Functional Low-Fat Goat Feta Cheese Formulated with Dietary Fiber as a Fat Replacer: Physicochemical, Textural, and Sensory Interactions

Abstract

Consumer scrutiny of fat content in foods is becoming a notable trend in health concerns. This study aims to develop a novel functional low-fat goat feta cheese by utilizing polydextrose (PDX) and inulin as dietary fiber-based fat replacers to improve its overall characteristics. The physicochemical and textural properties, along with consumer acceptance, of the feta cheese were evaluated across three fat levels (full-fat [FFC], reduced-fat [RFC], low-fat [LFC]) and three fibers: PDX, inulin, and their combination. The intercorrelation of all characteristics was assessed through principal component analysis and Pearson’s correlation. Fat reduction significantly altered the cheese’s visual properties, increasing lightness and the total color difference, which inversely correlated with a* and b* values. Lower-fat cheeses exhibited decreased pH and increased lactic acid, with salinity playing a crucial role in both lactic acid development and texture. Under Scanning Electron Microscopy (SEM), PDX yielded a cheese matrix with a finer pore structure than inulin or the combined fibers. Lower-fat cheeses exhibited greater hardness, with PDX resulting in the highest hardness among the fiber treatments. Crucially, the RFC with PDX was as well-received by consumers as the FFC. These findings not only empower goat farmers and cheese entrepreneurs to increase their product value for niche market but also contribute to sustainability by providing a healthier food option for functional benefits.

1. Introduction

Feta is a soft, white cheese, traditionally ripened in brine. It is traditionally manufactured from goat milk, but nowadays different types of milk, including sheep, cow, and buffalo milk, are used to produce this type of cheese [1]. Feta has a salty and tangy flavor, and can be produced from whole, partially skimmed, or skim milk. Whole milk feta typically contains 45–60% moisture, 10–20% fat, 15–20% protein, and 5–10% salt, and has a pH of 4.6–5.3 [2,3,4,5]. While full-fat feta cheese (FFC) can pose health risks such as high blood pressure, cardiovascular disease, and elevated cholesterol due to its high fat content, low-fat cheeses are considered dietetic products and offer a strong foundation for developing functional foods [1,6]. Globally, low-fat dairy products are the most sought-after among low-fat foods, with demand for reduced-, low-, and non-fat cheese rising significantly since 1980 [7]. Especially when enhanced with dietary fiber replacement, LFC is beneficial for dieters and heart patients. Despite production challenges related to flavor and texture, the market for LFC is expanding rapidly due to the negative health implications of FFC [8]. However, fat is a key determinant of cheese characteristics, influencing its body and texture by occupying the interstitial spaces of the protein and mineral structure and significantly contributing to taste quality [9]. Fat reduction in cheese commonly induces textural, functional, and sensory impairments [10,11]. The removal of fat increases the influence of caseins on texture development; however, in low-fat cheeses, inadequate casein proteolysis often yields a relatively firm texture [12]. Low-fat products are usually characterized as having a gummy body and an atypical flavor compared with their respective full-fat varieties. Characteristics of low- or reduced-fat cheeses may include a bland flavor profile, a firm, rubbery texture, undesirable color variations, and off-flavors [11]. To mitigate the negative effects of fat reduction in low-fat cheese production, three main approaches are employed: modifications in cheesemaking procedures, the use of adjunct starter cultures, and the incorporation of fat replacers [12]. Fat replacers, being water-dispersible, enhance the sensory and functional properties of low-fat cheeses by providing a bulking effect through moisture retention, and imparting a sense of lubricity and creaminess [13]. In the EU, feta cheese is a Protected Designation of Origin (PDO) product, with its composition and production strictly regulated [14]. However, Thailand does not have a specific PDO for feta cheese, allowing feta-style cheeses more compositional flexibility. Thailand’s food additive rules generally follow the Codex Alimentarius Commission’s GSFA, so additives like inulin or polydextrose permitted by Codex are likely considered by the Thai FDA, often with set maximum levels [15].

Dietary fiber is essential for overall health, promoting digestion and reducing the risk of chronic diseases like cardiovascular disease and diabetes. Some studies suggest that a daily intake of 10 g of inulin could reduce energy intake, blood glucose, triglycerides, and cholesterol [16]. For polydextrose, a safe consumption level is approximately 90 g per day (or 1.3 g/kg body weight), or 50 g as a single dose [17]. The fiber is primarily found in plant-based foods such as fruits, vegetables, whole grains, and legumes [18]. Inulin and polydextrose are well-known dietary fibers valued for their health benefits and use in food products, including ice cream [19], yogurt [20], and cheese [21]. Inulin, a soluble fructan polysaccharide found in plants like chicory root, is especially popular for its prebiotic effects. It promotes gut health by fostering beneficial bacteria, improving calcium absorption, and regulating blood sugar [22]. Additionally, inulin has the ability to replace fat and sugar in various food formulations, making it a valuable ingredient in the development of functional foods. Polydextrose (PDX) is a highly branched, randomly bonded glucose polymer, also characterized as a randomly linked glucose oligomer with small amounts of sorbitol and citric acid, exhibiting an average degree of polymerization of 12, ranging from 2 to 120 [17,23]. PDX’s complex structure prevents its digestion in the small intestine, allowing it to reach the colon where it is partially fermented by gut microbiota, with about 60% excreted in feces [24,25]. PDX’s fat-like plasticizing effects, achieved by retaining moisture, make it ideal for creating soft, melting textures in bakery products (e.g., layer cakes), confections (e.g., soft candies), and frozen desserts (e.g., ice cream) [26,27,28]. It functions as a low-calorie fat replacer and bulking agent in butter [29]. Beyond its role as a fat replacer, it could also function as a prebiotic, potentially enhancing the quality attributes of fat-free buffalo yogurt [26]. As the host does not directly utilize PDX, it provides 1 kcal/g through short-chain fatty acids produced by microbial fermentation, leading to its recognition in many countries for its dietary fiber-like physiological effects and prebiotic potential [25,30]. PDX, with its neutral taste and high-water solubility, functions as a low-calorie bulking agent in various foods like baked goods, confectionery, dairy, and beverages, creating a non-viscous solution. Its bulking and gelling properties also make it a valuable fat replacer, enhancing texture and mouthfeel without impacting nutritional value [17,31,32]. Consequently, both commercial dietary fibers are widely applied within the food industry to enhance flavor, texture, and nutritional value through fat replacement.

Driven by this rationale, the primary aim of this research was to develop a healthier goat milk feta cheese with improved texture and flavor by replacing the fat with inulin and polydextrose for potential stakeholder application. A comprehensive investigation was conducted to thoroughly understand the influence of varying fat levels and different dietary fibers on the physicochemical characteristics, textural characteristics, and microstructure of feta cheese, as well as on its sensory attributes. The incorporation of inulin and polydextrose as fat replacers in feta cheese aligns with sustainability by offering a healthier food option that meets consumer demands for wellness. This is achieved through functional benefits like promoting digestive health, enhancing satiety, and also extending the product’s storage life and potentially offering cost efficiencies in production.

2. Materials and Methods

2.1. Materials

Raw goat’s milk was obtained from Mae Tha Nuea Royal Project Development Center, Chiang Mai, Thailand. A freeze-dried mixture of Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris (Chr. Hansen Holding A/S, Hoersholm, Denmark) was used as the starter culture, and rennet (SACCO System, Cadorago, Italy) was utilized as the coagulant. Food-grade inulin and polydextrose powder (Krungthepchemi, Bangkok, Thailand) were applied as fat replacers.

2.2. Optimization of Dietary Fiber Types and Goat Milk Fat Levels for Low-Fat Feta Cheese

Raw goat milk with varying fat content levels—full-fat (F; 3.42%), 50% reduced-fat (R; 1.70%), and low-fat (L; 0.29%)—was prepared using an Elecrem No. 3 Cream Separator (Elecrem SAS, Paris, France). Two commercial dietary fibers were used [33]: PDX at 1.0% by weight, inulin at 1.0% by weight, and a combination of both at 0.5% each by weight. A 3 × 3 factorial design with a completely randomized design (CRD) was applied, with treatment details presented in

Table 1. Treatment plan of full-fat (FFC), reduced-fat (RFC), and low-fat (LFC) goat milk feta cheese with dietary fibers using a completely randomized factorial design.

Goat Milk Fat Levels	1.0% PDX (P)	1.0% Inulin (I)	0.5% PDX + 0.5% Inulin (PI)
CTRL	-	-	-
Full-fat (FFC)	FP	FI	FPI
Reduced-fat (RFC)	RP	RI	RPI
Low-fat (LFC)	LP	LI	LPI

. The control treatment (CTRL) consisted of full-fat milk with no dietary fiber supplementation. A schematic diagram for the preparation of the feta cheese is illustrated in Figure 1 [34]. Subsequently, the physicochemical properties, texture profile, microstructure, and sensory attributes of all the feta cheeses were assessed.

2.3. Physicochemical Characterization

2.3.1. CIE Color

The color of the feta cheese was measured using the CIE Lab system with a handheld spectrophotometer (NS800, 3nh, Guangzhou, China). L* values represent lightness (0 = black, 100 = white), a* values indicate redness (+) or greenness (−), and b* values indicate yellowness (+) or blueness (−) [35]. To assess the overall color changes, the total color difference (ΔE) was calculated between the feta cheese samples (L*, a*, b*) and the control (CTRL) (L₀*, a₀*, b₀*), as shown below [36].

$${\mathrm{\Delta }\mathrm{E}}_{\mathrm{ab}}=\sqrt{{\left({\mathrm{L}}^{*}{- \mathrm{L}}_0^{*}\right)}^2+{\left({\mathrm{a}}^{*}{- \mathrm{a}}_0^{*}\right)}^2+{\left({\mathrm{b}}^{*}{- \mathrm{b}}_0^{*}\right)}^2}$$

(1)

2.3.2. Moisture Content

Moisture content analysis was performed following AOAC [37] procedures, utilizing 5 g samples and conducting triplicate measurements. The resulting data were used to calculate moisture content on a dry weight basis.

2.3.3. Water Activity (a_w)

The water activity (a_w) of the feta cheese was measured in triplicate using a LabMaster NEO Water Activity Meter (UK) [38]. Samples were carefully placed into a_w boxes, maintaining proper fill levels. The boxes were then positioned within the instrument chamber and allowed to equilibrate. Upon completion of the measurement, the recorded a_w value was documented.

2.3.4. pH Value

pH was measured using a portable pH meter (Water Proof pH Testr^® 30, Bangkok, Thailand) by blending 10 g samples with 20 mL of deionized water at 5000 rpm for 20 s using the ultra Turrax homogenizer (IKA T25, IKA Works (Thailand) Co. Ltd., Bangkok, Thailand), with triplicate replicates [39].

2.3.5. Lactic Acid Content

Lactic acid content was quantified by titration, using a method adapted from that described by Subramanian and Rodriguez-Saona [40]. Samples were prepared according to the pH measurement protocol and then centrifuged at 6000 rpm for 10 min. A 2 mL aliquot was mixed with 23 mL deionized water and 5 drops of phenolphthalein, then titrated with 0.1 N sodium hydroxide to a pink endpoint. Results were reported as a percentage of lactic acid.

2.3.6. Lipid Content

Lipid content analysis was conducted using the Soxhlet method [41] with a Soxtec Tecator Extraction System (Model FOSS ST243, Hilleroed, Denmark). For fat extraction, 1.0 g of the sample on filter paper was weighed in an aluminum can and dried in an oven for 2 h. The sample was then folded into a thimble and placed in a Soxhlet extraction unit. Approximately 160 mL of petroleum ether was added, and the system was pre-cooled for 30 min at 10 °C, with the heat set to 4–5. Extraction time was determined based on sample fat content. After extraction, the petroleum ether was evaporated in a fume hood. The aluminum can was dried at 105 °C for 2 h, cooled in a desiccator, and weighed.

2.4. Textural Profile Analysis

The texture profile analysis (TPA) of the feta cheese samples was determined using a TA.HDplusC texture analyzer (Stable Micro Systems, Surrey, UK). Our method was adapted from Rashidi et al. [42]. Cubes (2 × 2 × 1.5 cm) were prepared from the central portion of each cheese block, with 10 replicates per sample. The cheese samples underwent a double compression test using a 50 mm diameter cylindrical aluminum probe (P50), compressing them to 4.5 mm (30% compression) at a speed of 1 mm/s with a 10 g initial contact force, mimicking a molar bite. The analyzed texture characteristics included hardness (g), adhesiveness, cohesiveness, springiness, and chewiness.

2.5. Microstructure

Scanning Electron Microscopy (SEM) was used to monitor the microstructure of feta cheeses. A thin slice of feta cheese was mounted on a specimen stub with double-sided tape and sputter-coated with gold. The samples were imaged using SEM (JEOL JSM-5910, Japan, Tokyo) at ×2000 magnification and 10 kV accelerating voltage [35].

2.6. Sensory Evaluation

Sensory evaluation of feta cheese products was conducted by seven expert panelists from the Chiang Mai Livestock Product Research and Development Centre, due to their familiarity with the feta-cheese-adapted method from Khiabanian et al. [43]. A 9-point Hedonic scale (1 = least liked, 9 = most liked) was used to evaluate appearance, color, aroma, taste/flavor, texture, aftertaste, and overall preference. Data were analyzed using one-way ANOVA (F-test) and Duncan’s multiple range test, with a 95% confidence level.

2.7. Statistical Analyses

Physicochemical and textural properties were analyzed with at least biological and technical triplicates. Data were analyzed using F-tests, one-way ANOVA, and Duncan’s multiple range test. Significance was defined as p ≤ 0.05 (95% confidence). Statistical analyses were performed using IBM SPSS version 16. Principal component analysis (PCA) and Pearson’s correlation were employed to investigate the correlation between several physicochemical characteristics, texture profiles, and sensory tests of all the feta cheeses (XLSTAT-2024 V.3 Software, Addinsoft, New York, NY, USA).

3. Results and Discussion

3.1. Physicochemical Characteristics

3.1.1. Color, Moisture Content, and Water Activity

The color, moisture content (dry basis), and water activity, key physical properties of full-fat (FFC), reduced-fat (RFC), and low-fat (LFC) feta cheeses with commercial dietary fiber fat replacers are presented in

Table 2. Color, moisture content, and water activity of FFC, RFC, and LFC with dietary fibers as a fat replacer.

Treatments	Color				Moisture Content (%Dry Basis)	aw
	L*	a*	b*	ΔE
Control	90.57 ± 0.74 a	−1.76 ± 0.89 f	11.76 ± 1.14 d	-	65.13 ± 0.33 a	0.8873 ± 0.0032 a
FP	90.90 ± 0.65 bc	−0.74 ± 0.14 bcd	12.64 ± 0.42 c	2.07 ± 1.01 bc	70.99 ± 0.35 c	0.8935 ± 0.0005 a
FI	90.50 ± 0.49 cd	−1.07 ± 0.21 de	12.99 ± 0.73 abc	2.33 ± 1.04 bcd	74.07 ± 0.69 d	0.8986 ± 0.0014 bc
FPI	90.03 ± 0.36 d	−0.77 ± 0.09 bcd	13.47 ± 0.57 a	2.79 ± 1.25 bcd	68.74 ± 0.50 b	0.9009 ± 0.0003 cd
RP	91.33 ± 0.29 ab	−0.28 ± 0.13 a	11.81 ± 0.43 d	2.13 ± 0.71 bc	92.76 ± 0.23 f	0.9099 ± 0.0008 d
RI	91.63 ± 0.46 a	−0.38 ± 0.19 a	11.70 ± 0.42 d	1.88 ± 0.79 b	107.28 ± 0.23 i	0.9321 ± 0.0026 e
RPI	90.33 ± 0.30 cd	−0.64 ± 0.08 abc	12.82 ± 0.34 bc	2.40 ± 0.92 bcd	89.77 ± 0.53 e	0.9523 ± 0.0077 f
LP	88.46 ± 1.05 e	−0.59 ± 0.05 ab	13.16 ± 0.64 abc	3.83 ± 1.44 d	103.24 ± 0.41 h	0.8997 ± 0.0015 bcd
LI	88.92 ± 0.57 e	−1.27 ± 0.15 e	13.19 ± 0.27 abc	3.30 ± 1.02 bcd	101.06 ± 0.96 g	0.8904 ± 0.0013 ab
LPI	88.81 ± 0.46 e	−0.98 ± 0.15 cde	13.35 ± 0.49 ab	3.58 ± 0.89 cd	103.10 ± 0.61 h	0.8940 ± 0.0016 abc

L* represents lightness, a* represents the green color (−a*) to red color (+a*), b* represents the blue color (−b*) to yellow color (+b*), and ΔE is the color difference. ^a–i Different letters in the same column indicate significant differences (p ≤ 0.05) between means (Duncan’s multiple range test). FP = full-fat goat milk with 1.0% PDX, FI = full-fat goat milk with 1.0% inulin, FPI = full-fat goat milk with 0.5% PDX and 0.5% inulin, RP = reduced-fat goat milk with 1.0% PDX, RI = reduced-fat goat milk with 1.0% inulin, RPI = reduced-fat goat milk with 0.5% PDX and 0.5% inulin, LP = low-fat goat milk with 1.0% PDX, LI = low-fat goat milk with 1.0% inulin, LPI = low-fat goat milk with 0.5% PDX and 0.5% inulin.

. The full-fat control feta cheese (CTRL), without dietary fiber, had color parameters of L* = 90.57 ± 0.74, a* = −1.76 ± 0.89, and b* = 11.76 ± 1.14. The total color difference (ΔE) compared to CTRL ranged from 2.07 to 2.79 for FFC, 1.88 to 2.40 for RFC, and 3.30 to 3.83 for LFC. The L* values for FFC, RFC, and LFC ranged from 90.03–90.90, 90.33–91.63, and 88.46–88.92, respectively. Their a* values were −1.07 to −0.74 (FFC), −0.64 to −0.28 (RFC), and −1.27 to −0.59 (LFC). The b* values were 12.64–13.47 for FFC, 11.70–12.82 for RFC, and 13.16–13.35 for LFC. Statistically significant differences (p ≤ 0.05) indicated that reducing the fat content led to increased lightness and a greater overall color difference in the feta cheese. Concurrently, as depicted in Figure 2, the values for a* and b* increased with higher fat levels, suggesting a noticeable color variation dependent on fat content. A finding in line with Sánchez-Macías et al. [9] indicated that as milk fat content decreased, external and internal red index values fluctuated during the ripening of each cheese type, yet remained higher in RFC and LFC cheeses than in FFC artisan cheese. The different dietary fibers did not result in apparent variations in the cheese color. This could be attributed to the white color and high solubility of the fat replacers, allowing for their uniform dispersion throughout the cheese matrix. Given that cheese color significantly influences consumer acceptance, it is crucial to ensure that the fat replacers used do not negatively impact the color of RFC. Regarding the results, the dietary fiber additions do not affect the feta cheese color, and the processing conditions did not trigger non-enzymatic browning, which is possible in carbohydrate-based fat replacers due to the Maillard reaction. This finding aligns with the results reported by Schädle et al. [44] who observed similar outcomes when incorporating fat replacers such as inulin, corn dextrin, polydextrose, and microparticulated whey protein in processed cheese.

For moisture content, the CTRL cheese exhibited a value of 65.13% ± 0.33. The moisture content of FFC with added dietary fiber ranged from 68.74% to 74.07%. The RFC showed values between 89.77% and 107.28%, while the LFC ranged from 101.06% to 103.24%. These findings show an inverse relationship between fat content and moisture content, suggesting that lower fat content results in higher moisture retention. This phenomenon may be attributed to the water-absorbing capacity of the dietary fibers within the cheese matrix. Similarly, Guinee et al. [45] found that the moisture content in cheese increased significantly in the reduced-fat and fiber-added groups. The incorporation of dietary fiber, particularly inulin, led to an increase in moisture content. Inulin, a fructose-based polysaccharide, forms long chains connected by glycosidic bonds. This structure enables it to create gels and enhance water retention within the product more effectively than formulations containing polydextrose (PDX). While PDX, with its more disordered structure, can retain some water, its capacity is less pronounced compared to inulin. Karimi et al. [46] similarly observed that low-fat cheese containing inulin exhibited higher moisture content compared to the original cheese. This was attributed to inulin’s effective water-binding capacity, resulting in a denser and softer cheese texture.

Regarding water activity (a_w), the CTRL cheese presented a value of 0.8873 ± 0.0032. Meanwhile, the addition of dietary fiber to FFC resulted in an a_w range of 0.8935 to 0.9009. The RFC showed considerably higher a_w values (0.9099–0.9523) compared to both the CTRL and LFC (0.8904–0.8997). The data reveal a positive association between fat content and a_w, suggesting that cheeses with less fat exhibit lower a_w values. This could be due to the interaction of hydrocolloids with water, potentially entrapping it more effectively in lower fat systems and consequently decreasing the ease with which water can be removed from the curd [47]. This phenomenon takes place when rennet hydrolyzes kappa-casein, exposing previously hidden hydrophobic regions that then associate to form a coagulated mass. Consequently, this coagulation network entraps water, preventing its expulsion [48]. Water activity is a critical factor in the preservation of fresh food, as elevated a_w levels support the proliferation of spoilage microorganisms such as molds and yeasts [49].

3.1.2. Chemical Composition

Crucial for cheese quality assessment, pH plays a vital role in the aggregation and enzymatic stages of milk coagulation, as well as in the effectiveness of rennet clotting [50]. According to

Table 3. Chemical compositions of FFC, RFC, and LFC with dietary fibers as a fat replacer.

Treatments	Lipid Content (%)	pH Value	Lactic Acid Content (%)	Salt Content (ppt)
Control	26.94 ± 0.55 a	5.70 ± 0.05 a	0.5175 ± 0.056 a	34.3 ± 0.94 ba
FP	24.26 ± 0.84 b	5.54 ± 0.09 ab	0.5337 ± 0.009 a	35.7 ± 0.47 ba
FI	25.08 ± 0.11 ab	5.53 ± 0.11 ab	0.5472 ± 0.010 a	33.7 ± 0.91 a
FPI	26.42 ± 0.30 ab	5.49 ± 0.07 ab	0.5310 ± 0.015 a	33.3 ± 1.25 a
RP	12.57 ± 1.56 cd	5.49 ± 0.13 ab	0.7659 ± 0.020 d	35.7 ± 0.47 ba
RI	10.55 ± 0.80 d	5.41 ± 0.09 b	0.6534 ± 0.020 b	35.7 ± 0.47 ba
RPI	13.16± 0.20 c	5.30 ± 0.04 b	0.7245 ± 0.009 dc	37.3 ± 1.25 cb
LP	0.38 ± 0.06 e	5.02 ± 0.02 c	0.6856 ± 0.014 cb	39.7 ± 0.47 dc
LI	0.70 ± 0.44 e	5.00 ± 0.02 c	0.7038 ± 0.020 cb	41.3 ± 1.25 d
LPI	0.58 ± 0.06 e	4.99 ± 0.02 c	0.7218± 0.005 dc	42.3 ± 0.47 d

^a–e Different letters in the same column indicate significant differences (p ≤ 0.05) between means (Duncan’s multiple range test). FP = full-fat goat milk with 1.0% PDX, FI = full-fat goat milk with 1.0% inulin, FPI = full-fat goat milk with 0.5% PDX and 0.5% inulin, RP = reduced-fat goat milk with 1.0% PDX, RI = reduced-fat goat milk with 1.0% inulin, RPI = reduced-fat goat milk with 0.5% PDX and 0.5% inulin, LP = low-fat goat milk with 1.0% PDX, LI = low-fat goat milk with 1.0% inulin, LPI = low-fat goat milk with 0.5% PDX and 0.5% inulin.

, the pH values of the feta cheeses generally decreased with lower fat content. The CTRL (26.94% ± 0.55 lipid) had the highest pH (5.70 ± 0.05), followed by FFC (24.26–26.42% lipid, pH 5.49–5.54), RFC (10.55–13.16% lipid, pH 5.30–5.49), and finally LFC (0.38–0.70% lipid) with the lowest pH (4.99–5.02). The observed decrease in pH and increase in lactic acid with fat reduction can be attributed to the role of fat in controlling acid production [51]. A lower fat content in feta cheese results in a lower pH, coinciding with elevated lactic acid levels. Concurrently, McCarthy et al. [52] reported that the lactic acid content in cheddar-style cheeses—full-fat (33%), reduced-fat (22%), and half-fat (16%)—increased significantly as the fat content was reduced. In low-fat cheeses, the reduced inhibition by fat may promote the growth of acid-producing microorganisms, thus leading to increased lactic acid formation. Primarily, the pH decline in cheese stems from lactose fermentation by lactic acid bacteria, yielding lactic acid, alongside fat deterioration during the ripening phase [53]. Additionally, the speed at which acid develops profoundly affects cheese composition, notably the moisture level. Thus, the acidity of cheese plays a vital role in establishing its final quality and flavor profile. Lactic acid bacteria proliferation and subsequent lactic acid production lead to both increased lactic acid and reduced fat levels. This not only improves cheese flavor but also preserves it from spoilage and firms its texture. This same factor is crucial for initiating oxidation, racemization, and microbial metabolism [54]. Our result lines up with the findings of Sánchez-Macías et al. [9], who found that in their low-fat artisan goat cheese production, fat reduction led to increased external and internal acidity.

According with salinity, the CTRL cheese had 34.3 ± 0.94 ppt. FFC showed a similar range of 33.3–35.7 ppt. Notably, the salt content increased in the RFC (35.7–37.3 ppt) and reached its highest levels in the LFC (39.7–42.3 ppt). Accordingly, the LFC exhibited a higher salt content compared to the others. Brining plays a vital role in cheese production, contributing significantly to flavor development and microbial control [55]. Remarkably, only 40 g of cheese at 2% salt represents 16% of the WHO’s (2013) recommended daily salt intake. Beyond its direct contribution to the well-liked salty taste, NaCl indirectly shapes cheese flavor by controlling microbial and enzymatic activities. These activities influence lactose metabolism, pH, and the breakdown of fats and casein, leading to the formation of flavor compounds like peptides, free amino acids, and free fatty acids [56].

3.2. Textural Profile

Texture analysis is a widely applied technique to replicate the oral processing of food products and exhibits a correlation with human sensory evaluations [57]. The force-deformation characteristics of the prepared feta cheeses are illustrated in Figure 3.

Table 4. Texture profile analysis of FFC, RFC, and LFC with dietary fibers as a fat replacer.

Treatment	Hardness (g)	Cohesiveness	Springiness	Chewiness
CTRL	9432 ± 946 c	0.2846 ± 0.0488 d	0.3543 ± 0.0477 c	1071 ± 323 b
FP	7847 ± 901 c	0.3225 ± 0.0363 cd	0.4071 ± 0.0244 bc	1037 ± 222 b
FI	7487 ± 1322 c	0.3064 ±0.0229 cd	0.3852 ± 0.0250 bc	891 ± 225 b
FPI	6904 ± 703 c	0.3078 ± 0.0386 cd	0.3809 ± 0.0296 bc	813 ± 169 b
RP	10,367 ± 1073 c	0.4110 ± 0.0764 b	0.4464 ± 0.0709 ab	1944 ± 738 b
RI	7964 ± 975 c	0.4293 ± 0.0647 ab	0.4368 ± 0.0713 ab	1504 ± 444 b
RPI	10,492 ± 1285 c	0.3852 ± 0.0298 bc	0.4313 ± 0.0280 abc	1755 ± 339 b
LP	23,021 ± 3692 b	0.5054 ± 0.0550 a	0.4994 ± 0.0730 a	5798 ± 1376 a
LI	27,328 ± 3948 a	0.5106 ± 0.0600 a	0.4573 ± 0.0379 ab	6391 ± 1398 a
LPI	24,293 ± 4888 ab	0.5020 ± 0.0439 a	0.4894 ± 0.0531 a	5905 ± 1046 a

^a–d Different letters in the same column indicate significant differences (p ≤ 0.05) between means (Duncan’s multiple range test). FP = full-fat goat milk with 1.0% PDX, FI = full-fat goat milk with 1.0% inulin, FPI = full-fat goat milk with 0.5% PDX and 0.5% inulin, RP = reduced-fat goat milk with 1.0% PDX, RI = reduced-fat goat milk with 1.0% inulin, RPI = reduced-fat goat milk with 0.5% PDX and 0.5% inulin, LP = low-fat goat milk with 1.0% PDX, LI = low-fat goat milk with 1.0% inulin, LPI = low-fat goat milk with 0.5% PDX and 0.5% inulin.

details the textural properties of all the feta cheeses, considering the inclusion of various dietary fibers and different fat levels. Hardness is quantified as the maximum force (F₁) encountered during the initial compression cycle, simulating the force required for mastication between molar teeth [58]. Based on the findings, the hardness of the FFC and RFC did not differ significantly (p > 0.05). Conversely, the LFC displayed a statistically highly significant difference in hardness when compared to all other samples. The parameters of cohesiveness, springiness, and chewiness showed a trend consistent with that of hardness (p ≤ 0.05). The process of fat removal in cheese is generally associated with several rheological, textural, functional, and sensory impairments, especially a rubbery texture, flavorlessness, bitterness, off-flavors, limited meltability, and an undesirable color [59]. With a reduction in fat content, the protein matrix in cheese becomes more compact, leading to a firmer and chewier texture. In food formulations where fat ingredients are minimized, the inclusion of other components is often necessary to fulfill fat’s role in sustaining organoleptic attributes [60]. The LI sample presented the highest hardness value (27,328 g), succeeded by LPI (24,293 g) and LP (23,021 g). FFC displayed inferior texture profiles, specifically lower hardness, chewiness, and springiness, when compared to RFC and LFC. This can be attributed, in part, to the observation in Figure 3 that a lower fat content in inulin-added feta cheese corresponded to a higher slope of the first peak (hardness). This is consistent with Fox et al.’s [61] research on cheese structure, which explains that the denser protein network in reduced-fat cheese leads to increased firmness, dryness, and decreased adhesiveness—a conclusion reinforced by Papademas and Bintsis [62]. These differences in hardness profiles could be due to the binding ability and water-holding capacity of the fat and inulin mixture. Meanwhile, the same characteristics were observed in the CTRL cheese and the RFC versions containing either 1% PDX or a mixture of 0.5% PDX and 0.5% inulin. Dietary fiber incorporation softened the cheese, with inulin proving more effective than PDX in achieving this. These observations emphasize the crucial role of fat in the textural attributes of feta cheese, including its elasticity, softness, and water-holding capacity.

Our findings, showing inulin’s softening effect across all goat fat levels in feta cheese—especially on the cohesiveness of low-fat feta cheese—corroborate Karimi et al.’s [46] findings, where inulin’s gelling ability as a fat substitute yielded a texture more comparable to full-fat cheese. Wadhwani [63] compared four fibers (inulin, low-methoxy pectin, polydextrose, and resistant starch) to improve low-fat mozzarella and cheddar cheese quality. Inulin emerged as the most effective in cheese systems, enhancing the texture of LFC by reducing hardness and maintaining cohesiveness and springiness. Simultaneously, PDX, with its excellent processing properties and potential health benefits, is a widely used low-calorie bulking agent for partially replacing fats and sugars in various foods. Its capacity to form a viscous gel-like matrix imparts a creamy mouthfeel, leading to its widespread use as a fat replacer in low-fat dairy products [64]. However, both inulin and PDX are classified as a polysaccharide type but have different structures and chemical compositions for each fiber. PDX (DP 12) features a highly branched polymer mainly consisting of glucose with small, randomly distributed quantities of sorbitol and citric acid; inulin (DP 23) primarily comprises fructose in its polymer and may contain a small proportion of glucose [65]. Therefore, the shorter chain length of PDX could facilitate a more even extension of its branching structure into casein aggregates, leading to more extensive protein–carbohydrate interactions. This enhanced interaction would contribute to better curd stability, evidenced by a higher hardness value, which may also be linked to the cheese’s porosity [66].

Cohesiveness, frequently synonymous with consistency, quantifies the internal forces maintaining a food’s structure and its resistance to fracture upon deformation [67]. It is quantified by the ratio of the positive force area of the second compression cycle to that of the first, providing an index of the product’s structural integrity [68]. The cohesiveness value for the CTRL sample was determined to be 0.2846 ± 0.0488. The FFC, RFC, and LFC were found to be in the ranges of 0.3064–0.3225, 0.3852–0.4293, and 0.5020–0.5106, respectively. A positive correlation was observed between the degree of fat content reduction and the resulting cohesiveness value. The highest value of feta cheese with dietary fiber obtained was for LI (0.5106 ± 0.0600), and the lowest was for FI (0.3064 ± 0.0229). While both feta cheeses contained inulin fiber, the one with the lower fat content (LI) exhibited significantly higher cohesiveness compared to the one with the higher fat content (p ≤ 0.05). Springiness, a textural parameter correlated with the sample’s elasticity, refers to the reversible ability of food to recover its shape between the first and second bite during texture profile analysis. Higher springiness indicates that more mastication energy is required in the mouth [67]. The springiness value of the CTRL cheese was 0.3543 ± 0.0477. The FFC ranged from 0.3809 to 0.4071, the RFC from 0.4313 to 0.4464, and the LFC from 0.4573 to 0.4994. Particularly, a positive association existed between the extent of fat content reduction and the resulting springiness. When considering the feta cheese with dietary fiber, the LP sample yielded the highest springiness (0.4994 ± 0.0737), and FPI had the lowest (0.3809 ± 0.0296). A consistent trend was also evident for chewiness, whereby greater reduction in fat content correlated with higher chewiness values. Chewiness, typically reported for solid foods, quantifies the energy required for mastication and is defined as the product of gumminess and springiness [68]. The LFC presented the highest chewiness range (5798–6391), followed by the RFC (1504–1944) and the FFC (813–1031), the latter being comparable to the chewiness observed in the CTRL sample (1071 ± 323). The functional characteristics of fat content and commercial dietary fibers played a key role in determining the texture of the feta cheese. As a result, the texture profiles of RFC supplemented with these fibers were surprisingly close to those of the FFC and the CTRL cheese.

To further understand the relationships among the physicochemical properties of low-fat feta cheese with different dietary fiber treatments, principal component analysis (PCA) was performed. The first two principal components of the PCA accounted for a total of 79.40% of the variance (PC1 = 58.56% and PC2 = 20.84%), as presented in the PCA score plot in Figure 4. The score plot data indicate that the full-fat feta cheeses (samples 2, 3, and 4) clustered with the control (CTRL, sample 1), while the reduced-fat (samples 5, 6, and 7) and low-fat (samples 8, 9, and 10) feta cheeses formed separate groups. A consistent trend was observed for the physicochemical characteristics within each group. Observing the score plot, which illustrates the relationship between varying fat contents in feta cheeses and their physicochemical properties, we can infer several correlations. Specifically, hardness, chewiness, and total salinity appear to be associated with the low-fat feta cheeses (samples 8, 9, and 10). This is probably because the reduced fat content resulted in higher water content, which consequently altered salt solubility in the cheese. The salt content seems to strengthen the bonds within the cheese structure, consequently resulting in higher values for both hardness and chewiness. Higher salt levels also cause the casein phase to swell, leading to the adsorption and absorption of moisture by the casein matrix, reaching at least 1.6% NaCl in mozzarella, as shown by Rowney et al. [69]. Meanwhile, the water activity, lightness (L*), and redness (a*) of the RFC with all fibers (samples 5, 6, 7) are interrelated. Thus, higher water activity in the samples is associated with greater lightness and redness. On the contrary, water activity exhibits an inverse relationship with the salinity level (salt content) of the cheese products. Water activity positively correlated with water content but negatively correlated with the moisture phase concentrations of nitrogen, ash, and salt [70]. These trends align with the findings of Saurel, Pajonk, and Andrieu [71], who reported that district variations in the water activity of Emmental cheese were strongly influenced by local salt concentration distributions and free amino acid levels. In addition, the low dry basis moisture content correlated between the CTRL and all FFC samples supplemented with dietary fibers. The lower moisture content in these cheeses is likely due to their high fat content. Generally, a higher fat content in cheese is associated with lower levels of moisture and protein, as well as with reduced firmness [72].

For a more comprehensive analysis of the relationships between physicochemical attributes (moisture content, a_w, pH, salinity, lactic acid, color) and textural profile (hardness, springiness, cohesiveness, chewiness) in all the feta cheeses, a correlation matrix is shown in Figure 5. The direction and strength of the correlations are represented by the color scale, which spans from −1.0 to 1.0. Positive correlations are shown in warm colors (yellow to red), and negative correlations are shown in cool colors (green to purple). The strong positive correlation between moisture and pH (r = 0.8) signifies that higher pH values are linked to increased moisture content. While this elevated moisture can negatively affect food safety and preservation, the inverse relationship—lower pH and reduced moisture—typically leads to a longer product shelf life. In contrast, moisture content displayed a perfect negative correlation with cohesiveness (r = −1.0). Cohesiveness, defined as the internal strength of the cheese body resisting rupture during complete biting, is thus inversely related to moisture [73]. Similar strong negative correlations were observed with chewiness (r = −0.7), springiness (r = −0.7), and hardness (r = −0.6), suggesting that reduced moisture promotes higher values in these textural attributes. Additionally, a strong negative relationship existed between moisture content and lactic acid, potentially because lactic acid bacteria (LAB) thrive and produce more acid under a lower water content. Salinity exhibited a strong positive relationship with all measured textural characteristics, with correlation coefficients ranging from 0.8 to 1.0. This aligns with previous findings that sodium chloride increases cheese hardness [74]. This strong association is likely due to the ability of salt to strengthen the bonds within the cheese matrix. Brine salting of cheese is characterized by the influx of NaCl ions (Na⁺ and Cl⁻) into the cheese, driven by the osmotic pressure gradient. Concurrently, water diffuses out of the cheese to balance this gradient, and this dehydration is amplified by protein changes caused by the salt, which promote moisture expulsion [75,76]. Salinity also has a strong correlation with lactic acid (r = 0.8). These findings indicate that salinity enhances the favorable environment for LAB growth and subsequent lactic acid production. There is a noteworthy positive association (r = 0.8) between cohesiveness and hardness, indicating that foods with higher hardness have a tendency to be more cohesive. Knowing this link is essential to comprehending food product sensory profiles. Furthermore, there is a strong positive association (r = 0.8) between cohesiveness and springiness, as well as between chewiness and springiness (r ≈ 0.7), suggesting that foods with higher springiness are also typically chewier and gummier. Recognizing these correlations provides a basis for manipulating dietary attributes to attain specific textural properties, including consistency and mouthfeel. Remarkably, salinity exerted a strong influence on both the production of lactic acid and the resulting textural characteristics. Consequently, this correlation analysis provides valuable insights that can guide the development and improvement of food products.

3.3. Scanning Electron Microscopy

SEM was performed to characterize the surface morphology of the feta cheese samples containing dietary fibers, in comparison to a CTRL sample, as shown in Figure 6. SEM imaging revealed distinct surface characteristics depending on the level of goat milk used in production. Remarkably, a higher degree of fat reduction correlated with increased sample porosity. SEM micrographs of CTRL and FFC revealed a porous protein structure interspersed with fat globules. The pores correspond to the spaces occupied by fat. Markedly, the RFC and LFC micrographs displayed a distinctly different, denser protein matrix with dietary fibers due to the reduced presence of fat globules [77]. Research by Islam et al. [78] revealed that cheddar cheeses containing inulin exhibited a significantly more uniform and smoother protein matrix. They observed no deceptive honeycombing structures, suggesting that inulin’s ability to constrain free water likely prevents the formation of such structures. This aligns with findings by Kip et al. [79], who reported that when inulin is incorporated during coagulation and fermentation, it can form a complex with protein, becoming an integral part of the protein network. In agreement with Sarwar et al. [80], as the cheese fat content decreased, the size of the fat globules also diminished. Correspondingly, the protein matrix became denser with reduced space between cross-links. These observations corroborate the work of Junyusen et al. [81] on RFC, which indicated that a lower fat content enhances the establishment of protein matrix cross-links, leading to a denser structural network. The fat content significantly influenced the structure of the feta cheese. This was evident in its hardness: the feta cheese with a lower fat content consistently showed greater hardness values.

3.4. Sensory Attribute

The descriptive sensory profiles of the cheese samples are detailed in

Table 5. Sensory evaluation of FFC, RFC, and LFC with dietary fibers as a fat replacer.

Sensory Characteristics	CTRL	FP	FI	FPI	RP	RI	RPI	LP	LI	LPI
Appearance	7.71 ± 1.25 ns	7.86 ± 1.07 ns	7.86 ± 0.90 ns	7.71 ± 0.95 ns	7.71 ± 0.95 ns	7.86 ± 0.90 ns	7.29 ± 0.76 ns	7.29 ± 1.25 ns	7.14 ± 1.07 ns	7.14 ± 0.90 ns
Color	7.57 ± 0.90 ns	7.43 ± 0.90 ns	7.71 ± 0.88 ns	7.43 ± 0.90 ns	7.43 ± 0.90 ns	7.57 ± 0.90 ns	7.29 ± 1.03 ns	7.14 ± 1.12 ns	6.71 ± 1.03 ns	6.71 ± 1.03 ns
Aroma	7.71 ± 0.95 ns	7.43 ± 1.27 ns	7.57 ± 0.98 ns	7.57 ± 0.98 ns	7.29 ± 0.95 ns	7.29 ± 0.95 ns	7.14 ± 1.57 ns	6.71 ± 1.38 ns	6.57 ± 1.13 ns	6.71 ± 1.11 ns
Saltiness	6.71 ± 1.50 b	7.29 ± 1.11 a	6.43 ± 1.13 ab	6.86 ± 0.90 ab	7.00 ± 1.15 ab	6.29 ± 1.50 ab	6.57 ± 1.40 ab	5.43 ± 1.40 a	5.43 ± 1.62 a	5.57 ± 1.62 a
Sourness	6.57 ± 0.98 b	6.86 ± 1.21 a	6.29 ± 0.95 abc	6.29 ± 0.95 abc	6.43 ± 0.98 abc	5.86 ± 1.07 abc	6.14 ± 1.35 abc	5.29 ± 1.11 bc	5.29 ± 1.11 bc	5.14 ± 1.21 c
Softness	6.00 ± 1.29 a	7.00 ± 1.15 a	7.14 ± 1.07 a	7.14 ± 1.07 a	6.29 ± 1.25 a	6.14 ± 1.21 a	6.29 ± 1.25 a	3.57 ± 1.90 b	3.43 ± 1.51 b	3.57 ± 2.15 b
Firmness	6.43 ± 0.98 a	7.00 ± 1.00 a	7.00 ± 0.58 a	7.14 ± 0.90 a	6.86 ± 0.90 a	6.86 ± 0.90 a	6.57 ± 1.13 a	3.71 ± 2.50 b	3.86 ± 2.48 b	3.57 ± 2.15 b
Crumbliness	6.86 ± 0.69 a	6.86 ± 1.07 a	7.14 ± 0.69 a	7.14 ± 1.07 a	6.57 ± 1.13 a	6.00 ± 1.41 a	6.00 ± 1.15 a	4.00 ± 1.83 b	3.86 ± 1.95 b	3.57 ± 2.07 b
Aftertaste	6.86 ± 0.90 a	7.00 ± 0.98 a	6.86 ± 0.98 a	7.14 ± 0.69 a	7.00 ± 0.76 a	6.86 ± 1.13 a	6.29 ± 1.27 a	5.14 ± 1.86 ab	5.57 ± 1.38 ab	5.00 ± 1.77 c
Overall acceptance	6.86 ± 0.90 a	7.43 ± 0.98 a	7.43 ± 0.98 a	7.14 ± 0.69 a	6.71 ± 0.76 a	6.43 ± 1.13 a	6.43 ± 1.27 a	3.86 ± 1.86 b	3.71 ± 1.38 b	3.86 ± 1.77 b

^a–c Different letters in the same column indicate significant differences (p ≤ 0.05) between means (Duncan’s multiple range test). ns = not significant. FP = full-fat goat milk with 1.0% PDX, FI = full-fat goat milk with 1.0% inulin, FPI = full-fat goat milk with 0.5% PDX and 0.5% inulin, RP = reduced-fat goat milk with 1.0% PDX, RI = reduced-fat goat milk with 1.0% inulin, RPI = reduced-fat goat milk with 0.5% PDX and 0.5% inulin, LP = low-fat goat milk with 1.0% PDX, LI = low-fat goat milk with 1.0% inulin, LPI = low-fat goat milk with 0.5% PDX and 0.5% inulin.

and Figure 7. Spiderweb plots specifically visualize the attributes that the panelists could significantly distinguish (p ≤ 0.05). The sensory attributes [taste (saltiness, sourness, aftertaste), texture (softness, firmness, crumbliness)], and overall acceptance were significantly differentiated (p ≤ 0.05) by seven expert panelists and varied between the cheeses (Figure 7). In terms of saltiness, the LFC exhibited statistically lower scores (5.43–5.57) compared to the FFC (6.43–7.29) and RFC (6.29–7.00). Despite these lower sensory scores, it can be inferred that LFC contained the highest salt concentration, consistent with the data in Table 3. According to Ayyash and Shah [82], fat content played such a critical role in modulating salt perception in Halloumi cheese that there was a need to optimize its microstructure when reducing sodium or replacing fat. A balance of salt levels, fat content, proteolysis, and mineral interactions enhances sensory quality preservation. In contrast, the panelists perceived FFC as the sourest (6.29–6.86), with sourness decreasing in RFC (5.86–6.43) and being lowest in LFC (5.14–5.29). This sensory finding is the opposite of the pH and lactic acid measurements presented in Table 3. It proved that sodium reduction or fat replacement requires the optimization of cheese microstructure—balancing not just salt levels, but also fat content, proteolysis, and mineral interactions to maintain sensory quality [83]. FFC tasted the sourest, despite its higher pH. This could be attributed to the ability of fat matrices to retain acids and release them gradually. The prolonged interaction with taste receptors, facilitated by hydrophobic interactions, alters flavor perception [84]. These results imply that feta cheese is expected to be mildly sour, in contrast to having a strong sour taste. Similarly, the scores for aftertaste and all texture attributes (softness, firmness, and crumbliness) exhibited the same trend. When the fat reduction was higher, the panelists’ acceptance was found to be lower. Removing fat enhances casein’s role in texture formation, yet insufficient proteolysis in LFC frequently results in a firm texture. Subsequently, low-fat products often develop a gummy body and an atypical flavor compared to full-fat cheeses, also frequently exhibiting a bland taste, a firm, rubbery consistency, undesirable color changes, and off-flavors [11,12]. This trend is supported by the overall acceptance scores, which showed that cheeses with lower fat contents received lower ratings. For clearer visualization, Figure 7 presents a similar trend line for CTRL, FFC, and RFC, unlike the distinctly different lines for all the LFC samples.

Regarding overall acceptance scores, the RFC with PDX (RP) gave the highest ratings among the reduced-fat feta cheeses and was not statistically different from the CTRL and FFC. Therefore, RP treatment appears to be an optimal formulation for the commercial production of reduced-fat feta cheese with dietary fiber.

To provide a clearer understanding of the correlations among the sensorial attributes (appearance, color, aroma, saltiness, sourness, softness, firmness, crumbliness, aftertaste, overall acceptance), the physicochemical properties (pH, salt content, lactic acid, L*, a*, b*), and the textural profile characteristics (hardness, springiness, cohesiveness, chewiness) of all the feta cheeses, a correlation matrix is illustrated in Figure 8. The color spectrum, spanning −1.0 to 1.0, visually represents the direction and strength of the correlations. Cool colors (from dark green to light green) denote positive correlations, and warm colors (from dark red to light red) denote negative correlations. The pH value presented a positive correlation with aftertaste and overall acceptance (r = 0.8), indicating that lower pH values were associated with decreased scores for both attributes. Conversely, salt content exhibited a negative correlation (r = −1.0 to −0.2) with all sensory attributes, implying that higher salt content led to lower scores across all sensory tests. Similarly, lactic acid showed a negative trend. The lightness (L* value) of the feta cheese showed a positive correlation (0.0–0.8) with all textural properties in the sensory test, indicating that the lighter cheese samples received higher consumer acceptance scores for texture. Ultimately, the negative correlation (0.0 to −0.8) between the cheeses’ textural characteristics and their sensorial attributes revealed an inverse relationship: higher scores for hardness, springiness, cohesiveness, and chewiness corresponded to lower sensory scores.

In conclusion, high consumer acceptance of feta cheese with dietary fibers as a fat replacer was driven by a combination of factors: low acidity (high pH, low lactic acid), low salinity, high lightness, and reduced hardness, springiness, cohesiveness, and chewiness, highlighting the significant influence of physicochemical properties and texture attributes on sensory perception.

4. Conclusions

Reduced-fat food products play a key role in preventing diet-related diseases and delivering more protein, but often face challenges with sensory and textural quality. This study demonstrated the potential of polydextrose (PDX) and inulin as effective fat replacers in goat milk feta cheese. While fat reduction led to visual changes and altered biochemical profiles, the incorporation of dietary fibers, particularly PDX, mitigated some of the textural drawbacks. Remarkably, the 50% reduced-fat cheese supplemented with PDX (RP) achieved consumer acceptance comparable to the full-fat and control samples, highlighting its potential for commercial viability. The finer pore structure imparted by PDX, alongside its contribution to hardness in lower-fat cheeses, suggests a key role in mimicking desirable textural attributes. The ripening process in low-fat feta cheese was not within the scope of this research. Consequently, to evaluate the stability of the optimized RP formulation, a subsequent shelf-life assessment will be conducted, focusing on alterations in its physicochemical and textural properties, and volatile compounds. These research findings will enable farmers to create novel, high-value products for future commercial launch in the functional food market.