Formulation and characterization of the quality parameters of jellies and candy pastes of purple pitanga ( Eugenia uniflora L . ) with reduced sugars

The objective of the present work was to characterize and microbiologically evaluate different formulations of jams and paste candies of purple pitanga with reduced sucrose contents. The formulations made for jams were “jam A” with a 100% proportion and “jam B” with a 50% proportion, all with the addition of pectin (1.5 g) and citric acid (0.45 g). For the paste candies the concentrations were “candy A” with 60% and “candy B” with 40%, all added with citric acid (0.6 g) and water (36 mL). The elaboration process followed all the quality control standards and, in sequence, the physicochemical (humidity; ash content; soluble solids; pH; titratable acidity; sugars; color parameters; anthocyanins; flavonoids) and microbiological (total and thermotolerant coliforms; molds and yeast; coagulase positive Staphylococcus and Research, Society and Development, v. 9, n. 8, e159985591, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i8.5591 3 Salmonella sp.) characterizations were performed. The results of the analyses have been compare only between formulations of the same type of product. All physicochemical data were within the standard parameters for candies and jams. As for the color aspect, the samples showed a characteristic intense red, differing only in the chromaticity and luminosity parameters in sweets and jellies respectively. The pitanga by-products presented varied concentrations of bioactive compounds, with emphasis on greater amounts of anthocyanin. For all microbiological aspects evaluated, the results were in accordance with the standards established by the legislation. Thus, the possibility of the development of purple pitanga jams and candies has been showned, with a reduction in sucrose content, but with interesting nutritional, microbiological and visual characteristics.

Salmonella sp.) characterizations were performed. The results of the analyses have been compare only between formulations of the same type of product. All physicochemical data were within the standard parameters for candies and jams. As for the color aspect, the samples showed a characteristic intense red, differing only in the chromaticity and luminosity parameters in sweets and jellies respectively. The pitanga by-products presented varied concentrations of bioactive compounds, with emphasis on greater amounts of anthocyanin.
For all microbiological aspects evaluated, the results were in accordance with the standards established by the legislation. Thus, the possibility of the development of purple pitanga jams and candies has been showned, with a reduction in sucrose content, but with interesting nutritional, microbiological and visual characteristics.

Introduction
Native from Brazil, the pitangueira is a plant that adapts to the climatic and edaphic conditions of the Northeast region of Brazil, where it is largely produced. Its fruits have an exotic flavor, varied coloring, of high nutritional quality and bioactive substances, such as phenolic acids, flavonoids, anthocyanins, carotenoids and vitamins, responsible for its high antioxidant potential (Vinholes et al., 2018).
Consideration of the growing search of the population, for foods that aggregate functionality to the pleasant taste, the pitanga becomes an interesting fruit to be used for the formulation of by-products. This use is relevant, since the pitanga has a relatively short shelf life after harvest, needing techniques that allow its long-term use (Sanches et al., 2017).
Therefore, pulps, candies, drinks, ice cream, jellies and liquors are examples of these byproducts obtained aiming to minimize fruit losses, in addition to adding nutritional value and interesting sensory characteristics (Frazon et al., 2018).
Jellies and candies are products obtained by mixing ingredients in proportions and suitable conditions, prepared from the boiling of fruit pulp with added sugar, acid and gelling agent until to reach the desired content of soluble solids (Brasil, 1978). Both have great acceptance and commercial importance for the fruit conserves industry in Brazil (Sanches et al., 2017).
However, according to current legislation, candies must be made from a mixture of vegetable ingredients and sugars in proportion 1:1. The same ratio is determined for jellies type extras, the ones with the lowest sugar content in their formulation (Brasil, 1978).
Nevertheless, sucrose consumption has been associated with the appearance of several diseases, being recommended its decreasing in the diet (Khan et al., 2019).

Materials and Methods
The study design of the present work is characterized as laboratory research of a quantitative nature, where part was carried out in the field, such as the collection of materials, and the other laboratory part, as the determination of physical-chemical, microbiological characteristics and statistical analysis (Pereira et al., 2018).

Raw materials
The

Formulations of Jams and Paste Candies
Previously sanitized pitangas were thawed for the pulping process of the fruit. The pulp obtained was crushed and the sieved input for the production of the final extract used in the formulation of jams and candies of purple pitangas.
Jellies and candies were obtained using different proportions of sugar (sucrose): "Jam A" with a 100% proportion (150 g of fruit pulp for 150 g of sugar) and "jam B" with a 50% proportion (150 g of fruit pulp for 75 g of sugar), all with the addition of commercial pectin (1.5 g) and citric acid (0.45 g); "Candy A" with 60% (100 g of fruit pulp for 60 g of sugar) and "candy B" with 40% (100 g of fruit pulp for 40 g of sugar), all added with citric acid (0.6 g) and water (36 mL). Research, Society and Development, v. 9, n. 8, e159985591, 2020 (CC BY 4. (Curi et al., 2018).
After reaching 65 °Brix (jellies) and 60 °Brix (candy) (digital bench-top refractometer Milwaukee MA871 digital model), the products were packaged in sterile glass containers, with a capacity of 120 g, at a temperature of 85 -90 ºC and then stored at 6 ° C until the moment of the physical-chemical and microbiological analyzes. The general flowchart of processing is also shown in Figure 1. As different products were processed, the description in the flowchart facilitates the visualization of all the steps, in sequence, necessary for production and final storage, making it extremely useful for reproducing the study.

Determination of physicochemical parameters
To characterize quality parameters in the jams and paste candies, the analyzes of total soluble solids (TSS), titratable acidity (TA), pH, total humidity, ash content, total sugars, reducers sugars, and color were performed. Research, Society and Development, v. 9, n. 8, e159985591, 2020 (CC BY 4. (IAL, 2008). TA was determined by titration with NaOH (0,1 N) and use of phenolphthalein (1%) as indicator. Results of TA measurements were expressed in g of citric acid/100 g of product (IAL, 2008). pH values were measured with a digital pH meter (Model PHS-3E digital ion, Jiangshu Instruments, Jiangshu, China) (IAL, 2008).
For the analysis of humidity content, the desiccation method was used, by drying process in an oven at 105 ºC until constant weight, using 5g of the sample in previously tared and humidity-free porcelain crucibles (IAL, 2008). At the end of the humidity analysis, samples were used (3 to 5g), arranged in capsules, for ash determination, according to the incineration methodology (IAL, 2008). Total and reducing sugars were determined using the Eynon-Lane titration redox method (IAL, 2008).
The color was measured at room temperature using the electronic colorimeter GRETAG MACBETH, model COLOR-EYE 2180 (New Windsor, USA), with determination by the CIELab system: L* (0: dark, 100: white), a* (negative value: green, positive value: red) and b* (negative value: blue, positive value: yellow), in addition to the termination of C * (chroma) and tonality angle (anglo hue -h°) according to the International Lighting Commission (CIE, 1986).

Quantification of Anthocyanins and yellow flavonoids
Quantification of anthocyanins and yellow flavonoids was performed only on paste candies as an evaluative parameter for the products of derivatives of purple pitanga. An ethanol extracting solution was prepared -1.5N HCl, in which one gram of the sample was dissolved in 50 mL of the extracting solution, remaining at rest, protected from light, under refrigeration, for a period of 16 hours. Subsequently the material, protected from light, was filtered using vacuum filtration read on a spectrophotometer in wavelength of 535 nm for anthocyanin and 374 nm for flavonoids. The results were calculated and expressed in mg of total anthocyanins/ 100mL (reading at 535 nm) and mg of flavonoids/100 mL (reading at 374 nm), according to equations 1 and 2, respectively (Francis, 1982).

Determination of microbiological parameters
Microbiological analyzes were performed to characterize the hygienic-sanitary parameters of the jellies and candies produced, following the standards of Brazilian legislation

Statistical analysis
The analysis of the evaluation of the general quality parameters (physical-chemical and microbiological analysis) were performed in triplicate and all results were expressed as the average values of the data obtained.
Statistical analyzes were performed using descriptive statistics (mean and standard deviation) and inferential (ANOVA tests, followed by Student's tests) to determine differences (p ≤ 0,05) between the results obtained. For statistical analysis, the Sigma Stat software. 3.5.

Physicochemical characterization
Jams and candies had a characteristic flavor and aroma of the purple pitanga. The cooking time required to obtain the final product was higher in formulations with reduced sugar, that is, with lower carbohydrate content for the gelation process.
Results of the characterization of the physical-chemical quality parameters of the jams and candies of purple pitanga are shown in Table 1. Research, Society and Development, v. 9, n. 8, e159985591, 2020 (CC BY 4. It is observed that the average of the values determined for the humidity of the jellies, even though different between formulations (p ≤ 0,05), are within the range found for most fruit jellies. These values being also according to the quality standard established by the Brazilian legislation (Brazil, 1978), which indicates the maximum humidity content for fruit jellies lower to 38% (Barros et al., 2019). For paste candies this parameter did not vary between the different formulations.
It was found that the jellies in both formulations, presented average levels of soluble solids close to 65 ºBrix, contents that are usually found in conventional fruit jellies (62 °Brix) (Barros et al., 2019). However, due to reduced sugar content in candy formulations, soluble solids showed reduced values, ranging from 59 to 60 ° Brix.
The content of soluble solids is considered an indicator of the amount of sugars present in the food (Vieira et al., 2017). This relationship was observed for pitanga jellies in which the amounts of total sugars were relatively close to the soluble solids content. High levels of total soluble solids (TSS) associated with low water content and pH may favor the formation of crystallization of sucrose, which is responsible for improving the viscosity and texture of the product (Oliveira et al., 2019).
It has been found through the results that there was no significant difference between the two formulations of jams and candies in the parameter of fixed mineral residue (ash).
However, both products showed higher values when compared to those found in fresh natural  (Oliveira et al., 2006). This fact can be related to the composition of the plant matrix, as well as demerara sugar. According to Bettani et al. (2014), demerara sugar has higher levels of fixed mineral residue than refined sugars, and this may have contributed to the values obtained in this study.
Formulations presented pH classified as acids, with little difference between the candy samples (throughout processing). The acidic pH is characteristic of the pitanga fruit, as reported in previous studies (Oliveira et al., 2006). It is important to note that the optimal pH for gel formation varies between 3.0 and 3.4, depending on the final content of soluble solids. Therefore, citric acid has been used in the formulation of jellies to correct the initial pH the extracts, aiming adequate gelling in the final product (Vieira et al., 2017).
For acidity, candies and jellies showed higher levels when compared to those found by Curi et al. (2018) in jelly formulated with 100% pitanga (TA = 0.59). Acidity content has been attributed to the type of fruit, maturation stage and presence of organic acids. The acidity values tend to decrease when the maturation stage evolves.
It has been found that the levels of total sugars and reducers were higher in jelly and candy formulations A, which had higher concentrations of sucrose. This decrease for sugars (sucrose) added has a positive effect on the chemical and sensory quality of the jelly, as it avoids the extremely candy taste, emphasizing the characteristics of the fruit (Lago et al., 2006). For reducing sugar content, this difference can be explained due to the lower conversion of sucrose to glucose (inverted sugar) in products with reduced sugar (50%).

Color analysis
The color parameters of purple pitanga jellies and candies were evaluated through instrumental analysis using colorimeter, and the results are shown in Table 2. The luminosity values were similar for both samples tested. Research, Society andDevelopment, v. 9, n. 8, e159985591, 2020 (CC BY 4.0) | ISSN 2525-3409 | DOI: http://dx.doi.org/10.33448/rsd-v9i8.5591 a-b : Mean values (± standard deviation) in the same column with different subscript lowercase letters are significantly different (p ≤ 0.05), based on Student test). Source: Authors (2020).
The color parameter a (+) indicates that the prevalent color in the four samples was red. The color parameter b (+), indicating the presence of the yellow component, was higher in the formulation with greater amount of fruit pulp (100% jelly). This product also presented a less dark / red color, characterized by the values of C* (parameter related to color intensity) higher in this formulation (Aguiar et al., 2016). °Hue angle indicates the color tone, ranging from 0 ° (red), 90 ° (yellow), 180 ° (green) and 360 ° (blue). In this way, both samples remained close to the origin, indicating to be a red sample and corroborating with the parameter a* which indicated positive values inherent to the mentioned color.

Contents of anthocyanins and yellow flavonoids
The levels of yellow flavonoids and anthocyanins were determined in the candy formulations, described in Table 3. a-b Mean values (± standard deviation) in the same column with different subscript lowercase letters are significantly different (p ≤ 0.05), based on Student test). * The results were calculated according to the methodology and expressed in (mg of total anthocyanins / 100mL) and ** (mg of flavonoids / 100 mL). Source: Authors (2020).  According to the results found, the pitanga by-products presented varied concentrations of bioactive compounds. Among the pigments evaluated, anthocyanin was predominant in the samples tested, with values similar to those reported by Lima et al. (2002) who observed levels of total anthocyanins in the purple pitanga pulp of 26 mg.100 g -1 . This finding is characteristic of the fruit, since the major pigment of pitanga is anthocyanin, which increases its concentrations according to the maturation period (Lima et al., 2002).
The yellow flavonoid values were also similar to those found by Lima et al. (2002) in the purple pitanga pulp (18 mg.100 g -1 ). According to Malaman et al. (2011), pitanga is rich in phenolic compounds and these are normally present in the form of esters, glycosides and many of them are flavonoids.
According to Silva (2010), the absence of bacteria in certain foods may be due to conditions that disadvantage their survival, as low pH and strains injured by the manufacturing process, in this case, exposure of fruits to high temperatures. The high levels of soluble solids and the humidity obtained can also ensure the microbiological stability of the product (Vieira et al., 2017).
These data also suggest that there were adequate processing procedures, such as sanctification of the fruits and equipment used, in addition to the effectiveness of the conservation methods employed. The combination of all these characteristics allows the microbiological stability of the product, making it an alternative to prolong the useful life of fruits and their derivatives.

Conclusion and Suggestions
It was possible to verify that the fruit of the pitangueira has good potential for production jellies and candies, no need to add sugar in large proportions.
Thus, the jelly in proportion of 50% of sugar and the candy formulated with 40% sugar were characterized with optimal nutritional properties, due to decreased sugars (sucrose, glucose) and attractive color aspects. Furthermore, the processing performed was effective, obtaining products with interesting nutritional potential and physical-chemical and microbiological quality within normal standards.
However, it is necessary to continue the study in order to assess the sensory quality of jellies and paste candies, besides possible functional characteristics (e.g., antioxidant properties), derivatives to the biotive compounds present in the formulations.