Fruit‐based drink sensory, physicochemical, and antioxidant properties in the Amazon region: Murici (Byrsonima crassifolia (L.) Kunth and verbascifolia (L.) DC) and tapereba (Spondia mombin)

Abstract Increased fruit consumption due its protective effect on the organism is accompanied by the development of the processing industry of these products. The aim of this work was to optimize fruit pulp‐based beverage formulations from the murici and tapereba Amazon region, taking into account their sensory acceptance and antioxidant activity. Total soluble solid content, reducing sugar content, titratable acidity contents, pH, and ascorbic acid content were determined in pulps and formulations. The total content phenolic compounds and antioxidant activity were also evaluated. A 22 factorial experiment was formulated to optimize ingredients for the production of murici and tapereba fruit drinks. The murici pulp had higher acidity and higher ascorbic acid content. The analysis of phenolic compounds and antioxidant activity presented higher quantity in tapereba pulp. Tapereba‐based beverages had better acceptance by the evaluated criteria. Fruit‐based beverages murici and tapereba are a well‐accepted product and have important nutritional characteristics.


| Physicochemical characterization
Proximate physicochemical composition of pulps and formulations of fruit-based beverages murici and tapereba had the following analyses in triplicate: total titratable acidity, reducing sugars, total soluble solids (°Brix), pH, and vitamin C according to the official method (Association of Official Analytical Chemists 2000).

| Color analysis
Color analysis in the pulps murici and tapereba was performed using a Konica Minolta CM-5 digital colorimeter, with using the parameters L* (lightness), a* (red/green intensity), and b* (yellow/blue intensity) of the CIE Laboratory system (Commission Internationale de l'Eclairage). All analyses were performed in triplicate. The equipment was calibrated according to the manufacturer's instructions.
Approximately 50 g of previously homogenized sample was used (Lima et al., 2015).

| Total phenolic content
Total phenolic content was determined by the Folin-Ciocalteu method, which was adapted from Bernards et al. (2018). The drinks based on murici and tapereba and 2.5 ml Ciocalteu reagent solution 10% were combined and then mixed well using a vortex. The mixture was allowed to react for 5 min, then 2 ml of 4% sodium carbonate solution was added and mixed well, and the solution was incubated at room temperature (25°C) in the dark for 2 hr. The absorbance was measured at 750 nm using a spectrophotometer (Turner 340), and the results were expressed in gallic acid equivalents, mg/100 g organic grape peel flour using a gallic acid (2.5-50 µg/µl) standard curve.

| DPPH assay
DPPH methanolic solution (0.06 mM) was mixed with 0.5 ml of pulps and formulations of fruit-based beverages on murici and tapereba in the three concentrations. The reaction mixture was turned completely and left in the dark at controlled temperature for 60 min. The absorbance of the blend assays was measured applying a spectrophotometer (Turner 340) at 515 nm in triplicate (Abreu et al., 2019).

| TEAC assay
TEAC assay was performed following the procedure proposed by Rufino et al. (2010). The ABTS radical (7 mM) was prepared and kept in the dark at room temperature for 16 hr before use. The ABTS solution was diluted with ethanol with an absorbance of 0.70 ± 0.02 at 734 nm. After adding 30 μl of pulps and formulations of fruit-based beverages on murici and tapereba or Trolox standard to 3 ml diluted ABTS solution, the absorbance was recorded at six minutes after addition. The analyses were performed in triplicate on the spectrophotometer (Turner 340). The blank assay used ethanol and antiradical activity was expressed as μmol TE/g.
The Trolox standard was prepared at eight concentrations. For white aliquots and control, the PBS solution was used. The Trolox standard and fruit-based beverages murici and tapereba were added to the plate in increasing concentration and in duplicate. Then, 120 μl of the fluorescein solution was added, and then, the AAPH solution was added to all wells, except for the control. The fluorescence drop reading was measured using an automated plate reader (SpectraMax i3x, Molecular Devices) with 96-well plates at 485/520 nm.

| Experimental design
The production of the formulations for the drinks was carried out according to the proportions for each independent variable (Table S1).
In order to optimize the developed murici-and tapereba-based drinks, factorial design 2 2 was used, in which the independent variables were concentration of tapereba or murici pulps in percentage (X 1 ) and sugar concentration in percentage (X 2 ) and the dependent variables were the appearance (Y 1 ), flavor (Y 2 ), texture (Y 3 ), and overall impression (Y 4 ). A total of eleven formulations were produced, containing four axial points and three central points, producing a total of eleven samples for use in the acceptance tests (Rodrigues & Iemma, 2005).

| Sensory evaluation
Sensorial evaluation of drinks based on murici and tapereba was carried out by 85 consumers. The parameters included in the analysis were appearance, taste, texture, and overall impression. The methodology used a hedonic scale of nine points ranging from 1 (not very liking) to 9 (really enjoyed) (Abreu et al., 2019). Sensory analyses were performed in the Laboratory of Sensory Analysis of Federal University of the State of Rio de Janeiro (LASEN). The data were collected by means of paper sheets. Sensory panelists of consumers were recruited for the evaluation. The tasters were recruited for their availability, interest, and frequency of consumption. The majority of the panel was composed of faculty, staff, and students from the Federal University of the State of Rio de Janeiro.
It received approximately 30ml of each product sample in disposable plastic cups encoded with three-digit temperature-controlled random numbers in monadic form and using a complete balanced block design (Macfie, Bratchell, Greenhoff, & Vallis, 1989). The research protocol of the study was approved by the Research Ethics Committee of the University of the State of Rio de Janeiro (CAAE no. 39693914.8.0000.5285).

| Statistical analysis
The univariate analysis of variance (ANOVA) with the Tukey posttest at a 95% confidence for antioxidant assays and Dunn's for sensory tests were used to determine and compare the statistical differences, depending on the distribution of data. Experimental data were analyzed statistically using STATISTICA 7.0 (StatSoft, South America). The results were expressed as the mean and standard deviation.
Acidity is one of the criteria affecting the flavor-based classification of fruits; fruits with citric acid levels ranging from 0.08% to 1.95% can be classified as light-flavored and are well accepted for fresh fruit consumption (Souza, Aparecida, Pereira, Queiroz, & Borges, 2012). Despite having acidic characteristics, murici and tapereba pulps fall into this evaluation category. Livre et al. (2010) evaluated nature pulp of fruits of the Amazon and found values of pH (3.7 ± 0.00; 2.9 ± 0.4) and total acidity (1.0 ± 0.1; 1.3 ± 0.1%) for murici and tapereba similar to those found in the present study. Tiburski et al. (2011) found values of pH (2.83 ± 0.01), titratable acidity (1.46 ± 0.01 g/100 g) and soluble solids (10.2 ± 0.1 °Brix) like to those found in our study for tapeworm pulp.
Pulp of tapereba presented a higher content of reducing sugars (9.90 ± 0.43 g/100 g) and soluble solids (9.80 ± 0.10 °Brix) when compared to the murici pulp (4.20 ± 0.01 g/100 g and 3.79 ± 0.14 °Brix, respectively) (p < .05) ( murici and tapereba pulps' identity and quality standards. The total soluble content of solids is associated with sugars and organic acids, a feature of interest as the consumer market prefers sweet fruit (Beckles, 2012).
A similar study found murici and tapereba pasteurized pulp values and found 1.5 ± 0.1 and 6.0 ± 0.7 °Brix values, respectively (Livre et al., 2010), and these values are lower than those found in the present study and may be related to the process of fruit maturation, according to da Silva et al. (2016). The increase of the soluble solids can be explained by the evaporation of water during the pasteurization process (Sales & Waughon, 2013 Table 2).
Colorimetric evaluation is an important criterion for the physical evaluation of fruits, influenced by the processing and storage in which they are submitted. Therefore, its composition is affected by this parameter, for example, the chromaticity coordinate b *, which evidences the yellowish color, is directly related to the pulps which have carotenoids in their composition (Matietto et al., 2010), as observed by the murici and tapereba pulps.
In this study, we found that the total phenolic values of murici pulp were higher than those found by murici pulp in the study of Souza et al. (2012). Tapereba pulp also reported higher total phenolic values compared to the (Tiburski et al., 2011) study, which performed similar analyses to those conducted in the present study. Yellow mombin phenolic content is only lower than acerola (Malpighia emarginata) (580.1 mg GAE/100 g) (Bramorski et al., 2011).
Pulp of tapereba presented higher antioxidant activity according to DPPH (55.78 ± 1.65%), TEAC (64.66 ± 2.76 μM Trolox/g), and FRAP (9.45 ± 0.76 μmol sulfate/g) when compared to the murici pulp (p < .05). Statistical differences were observed between the murici and tapereba pulps in almost all evaluated parameters of antioxidant activity (p < .05), except for the antioxidant capacity of the ORAC assay, which showed similarity between the analyzed pulps (p > .05) ( Table 2). The value of the antioxidant activity of tapereba pulp is similar to that found by Tiburski et al. (2011) according to your study with tapereba pulp. According to Souza et al. (2012), this antioxidant activity value is equivalent to some murici pulp. Antioxidant activity high in fruit pulp murici and tapereba may be associated with their vitamin C and phenolic compounds content, as well as the presence of carotenoids in their composition.

| Experimental design
The experiments were conducted and optimized, where the pulp and sucrose were independent variables and flavor, texture, appearance, and overall acceptance were the dependent variables after the formulations and sensory evaluation of murici-and tapereba-based drinks. The experiments were performed in different combinations of independent variables, and the means obtained from the analysis of acceptance are shown in Table S2.
After analyzing the acceptance test, both the murici-based beverage formulations and the tapereba-based beverages showed better acceptability with regard to the appearance of the attribute, which can be justified by their visually appealing yellow to orange coloration (Paakki, Aaltojärvi, Sandell, & Hopia, 2019).
The results from the experimental data show that the pulp concentrations affected the averages of the color, texture, and overall impression F I G U R E 2 Response surface modeling three dimensions charts for the dependent (appearance, flavor, texture, and overall impression) variables of the drinks based on murici and tapereba considering the independent variables pulp and sugar

| CON CLUS ION
Murici and tapereba beverages are a well-accepted product with significant nutritional features. The fruits studied are sources of bioactive compounds that provide protection for the body, and this function has been observed in the high antioxidant activity reported in the formulations, indicating that these products may bring benefits to the consumer's health. Further studies should be carried out to analyze the best production techniques, guaranteeing the quality of the beverages.

ACK N OWLED G M ENTS
We thank the volunteer tasters. This study was funded by the Rio de Janeiro Research Support Foundation (FAPERJ) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES).

CO N FLI C T O F I NTE R E S T
The authors declare no conflict of interest.

E TH I C A L S TATEM ENT
The study's protocols and procedures were ethically reviewed and