing. Saudi Arabia produces substantial volumes of surplus dates each year, much of which are discarded or underutilized. Transforming these into functional ingredients such as date powder supports circular economy principles and aligns with national food security strategies. Râpă, Brito, and their teams [32,33] emphasized that valorizing agricultural by-products into food applications contributes to waste minimization, resource efficiency, and environmental sustainability. Thus, integrating date powder into chocolate manufacturing not only enhances the nutritional and sensory aspects of the product but also advances economic diversification within the agri-food sector.

Collectively, the outcomes of this study underscore that Sukkari date powder can serve as an effective natural sweetener in milk chocolate formulations. Moderate levels of substitution improve mineral and antioxidant content, maintain oxidative and sensory stability, and reduce total energy. These findings are consistent with the broader literature on natural sweeteners and fruit-derived powders, which report on improved nutritional profiles and acceptable sensory properties when used in partial replacement of refined sugars [22,25]. A useful example of sustainable innovation that promotes both economic resilience and public health is the incorporation of locally sourced date powder into candy manufacturing. To completely describe the functional potential of date powder in chocolate and other food matrices, future research should concentrate on pilot-scale trials, consumer perception in various markets, and in vivo studies assessing glycemic response and antioxidant bioavailability.

5. Conclusions

The findings of this study demonstrate that date powder derived from non-marketable Sukkari and surplus dates can serve as a viable natural sweetener in milk chocolate production. Incorporating date powder at moderate substitution levels improved the nutritional profile by reducing energy content while maintaining acceptable physicochemical and sensory qualities over six months of storage. Specifically, substitution at 20% for molding chocolate and 40% for coating chocolate provided products comparable in quality and consumer acceptability to conventional formulations. Higher substitution levels, while technically feasible, resulted in increased viscosity and reduced sensory appeal, limiting their practical application. Overall, the results highlight the potential of date powder as a sustainable alternative to refined sugar, offering value-added utilization of surplus dates, reducing dependence on imported sugar, and supporting the development of healthier confectionery products. Future research should further explore process optimization, consumer acceptance on a broader scale, and the potential functional health benefits of incorporating date powder in chocolate and other food systems.