RUNNING TITLE: GLUTEN-FREE BISCUIT FOR AUTISM CHILDREN GLUTEN-FREE BISCUIT FOR CHILDREN WITH AUTISM SPECTRUM DISORDER MADE FROM MODIFIED TARO FLOUR AND COCONUT PULP FLOUR

Hamka^1*, Farida Aryani², Silvia Darmans³, Rindawati⁴, Dicky Aditya Warman⁵

Politeknik Pertanian Negeri Samarinda, Samarinda, Indonesia

[email protected]^*, [email protected], [email protected], [email protected], [email protected]

ABSTRACT

Autism spectrum disorder (ASD) is common in children, many of whom require a gluten-free diet. This study explored gluten-free biscuits made with modified taro flour and coconut pulp flour, which are rich in carbohydrates, fats, fiber, and protein. The goal was to assess the physical, sensory, and chemical properties of biscuits made with different ratios of these flours. The research used four formulations of taro flour to coconut pulp flour: P0 (100:0), P1 (70:30), P2 (50:50), and P3 (30:70), with five replications. Data were analyzed using ANOVA and the Duncan Multiple Range Test (DMRT) at a 5% significance level. Results showed that the P2 (50:50) formulation produced the heaviest biscuits (5.32g) and scored highest in color (3.82) and taste (3.78) in sensory tests. The P3 (30:70) formulation was rated best for aroma (3.56) and texture (3.82). Chemical analysis revealed that P0 (100:0) had the highest water (1.85%), ash (2.22%), and carbohydrate content (61.32%). The P2 (50:50) formulation had the highest protein content (4.42%), while P3 (30:70) had the most fat (49.03%) and fiber (7.96%). This study concluded that modified taro flour and coconut pulp flour are effective in creating nutritious, gluten-free biscuits, offering a suitable alternative for children with ASD.

Keywords: autism spectrum disorder, coconut pulp flour, gluten-free biscuits, modified taro flour

Corresponding Author: Hamka

E-mail: [email protected]

INTRODUCTION

Autism Spectrum Disorder (ASD) or autism is a symptom of neurodevelopmental delay that can affect the person to interact, communicate, and usually behave in the environment (Sampaio et al., 2022). It is characterized by alterations in social interaction, cognitive function, oral communication, social-emotional interaction, and intellectual impairment, as well as problems in motor function and learning and obsessive-repetitive repetitive behaviors that begin in childhood and persist (Valenzuela-Zamora et al., 2022). To date, there is no recommended medication to treat the main symptoms of ASD disorder (Stepanova et al., 2017). Children with ASD disorder's food choices require specific and selective food preferences. They may only eat certain food types or need help trying new foods. Children with ASD are in dire need of nutritional intake along with proper parenting for growth. Children with ASD are highly incompatible with foods made from wheat flour (Kohli et al., 2023) and dairy products. Hence, a gluten-free diet is necessary to improve nutritional intake and good quality of life (Hodges et al., 2020), delaying and stopping degenerative processes. However, the risk that will arise when ASD children apply this diet pattern will experience calcium deficiency, which results in symptoms of rickets in the bones and weakening of muscle nerve function.

Children with Autism Spectrum Disorder (ASD) often have unique and complex nutritional needs due to selective eating habits and sensitivities, particularly to gluten, which is found in wheat products. These children may suffer from gastrointestinal disorders and behavioral issues linked to gluten consumption, necessitating a gluten-free diet to improve their overall health and quality of life. However, many gluten-free foods lack essential nutrients, particularly fiber, protein, and healthy fats, which are crucial for growth and development in children with ASD. This research addresses the gap by developing gluten-free biscuits formulated from modified taro flour and coconut pulp flour, both of which are nutrient-dense and suitable for gluten-free diets. While previous studies have focused on gluten-free alternatives, there has been limited exploration of how these specific flours can meet the nutritional needs of children with ASD.

One of the efforts to implement a gluten-free diet for children with ASD is to process food products or snacks in the form of gluten-free biscuit products. Biscuits are edible baked goods that generally contain flour (Owheruo et al., 2023). Biscuits are a universal snack; most people like biscuits because they have a long shelf life, are easy to carry, are liked by babies, children, and even adults, and have a variety of flavors (Olaimat et al., 2023; Roger et al., 2022).

One alternative food ingredient that can be processed into gluten-free biscuits is the formulation of modified taro flour combined with coconut pulp flour. Modified taro flour has a high nutritional content, is gluten-free, rich in carbohydrates and fiber (Ali, 2023), and is helpful for the health of the body. Similarly, coconut pulp flour has a high fiber content (Azis & Akolo, 2018) because it contains high cellulose, low carbohydrates, trans-free fatty acids, does not contain gluten, and gives a savory taste, so it is perfect for health and is suitable for making as an additional ingredient in biscuit making (Adeloye et al., 2020). Modified taro flour formulated with coconut pulp flour can be used as a raw material substitute for wheat flour when making gluten-free biscuits.

This study analyzed the proximate ingredients of modified taro flour, coconut pulp flour, and gluten-free biscuits, their physical characteristics, and sensory testing of gluten-free biscuits made from modified taro flour formulated with coconut pulp flour according to the specified treatment.

METHODS

The biscuit formulation was modified to the method described (El-Sharnouby et al., 2012). The biscuit ingredients, namely modified taro flour and coconut pulp flour, were added with margarine, sugar, eggs, baking powder, and vanilla and mixed using a hand mixer (Philips HR 2874 model) for 15 minutes at the highest speed until the mixture became thick. The biscuit formulation can be seen in Table 1. The percentage of the main components is as follows: 37% taro flour and coconut pulp flour (according to the ratio per treatment), 37% margarine, 18% sugar, and 5.6% chicken egg yolk. Other ingredients were added at the following rates: 0.75% baking powder and 0.37% vanilla powder. This recipe was optimized based on preliminary experiments to evaluate the sensory properties of the developed biscuits.

Biscuit processing was carried out at the Plantation Product Processing Laboratory of Samarinda State Agricultural Polytechnic. The procedures to produce various biscuit formulations are as follows: 100 g butter and 50 g sugar were mixed using a hand mixer for 15 minutes until the mixture was homogeneous, then 15 g egg yolk was added and mixed for 3 minutes. The following ingredients were added: 30-100 g of modified taro flour (according to treatment) and 30-70 g of coconut pulp flour (according to treatment). After adding modified taro flour and coconut pulp flour in the dough, baking powder of 2 g and vanilla powder of 1 g were added. All the ingredients were mixed using a hand mixer for 12 minutes until a homogeneous dough was obtained, then the dough was molded uniformly according to the size and weight of the ingredients; each molded ingredient weighed 25 g and was baked in an oven (Memmert UN55 model) at 150°C for 20 minutes. After baking, the biscuits were cooled to room temperature and packaged using airtight jars.

Table 1. Composition of gluten-free biscuits for children with autism spectrum disorder from modified taro flour formulated with coconut pulp flour.

Formulation	Modified taro flour (g)	Coconut pulp flour (g)	Margarine (g)	Sugar (g)	Vanilla powder (g)	Baking powder (g)	Egg yolk (g)
P0 (100:0)	100	0	100	50	1	2	15
P1 (70:30)	70	30	100	50	1	2	15
P2 (50:50)	50	50	100	50	1	2	15
P3 (30:70)	30	70	100	50	1	2	15

Proximate testing on the raw materials of modified taro flour and coconut pulp flour, as well as gluten-free biscuits from modified taro flour formulated with coconut pulp flour, was conducted at the Agricultural Instrument Standardization Testing Laboratory, P.M. Noor Street, North Samarinda District using the standard procedures of the Association of Official Agricultural Chemists (A.O.A.C., 2019).

The proximate analysis was conducted to determine the moisture, ash, protein, fat, fiber, and carbohydrate content of the modified taro flour, coconut pulp flour, and the resulting gluten-free biscuits. These tests followed standard procedures from the Association of Official Agricultural Chemists (AOAC, 2019) at the Agricultural Instrument Standardization Testing Laboratory, Samarinda. In parallel, sensory testing was conducted to evaluate the physical and sensory attributes of the gluten-free biscuits, including color, aroma, texture, and taste. A panel of 25 individuals, aged between 20 and 45, with previous experience in evaluating food products and no known food allergies, was selected for this purpose. The panelists were familiar with biscuit products and included nutritionists, food technologists, and parents of children with Autism Spectrum Disorder (ASD), making their input particularly valuable. The inclusion of parents of children with ASD was crucial, as they could provide insight into the suitability of the biscuits for children with selective eating habits typical of ASD.

The sensory evaluation was done using a 5-point hedonic scale, where one indicated "strongly disliked" and five indicated "strongly preferred." This testing aimed to ensure that the gluten-free biscuits would meet nutritional requirements and be acceptable in terms of sensory appeal, which is often a critical factor for children with ASD, who may have heightened sensitivities to certain textures and flavors.

By including this group of panelists, the study ensured that the biscuits were evaluated with an understanding of the sensory challenges faced by children with ASD, making the results more relevant and applicable to their unique dietary needs. Moisture content is the amount of water in an ingredient or food product. Its purpose is to determine the shelf-life quality, texture, structure, and flavor of food ingredients or products. Ash content is the inorganic residue from the combustion or oxidation process of an ingredient or food product's organic components. Ash content testing aims to show the purity, mineral content, and cleanliness of the food produced and to evaluate the nutritional value and total toxic minerals contained in an ingredient or food product (separating organic and inorganic materials).

The crude protein content test, determined using the Kjeldahl method, measures both digestible and indigestible proteins in an ingredient or food product. This test is essential for assessing the nutritional value by determining the overall protein content. The fat content test, performed using the Soxhlet method, evaluates the amount of fat present in an ingredient or food product. This test helps determine the caloric quality of the food, contributing to the overall nutritional analysis.

Using the gravimetric method, the crude fiber content test measures the indigestible portion of an ingredient or food product. This test aims to assess the nutritional content, specifically focusing on the fiber that the human body cannot digest.

The carbohydrate content test, calculated by difference, determines the amount of carbohydrates in the form of polymeric compounds within food ingredients or products. Carbohydrates serve as a primary source of calories and are a significant part of the food's nutritional profile. Lastly, the physical characteristics of biscuit samples were analyzed at the Plantation Product Processing Laboratory of the Samarinda State Agricultural Polytechnic. These tests were conducted in accordance with the guidelines established by the Association of Official Agricultural Chemists, ensuring standardized and reliable results (A.O.A.C., 2019). The parameters observed in the physical characteristics of biscuits are as follows:

The thickness of the biscuits was measured by placing them vertically and then measuring the thickness using a Micro Digital Caliper. The average measurement result became the biscuit thickness count (mm). The diameter of the biscuits was measured by placing the biscuits horizontally and then measuring the diameter using a Micro Digital Caliper tool. The average measurement result became the biscuit diameter count (mm). The biscuit width ratio measurement was calculated by dividing the average biscuit diameter by the average biscuit thickness (mm). The average weight of biscuits was measured by weighing the biscuit samples using a digital analytical balance (mm).

Sensory testing aims to determine the quality of ingredients or food products using human senses. This study used 25 panelists who were familiar with biscuits and did not have food allergies. Before testing, panelists were given information about the purpose of the study, and panelists were asked to sign a written consent form (Pasqualone et al., 2020). The sensory testing was based on product characteristics, including color, aroma, texture and taste, and overall acceptability, measured using a 5-point descriptive hedonic scale with a value of 5 representing "strongly preferred" and the lowest value of 1 representing "strongly disliked."

The STATCAL Statistical Package was used to analyze the data. A one-way analysis of variance (ANOVA) test was used to test for differences between treatments. Mean separation was performed using the DMRT (Duncan Multiple Range Test) test. Results with P values less than 0.05 were considered statistically significant.

RESULTS AND DISCUSSIONS

The table shows the proximate analysis results on modified taro flour, coconut pulp flour, and gluten-free biscuit formulations.

Table 2. Proximate analysis of modified taro flour, coconut pulp flour, and gluten-free biscuit formulation for children with Autism Spectrum Disorder.

Raw materials	Moisture (%)	Ash (%)	Protein (%)	Fat (%)	Fiber (%)	Carbohydrate (%)
Modified taro flour	7,47	2,37	4,87	0,41	1,20	84,88
Coconut pulp flour	2,99	1,57	5,54	49,07	24,63	40,83
Formulation
P0 (100:0)	1,85±0,49^a	2,22±0,05^a	3,96±0,21^a	30,65±1,93^a	3,25±0,38^a	61,32±2,22^d
P1 (70:30)	1,81±0,25^a	2,01±0,42^a	4,30±0,14^a	38,38±0,78^b	4,99±0,81^b	53,50±0,64^c
P2 (50:50)	1,77±0,25^a	1,95±0,37^a	4,42±1,10^a	43,97±1,17^c	6,58±0,64^c	47,90±2,40^b
P3 (30:70)	1,58±0,25^a	1,78±0,08^a	4,03±0,42^a	49,03±2,98^d	7,96±0,70^d	43,38±3,44^a

Description:

P0 (100:0) = Comparison of taro flour (100g) with coconut pulp flour (0g)

P1 (70:30) = Comparison of taro flour (70g) with coconut pulp flour (30g)

P2 (50:50) = Comparison of taro flour (50g) with coconut pulp flour (50g)

P3 (30:70) = Comparison of taro flour (30g) with coconut pulp flour (70g)

Values are the mean of three replicates ± SD.

Proximate test data in the same row followed by the same letter indicate not significantly different (DMRT test α 5%). The results of the proximate analysis of modified raw materials for taro flour and coconut pulp flour are in Table 2. The moisture and ash content of modified taro flour were higher than those of coconut pulp flour, with values of 7.47% and 2.37% of dry weight, respectively. The protein content of modified taro flour and coconut pulp flour, namely 4.87% and 5.54%, is in the low protein content category when com to the protein content of other types of flour. Coconut pulp flour has a higher fat content value of 49.07% than modified taro flour at 0.41%. Similarly, the fiber value of coconut pulp flour is higher at 49.67%. At the same time, the value of the fiber content of modified taro flour was 1.20%. The nutritional value of carbohydrates in taro flour is very high at 84.88%, twice the value of coconut pulp flour, which is only 40.43%.

(a)

(b)

(c)

Figure 1.

(a) Modified taro flour, (b) coconut pulp flour, and (c) gluten-free biscuits made from taro flour formulated with coconut pulp flour.

Table 2 shows the moisture content of gluten-free biscuits made from modified taro flour with a coconut pulp flour formulation. Treatment P0 obtained the highest moisture content compared to other treatments, with a moisture content value of 1.85%. The highest ash content in preparing gluten-free biscuits was in the P0 treatment. The high ash content of taro flour mixed with desiccated coconut biscuits is due to the high ash content of taro. Gluten-free biscuits in treatment P2 with a ratio of 50 g taro flour formulated with 50 g coconut pulp flour showed the highest protein content of 4.42% compared to other treatments in the preparation of gluten-free biscuits made from taro flour and coconut pulp flour. Table 2 shows that the protein content of taro flour and coconut pulp flour is almost the same, namely 4.87% and 5.54%.

The fat content of gluten-free biscuits from modified taro flour formulated with coconut pulp flour, based on Table 2, showed the highest fat content value of 49.03% in treatment P3 compared to others. This is because the amount of coconut pulp flour added is more than taro flour, so the fat content shows the highest value. Based on Table 2, it can be seen that the essential ingredient composition of coconut pulp flour shows a high-fat content of 49.07% compared to taro flour, which only has a fat content of 0.41%.

Based on Table 2, the fiber content of gluten-free biscuits showed the highest result in treatment P3, 7.96%, compared to other treatments. The carbohydrate content of biscuits is based on Table 2. The carbohydrate content of gluten-free biscuits made from taro flour formulated with coconut pulp flour showed the highest value of 61.32% in treatment P0 (100:0) compared to other treatments.

The physical characteristics of gluten-free biscuits from modified taro flour formulated with coconut pulp flour according to the treatments from the test parameters of diameter, thickness, spread ratio, and weight are presented in Table 3. The results showed that the diameter, thickness, ratio, and weight of the biscuits from each treatment did not show a significant increase for each treatment. The highest combination treatment of taro flour and coconut pulp flour for biscuit products produced from mixing taro flour and coconut pulp flour is in the treatment of 50% taro flour, and 50% coconut pulp flour composition with the respective values for the diameter, thickness, weight tests are 38 mm, 11.2 mm, 5.32 g. For the parameters of the highest distribution ratio in the treatment of 50% taro flour and 50% coconut pulp flour, For the highest distribution ratio parameter in the treatment of the ratio of taro flour and coconut, pulp flour was 70% versus 30%, with a value of 3.63.

Table 3. Physical Characteristics Measurement of Gluten-Free Biscuits for Autism Spectrum Disorder Children from Modified Taro Flour Formulated with Coconut Shell Flour

Formulation Modified taro flour : Coconut pulp flour	Diameter (D, mm)	Thickness (T, mm)	Width ratio (D/T)	Weight (g)
P0 (100:0)	37.2±2,59^a	10.4±0,55^a	3.57±2,59^a	5.2±0,16^a
P1 (70:30)	37.8±1,64^a	10.4±0,89^a	3.63±1,64^a	5.26±0,09^a
P2 (50:50)	38±2,35^a	11.2±0,84^a	3.39±2,17^a	5.32±0,33^a
P3 (30:70)	37.2±2,49^a	11±0,00^a	3.38±2,49^a	5.22±0,26^a

Values are the mean of three replicates ± SD.

Physical test data in the row followed by the letter indicate no significant difference (DMRT test α 5%).

Sensory testing of the biscuits is presented in Figure 2. The results showed that for hedonic testing on color and taste, the highest level of panelist liking was in treatment P2 with a score of 3.82 for color and taste with a score of 3.78 for taste, and the lowest was in treatment P0 with a score of 3.24 for color and taste with a score of 3.18 for taste. As for the testing of aroma and texture, the panelists liked the highest value in the P3 treatment with a value of 3.56 on the scale of liking for aroma and taste with a value of 3.82 on the scale of liking for texture and the lowest level of liking in the P0 treatment with a value of 3.18 on the scale of somewhat liking for aroma and texture with a value of 3.51 on the scale of liking. The high level of panelist preference for aroma and texture in gluten-free biscuits is in the P3 treatment because the fat content of coconut pulp flour produces a fragrant aroma in biscuits with a crisper texture.

During sensory testing of gluten-free biscuits in the color test, the highest value was in the P2 treatment with a value of 2.70, somewhat like, and the lowest in the P1 treatment with a value of 2.40. In the aroma and texture tests, the P3 treatment showed the results of the highest level of liking of each treatment with an aroma value of 3.42 instead of like scale and texture with a value of 3.81 like scale and the lowest level of liking test for aroma and texture in the P0 treatment which is 3.10 instead like scale for aroma test and texture test with a value of 3.55 like scale. The taste of the biscuit sample from mixing taro flour and coconut pulp flour with a ratio of P2 was liked by the panelists with a value of 3.88 on the scale of liking and the lowest in the P0 treatment with a value of 3.21 on the scale of mild liking.

Figure 2.

Graph of Hedonic Test of Gluten-Free Biscuits

Figure 3.

Graph of Descriptive Test of Gluten-Free Biscuits

Discussions

The high-water content values show that taro flour is more water-bound than coconut pulp flour. Likewise, the high value of ash content in modified taro flour is not measured by SNI (3751: 2009), which shows that the value of ash content for modified taro flour is 0.07. This is because of the modification process that occurs in the processing of modified taro flour with the addition of food chemicals in the form of lactic acid; during fermentation, microbes in the form of Lactic Acid Bacteria (LAB) produce pectinolytic and cellulolytic enzymes that can destroy cell walls, resulting in the liberation of starch granules, to increase viscosity, gelation ability, rehydration power, and ease of dissolving in flour. In addition, it is also influenced by the length of fermentation, which affects the water content. The longer the fermentation, the more water diffuses into the intercellular space of taro tubers, thus increasing the water content and the length of drying that is not long enough can cause the bound water contained in the material not to evaporate too much so that the water content remains high. The high value of ash content in modified taro flour is thought to be due to the texture and physical properties of the material that produces large particles during milling that do not pass during the sieving process so that it can affect the increase in moisture content and ash content in modified taro flour.

The increase in viscosity, gelation ability, rehydration power, ease of dissolution, and changes in the taste of modified flour to neutral due to the presence of Lactic Acid Bacteria during the fermentation process of modified flour produces pectinolytic and cellulolytic enzymes that can destroy cell walls and free starch granules (Triyono et al., 2019). Microbes produce enzymes that can hydrolyze starch into sugar and turn it into organic acids, especially lactic acid. In line with research (Zhang et al., 2022), the value of ash content contained in modified taro flour will affect the quality of the final product in the form of color and dough stability of the processed product. In addition, it was also explained that the factor that caused the high ash content value in modified taro flour was thought to be due to the non-uniform age of the taro used.

The modification process involves physical, chemical, or enzymatic treatments that can result in protein denaturation or reduction of protein content by separating protein fractions. In addition, taro itself naturally has a lower protein content than other protein sources such as soya, wheat, and other types. According to (Saxby et al., 2020)the article, the protein content in flour is inversely proportional to the amount of starch and lipid content. When flour has a high protein content, the starch and lipid content in the flour will be lower, and vice versa. In summary, protein is associated with good water absorption capacity—a high water absorption rate results in the formation of more pores. Thus, high protein content impacts the absorption of water molecules, resulting in low compressive strength, low hardness, and formation of crumbly cookies; the opposite occurs when using low-protein flours. (Abdelaleem & Al-Azab, 2021), The flour's protein content is divided into six groups, namely hard red winter, soft red winter, stiff red spring, hard white, soft white, and durum.

While squeezing the coconut from the coconut milk, much coconut fat is left in the coconut pulp. Although the amount of fat is removed through oil production, coconut flour still has a fat component, primarily medium-chain saturated fatty acids such as lauric acid and myristic acid. Traces of unsaturated fatty acids such as oleic acid, linoleic acid, and linolenic acid have also been found (Jiamjariyatam et al., 2021).

The fiber content of the modified taro flour was 1.20%. This is because the fiber contained in coconut pulp flour contains much water-insoluble dietary fiber and is rich in cellulose and lignin. According to (Himeda et al., 2014), dietary fiber generally consists of plant cell wall complex carbohydrates, such as cellulose, hemicellulose, pectin, and lignin, as well as intracellular polysaccharides such as gum and mucilage that are not hydrolyzed by human digestive enzymes. According to this (Adeloye et al., 2020), using raw flour materials with high fiber values in specific amounts and particle sizes will affect the final characteristics of a food product. Using raw materials containing water-soluble fiber (Soluble Dietary Fiber) will produce products with a more clayey texture. In contrast, the insoluble fiber component (Insoluble Dietary Fiber) will produce products with more brittle characteristics.

Modifying flour can reduce the moisture content or change the starch structure, which increases the carbohydrate value contained in the flour. Modified taro flour is gluten-free, can improve properties such as texture, stability, and water-binding ability, and has a lower glycemic index than unmodified flour. Meanwhile, coconut pulp flour has a lower carbohydrate content due to the processing process that removes most of the natural sugar content in the coconut. This process involves drying and milling the coconut pulp after extraction of the coconut milk. As a result, most of the carbohydrates found in coconut, such as sugar and fiber, are removed or significantly reduced. As explained (Nandiyanto et al., 2022), this process occurs when starch is heated in water and then cooled. The disrupted amylose and amylopectin chains gradually recombine into an ordered structure. In addition, the carbohydrate absorbs a large number of water molecules, causing minor damage to the starch. The distinctive nutritional composition of both flours influences the manufacture of gluten-free biscuits as the main component to increase the nutritional value of the product.

The moisture content of gluten-free biscuits showed a low value. This is thought to be due to the P0 treatment using modified taro flour without the addition of coconut pulp flour. Modified taro flour has a change in starch structure and can increase water binding ability and dough stability, resulting in a drier final product. On the other hand, coconut pulp flour, which is rich in fiber, has higher water absorption than coconut pulp flour, which can increase water retention in the dough and produce biscuits with higher moisture content. In addition, improper drying methods can affect the moisture content of biscuits, such as temperatures that are too low and the duration of the oven that is too short. As explained again (Nandiyanto et al., 2022), the high concentration of dietary fiber in coconut pulp flour causes moisture retention, resulting in softer cookies.

Meanwhile, the lower protein content in the cookies results in smaller pores and a dense texture. Biscuits are oven-processed bacterial products with no more than 5% moisture content. The drying method used to prepare taro flour can affect its properties, including water absorption capacity and moisture content (Himeda et al., 2014). Similarly, the processing method used to make biscuits can affect their moisture content.

The high ash content in taro flour mixed with desiccated coconut biscuits is due to the high ash content in taro. Taro is known to have high ash content due to the oxalate content in taro (Temesgen & Retta, 2015). The ash content of taro ranges from 1.5% to 3.5% (Kaur et al., 2013). Due to the low protein and high ash content in taro flour, substituting wheat flour with taro flour will cause a decrease in protein (Himeda et al., 2014).

Taro has a higher protein content than other root crops, although taro is not a significant source of protein (Ferdaus et al., 2023). Taro flour has a lower protein content than wheat flour, commonly used in biscuit production (Himeda et al., 2014). Added by Provost et al. (2016), protein can affect product characteristics because protein can be denatured in baking. Low protein content will result in a crumbled texture. In addition, a study found that adding coconut pulp flour to composite flour decreased the soluble protein content (Afoakwah et al., 2019).

It can be seen that the base material composition of coconut pulp flour shows a high-fat content of 49.07% compared to taro flour, which only has a fat content of 0.41%. Taro root contains high starch and flour (Shaheryar et al., 2023); semi-cooked taro flour can be used as a starting material for food formulations (Ferdaus et al., 2023). It is suspected that the modified taro flour added in the formulation contains high amounts of starch, which may contribute to the overall fat content of the product. It was also explained (Hanafi et al., 2022) that coconut flour is made from dried coconut pulp and has a higher fat content than other flours. The coconut pulp used in the formulation may contribute to the product's high-fat content.

Modified taro flour and coconut pulp flour contain high dietary fiber due to combining fiber from coconut pulp with additional fiber that may be modified from taro flour. Coconut pulp is rich in water-insoluble dietary fiber, while modifications to taro flour can increase the content of certain fibers in biscuit products. According to (Saxby et al., 2020) the article, the dietary fiber content of the product is influenced by the fiber content of the raw materials used. This dietary fiber content resulted from the modified taro flour that increased the resistant starch and dietary fiber content of the natural flour, as well as the dietary fiber content of the coconut pulp flour. The high dietary fiber content can be an advantage of the product.

Some dietary fibers are prebiotic as they promote the growth of probiotic bacteria in the gut and the production of healthy short-chain fatty acids. Maintaining a homeostatic gut microbiota through dietary modification to include high-fiber foods has been shown to reduce the risk of colorectal cancer (Saxby et al., 2020). Additionally, coconut residue dietary fiber has been found to have probiotic survival ability and sensory attributes (Hanafi et al., 2022).

Based on Table 2, the carbohydrate content composition of gluten-free biscuits made from taro flour formulated with coconut pulp flour showed the highest value of 61.32% in treatment P0 (100:0) when compared to other treatments. This is because taro has a high carbohydrate content of 86.11% and a starch content of 70-80% in its dry roots (Ferdaus et al., 2023). At the same time, coconut pulp flour tends to have a low carbohydrate content.

Protein and dietary fiber have a more remarkable ability to bind water, which will reduce the extent to which the dough spreads. In addition, when the water content is high, more sugar dissolves during dough kneading, which in turn will cause the dough to become thicker and reduce spreading (Sakr & Hussien, 2017).

In line with research (Olaimat et al., 2023), fat affects the aroma and texture of biscuits to be significantly improved. Another factor is that modified taro flour and coconut pulp flour are included in the low-protein flour category. Supported by (Sahagún et al., 2018), protein can affect product characteristics because protein can be denatured in the baking process. Low protein content will result in a crumbled texture.

The results of the proximate analysis and sensory testing revealed significant differences across the formulations of gluten-free biscuits made from modified taro flour and coconut pulp flour. The P0 formulation (100% taro flour) showed the highest moisture and ash content, likely due to the higher water retention in taro flour and the high ash content associated with its natural mineral composition. However, the P2 formulation (50% taro flour and 50% coconut pulp flour) performed best in terms of protein content, which can be attributed to the balanced combination of flours that maximized protein retention. The P3 formulation (30% taro flour and 70% coconut pulp flour) had the highest fat and fiber content, as coconut pulp flour is rich in these nutrients.

From a sensory perspective, the P2 formulation was favored for its color and taste, likely due to the balanced mixture of taro and coconut, which created a visually appealing color and a mild, pleasant taste. The P3 formulation scored highest for aroma and texture, likely benefiting from the high-fat content in coconut pulp flour, which contributed to a richer aroma and crispier texture.

These findings suggest that the combination of taro and coconut pulp flour can be optimized to enhance gluten-free products’ nutritional and sensory qualities. The P2 formulation, in particular, offers a promising balance of nutrients and consumer acceptability, making it suitable for children with Autism Spectrum Disorder (ASD), who often have selective eating preferences. This combination not only meets the nutritional needs of a gluten-free diet but also addresses the sensory sensitivities common in children with ASD, making it a viable option for improving their dietary intake.

The level of panelists' liking for the color of the biscuits may be due to the light brown color produced through the Maillard reaction in the presence of high levels of protein in coconut pulp flour and also the natural color of taro flour. In the aroma and texture tests, the P3 treatment showed the highest level of liking from each treatment, with an aroma value of 3.42, rather like than texture, with a value of 3.81, and the lowest level of liking for aroma and texture in the P0 treatment which was 3.10 somewhat like for the aroma test and texture test with a value of 3.55 like. The taste of the biscuit sample from mixing taro flour and coconut pulp flour with a ratio of P2 was liked by the panelists with a value of 3.88 on the scale of liking and the lowest in the P0 treatment with a value of 3.21 on the scale of mild liking. The acceptance scale of biscuits made from taro flour mixed with coconut pulp flour produced a panelist acceptance scale of taste due to the positive effect of the appearance of biscuits on color, aroma, and texture.

CONCLUSIONS

This study demonstrated that modified taro flour and coconut pulp flour can be effectively combined to produce nutritious, gluten-free biscuits suitable for children with Autism Spectrum Disorder (ASD). Among the formulations, the P2 (50% taro and 50% coconut pulp) biscuit offers the best balance between nutritional content and sensory appeal, making it an ideal candidate for inclusion in the daily diets of children with ASD. These biscuits provide essential nutrients such as protein, fiber, and healthy fats while avoiding gluten, a common trigger for digestive and behavioral issues in children with ASD. The sensory attributes, particularly in taste, color, aroma, and texture, make them more likely to be accepted by children, addressing the common challenge of selective eating behaviors associated with ASD. In practical terms, these biscuits could be integrated into school meals or used as convenient snacks at home, helping parents and caregivers ensure that children with ASD receive a balanced, gluten-free diet. They also offer a potential solution for parents who struggle to find nutritious, gluten-free snacks that their children will enjoy. For future research, it is recommended to explore the long-term acceptability of these biscuits among children with ASD, as well as their sustained nutritional impact on growth and health. Studies could also examine the feasibility of commercial production, focusing on optimizing cost and ingredient sourcing while maintaining the nutritional quality and sensory characteristics that make the biscuits appealing to this specific population.

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