Factors affecting consumers’ acceptability of fiber drink products

The objective of this study was to evaluate factors that impact consumers’ acceptability of fiber drink products. The influence of both the sensory and non-sensory factors on the liking of fiber drink was investigated using 121 consumers (mean age 20.3 ± 3.2-year-old). Six commercial fiber drink samples were investigated in this study with different flavor and characteristics. The CATA (Check-All-That-Apply) method was implemented for descriptive measurement of the fiber drink samples and consumer acceptance was measured using 9-point hedonic scale. The result showed that both sensory and non-sensory characteristics were able to impact liking of fiber drink samples. The sensorial characteristics of bright color (p< 0.001), sweet aroma (p< 0.001), fruity aroma (p< 0.001), berry aroma (p=0.043), sweet taste (p< 0.001), and fruity taste (p< 0.001), were shown to significantly impact liking. In contrast, attributes of darker (p< 0.001) and green (p< 0.001) color, texture of sandy (p=0.002), clumpy (p< 0.001), puree (p=0.009) and gel-like (p< 0.001) were significantly decreasing liking. For the non-sensory attributes, factors associated with health and wellness have significantly impact liking with artificial (p=0.018) and nauseated (p<0.001) showed to negatively impact liking. This is the baseline study to understand factors impacting the acceptability of consumers in fiber drink samples and can be used to develop fiber drink products with the most acceptable profiles based on consumers’ evaluations.


Introduction
The prevalence of obesity is increasing globally with the number of people being overweight and obese nearly tripled since 1975 [1].According to WHO, almost 40% of adults were overweight (650 million) and 13% of them were classified as obese.Obesity is the risk of degenerative diseases such as type-2 diabetes, cardiovascular diseases, hypertension, stroke, and cancer as well as significantly impacting mental health [2].It has been reported that around 2.8 million people die yearly due to complications of diseases related to overweight or obesity [3].This condition accelerates the development of foods that can prevent obesity [4], such as using fibers in powdered drinks [5].
Dietary fiber is believed to reduce obesity-related disorders [4,6].Multiple epidemiological studies have demonstrated a significant reduction in risk of obesity, type-2 diabetes, cardiovascular diseases, colorectal cancer and pre-menopausal breast cancer with higher dietary fiber intake [6].Moreover, dietary fibers show to have an effect throughout the digestive tract and stimulate the gut hormones that altered satiety and hunger levels [4] thus resulting in lower food intake and decrease total calories consumption.The recommended dietary fiber intake for adult population in a day is suggested to be around 25-30 gr [7].However, most of people did not able to meet the recommended intake levels, especially for those implementing diet high in sugar and fat [8].Fruit and vegetables are sourced of 1324 (2024) 012114 IOP Publishing doi:10.1088/1755-1315/1324/1/012114 2 dietary fibers, however, the dietary intake of these food categories is not sufficient, thus contributing to the low dietary fiber intake.The European countries reported consuming an average of 18-24 g/day, and around 17 g/day in North America, while in Indonesia more than 80% of the population was reported to not meet the dietary recommendation for fiber [9].
The fibrous drink is one of the products that provide additional fiber to meet dietary needs.The high-fiber powder drinks have improved dietary fiber consumption and resulted in regular defecation and weight loss [10,11].Powdered fiber drink products are available in the market with different types of flavors addressing supplementation of fruits and vegetables and highlight the effect for weight management including prevention of overweight or obesity.This study aimed to analyze attributes impacting consumers' acceptability of fiber drink products.The attributes were divided into sensory and non-sensory attributes and the impact of these attributes on liking was investigated.By understanding the factors impacting liking both internally (from sensory attributes) and externally (non-sensory) may support in developing ideal characteristics of the food product based on consumer's assessment.There has been a limited study addressing the sensory factors impacting liking of fiber drinks previously since this product is considered as new product categories in the market.This study was aimed to reach SDGs related to developing food for good health and well-being.

Participants and ethic
There was a total of 121 participants involved in this study (mean age 20.3 ± 3.2-year-old, 22% males and 78% females).The participants were selected based on their consumption of fiber drinks product (users).Participants that have consumed and familiar with fiber drink were then selected to participate in this study.All the participations were based on voluntary, however, a digital written consent form was provided in addition to verbal consent.The aim of the evaluation was also explained to the panelists at the beginning of the test.The data collection has followed the declaration of Helsinki of using human subjects [12].

Fiber drink samples and preparation
There were six commercial powdered fiber drink samples evaluated in this study.This samples includes Realfood Cleanse Passion Power® (RF), GutViber® (GF), Fyberfyt® (FB), Flimty (blackcurrant)® (F-black), Flimty (raspberry)® (F-raps), and Bionfit® (BN).The composition of each sample not revealed in this publication since some of the samples (BN, RF) were still in the development stage, thus the composition remained confidential.The selection of the samples based on internal Focus Group Discussion (FGD) for the fiber drink powder products that were considered as the most popular in the market.All the samples were purchased from the local supermarket.
The powdered fiber drink was prepared by dissolving it at the exact amount of water following the serving suggestion (15 gr/150 ml of water).The mixture was then mix with stirrer until all the powder were completely dissolved.The fiber drink was served at maximum of 20 ml in a 50-ml disposable cups for each panellist.A spoon was provided to evaluate texture of the samples, All the samples were labelled with a three-digit random code and evaluated in a blind test.It was very important to keep the time short between preparing the samples until the samples evaluated by the panellists since all of the products were high in fiber and the consistency can change rapidly.

Sensory evaluation test
There were descriptive and affective testing conducted in this study.The descriptive method to evaluate the profiles of the samples was conducted using the CATA method while the acceptance testing was employed to measure consumers acceptability.All the tests were conducted at the Sensory Laboratory, Binus University, Alam Sutera Campus.The samples were presented in a monadicrandomized order.A glass of mineral water was also prepared, and the panellist was instructed to rinse their mouth with mineral water before the evaluation and in between tastings.A sufficient break of 1-2 minutes was also provided before the panellist move to the next sample.This practice was conducted to ensure that there was no aftertaste sensation that may affect the evaluation [13].In the CATA method, the panellist was instructed to check the attributes that they perceived available in the samples [14].The CATA method was reported as a simple and efficient descriptive method [15] with high similarity results as compared to the classical descriptive analysis [15,16].In addition, real consumers (users) were used to evaluate the product in this method makes CATA appointed as consumer-oriented method in providing information and feedback of the product.CATA has been reported to provide a reliable and similar results with what obtained using classical descriptive analysis method [17].
The consumers' acceptability levels of fiber drink samples was measured using 9-point hedonic scale anchored with 1 "dislike extremely" and 9 "like extremely" [18].The overall liking of the samples was evaluated at the beginning of the test before the CATA evaluation to avoid any bias from sensory characteristics.There was a total of 28 sensorial attributes (visual, aroma, taste, and texture) and 12 non-sensory attributes evaluated in this study.The CATA attributes were generated based on the previous studies that also evaluates the sensory characterization of a powdered drink product [5,19].The complete attributes can be seen on the Table 1.
• Fruit and vegetable substitute

Data analysis
The sensory attributes obtained based on CATA and the hedonic data were analysed using correspondence analysis.The impact of the sensory and the non-sensory attributes on the liking were further analysed using penalty analysis.The liking score was also analyse using analysis of variance (ANOVA) and significant level of 5% was used in the data analysis.All the data was analysed using XLSTAT sensory (Addinsoft, France, version 2022.1).

Association between sensory characteristic and consumer's acceptability
The sensory profiles data obtained from CATA and consumer liking was projected using correspondence analysis (CA) presented in Figure 1.The CA mapping of F1 and F2 representing 89% of data variability.Based on F1 the clusters were divided based on fruity flavor (RF, F-black, F-rasp, BN) on the left side while the right side was characterized by vegetables flavor (GF, FB).Moreover, F-black, F-rasp and BN were shared similar characteristics such as taste and aroma of berries and artificial while samples of RF was characterized by bright and yellow color, easy to stir, and watery texture.GF and FB were located in the different direction of the mapping indicating that these samples have distinct characteristics compared to the other samples and characterized by vegetable taste, bitterness, clumpy, puree-like texture, and was perceived as able to promote nauseous. 4 Based on the CA mapping, the overall liking attribute was closely related to aroma and taste of sweet, aroma and taste of fruity, watery texture, easy to stir and fresh, and these characteristics are available in the RF samples.The ANOVA analysis also revealed that RF sample has a significant highest liking score (mean value 6.61±1.86)while GF (3.47±2.00)and FB (4.05±2.18)has the lowest liking score.In addition, F-rasp (6.03±2.09),F-black (5.06±2.10)and BN (4.69±2.41)were not significant differences for their acceptability level.The results from ANOVA data were aligned with the data obtained from the correspondence analysis.
The watery texture was related to overall liking of fiber drink samples indicating that the more watery-like texture of the samples will increase consumers liking.Addition of fiber in a drink will change the viscosity and texture of the product significantly [20] since fiber is highly hygroscopic [21].This characteristic promotes digestive health since fiber help to solidify stools due to high water absorption capacity and provide bulking [5,11].Fiber supplementation in the diet was reported to support the recovery of patient with acute constipation and irritable bowel syndrome [11].However, the amount of fiber in the fiber drink should be carefully added, because the high fiber content can contribute to the puree-like and gel-like texture and these texture profiles were not preferred by consumers especially for fiber-drink samples despite the importance of this texture as bulking agent and support digestive health [11].The results show that both sensorial attributes and non-sensorial attributes were able to influence the overall liking of fiber drink samples.Characteristics of fruity taste and sweetness shown to be closely associated with liking while the taste of bitterness and vegetables were located in different direction of liking, thus indicating these profiles may contribute to dislike of the product.The food acceptance influenced by multiple factors from diverse sensory modalities involving both intrinsic and extrinsic factors [22].The intrinsic factors are inherent to the product itself and relate to the sensory attributes or profiles such as appearance, taste, aroma and texture [23].In contrast, extrinsic factors can relate to the product but not physically a part of it such as packaging, information on claim, price, and other non-sensory characteristic attributes [22,23].According to the previous study, extrinsic factors such as health and wellness was predominated the acceptance value of ready to eat salad [24].This also align with the study reported by Kim et al. [25] that revealed the extrinsic factors of organic label in foods was able to significantly influence the overall liking of consumers.This corroborates with the results obtained in this study that also demonstrated the impact of the non-sensory attributes on liking of fiber drink samples.

The effect of sensory attributes on the acceptability of fiber drink
In order to know the impact of each sensorial attribute to consumer acceptability, a penalty analysis was employed, and the data is presented in Table 2 for the sensory attributes.The bright color (p< 0.001) was positively impacting liking while darker (p< 0.001) and green (p< 0.001) color of the fiber drink samples shown to decrease consumers acceptability.The aroma and taste of sweet and fruity (p< 0.001) as well as berries aroma (p=0.043) were also able to positively impact consumer liking.In contrast, texture of sandy (p=0.002),clumpy (p< 0.001), puree (p=0.009) and gel-like (p< 0.001) were negatively impact the liking of the fiber drink products.According to a study by Spence [26], color is one of the most important product-intrinsic sensory cue.
Visual of color can setting consumer's expectation and affect the like and dislike of a certain taste and flavor of a food and drink [26].Color can determine the flavor and taste of beverages based on visual recognition [27].For example, based on this study, a yellow color in RF samples may represent the citrus and fruity flavor of the fiber drink while the green color perceived in GF and FB representing vegetables colors.Moreover, bright color like yellow and red were preferred than green or darker color [28] and this aligned with results obtained in this study, in which yellow and bright color provide positive impact on liking while darker color like green may associated with decrease in liking.
The aroma attributes of fruity, berry, and sweet were shown to positively impact liking of the fiber drink samples.These aromas provide pleasant odors and were liked by people.This result corroborates with the previous study stated that sweetness was initially liked since childhood and this taste closely associated with pleasantness [29].Moreover, fruity aromas including aroma of berries were generated from volatile compounds and consisted of combinations between acetaldehyde, ethyl butanoate, ethyl methyl propionate, hexanal, limonen and linanool [30].The positive impact was also generated from sweetness and fruity taste.Sweet taste is initially preferred since infants [31] because this taste associated with sugar and human body need sugar for its metabolism process [32] while fruity taste provide pleasant volatile compounds that mostly liked by people [30].
The addition of fiber may alter the textural properties of a food product [5] since dietary fiber increase water holding capacity thus promote gel formation.Based on our results, the gel-like and puree texture of fiber drink product has negative impact on liking.Moreover, consumer was also reporting their disliking for the textural attributes of clumpy and sandy.The texture of commercial fiber drinks determined by the type of fibers content.In this study, most of fiber drink samples were using psyllium husk and inulin as the source of fibers.Both inulin and psyllium husk are categorized as soluble fibers [21].Inulin is a fermented fiber and provided the bulking capacity of the stools and promotes gut health [5] while psyllium has been reported to have a high fiber and mucilage content which bulk up the stools, offers laxative effects, soothes the gastrointestinal tracts and help regulate blood sugars [33].Most of the fiber drink samples have a gel-like texture characteristics since it contains both psyllium husk and inulin, the watery texture in some sample (RF) may be due to the lower inulin and psyllium husk addition in the powdered-fiber drink formulation.

The effect of the non-sensory attributes on the acceptability of fiber drink
The penalty analysis was also conducted for the 12 non-sensory attributes involved in this study.The results show that all non-sensory attributes were significantly impact liking of fiber drink except for "rich in fiber" (p=0.067) and "fullness" (p=0.256).Interestingly, the attribute of "rich in fiber" was not give any significant impact for consumer acceptance of fiber drink products despite that all of the samples were rich in fiber.This may be due to the consumers knowledge, since the participants may already inform regarding the product characteristic that is usually high in fiber.This resulting in no differences for these attributes.Extrinsic factors have been reported to impact significantly food acceptance, including purchase interest and decision to consume or not to consume a food product [23].The previous studies have been clearly demonstrated the significant and impactful effect of sensory cues on consumer acceptability and these has been revealed for several foods products including in cheese [34], salad [24], orange juice [25], and milk tea beverages [35].In this study, the extrinsic factors related to the fiber drink perception such as health and wellbeing (healthy, nutritious, nourishing, fruit juices, fruit and vegetable substitute, natural, fresh) as well as the convenience aspect (easy to stir) were demonstrated to be able to influence consumer acceptability of fiber drink product.This suggests that the non-sensory aspects should also be considered in the development of powdered-fiber dink product to build the desire characteristic that match with consumers' perception.

Conclusion and recommendation
The results showed that the consumers acceptability for fiber drink were determined by both sensory and non-sensory attributes.The attributes of bright color, aroma and taste of fruity and sweetness as well as aroma of berries were positively impacting liking while darker and green color, sandy and lumpy texture as well as puree and gel-liked were negatively impact liking.Moreover, the non-sensory attributes of artificial and nauseated should be avoided in this product.These results can be used to further develop fiber drink product that suited with consumer ideal product by adding attributes that are able to increase consumers' satisfactions and liking and to avoid attributes that may negatively impact liking.
It is suggested to explore the texture attributes of fiber drink using classical descriptive method since powdered fiber drink characterized by high water absorption capacity and the wrong preparation may lead to clumpy and sandy texture and these texture attributes will impact liking significantly.Lastly, the evaluation using trained panelist is also suggested to confirm the results obtained based on CATA evaluation.

Table 1 .
CATA attributes of fiber drink samples

Table 2 .
Penalty analysis of sensory and attributes of fiber drink

Table 3 .
Penalty analysis of the non-sensory attributes of fiber drink p-value based on penalty analysis of CATA attributes the sign of (positive) or -(negative) in mean impact indicating the impact on liking