Physical and organoleptic characteristics of jelly candy from beetroot (Beta vulgaris L.) and red dragon fruit skin (Hylocereus polyrhizus)

Jelly candy is made from fruit juice and gelling ingredients as well as additional sweeteners. Jelly candy ingredients are often used as an alternative snack for people with diabetes, and contain nutrients and are high in fiber, so that they can meet nutritional needs and as well as help people avoid hyperglycemia. This study aims to investigate the physical and sensory characteristics of jelly candy made with natural coloring agents from beetroot and red dragon fruit skin. This study was designed by examining 3 (three) variables, namely: 1) type of dye (P), gelling agent (G) and the ratio of stevia:sucrose (R). The parameters analyzed were physical (texture and color) and organoleptic properties (color, aroma, taste and texture). The results showed that the texture, color (L*, a*, and b*), and organoleptic (color) parameters were influenced by the addition of coloring agents (P). The value of texture, color (b*), and organoleptic (color) are all impacted by the inclusion of gelling agents (gelatin and pectin). The textural value is influenced by the stevia: sucrose ratio. Based on the analysis, the best treatment was the combination of red dragon fruit skin with gelatin and stevia: sucrose ratio of 0%:30% with the texture value (10.03 g/mm), color *L (26.27), a*( 15.47), b*(8.27) and organoleptic properties (color) was 3.39-3.44 (neutral).


Introduction
Jelly candy is made from a mixture of fruit juices, gelling agents and other additional sweeteners.Jelly candy can be used as a source of energy because it can quickly replace the energy lost during work, and people like jelly candy because of its unique properties [1].The characteristics of jelly candy are that it is clear (transparent) and has a chewy texture.Mufida et.al. [2] stated that jelly candy is a soft candy and is a type of solid snack made from sugar or a mixture of sugar and sweetener.
Jelly candy which can be consumed as an alternative snack for people with diabetes , must contain nutrients and should be high in fiber so that the nutritional values can be met to avoid hyperglycemia [3].Ingredients such as beetroot and red dragon fruit skin are included in the group of ingredients to fulfill these requirements.Beetroot has nutritional content in the from of 13.6% cellulose fiber, vitamin A, vitamin B and vitamin C [4].According to Setiawan et.al. [5], beetroot contains betalain pigment and has anti-cancer properties.Another natural dye that is good for human health is the skin of red dragon fruit which contains anthocyanin.Natural sweeteners are also needed to minimize the 1297 (2024) 012081 IOP Publishing doi:10.1088/1755-1315/1297/1/012081 2 use of artificial sweeteners and increase the nutritional value of jelly candy.The sweeteners used are stevia and sucrose.
An important factor that influences the quality of jelly candy is the gel formation.The gel formed is greatly influenced by the gelling agent, pH, temperature and electrolyte components [6].Therefore, the best ingredients with a certain formulation are needed to obtain the best quality jelly candy.The gelling agents used in this research were gelatin and pectin.
Currently, there are different types of jelly candies which sometimes use non-food colorings agents and artificial sweeteners.If these products are consumed continuously, they can be harmful to human health.This research aims to determine the effect of the addition of natural coloring agents from beetroot and red dragon fruit skin, the ratio of sweeteners (stevia: sucrose) and type of gelling agents (gelatin and pectin) on the physical and sensory characteristics of jelly candy.

Research Materials
The ingredients used in this research were beetroot and red dragon fruit skin which were obtained from traditional markets in Banda Aceh while gelatin (Hakiki brand), pectin, stevia, sucrose, citric acid and mint essence were obtained rom supermarkets in Banda Aceh.

Research procedure.
Preparation of beetroot juice and red dragon fruit skin is referred to Multiningsih et.al. [8].
 First, beetroot and red dragon fruit skin were cleaned of dirt and washed thoroughly. Beetroot (250 g) was peeled while the skins of red dragon fruitwas collected (250 g). Both ingredients were washed until clean, then cut into smaller pieces, grinded and water was added with a ratio of 1:2. The extract was filtered with a filter cloth to obtain beetroot and red dragon fruit skin extracts.

2.4
The process of making jelly candy [9].A measurement of 150 ml each of beet tuber extract or red dragon fruit peel was taken, heated at 80 ºC, then stevia and sucrose were added in a ratio of 0:30%, 10:20%, 20:10% and 30:0%.Next, 25 grams of gelling agent was added, namely gelatin or pectin, which was then stirred for 5 minutes until the solid ingredients were dissolved up to at least 65%.Then the temperature was lowered to 40ºC, and 1 ml of mint essence and 0.5 gram of citric acid were addedand stirred again, and then the heat was turned off.The mixture was then poured into a molding container and left to cool at room temperature 25-30ºC for ± 1 hour.The mixture was then placed in the refrigerator at 50ºC for 24 hours.After removing the mixture from the refrigerator, the jelly candy is left at room temperature for ± 1 hour.Finally, the jelly candy is removed from the mold and analyzed.
2.5 Physical Analysis 2.5.1 Texture Test.Texture testing was carried out using an LFRA (Leatherhead Food Research Association) texture analyzer (Brookfield), to see the hardness, elasticity and stickiness of jelly candy products.The research procedure consists of the product being pressed using an LFRA texture analyzer with a certain pressing depth, and then the resulting measurement results are displayed in graphical form.Hardness is seen from the peak value at the first pressure, elasticity is calculated from the comparison of the distance traveled by the product at the second pressure and the first pressure.Stickiness is calculated by multiplying the hardness value by the area under the curve on the second press and divided by the area under the curve on the first press [10].

Color Test.
Color analysis used an LS171 colorimeter with the Hunter L* (black-white), a* (green-red) and b* (blue-yellow) color systems.The chromameter was first calibrated with the standard white color found on the tool.Then the roller (colorimeter locating plate) was placed on top of the sample.The button is then pressed and then two seconds must be allowed to pass.The results of the white degree analysis produced are the values L*, a*, b*.The color base used as the standard is white for measuring the total color degree [11].

Organoleptic (Hedonic).
This test involved 25 semi-trained panelists and the parameters tested included color, aroma, texture and taste.The numerical scale used was a value of 1 to 5. The values were (1) really don't like, (2) don't like, (3) neutral, (4) like, and (5) really like.For data analysis, the scale was converted into numbers so that statistical analysis could be carried out [12].

Results and discussion
3.1 Physical Analysis 3.1.1Texture Test.The texture of jelly candy is an important parameter to determine the level of elasticity of the resulting product, and to determine whether the product is hard or soft.There are several factors that influence the texture of jelly candy, namely water content, sugar concentration and pH.The results of variance analysis showed that the type of dye (P), the type of gelling agent (G), and the sugar ratio (stevia:sucrose) (R) as well as the interaction of the three treatments (PGR) have a very significant effect (P≤0.01) on the texture value of the candy.The average texture analysis results can be seen in Figure 1.The results (Figure 1) show that the highest texture value (15.57g/mm) was obtained by adding beetroot coloring with the gelling agent gelatin and a stevia:sucrose sugar ratio of 10%:20%.The lowest texture value (3.50 g/mm) was obtained by adding red dragon fruit skin coloring with pectin gelling agent.In the treatment, the sugar ratio of stevia:sucrose 30%: 0% showed a decrease in the texture value for all types of dyes and gelling agents.Handayani et.al. [13] wrote regarding the coffee jelly candy using 60% and 40% sucrose, and they obtained texture values of 97.27 g/mm and 25.87 g/mm.These texture values are different from this research in that when using the stevia:sucrose sugar ratio (10%:20%) the highest texture value was obtained at 15.57 g/mm.This shows that sucrose has a significant influence on the texture of jelly candy.Sucrose also plays a significant role in making the texture of jelly candy harder.
Simorangkir et.al. [14] in his research found that by adding 25% sucrose produced a jelly candy texture that was slightly chewy and did not crystallize.This is due to the presence of glucose syrup which preventsthe crystallization process.The added sucrose plays a role in forming a soft gel.Adding too much sucrose can cause crystallization on the surface of the gel and if there is too little sucrose a soft gel will form.The texture of a candy can be felt with the mouth or touched with the fingers and is an important parameter in jelly candy products.
Gelatin produces a textured gel [15], this is in accordance with this research which has the highest texture value (15.57g/mm) when adding gelatin as a gelling agent.The advantages of gelatin are when heated it will melt and when cooled it will form a gel again (heat reversible).The characteristic properties of gelatin are that it is tasteless, odorless, colorless, soluble in water and is an acetic acid.Jelly candy made from gelatin has a more elastic texture compared to pectin [16].

Color Test.
Color is an important attribute for the appearance offood ingredients.Color testing was carried out using the Hunter color system L*(black-white), a*(green-red), b*(blue-yellow) in accordance with Kaemba et.al.[17].According to Leonet.al.[18], the L* value represents brightness which has a value of 0 (black) to 100 (white).The a* value represents reflected light that produces a mixed chromatic color of green-red with red (+127) and green (-128) values.The b* value represents a mixed chromatic color of blue-yellow with a yellow value (+127) and a blue value (-128).
Based on the results of variance analysis, it shows that the L* and *a values have a very significant effect (P≤0.01) on the type of dye (P).Meanwhile, color b* has a significant effect (P≤0.05) on the type of dye (P) and the type of gelling agent (G).The average color analysis results can be seen in Tables 1 and 2.  The measurement results (Table 1) show that the highest L* value (26.27) was obtained for the sample with red dragon fruit skin dye, while the L* value for the sample with beetroot dye was around 16.85.A higher L* value indicates a brighter color.Conversely, a lower L* value indicates a darker color.Differences in the stability of natural colors in food products are influenced by several factors, namely pigment concentration, pH, Aw, light, iron, enzymes, temperature and product processing time [19].
The highest a* value was found in the sample with red dragon fruit skin dye with a value of 15.47, while the lowest a* value was 4.24 with the addition of beetroot dye.A high value indicates that the sample color is closer to red.This is in accordance with the color appearance seen in Table 1.This is different from the b* color values (Table 2) which obtained positive and negative b* values.The difference in these values shows that the dominant high b* value indicates that the sample color is close to yellow and the lower the b* value, the sample color is closer to blue.The highest b* value (8.27) was found from adding red dragon fruit peel with gelatin, then the lowest value (-0.24) was obtained from adding beetroot and pectin.
A study by Nizori et.al. [20] related to natural dyes from red dragon fruit peel extract obtained values L* (39.44-49.67),a* (59), and b* (14).Research by Lembong and Utama [21] related to natural dyes from red beets obtained values L*(5.70-6.01),a*(4.36-9.02)and b*(0.20-2.33).This value is close to the research results obtained according to the data (Table 1 and Table 2).Based on the colors in Table 1 and Table 2, beetroot juice has betacyanin pigment (red-violet) and purple pigment, while the color of red dragon fruit peel juice is red.This color is caused by the anthocyanin content which is influenced by pH.At pH 1-4 (acid) anthocyanin is red and if the pH increases to neutral or alkaline it will be purple to blue [22].

Organoleptic (Hedonic) Test 3.2.1 Color.
Color plays an important role in determining consumer perception and influences consumer attraction [23].Color is also a factor that must be considered in product development because the panelists will assess a product visually.The research results show that the type of dye (P) has a very significant effect (P≤0.01) and gelling agent type (G) significantly effects (P≤0.05) the organoleptic (color) of jelly candy.The average data from the analysis results can be seen in Figure 2 and Figure 3.The results (Figure 2) stated that the highest color value of 3.44 was obtained from red dragon fruit skin dye, while the lowest color value was 3.15 for beetroot.Based on the graph, there is no difference between the addition of beetroot and red dragon fruit skin.In the DMRT0.05,the effect of the type of gelling agent (Figure 3) on the color value of jelly candy also showed results that were no different from the gelling agent used, where the highest color value was 3.39 (neutral) (gelatin) and the lowest was 3.39 (neutral) of pectin 3.20 (neutral).This shows that after treatment with beetroot and pectin, the color indicator of the jelly candy decreased.This decrease is thought to be caused by the addition of beetroot juice and pectin and sucrose when producing jelly candy so that ittends to be come darker.The use of pectin and sucrose in a product produces a darker color due to the Maillard reaction.The Maillard reaction is a reaction that occurs between reducing sugars and amino acids due to heating [23].According to Wahyuni [24], panelists don't like dark colors because they are less attractive, thus the panelists prefered bright colors.This decrease made the panelists' assessment of the color attribute of beetroot jelly candy lower.The following is the appearance of beetroot jelly candy and red dragon fruit skin in Figure 4. Aroma is one of the parameters that can be observed with the sense of smell.The aroma that is smelled can be measured, giving rise to various opinions in assessing the quality of the aroma.Differences in opinion are caused by each person having a different sense of smell [23].Based on variance analysis, it showed that the type of dye (P), type of gelling agent (G) and sugar ratio (stevia:sucrose) had no significant effect (P≥0.05) on the organoleptic (aroma) of the jelly candy so no further testing was carried out.
The organoleptic assessment of the aroma of beetroot jelly candy and red dragon fruit skin has a value range of 2.82-3.56.The results of the organoleptic aroma test on jelly candy showed that the highest aroma parameter value 3.56 (neutral) was found in the beetroot samples with gelling agent and the stevia:sucrose sugar ratio (10%:20%).The lowest aroma value was 2.82 (don't like) and was obtained in samples of red dragon fruit skin with gelling agent and the addition of a stevia:sucrose sugar ratio (30%:0%).Based on these results, beetroot has a preferred aroma value than red dragon fruit skin.This is because the panelists like the distinctive aroma of beetroot.Beetroot has a distinctive earthy taste [25].

Taste.
Taste is one of the determining factors of the quality of a product, and is most closely considered by consumers after color.There are several factors that influence taste, namely chemical compounds, temperature, concentration and interactions with other flavor components.Taste is also a very important component in determining the level of consumer acceptance [23].Based on variance analysis, it shows that the type of coloring (P), the type of gelling agent (G) and the stevia:sucrose sugar ratio do not have a significant effect (P≥0.05) on the organoleptic (taste) of the jelly candy, so no further tests were carried out.
The taste assessment of beetroot and red dragon fruit peel jelly candy has a value range of 2.90-3.64.The results of the organoleptic taste test for jelly candy showed that the highest taste parameter value was 3.64 (neutral) and was found in samples of red dragon fruit peel with gelling agent, and a stevia:sucrose sugar ratio (0%:30%).The lowest aroma value of 2.90 (don't like) was found in the beetroot sample with gelling agent and the addition of the stevia:sucrose sugar ratio (20%:10%).Based on these results, the panelists preferred red dragon fruit skin jelly candy with a stevia:sucrose sugar ratio (0%:30%) to beetroot jelly candy with the addition of a stevia:sucrose sugar ratio (20%:10%).This is thought to be because the addition of stevia and sucrose sugar greatly influences organoleptic parameters.The decrease in panelists' like ability was caused by the addition of different concentrations of stevia and sucrose.If a high amount of sucrose is added, it will affect the sweet taste of the jelly candy, while adding too much stevia will produce a slightly bitter taste [26].

3.2.4
Texture.One of the properties of the product is that it can be felt by touching the skin.The chewy texture can be observed by tasting the product and is felt by pressing the product between the roof of the mouth and the tongue [27].Based on variance analysis, it shows that the type of dye (P), the type of gelling agent (G) and the ratio of stevia sugar: sucrose do not have a significant effect (P≥0.05) on the organoleptic (texture) of jelly candy, so no further testing was needed.
Organoleptic assessment of the texture of beetroot jelly candy and red dragon fruit skin had values ranging from 2.74 to 3.28.The results of the analysis of the texture value of jelly candy showed that the highest texture parameter value, namely 3.28 (neutral), was found in the beetroot sample with gelling agent (pectin) and the stevia:sucrose sugar ratio (10%:20%).The lowest texture value, namely 2.74 (don't like) was found in the beetroot sample with gelling agent (gelatin) and the addition of the stevia:sucrose sugar ratio (30%:0%).Based on these results, the beetroot jelly candy with the stevia:sucrose sugar ratio (30%:0%) was rated better by the panelists than the beetroot jelly candy with the addition of the stevia:sucrose sugar ratio (10%:20%).This is thought to be because there was no addition of sucrose so the panelists did not like it [28].

Conclusions
Based on the results of the research that has been carried out, it can be concluded that beetroot jelly candy and red dragon fruit skin have a significant influence on the brightness of the colors (L*, a*, and b*) produced.The organoleptic results (color) did not show a significant influence by the panelists.The addition of gelatin and sucrose produced a chewier texture for the resulting jelly candy.

Figure 1 .
Figure 1.The texture values of jelly candy based on the type of coloring and gelling agents and stevia:sucrose sugar ratio (numbers followed by the same letter indicate the results are not significantly different)

6 Figure 2 .Figure 3 .
Figure 2. Graph of the influence of the type of coloring (P) of jelly candy on the color value (numbers followed by the same letter indicate the results are not significantly different)

Table 1 .
Color Analysis Values L* and a* of Jelly Candy Note: Numbers followed by the same letter indicate results that are not significantly different

Table 2 .
Color Analysis Value b* of Jelly Candy Note: Numbers followed by the same letter indicate results that are not significantly different