Improving the Nutritional Value and Physical Properties of Gluten-Free Mushroom Soup by Substituting Rice Flour with Quinoa Seed Flour

Abstract

Gluten-free products were initially for people with gluten-related disorders but are now popular with regular consumers. Research is investigating the health benefits of other gluten-free pseudo cereals, like quinoa, with higher nutritional value. This study aimed to explore the impact of substituting 30% rice flour (RF) in gluten-free mushroom instant dry soup with quinoa seed flour (QSF) at different levels on its nutritional, physicochemical, sensory characteristics, and the antioxidant activity. The results showed that replacing RF with QSF led to a significant improvement in the nutritional profile of the soup, with a linear increase in crude protein, fat, ash, crude fiber, total polyphenol, flavonoids, and antioxidant activity levels as the substitution rate increased. Moreover, macro- and microelements and essential amino acids increased significantly in the soup samples by adding QSF instead of RF, from 10 to 30%, compared to the control, which contained 30% of RF. However, the other total carbohydrate content decreased with the rise in the QSF concentration in the soup. In addition, substituting RF with QSF improved the soup samples’ rehydration ratio and total soluble solids. However, the color parameters (a* and b*) were increased with a decrease in L*. The sensory analysis revealed that the maximum substitution rate of QSF maintained the highest consumer acceptability, odor, flavor, texture, and appearance of the gluten-free mushroom instant soup samples. In conclusion, adding QSF to non-gluten soups improves their physical and chemical characteristics, nutritional impact, and organoleptic properties due to phytochemicals.

1. Introduction

Dehydrated soup mixes are convenient and typically contain cornstarch, spices, salt, flavors, and enhancers [1]. A soup is created by boiling meat, vegetables, or other ingredients in hot water or stock until the flavor is extracted into a broth. Soups are often recommended to aid in recovery from illness, especially if the patient can only consume liquids. At the beginning of a meal, they can also be served as an appetizer to stimulate the appetite and promote digestive juice flow in the stomach [2].

Researchers are constantly working to enhance the nutritional value of instant soups by incorporating plant-based sources of proteins, minerals, and vitamins that are suitable for vegetarians and others. One of the safest and most complete foods that people of all ages can consume is an instant dry soup made from mushrooms [3]. Mushrooms are a highly nutritious but underutilized resource. They have been a part of human diets since ancient times [4]. Mushrooms are rich in fiber and nutrients like proteins, minerals, and vitamins, with low fat and calories [5]. Edible mushrooms are a great source of essential nutrients. They contain all the essential amino acids, iron, phosphorus, and vitamins such as ascorbic acid, thiamine, riboflavin, niacin, and ergosterol [6]. They are low in fat, high in protein, and low in energy content, making them a valuable part of our diet. Studies have also shown that mushrooms have antiviral, anti-tumor, antithrombotic, and immune-modulating properties [7]. The polysaccharides obtained from edible mushrooms, especially β-glucans, have received attention due to their antioxidant, antidiabetic, anticarcinogenic, immune-modulating effects, and health benefits [8]. It is worth noting that these mushrooms can also be used to create drugs with anti-tumor, antimicrobial, and antioxidant properties.

According to Saed et al. [3], wheat flour constitutes over 25% of the dried instant mushroom soup. However, individuals diagnosed with celiac disease are required to remove gluten from their diet to maintain good health. This autoimmune disorder is triggered by exposure to dietary gluten and affects about 1% of the world’s population [9]. Symptoms include inflammation of the mucosal walls, atrophy of the villi, and crypt hyperplasia. The only recommended treatment is to follow a gluten-free diet for life. In addition, many people without celiac disease are adopting a strict gluten-free diet. Many believe it to be a healthy practice that may help prevent celiac disease [10]. It is worth noting that following a gluten-free diet may result in nutrient imbalances since nutrients are not adequately absorbed, and there can be a lack of essential vitamins and minerals [11]. Scientists are exploring using gluten-free minor cereals such as sorghum, teff, millet, wild rice, and pseudocereals like quinoa, canihua, chia, and amaranth to develop alternatives to traditional cereals. These crops contain high levels of nutrients and bioactive compounds, which can improve the nutritional quality of gluten-free products [12].

Rice flour (RF) is an excellent option for preparing food for individuals who have celiac disease. It has low levels of prolamins, known to release peptides that act as toxins for celiac patients. This makes cereals like wheat, rye, barley, and oats unsuitable for consumption by individuals with celiac disease. RF is especially suitable for people with celiac disease because of its unique nutritional properties, hypoallergenic nature, colorless appearance, and bland taste [13]. It is frequently used in baby foods [14], bread [15], cupcakes [16], biscuits [17], and other gluten-free products. However, RF showed the lowest protein, minerals, and crude fiber values with the highest carbohydrate content compared to other cereals like yellow corn, quinoa, chickpea, and others [15,16].

Quinoa (Chenopodium quinoa, Wild) has been cultivated in the Andean region for about 7000 years. It is grown in more than 95 countries across Africa, Asia, and Europe [18]. The attention toward Quinoa seed flour (QSF) is due to its high protein content, which is more balanced in amino acid composition than cereal flour. In addition, QSF is a rich source of vitamins such as ascorbic acid, riboflavin, tocopherols, minerals including potassium, calcium, magnesium, iron, and zinc, and antioxidant compounds. Since QSF is naturally gluten-free, it can be used as a healthy, nutrient-dense alternative ingredient to develop functional gluten-free products. Special attention is given to quinoa blending with RF to improve the nutritional quality of gluten-free foods. The protein, carbohydrate, fat, and fiber content in QSF reaches its peak at approximately 16.4%, 75.82%, 12.4%, and 3.38%, respectively [19,20]. Consequently, substituting lower-nutritional-value cereals like RF with QSF is a potential target in gluten-free food products.

To our knowledge, there have yet to be any reports on the formulation of instant gluten-free mushroom soup made with rice, quinoa flour, or their mixtures. Therefore, the current study focused on preparing gluten-free mushroom instant dry soup with rice flour and the impact of RF substitution with QSF on the physicochemical, antioxidant, and sensory characteristics of the gluten-free mushroom instant soup formulas.

2. Materials and Methods

2.1. Materials

The fresh, edible white mushrooms (Agaricus bisporus) of the button variety, quinoa seeds (Chenopodium quinoa Willd.), and rice seeds (Oryza sativa) of the Sakha-104 variety were obtained from the Agriculture Research Center in Giza, Egypt. The skimmed milk powder, garlic powder, onion powder, black pepper powder, and salt were bought from the local market in Cairo, Egypt. Chemicals and analytical-grade reagents were used in the study. They were obtained from El-Gamhouria Trading Chemicals and Drugs Company in Cairo, Egypt.

2.2. Methods

2.2.1. Preparation of Mushrooms Powder

Ten kilograms of fresh button mushrooms were carefully cleaned, washed with tap water, and sliced into small pieces with a thickness of 7 mm. These slices were then blanched in water maintained at 100 ± 3 °C for 3 min. Subsequently, they were dehydrated in a special air-drying oven at 60 ± 3 °C for 12 h until their moisture content reached approximately 10%. The dried mushroom slices were then divided into two halves. One of these halves was grounded using a Braun JB3060 Tribute Collection Blender from Neu-Isenburg, Germany, to obtain particles that could pass through 20-mesh sieves. The other half was left as is. Finally, the dried mushroom slices were packaged in plastic bags and stored at 4 ± 1 °C.

2.2.2. Preparation of Quinoa Seed Flour

The quinoa seeds were cleaned by removing foreign matter and washing with tap water to remove saponins and then dehydrated in an air-drying oven at 60 ± 3 °C for 12 h until their moisture content reached about 10%, and then ground to particles passing through a 20-mesh sieve, and packaged in plastic bags and stored under cooling conditions (4 ± 1 °C).

2.2.3. Preparation of Rice Flour, Sakha-104 Variety

The rice seeds were cleaned and washed with tap water and then dehydrated in an air-drying oven at 60 ± 3 °C for 12 h until their moisture content reached approximately 11.8%; they were then ground into particles, passing through a 20-mesh sieve and packaged in a plastic bag and stored under cooling conditions (4 ± 1 °C).

2.2.4. Formulation of Dried Mushroom Soups

Table 1. Formulation of gluten-free instant mushroom soup samples containing RF and QSF.

Ingredients (%)	Blends of Instant Mushroom Soup Samples
	Control	10% QSF	20% QSF	30% QSF
Dried mushroom powder	28	28	28	28
Dried mushroom slices	20	20	20	20
Rice flour (RF)	30	20	10	-
Quinoa seed flour (QSF)	-	10	20	30
Skim milk powder	15	15	15	15
Garlic powder	1.0	1.0	1.0	1.0
Onion powder	2.0	2.0	2.0	2.0
Black pepper powder	1.0	1.0	1.0	1.0
Salt (sodium chloride)	3.0	3.0	3.0	3.0
Total	100	100	100	100

and Figure 1 present four different blends of gluten-free instant mushroom soup: a control containing 30% RF and three other samples with varying levels of QSF (10, 20, and 30%) as RF replacers based on Kumar’s recipe with modifications [6]. The dried mushroom powder and slices, RF (30% of the total formula), and QSF (with levels of 10, 20, and 30% of the total formula) as RF replacers, and other ingredients (skim milk powder, garlic powder, onion powder, black pepper powder, and salt) were mixed for the preparation of four blends of gluten-free instant mushroom soup samples and packaged in polyethylene bags, and stored under cooling conditions at 4 ± 1 °C.

2.2.5. Chemical Analysis

The gluten-free mushroom soup samples underwent analysis for moisture, crude protein, fat, ash, and crude fiber using the AOAC method [21]. Other total carbohydrates were then calculated using the difference. The soup samples’ mineral content (Ca, Mg, P, K, Fe, Cu, Zn, and Mn) was determined by the standard AOAC method [21]. An automatic amino acid analyzer (Beckman, N3209100- PK 7312-03, Beckman Coulter, Inc., Pasadena, CA, USA) measured essential amino acids using the method described by Cosmos and Simon-Sarkadi [22]. The amino acid score (AAS) was calculated according to the FAO [23] as follows:

AAS% = (mg of tested amino acid in 1 g tested protein/mg of amino acid in reference protein) × 100

Five grams of each sample were extracted in 50 mL of 70% methanol solution. The mixture was shaken for one hour and filtered through the Whatman No.1 paper. The extracts were labeled and kept to analyze their total phenolic and flavonoid contents, as well as their radical scavenging activities. The total phenolic contents were measured at 760 nm using a spectrophotometer (UV Shimadzu 1601, Tokyo, Japan) and the Folin–Ciocalteu colorimetric method described by Singleton et al. [24]. The extracts (100 μL) were mixed with 2.5 mL of 10% Folin–Ciocalteu reagent and reacted for 5 min before 2.5 mL of 7% sodium carbonate solution was added to the mixture. The mixture was left at room temperature for one hour. The results were expressed in mg as gallic acid equivalents (GAE) per 100 g DW. The analysis was repeated three times for each sample. The amount of flavonoid compounds in gluten-free instant mushroom samples was analyzed using the method described by Bahorun et al. [25]. The antioxidant reduction of ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) was used to assess the potential radical scavenging ability of the samples. Trolox was used as a reference compound to create the calibration curve. The inhibition percentage was calculated through absorbance at 734 nm using the formula developed by Re et al. [26]. Results were expressed as milligrams of rutin equivalents (RU)/100 g on dry weight basis.

2.2.6. Determination of Physical Properties

The pH levels of the gluten-free mushroom soup samples were determined using a calibrated pH meter (Beckman 3550; Beckman Instruments Inc., Fullerton, CA, USA), following the method described in AOAC [21]. The rehydration ratio test for preparing the samples was carried out as per Krokida and Marinos-Kouris’s method [27]. To rehydrate the dehydrated samples, they were immersed in a boiled water bath and agitated at a constant speed of 100 rpm. After 15 min, the samples were removed from the bath, blotted with tissue paper to remove any excess solution, and weighed. A vacuum oven was used to determine the water content of the samples during the dehydration and rehydration procedures and calculated as follows: Rehydration ratio: The weight of the rehydrated sample (g)/The weight of the dehydrated sample (g). The total soluble solids (%) was determined according to AOAC [21]. The prepared soup samples’ color was measured and calibrated using a white reference tile to determine the L* (Lightness), a* (Redness), and b* (Yellowness) values with a colorimeter (CR-400, Konica Minolta, Inc., Osaka, Japan), following the method described by Yam and Papadakis [28].

2.2.7. Sensory Evaluation

The procedure involved dissolving 25 g of each dried soup sample in 250 mL of boiling water at 100 ± 3 °C and rehydrating it for 3 min. The sensory assessment was carried out according to the method described by Dhiman et al. [29]. Twenty members from the Food Technology and Nutrition Division at the National Research Centre in Cairo, Egypt, including eight women and twelve men, evaluated the samples using a 0–10-point hedonic test to assess color, taste, flavor, texture, odor, appearance, and overall acceptability. Each sample was analyzed three times, and the presentation order was randomized.

2.2.8. Statistical Analysis

One-way ANOVA followed by the Duncan test via SPSS software was used to extract results, which were expressed as mean ± standard error.

3. Results and Discussion

3.1. Chemical Composition and Nutritional Value of Gluten-Free Mushroom Soup Samples Containing RF That QSF Replaced

The proximate analysis of QSF, RF, and mushroom powder is shown in

Table 2. Proximate composition, minerals, and essential amino acids of QSF, RF, and mushroom powder used in the current study (on dry-weight basis).

Components (%)	QSF	RF	Mushroom Powder
Chemical composition g/100 g
Moisture	10.16 ± 0.10 a	11.81 ± 0.11 c	10.77 ± 0.12 b
Crude protein	16.41 ± 0.12 b	6.90 ± 0.10 a	34.59 ± 0.11 c
Fat	3.67 ± 0.11 c	0.96 ± 0.10 a	2.64 ± 0.09 b
Ash	2.07 ± 0.09 b	0.31 ± 0.03 a	2.45 ± 0.10 c
Crude Fiber	3.85 ± 0.09 b	1.13 ± 0.02 a	7.59 ± 0.11 c
Other Total Carbohydrates	74.0 ± 0.12 b	90.70 ± 0.11 c	52.73 ± 0.12 a
Minerals (mg/100 g)
Ca	134.15 ± 0.12 b	11.78 ± 0.10 a	547.51 ± 0.17 c
Mg	215.51 ± 0.14 b	59.88 ± 0.11 a	289.26 ± 0.15 c
P	397.77 ± 0.15 c	106.02 ± 0.14 a	176.13 ± 0.14 b
K	902.33 ± 0.16 c	98.16 ± 0.11 a	427.48 ± 0.16 b
Fe	5.92 ± 0.09 b	0.28 ± 0.05 a	6.88 ± 0.09 c
Cu	0.63 ± 0.05 b	0.13 ± 0.02 a	3.17 ± 0.05 c
Zn	3.07 ± 0.09 b	0.89 ± 0.05 a	5.43 ± 0.08 c
Mn	2.05 ± 0.08 b	0.80 ± 0.04 a	1.22 ± 0.07 c
Essential Amino acids (g/100 g protein)
Valine	4.60 ± 0.08 b	4.70 ± 0.09 b	3.57 ± 0.07 a
Lysine	5.70 ± 0.09 c	3.33 ± 0.07 a	3.64 ± 0.08 b
Leucine	7.68 ± 0.09 b	6.61 ± 0.06 a	8.43 ± 0.07 c
Isoleucine	4.95 ± 0.08 c	3.28 ± 0.07 a	3.45 ± 0.06 b
Threonine	4.40 ± 0.07 b	3.51 ± 0.06 a	5.78 ± 0.08 c
Methionine + Cysteine	5.77 ± 0.08 b	4.81 ± 0.07 a	6.79 ± 0.09 c
Phenylalanine + Tyrosine	6.23 ± 0.06 a	6.94 ± 0.07 b	7.03 ± 0.08 b
Histidine	3.11 ± 0.06 c	1.97 ± 0.08 a	2.09 ± 0.09 b
Total Essential Amino acids	42.44 ± 0.09 b	35.15 ± 0.07 a	40.78 ± 0.08 b

Data are presented as means ± standard error (M ± SE). Rows with different superscripts reveal significant differences (p < 0.05).

. In agreement with Saed et al. [3], mushroom powder had the highest crude protein content (34.59%), ash content (2.45%), and fiber content (7.59%). Meanwhile, QSF followed mushroom powder with 16.41, 2.07, and 3.85% for its crude protein, ash, and crude fiber contents, respectively, as shown in Table 2, but had a higher fat content (3.67%), which aligns with Cannas et al. [17]. In contrast, RF had the highest other total carbohydrates (90.70%), with the lowest protein, fat, ash, and crude fiber contents compared to QSF and mushroom powder [17].

The higher amounts of potassium (902.33 mg), phosphorus (397.77 mg), and manganese (2.05 mg) were found in QSF, while calcium (547.51 mg), magnesium (289.26 mg), iron (6.88 mg), copper (3.17 mg), and zinc (5.43 mg) were more in the mushroom powder (Table 2). Mineral levels were lower in RF, in which phosphorus (106.02 mg) was dominant, followed by potassium (98.16 mg) and magnesium (59.88 mg). The results agree with those obtained by Tang et al. [30], Ram et al. [31], and Ramos et al. [32], who reported that QSF and RF are rich in minerals such as potassium, phosphorus, and magnesium.

According to Ballester-Sánchez et al. [33], Jayaprakash et al. [34], and Ramos et al. [32], the highest levels of essential amino acids, including leucine, valine, lysine, and threonine, were predominant in QSF, RF, and mushroom powder, albeit with varying quantities. The mushroom powder contained the highest amount of leucine, with 8.43 g/100 g protein, followed by QSF, with 7.68 g/100 g protein, and RF, with 6.61 g/100 g protein. Similarly, the mushroom powder had the highest amount of threonine at 5.78 g/100 g protein, followed by QSF at 4.40 g/100 g protein and RF at 3.51 g/100 g protein. In contrast, QSF had the highest amount of lysine at 5.70 g/100 g protein, followed by mushroom powder at 3.64 g/100 g protein and RF at 3.33 g/100 g protein. Valine was found in the highest amount in RF at 4.7 g/100 g protein, followed by QSF at 4.6 g/100 g protein and mushroom powder at 3.57 g/100 g protein. Lastly, the total amount of essential amino acids was highest in QSF at 42.44 g/100 g protein and lowest in RF at 35.15 g/100 g protein, as presented in Table 2.

The chemical compositions of the gluten-free mushroom soup control with 30% RF and the samples with QSF substituted RF are shown in

Table 3. Proximate composition of gluten-free mushroom instant soup powder made with RF and the impact of substitution with QSF (on a dry-weight basis).

Nutrients (%)	Dried soups Formulation *
	Control * (30% RF)	Substitution of RF with QSF
		10% QSF	20% QSF	30% QSF
Moisture	10.84 ± 0.12 a	10.90 ± 0.10 a	10.88 ± 0.12 a	10.86 ± 0.11 a
Crude protein	21.06 ± 0.14 a	21.97 ± 0.11 ab	22.91 ± 0.13 bc	23.88 ± 0.12 c
Fat	2.49 ± 0.08 a	2.75 ± 0.09 b	3.01 ± 0.10 c	3.29 ± 0.09 d
Ash	4.23 ± 0.09 a	4.42 ± 0.11 ab	4.61 ± 0.13 bc	4.77 ± 0.12 c
Crude Fiber	4.35 ± 0.10 a	4.63 ± 0.09 b	4.92 ± 0.10 c	5.19 ± 0.09 d
Other Total Carbohydrates	67.87 ± 0.19 c	66.23 ± 0.12 bc	64.55 ± 0.12 ab	62.87 ± 0.12 a

Data are presented as means ± standard error (M ± SE). Rows with different superscripts reveal significant differences (p < 0.05). * Control: gluten-free mushroom instant soup powder containing 30% RF.

. The results indicate that adding QSF to the gluten-free mushroom instant soups significantly increased (p < 0.05) the crude protein, ash, crude fiber, and fat contents. As the levels of QSF increased, the values of crude protein, ash, crude fiber, and fat increased significantly from 21.79 to 23.88 g/100 g, 4.42 to 4.77 g/100 g, 4.63 to 5.19 g/100 g, and 2.75 to 3.29 g/100 g, respectively. In comparison, the control sample had values of 21.06, 4.23, 4.35, and 2.49 g/100 g for protein, ash, crude fiber, and fat, respectively. However, the total carbohydrate content decreased significantly (p < 0.05) from 66.23 to 62.87 g/100 g when levels of added QSF were increased from 10% to 30% instead of RF, compared to the control sample, which contains 30% of RF, with a value of 67.87 g/100 g for total carbohydrates.

The results mentioned above agree with the research conducted by Cannas et al. [17], which evaluated the impact of substituting RF with QSF in gluten-free Ladyfinger biscuits ranging from 25–100%. The study indicated a significant improvement in the nutritional value of the biscuits, as the protein, fat, and ash levels increased linearly with the substitution rate. In the same line, Yaseen [16] found that gluten-free cupcakes made with QSF had higher levels of protein, ash, fat, and fiber compared to control 1 (100% yellow corn flour) and control 2 (100% rice flour).

Table 4 lists the macro- and microelements in gluten-free mushroom instant soup samples. The study involved replacing RF, which constitutes 30% in the control sample, with QSF from 10% to 30% in the mushroom soup samples. As a result, mineral levels increased significantly by varying amounts. Potassium (K) increased from 388.03 to 549.15 mg/100 g, phosphorus (P) increased from 199.54 to 257.73 mg/100 g, magnesium (Mg) increased from 220.66 to 251.83 mg/100 g, calcium (Ca) increased from 446.43 to 471.15 mg/100 g, iron (Fe) increased from 4.36 to 5.51 mg/100 g, zinc (Zn) increased from 2.97 to 3.34 mg/100 g, manganese (Mn) increased from 0.81 to 1.08 mg/100 g, and copper (Cu) increased from 1.61 to 1.74 mg/100 g. These levels were compared to the control mushroom-RF soup sample, which contained 307.54, 170.41, 205.14, 434.26, 3.81, 2.71, 0.64, and 1.55 mg/100 g of K, P, Mg, Ca, Fe, Zn, Mn, and Cu, respectively (as shown in Table 4).

The above findings are consistent with the research of Yaseen [16] and Ávila et al. [35], who discovered higher micro- and macro-element contents in cakes prepared with various whole-grain flours like cowpea, quinoa, proso millet, chickpeas, flaxseed, corn, and white rice. By adding QSF to gluten-free cupcakes, Yaseen [16] observed a significant increase in minerals, including K, Ca, Mg, and Fe, compared to the control sample. As reported by Ávila et al. [35], replacing RF with other whole-grain flours like QSF raised minerals like iron, magnesium, and zinc with 26%, 34.2%, and 20% of the Daily Reference Intake in cake samples, making them a good source of these minerals. Mineral deficiencies are not only linked to malnutrition but also to several age-related disorders. A diet with higher levels of calcium, magnesium, potassium, and iron has been shown to reduce the risk of all-cause dementia, particularly vascular dementia, hypertension, stroke, Alzheimer’s neuropathology, cognitive decline in older adults, and anemia. Moreover, zinc has been found to improve mental health and boost immune function [36]. Consequently, based on the above analysis (Table 4), a serving of the mushroom soup samples (25 g/250 mL) containing 30% of the QSF, which completely substituted RF in the control mixture, provided 11.78, 14.99, 9.20, 2.92, 17.25, 48.33, 7.64, and 11.74% of the %DRI for Ca, Mg, P, K, Fe, Cu, Zn, and Mn, respectively, according to IMO [37].

Table 4. Mineral contents (mg/100 g) of gluten-free mushroom instant soup powder made with RF and the impact of substitution with QSF (on a dry-weight basis).

Mineral Contents (mg/100 g)		Dried Soup Formulation				IMO **
		Control * (30% RF)	Substitution of RF with QSF **
			10% QSF	20% QSF	30% QSF
Ca	DP ***	434.26 ± 0.11 a	446.43 ± 0.10 ab	458.76 ± 0.11 bc	471.15 ± 0.10 c	1000 (mg/d)
	N.S.S	108.56	111.61	114.69	117.79
	%DRI	10.85	11.16	11.46	11.78
Mg	DP	205.14 ± 0.09 a	220.66 ± 0.08 b	236.30 ± 0.09 c	251.83 ± 0.08 d	420 (mg/d)
	N.S.S	51.28	55.17	59.08	62.96
	%DRI	12.20	13.14	14.06	14.99
P	DP	170.41 ± 0.07 a	199.54 ± 0.08 b	228.61 ± 0.06 c	257.73 ± 0.07 d	700 (mg/d)
	N.S.S	42.60	49.89	57.15	64.43
	%DRI	6.08	7.13	8.16	9.20
K	DP	307.54 ± 0.10 a	388.03 ± 0.11 b	468.51 ± 0.12 c	549.15 ± 0.11 d	4700 (mg/d)
	N.S.S	76.88	97.01	117.13	137.29
	%DRI	1.63	2.06	2.49	2.92
Fe	DP	3.81 ± 0.09 a	4.36 ± 0.12 b	4.90 ± 0.11 c	5.51 ± 0.11 d	8 (mg/d)
	N.S.S	0.95	1.09	1.23	1.38
	%DRI	11.87	13.63	15.38	17.25
Cu	DP	1.55 ± 0.09 a	1.61 ± 0.08 ab	1.67 ± 0.11 bc	1.74 ± 0.09 c	0.90 (mg/d)
	N.S.S	0.387	0.403	0.417	0.435
	%DRI	43.0	44.77	46.33	48.33
Zn	DP*	2.71 ± 0.09 a	2.97 ± 0.11 b	3.15 ± 0.09 c	3.34 ± 0.11 d	11 (mg/d)
	N.S.S	0.67	0.74	0.79	0.84
	%DRI	6.09	6.72	7.18	7.64
Mn	DP	0.64 ± 0.04 a	0.81 ± 0.05 b	0.97 ± 0.04 c	1.08 ± 0.05 d	2.3 (mg/d)
	N.S.S	0.160	0.202	0.243	0.270
	%DRI	6.95	8.78	10.56	11.74

Data are presented as means ± standard error (M ± SE). Rows with different superscripts reveal significant differences (p < 0.05). * Control: gluten-free mushroom instant soup powder containing 30% RF. ** IMO: Institute of Medicine of the National Academies [37]. *** DP: Dried Powder (g/100 g); N.S.S: Normal serving size (25 g/250 mL water); and %DRI: Daily Requirement intake for normal serving size compared with IMO.

Table 4. Mineral contents (mg/100 g) of gluten-free mushroom instant soup powder made with RF and the impact of substitution with QSF (on a dry-weight basis).

Mineral Contents (mg/100 g)		Dried Soup Formulation				IMO **
		Control * (30% RF)	Substitution of RF with QSF **
			10% QSF	20% QSF	30% QSF
Ca	DP ***	434.26 ± 0.11 a	446.43 ± 0.10 ab	458.76 ± 0.11 bc	471.15 ± 0.10 c	1000 (mg/d)
	N.S.S	108.56	111.61	114.69	117.79
	%DRI	10.85	11.16	11.46	11.78
Mg	DP	205.14 ± 0.09 a	220.66 ± 0.08 b	236.30 ± 0.09 c	251.83 ± 0.08 d	420 (mg/d)
	N.S.S	51.28	55.17	59.08	62.96
	%DRI	12.20	13.14	14.06	14.99
P	DP	170.41 ± 0.07 a	199.54 ± 0.08 b	228.61 ± 0.06 c	257.73 ± 0.07 d	700 (mg/d)
	N.S.S	42.60	49.89	57.15	64.43
	%DRI	6.08	7.13	8.16	9.20
K	DP	307.54 ± 0.10 a	388.03 ± 0.11 b	468.51 ± 0.12 c	549.15 ± 0.11 d	4700 (mg/d)
	N.S.S	76.88	97.01	117.13	137.29
	%DRI	1.63	2.06	2.49	2.92
Fe	DP	3.81 ± 0.09 a	4.36 ± 0.12 b	4.90 ± 0.11 c	5.51 ± 0.11 d	8 (mg/d)
	N.S.S	0.95	1.09	1.23	1.38
	%DRI	11.87	13.63	15.38	17.25
Cu	DP	1.55 ± 0.09 a	1.61 ± 0.08 ab	1.67 ± 0.11 bc	1.74 ± 0.09 c	0.90 (mg/d)
	N.S.S	0.387	0.403	0.417	0.435
	%DRI	43.0	44.77	46.33	48.33
Zn	DP*	2.71 ± 0.09 a	2.97 ± 0.11 b	3.15 ± 0.09 c	3.34 ± 0.11 d	11 (mg/d)
	N.S.S	0.67	0.74	0.79	0.84
	%DRI	6.09	6.72	7.18	7.64
Mn	DP	0.64 ± 0.04 a	0.81 ± 0.05 b	0.97 ± 0.04 c	1.08 ± 0.05 d	2.3 (mg/d)
	N.S.S	0.160	0.202	0.243	0.270
	%DRI	6.95	8.78	10.56	11.74

Data are presented as means ± standard error (M ± SE). Rows with different superscripts reveal significant differences (p < 0.05). * Control: gluten-free mushroom instant soup powder containing 30% RF. ** IMO: Institute of Medicine of the National Academies [37]. *** DP: Dried Powder (g/100 g); N.S.S: Normal serving size (25 g/250 mL water); and %DRI: Daily Requirement intake for normal serving size compared with IMO.

Table 5. Essential amino acids (g/100 g protein) of gluten-free mushroom instant soup powder made with RF and the impact of substitution with QSF.

Essential Amino Acids (g/100 g Protein)	Dried Soup Formulation				FAO [23]
	Control * (30% RF)	Substitution of RF with QSF
		10% QSF	20% QSF	30% QSF
Valine	3.76 ± 0.02 a	3.89 ± 0.03 ab	4.01 ± 0.02 bc	4.10 ± 0.02 c	3.88
Lysine	5.40 ± 0.02 a	5.64 ± 0.02 b	5.86 ± 0.03 c	6.09 ± 0.03 d	5.50
Leucine	7.03 ± 0.03 a	7.08 ± 0.03 a	7.13 ± 0.03 a	7.19 ± 0.03 a	7.00
Isoleucine	3.94 ± 0.02 a	4.12 ± 0.03 ab	4.29 ± 0.02 bc	4.46 ± 0.02 c	4.00
Threonine	4.78 ± 0.03 a	4.83 ± 0.03 a	4.89 ± 0.02 a	4.93 ± 0.02 a	4.00
Methionine + Cysteine	5.47 ± 0.02 a	5.50 ± 0.02 a	5.52 ± 0.02 a	5.56 ± 0.02 a	3.50
Phenylalanine + Tyrosine	6.86 ± 0.02 a	6.91 ± 0.03 a	6.96 ± 0.03 a	6.99 ± 0.03 a	6.80
Histidine	1.85 ± 0.01 a	1.89 ± 0.02 a	1.95 ± 0.02 a	1.99 ± 0.02 a	1.90
Total Essential Amino acids	39.09	39.86	40.61	41.31	36.58
Amino acid Score (%)	106.86	108.97	111.02	112.93	100%

Data are presented as means ± standard error (M ± SE). Rows with different superscripts reveal significant differences (p < 0.05). * Control: gluten-free mushroom instant soup powder containing 30% RF.

shows the essential amino acid levels of the gluten-free instant mushroom-RF soup control and samples that contained varying amounts of QSF replacing RF. Substituting RF with QSF significantly increased some of the essential amino acid content in gluten-free soups: valine, lysine, and isoleucine. Samples with complete substitution of RF with QSF had the highest essential amino acid content. Leucine (7.19 g/100 g protein), lysine (6.09 g/100 g protein), and the aromatic amino acid phenylalanine and tyrosine mixture (6.99 g/100 g protein) were the most abundant amino acids present in the samples. These findings suggest that the dried gluten-free soup samples containing QSF could be a viable alternative to RF.

Brito et al. [38] developed gluten-free QSF-based cookies and described them as a good source of essential amino acids, including valine, methionine, isoleucine, threonine, and phenylalanine, which agreed with the findings of the current study. Essential amino acid supplements can regulate metabolism and energy balance by affecting peripheral tissues like muscles, adipose tissue, and the liver. Furthermore, essential amino acid supplementation can promote mitochondria biogenesis in cardiac and skeletal muscles, prevent oxidative damage, enhance muscle protein synthesis and physical endurance, reduce body weight, and increase immune function. These effects have improved health span and metabolic health [39]. In the same way, the amino acid score (%) in the prepared gluten-free mushroom-QSF soup samples was increased by the complete substitution of RF with QSF (112.93%) as compared with the control soup sample (106.86%). Protein quality is evaluated by the amino acid score, which assesses the capacity of a diet to meet the metabolic demand for amino acids and nitrogen [23].

3.2. Antioxidant Activity of the Gluten-Free Mushroom Soup Samples Containing QSF Replacing RF

The total polyphenol, flavonoid, and antioxidant activities of the gluten-free instant soup samples were determined and are listed in

Table 6. Total polyphenols, total flavonoids, and radical scavenging activity (mg/100 g) of gluten-free mushroom instant soup powder made with RF and the impact of substitution with QSF.

Parameters	QSF	RF	Dried Soups Formulation
			Control * (30% RF)	Substitution of RF with QSF
				10% QSF	20% QSF	30% QSF
Total polyphenols (mg/100 g)	159.75 ± 0.21 B	44.30 ± 0.16 A	32.77 ± 0.33 a	44.31 ± 0.30 b	55.76 ± 0.29 c	67.16 ± 0.30 d
Total flavonoids (mg/100 g)	28.44 ± 0.16 B	5.20 ± 0.10 A	8.93 ± 0.20 a	11.24 ± 0.19 b	13.55 ± 0.21 c	15.87 ± 0.20 d
Radical Scavenging Activity (mg Trolox/100 g sample)	297.03 ± 0.22 B	98.44 ± 0.13 A	100.13 ± 0.21 a	114.89 ± 0.20 b	129.64 ± 0.22 c	144.34 ± 0.23 d

Data are presented as means ± standard error (M ± SE). Rows with different superscripts reveal significant differences (p < 0.05). Capital superscript letters represent significant differences in raw materials. * Control: gluten-free mushroom instant soup powder containing 30% RF.

. According to the obtained results, that containing QSF showed the highest amounts of total polyphenols and flavonoids (159.75 and 28.44 mg/100 g), followed by mushroom powder (81.84 and 6.11 mg/100 g), while RF had the least amounts (44.30 and 5.20 mg/100 g), as shown in Table 6. Notably, phenolic compounds contribute directly to antioxidant activity; consequently, the radical scavenging activity determined by the reduction of ABTS due to the antioxidant activity of the raw materials studied showed a higher scavenging activity for QSF (297.03 mg Trolox/100 g), followed by mushroom powder (119.44 mg Trolox/100 g) and RF was the minimum (98.44 mg Trolox/100 g). According to Jagadish et al. [40], the antioxidant activity of ethanolic extracts of raw and boiled A. bisporus determined by ABTS and DPPH assays was due to the amounts of total flavonoid components (16.4 and 15.2 mg/g quercetin equivalent) and phenolics (90.2 and 70.6 µg/mg pyrocatechol equivalent). Despite the antioxidant activity being proved by chemical and biochemical assays, Barros et al. [41] found the total phenolics and flavonoids for A. bisporus as 4.49 and 1.73 mg/g. Cannas et al. [17] showed higher polyphenol and flavonoid amounts for QSF (464 mg GAE/100 and 39.1 mg CE/100 g) compared to RF (40 mg GAE/100 and 0.9 mg CE/100 g), which affected the antioxidant activity performed by DPPH assay and detected as 53.5% for QSF and 26.3% for RF. Differences in polyphenol and flavonoid concentrations between this study’s raw materials and those in the literature may be due to genetic and agronomic factors like plant type, variety, climate, farming techniques, storage, maturity, and other factors [42].

According to Table 6, the total phenolic acid content values increased significantly (p < 0.05) from 44.31 to 67.13 mg/100 g when QSF was added to instant dry non-gluten mushroom soup instead of RF, compared to the control, which had 32.77 mg/100 g. Similarly, QSF raised the total flavonoid content from 11.24 to 15.87 mg/100 g compared to the control (8.93 mg/100 g). Coinciding with previous findings, the radical scavenging activity was the highest for the gluten-free mushroom soup with the total substitution of RF with QSF (144.34 mg Trolox/100 g), while the control sample with 30% RF had the lowest activity (100.13 mg Trolox/100 g). Previous findings align with the study of Cannas et al. [17], indicating that substituting with QSF significantly improves the polyphenol profile of biscuits. Total phenolic and flavonoid levels show a linear increase (p < 0.05) with the degree of substitution, resulting in a four-fold increase compared to the control biscuits.

3.3. Physical Properties of the Gluten-Free Mushroom Soup Samples Containing QSF Replacing RF

The physical properties of non-gluten instant mushroom soup samples supplemented with QSF to replace RF are provided in

Table 7. Physical properties of gluten-free mushroom instant soup powder made with RF and the impact of substitution with QSF.

Physical Properties	QSF	RF		Dried Soup Formulation
			Control * (30% RF)	Substitution of RF with QSF
				10% QSF	20% QSF	30% QSF
pH Value	6.89 ± 0.10 A	6.97 ± 0.09	6.92 ± 0.09 a	6.90 ± 0.08 a	6.87 ± 0.07 a	6.85 ± 0.09 a
Rehydration Ratio (g)	5.11 ± 0.20 B	2.32 ± 0.10 A	4.03 ± 0.23 a	4.17 ± 0.26 ab	4.27 ± 0.19 bc	4.40 ± 0.25 c
Total Soluble Solids (%)	29.98 ± 0.28 B	10.21 ± 0.14 A	15.23 ± 0.31 a	15.71 ± 0.31 b	16.09 ± 0.28 bc	16.41 ± 0.32 c
L*	70.33 ± 0.25 A	86.17 ± 0.22 B	75.03 ± 0.20 a	74.68 ± 0.19 a	74.30 ± 0.18 a	73.97 ± 0.20 a
a*	4.09 ± 0.19 B	2.73 ± 0.11 A	3.22 ± 0.16 a	3.45 ± 0.15 a	3.62 ± 0.15 ab	3.71 ± 0.17 bc
b*	25.58 ± 0.21 B	12.30 ± 0.12A	20.75 ± 0.19 a	21.87 ± 0.16 ab	22.08 ± 0.17 b	22.32 ± 0.15 bc

Data are presented as means ± standard error (M ± SE). Rows with different superscripts reveal significant differences (p < 0.05). Capital superscript letters represent significant differences in raw materials. * Control: gluten-free mushroom instant soup powder containing 30% RF.

. The pH values for the examined soup samples containing QSF were not significantly different (p < 0.05) from that of the control sample. However, adding QSF significantly increased all other physical parameters investigated in this study, as shown in Table 7. For example, the total substitution of RF with QSF increased the rehydration ratio from 4.07 to 4.4 g and the total soluble solids from 15.23 to 16.41%. Also, a reduction in L* with an increase in the a* and b* color parameters was observed.

In addition to proteins, dietary fibers improve water absorption and food texture. The rehydration behavior of the food significantly improved after adding QSF from 4.03 to 4.40 g, indicating that the material had degraded due to drying, as shown in Table 7. Despite the positive effect of QSF on the rehydration ratio of the formulated soup samples under investigation, Miranda et al. [43] reported that the drying operation reduced proteins by 10%, fat by 12%, and fibers and ashes by 27%. The ability to reconstitute a food product depends on its internal structure and the extent of damage to its water-holding elements, like fibers and proteins, during drying. The damage can result in reduced water diffusion, and products with higher rehydration ratios indicate minimal changes to protein and fiber structures [44]. The results of the current study show a better rehydration ratio than instant mushroom soup in samples in which wheat flour was substituted by Jerusalem artichoke and Cauliflower [3].

QSF contains various components such as starch, protein, dietary fiber, minerals, and solubilized phenolics. In addition to starch, the dissolved protein can also affect the solubility of QSF. The solubility of QSF decreases with an increase in temperature from approximately 17.5% at 60 °C to about 8% at 95 °C, as Solaesa et al. [45] reported. This could be due to the denaturation of dissolved proteins, such as albumins (~64 °C) and globulins (~94 °C), as explained by Li and Zhu [46]. Both proteins were solubilized at 60 °C, the exact drying temperature used in the current study. Therefore, the solubility of QSF was found to be the highest at this temperature [45].

The addition of QSF (10–30%) significantly affected the color coordinates (L*, a*, and b*) of the supplemented gluten-free instant soup samples, as shown in Table 7. Both color parameters a* (3.45–3.71) and b* (21.87–22.32) showed a significant increase, indicating an increase in redness and yellowness compared to the control sample (3.22 and 20.75). However, no significant differences in the L* values corresponded to lightness among the examined samples (Table 7). The increase in a* and b* was due to the high protein contents and sugars characterizing the QSF, which initiate nonenzymatic browning. The previous findings agreed with Baraket et al. [47], who replaced wheat flour in instant noodles with QSF (10-30%) and found a significant decrease in the L* value with a substantial increase in both a* and b* values compared to the control. The color parameters a* and b* observed in this study for QSF were higher than those reported by Solaesa et al. [45] for their quinoa samples, which may be attributed to differences in the variety and cultivation conditions used in both works.

3.4. Sensory Evaluation of the Gluten-Free Mushroom Soup Samples Containing CSF Replacing

Table 8. Sensory properties of the gluten-free mushroom soup samples containing QSF replacing RF.

Sensory Properties	Dried Soup Formulation
	Control * (30% RF)	Substitution of RF with QSF
		10% QSF	20% QSF	30% QSF
Color	8.09 ± 0.33 a	8.01 ± 0.35 a	7.86 ± 0.33 a	7.70 ± 0.30 a
Taste	8.12 ± 0.30 a	8.0 ± 0.29 a	7.82 ± 0.28 a	7.72 ± 0.31 a
Odor	7.80 ± 0.29 a	7.91 ± 0.25 a	8.0 ± 0.33 a	8.11 ± 0.27 a
Flavor	7.79 ± 0.31 a	8.04 ± 0.35 a	8.11 ± 0.29 a	8.16 ± 0.28 a
Texture	7.60 ± 0.30 a	7.75 ± 0.26 ab	7.90 ± 0.33 ab	8.13 ± 0.27 b
Appearance	7.67 ± 0.33 a	7.84 ± 0.35 a	7.91 ± 0.33 a	8.03 ± 0.29 a
Overall acceptability	7.85 ± 0.30 a	7.92 ± 0.33 a	7.94 ± 0.29 a	7.98 ± 0.27 a

Data are presented as means ± standard error (M ± SE). Rows with different superscripts reveal significant differences (p < 0.05). * Control: gluten-free mushroom instant soup powder containing 30% RF.

presents the results of the organoleptic evaluation of all the gluten-free mushroom soup samples that were prepared. Except for the texture, no significant differences were observed concerning the sensory attributes of the examined samples. The soup sample with complete substitution of RF with QSF received the highest score for odor, flavor, texture, appearance, and overall acceptability—8.11, 8.16, 8.13, 8.03, and 7.98, respectively—compared to the control sample, which received scores of 7.80, 7.79, 7.60, 7.67, and 7.85, respectively (Table 8). It is worth noting that the earlier results indicate a significant rise (p < 0.05) in the rehydration ratio (g), total soluble solids (%), as well as a* and b* values of the mushroom soup sample enriched with 30% QSF. In agreement with the above results, Barakat et al. [47] conducted a sensory evaluation of wheat noodles fortified with QSF, and their findings showed that the addition of either colored or non-colored QSF in low levels (up to 30%) could be used to manufacture wheat–quinoa noodles of acceptable quality. The results of the sensory research showed that quinoa-based noodles were generally well-liked and had several flavor and taste characteristics that were superior to wheat flour-based noodles.

4. Conclusions

Improving nutritional and sensory qualities in gluten-free foods is crucial to their development. Therefore, the current study evaluated the impact of substituting RF with QSF on mushroom instant dry soup’s nutritional, physicochemical, and sensory qualities. The replacement of RF with QSF, partially or entirely, improved various parameters, including protein, fat, ash, total phenolics, flavonoids, and antioxidant activity. Additionally, the contents of macro- and microelements and essential amino acids showed a significant increase with the substitution of RF with QSF at any ratio. This is the first study to evaluate the effects of such substitution on mushroom instant dry soup. Physical properties such as the rehydration ratio and total soluble solids were improved by increasing QSF supplementation rates. The sensory results revealed that the maximum substitution rate of QSF showed the highest consumer acceptability. The findings of the present study indicate the potential for QSF to improve the nutritional quality and organoleptic characteristics of gluten-free food products like mushroom instant dry soup.