Abstract

The present work had as objective the development of three cupuassu candy formulations, varying the type and concentration of the sweetener, and evaluation of the physical-chemical, microbiological and sensory characteristics during 180 days of storage. The cupuassu pulps used were obtained from the local market in the city of Imperatriz-MA. The three formulations were produced with partial substitution of sucrose, being cyclamate/saccharin in F1, sucralose in F2 and stevia in F3. The other ingredients were sugar and pectin. The candies were standardized at 70ºBrix and analyzed for pH, soluble solids content, titratable acidity, total sugars and reducing sugars. For microbiological analyzes, molds and yeasts, aerobic mesophilic bacteria and thermotolerant coliforms were analyzed. Sensory analysis was performed using the hedonic scale, the intention to purchase the product using the structured 5-point scale and the attributes acidity and sweetness using the Ideal scale. For the analysis of the results, a randomized block experiment was considered, studying the stability (0, 45, 90, 135 and 180 days) of the physical-chemical, microbiological and sensory characteristics for the three formulations mentioned above. In formulations F1, F2 and F3 there was a significant variation for pH and acidity; pH and SST and; pH, SST, total and reducing sugars, respectively, during the 180-day storage period. Microbiological analyzes showed the absence of all analyzed species, and the sensory attributes, purchasing attitude and ideal scale did not differ according to time for the three formulations, except for color and texture, for the quadratic model of formulation 3.

1. Introduction

The current consumer has been adapting to healthier eating habits and consequently eating less caloric foods. Based on this, there is a noticeable increase in the supply and diversification of these products, by the market, to supply this demand ¹. Among them is the fruit jam, increasingly spreading in the market due to its high acceptability, high nutritional power and long shelf life ².

According to the National Health Surveillance Agency - ANVISA, the paste or candy mass is the product resulting from the proper processing of the disintegrated edible parts of vegetables, with or without the use of water, added with sugars, pectin, acids, other ingredients and additives allowed, to acquire the desired consistency, and packaged to guarantee its conservation ³.

Candies are processed food products consisting mainly of fruit and sugar, much appreciated by the consumer in general. However, due to several reasons related to nutritional aspects, sugar intake, especially sucrose, is not advisable, increasing the demand for products that have substitutes for this compound ⁴. For this purpose, sweeteners are used, which can be natural or artificial.

Also, sweeteners can be divided into nutrients, which includes the sugars of alcohols (erythritol, sorbitol, mannitol, xylitol, maltitol and lactitol) ⁵, and non-nutritious (not metabolized by the body) or low-calorie, such as acesulfame potassium, aspartame, vantame, neotame, saccharin, sucralose and stevioside (sweet extract obtained from Stevia rebaudiana) ⁶. About these, saccharin has a sweetening power about 300 times greater than sucrose, however, it often reveals a bitter taste; cyclamate, 30 to 50 times higher than sucrose, and has an unpleasant bittersweet aftertaste ⁷; and Stevia rebaudiana, which also has about 300 times the sweetening power compared to sucrose, and is widely applied in the food industry due to its stability against heat and a wide pH range ⁸.

Cupuassu, as it has a wide variety of volatile compounds, which contribute to the richness of its flavor and aroma, has increasingly aroused the interest of the national and international market for the production of high quality sensory and nutritional products, such as jams, bulk juices and sweets ^{9, 10}. It comes from a tree native to the Amazon, and its economic value is deposited in the pulp, which has a light-yellow color, is acidic and fibrous, with an intense and pleasant aroma, in addition to high nutritional value, which makes it highly appreciated ¹¹.

Therefore, the aim was to develop three cupuassu candies formulations, using different types and concentrations of sweeteners and to verify their stability during 180 days of storage.

2. Material and Methods

The candies elaboration process was carried out at the Vegetable Processing Laboratory, analyzed at the Cereals and Food Microbiology Laboratory and sensorially evaluated at the Sensory Analysis Laboratory, both from the Advanced Campus of the Federal University of Maranhão (UFMA) in the city of Imperatriz - MA. Pasteurized and frozen cupuassu pulps were used to prepare the light candy, and the cyclamate/saccharin, sucralose and stevia sweeteners obtained from the local market in the city of Imperatriz-MA.

Three formulations were prepared, in triplicate, called F1, F2 and F3, respectively (Table 1), with partial substitution of sucrose by the respective sweetener. The other ingredients, for all formulations, were crystal sugar and pectin.

The pulp was thawed and transferred to an open pan, where cooking was carried out at atmospheric pressure, mixing manually. Sugar and the sweetener (according to the previously established formulation) were added gradually, along with the other ingredients, and then concentrated to the desired point (70 ºBrix).

The research project was registered at Brazil Platform and approved by the Research Ethics Committee under number 3.469.507.

Upon reaching the desired point of approximately 70 °Brix, the cadies were placed in glass containers, with a metallic lid, previously sterilized in an autoclave and then cooled in a cold-water bath for 15 minutes and then stored at room temperature.

After the preparation of the three formulations, the physical-chemical, microbiological and sensory characteristics were determined every 45 days, during 180 days of storage.

For the three analyzes (physical-chemical, microbiological and sensory), a stability study was carried out every 45 days for 180 days. They were evaluated employing regression analysis at 5% significance using the procedure (PROC REG) of the SAS statistical package ¹². Only models of up to third-degree (cubic), with a determination coefficient (R2) above 0.70 (70%) were considered. Data tabulation and graphs were made in Microsoft Excel 2016.

The three formulations were analyzed for pH, soluble solids content, acidity, total sugars and reducing sugars. The analyzes were performed in triplicate, according to the methodologies indicated by the Analytical Standards of the Adolfo Lutz Institute ¹³.

Microbiological analyzes were carried out following the methodology described by APHA (American Public Health Association) ¹⁴, where the Most Likely Number of total and thermotolerant coliforms (NMP g-1), mold and yeast count, and aerobic mesophilic bacteria, for all repetitions.

The sensory analysis was performed at the Sensory Analysis Laboratory of the Advanced Campus of the Federal University of Maranhão (UFMA) in the city of Imperatriz - MA, where 100 untrained testers of both sexes were recruited, with interest and availability to collaborate with the research. For participation, the tasters signed a consent form. The characterization of the team was carried out by applying a questionnaire, together with the sensory analysis form, to collect data on age group, sex, education and consumption habits related to the product under study.

Each individual received a plastic container encoded with random three-digit numbers, containing about 15g of the sample at room temperature. The samples were accompanied by water and salt biscuit and water for rinsing the mouth between the evaluations of each sample. The tasters were positioned in individual booths, where they were instructed to observe the overall characteristics of the product and to fill in the answer sheets.

The order of presentation of the samples was completely balanced ¹⁵. The overall acceptability was evaluated by a test on a hedonic scale of nine categories (1 - "highly disliked" 9 - "highly liked") ¹⁶, indicating how much they liked or disliked the samples about color, aroma, flavor, texture, acidity and overall impression.

The attributes of acidity and sweetness were individually evaluated on an ideal scale, where they ranged between “+3” for “Much stronger than ideal” and “-3” for “Much less strong than ideal”. The buying attitude for candies was also evaluated, where the taster can choose between 5 options, ranging from “certainly would buy” to “certainly not buy” ¹⁷.

It was considered an experiment in randomized blocks, where the types of cupuassu candy light were the treatments (F1, F2 and F3) and the tasters were the blocks, to evaluate the stability (0, 45, 90, 135 and 180 days) of the sensory attributes (color, aroma, flavor, texture, acidity, global impression), buying attitude, as well as, the ideal scale for acidity and sweetness.

3. Results

Table 2 shows the results of the physical-chemical analyzes of formulations F1, F2 and F3, during times 0, 45, 90, 135 and 180 days.

Studying the stability (0, 45, 90 and 135 days) of these characteristics for the three formulations, significant variations in pH and acidity were observed for formulation 1, pH and SST for formulation 2 and, pH, SST, total and reducing sugars for formulation 3, as shown in Table 3.

The results of candy acceptance, in the 5 studied times, regarding the attributes color, aroma, flavor, texture and acidity are presented in Table 4.

The results of the acidity and sweetness attributes, assessed individually using the ideal scale, are shown in Table 5.

The results of the acidity and sweetness attributes, assessed individually using the ideal scale, are shown in Table 6.

4. Discussion

The pH values of the three formulations did not show significant differences between them, but they varied with time. However, this value is still considered satisfactory, since it is below 4.5, hindering the proliferation of several microorganisms, in addition to being under the limits established by Brazilian legislation ¹⁸.

The results of the acidity variation for F1 showed changes according to time, with an increase in these values, with R2 equal to 0.628. Formulations F2 and F3 did not show significant variations during the study period.

The results of pH and titratable acidity of the products, confirm a slight reduction of dissociated ions of both formulations elaborated in relation to cupuassu pulp, where this reduction can be attributed to the addition of sucrose that corrects it, displacing the ionic balance. As verified by ¹⁹ that analyzed cupuassu candy with partial substitution of sucrose for sucralose sweetener.

A high content of soluble solids is observed, due to the addition of sucrose and sweeteners, according to the formulation. The variation observed between the three formulations, although not significant, is due only to the cooking time of the product. According to Table 2, the formulations F2 and F3, varied according to the time, having an increase in the values, however, without adjustment of the model, presenting R2 equal to 0.1512 and 0.3925, respectively. Formulation F1 did not show significant variation in TSS during 180 days. A result similar to that found in a study of the characterization and stability of sweet in mango tamarind paste ²⁰.

The results of the variation of total and reducing sugars for F3 showed changes according to time, with an increase in these values, but the model did not adjust according to what was proposed in the methodology, presenting R2 equal to 0.2712 and 0.2888, respectively. Formulation F1 and F2 did not show significant variations during the study period.

As for the levels of reducing and total sugars, it is possible to observe a smaller amount of reducing sugars in F2 in relation to the others, however, this decrease is not so marked due to the low concentration of sucralose in the product. ¹⁹ verified a lower amount of reducing sugars due to the low concentration of sucralose, in his analysis of cupuassu candy with partial substitution of sucrose by sucralose sweetener, when compared with conventional candies. The same result was found by other authors in the study of sweet light strawberry, where the percentages of sugar in formulations with partial substitution of sucrose, were considerably lower, compared to the standard formulation ²¹.

Studies indicate that sucralose is stable at high temperatures, however, some authors claim that in the presence of low pH and high temperature, it can be modified, interfering in this case in the amount of total sugars, which would justify the higher values of total sugars for F2 ²².

The microbiological analyzes of the three formulations, at all times, showed an absence of mold and yeast count (<10 CFU/mL), mesophilic aerobes and thermotolerant coliforms, according to the microbiological standard described by the RDC nº12/2001, showing that the samples were processed with adequate sanitary hygienic conditions and, consequently, present microbiological safety to be consumed and commercialized ²³. The same result was observed in the tamarind candy stored for 60 days ²⁰, in cupuassu candy produced by substituting sucrose for sucralose ¹⁹ and sugar cane candy with roasted peanuts and extruded rice bran ²⁴.

In relation to the sensory analysis, the notes for all evaluated attributes were presented in the acceptance zone, varying between the categories “I liked moderately” and “I liked too much” the hedonic scale, thus indicating an acceptance of these formulations. ²⁵, when studying the development and evaluation of the physical-chemical characteristics and the sensory acceptance of sweet in cupuassu candy, he observed the same in two of its formulations, where the AI (acceptance index) of at least 70% was reached, showing that the cadies were well accepted. A similar result was observed in the analysis of kinnow peel candy, which presented above note 7 for the flavor attributes, appearance, color, texture, aroma and mouth feel, during 60 days of storage ²⁶.

For the attributes color, aroma, flavor and texture, the three formulations had percentages higher than 7.00, demonstrating that the composition of the product did not affect the acceptance of the tasters. Regarding acidity, the three formulations showed values slightly below 7.00, probably due to the acidity characteristics of the cupuassu pulp. Given these results, it is noted that changes of this nature in the composition of the product, do not significantly alter these sensory attributes. This result was also observed in the study of pineapple light jelly ²⁷.

Analyzing the global impression results, it is possible to verify that the three formulations were well evaluated, confirming the acceptance percentages presented in the sensory attributes analyzed. Regarding the buying attitude, values ranging from 1 to 3 were observed, which correspond to attitudes of “certainly buy”, “probably buy” and “I have doubts if I would buy”, respectively. F2 obtained greater purchase intention, among the samples, however, the majority of the tasters evaluated the three formulations of the product positively, reflected in the notes applied to the other attributes.

In relation to acidity and sweetness, were obtained values ranging from -1 to 1, which correspond to the description of “slightly less strong than ideal”, “ideal” and “slightly stronger than ideal”, respectively. It can then be seen that the attributes acidity and sweetness, assessed individually using the ideal scale did not vary and that they are within the ideality profile, characterized by the score 0.

The scores of some tasters in "disliked a lot" and "disliked slightly", may have been influenced by the high residual flavor due to the use of sweetener, reinforced by comments like "strong flavor" and "bitter taste". Saccharin, approximately 300 times sweeter than sucrose, is known to reveal bitter and metallic aftertaste, even at low concentrations ²⁸.

From the regression analysis, it can be said that the sensory attributes did not differ statistically between the samples in both the linear and quadratic models, except for the quadratic model for color and texture in formulation F3 (Table 6). However, looking at the grades table (Table 2), it can be seen that the grades for these attributes are within the region of acceptance (above 7), leading to a belief that this change over time was not significant to the point of change the quality of the product. Therefore, it should be noted that the use of sweeteners did not influence the sensory evaluation of candies, indicating that partial substitution of sucrose in the cupuassu candy production is technologically feasible since the products had good sensory properties.

5. Conclusion

Through the experiments carried out, it was possible to develop three formulations of cupuassu candy light, using different types and concentrations of sweeteners, with a characteristic fruit aroma and flavor. The stability evaluation, during 180 days of storage, showed that some physical-chemical characteristics (pH and acidity in F1; pH and TSS in F2 and; pH, TSS, total sugars and reducers in F3) varied significantly, while the microbiological characteristics and sensory factors remained constant. However, these characteristics did not negatively influence the acceptance of the product, making it viable for commercialization.

Conflicts of Interest

All authors declare no competing interests.

Acknowledgments

Authors thank the University Federal of Maranhão for all the support during the experiments.

References