The effect of sago starch-based edible coating on the quality of red bell peppers (Capsicum Annuum L.) during storage

Red bell pepper is categorized as a perishable horticultural commodity with a short shelf life. Damage in red bell peppers is generally characterized by changes in the texture of fruits, wrinkled and other damage due to improper storage. Proper postharvest handling must be done to maintain product quality and prevent spoilage. Efforts are being made to keep red bell peppers fresh and shelf life by applying an edible coating. This study aimed to determine the effect of the concentration of sago starch as the ingredient for edible coatings with the addition of glycerol to maintain the quality of red bell pepper (Capsicum annuum L.) during storage at cold temperatures of ±10 °C and room temperature of ±27 °C. The edible coating based on the sago starch application method used is the dipping method with different concentrations (control, 100 g sago starch, and 200 g sago starch) stored at a cold temperature of ±10 °C and a temperature of room ±27 °C. Data analysis was carried out by measuring several parameters, weight loss, color, hardness, and total dissolved solids. The study of variance (ANOVA) showed that applying edible coating based on sago starch to red peppers could significantly affect weight loss and the level of fruit hardness but had no significant effect on changes and total dissolved solids contained in red peppers. Overall result treatment, the best treatment for maintaining the quality of red peppers during storage was edible coating based on sago starch with a concentration of 200 g and adding 10% glycerol with cold storage at ±10 °C (A3B1).


Introduction
Red bell peppers have high selling value due to their nutritional content but are easily perishable, easily damaged, and have a short shelf life due to their susceptibility to high-temperature storage [1].One way to maintain their quality is through proper postharvest handling, including the application of edible coatings.Edible coatings can extend the shelf life of fruits and vegetables by reducing respiration and evaporation and are usually applied by dipping the product into the coating solution [2].
Sago starch can be used as the primary material for edible coatings due to its high amylose content, which allows it to form a gel and stick to fruits and vegetables [3].Plasticizers were added to the edible coating to increase the flexibility of the coating and reduce peeling [4].
This study is to determine the effect of the concentration of sago starch as a primary ingredient for edible coatings with the addition of glycerol to maintain the quality of red peppers (Capsicum annum L.) during storage at cold temperatures of ±10 ˚C and room temperature of ±27 ˚C.It is used for making edible coatings based on sago starch and as a reference for further research.

Objective of the research
The purpose of this research is to determine the effect of the concentration of sago starch as a basic ingredient for edible coatings with the addition of glycerol to maintain the quality of red bell peppers (Capsicum Annum L.) during storage at cold temperatures of ±10 ˚C and room temperature of ±27 ˚C.Its use as a reference in making edible coatings based on sago starch and as a reference for further research.

Time and Place
This research was conducted during June 2022 until July 2022, at Laboratory of Processing, Agricultural Engineering Study Program, Hasanuddin University, Makassar, South Sulawesi.

Tools and Materials
The tools used in this study were used analytical balance, 1000 ml measuring cup, digital thermometer stick, thermometer hygrometer, refrigerator, digital fruit durometer stand, colorimeter, digital refractometer, induction cooker, mobile phone stopwatch, mortar and pestle, 80 mesh sieve, saucepan and foam tray.
The materials used in this study were red bell peppers obtained from the Tombolo Pao District, Gowa Regency, sago starch obtained from Jaya Village, Telluwanua District, Palopo City, glycerol, and distilled water.

Research procedure
This research experimentally used a completely randomized design (CRD) with three treatments or six experimental units obtained.Each experiment was repeated twice.therefore, the total sample required was 48 (forty-eight).Red bell peppers harvested from farmers were sorted based on fruit weight and uniform color.As well as ensure that the selected peppers are not damaged or physically disabled.

Material Preparatory.
Prepare red bell peppers obtained from farmers, sort them based on fruit weight and uniform color.As well as ensure that the selected peppers are not damaged or physically disabled.

The Process of Sago Starch Edible Coating
Making.The process of making sago starch edible coating solution is carried out as follows: 300 g of sago starch was sieved using an 80 mesh sieve.Next, dissolve 100 g and 200 g of sago starch in a measuring cup containing 1000 ml of distilled water each.Then, heat the solution using an induction cooker, stirring the solution of sago starch and distilled water until homogeneous.Glycerol with a concentration of 10% was added into a mixing solution of sago starch and distilled water.Then heat the edible coating solution at 70 ˚C for ± 10 minutes until it thickens.Furthermore, the resulting solution was stored at room temperature.

3.3.3.
Coating Process for Red Bell Peppers.The process of coating sago starch on red bell peppers is using the dipping method, while the application stages are as follows: First, wash red peppers using clean water, then dry them using an air dryer.Next, the red peppers dipped in the sago starch edible coating solution for 3 minutes.Drain the red peppers until the sago starch edible coating layer dries, then place the red peppers on a tray.

Weight Loss
During the storage process until the 16th day, red peppers experienced weight loss.The increase in the percentage of red pepper weight loss occurred because it was still undergoing respiration after fruit harvesting, resulting in decreased fruit quality.The chart below is shown the analysis of weight loss during storage at cold temperatures: Figure 1 shows that the weight loss percentage in cold temperature storage has increased.Red pepper samples without edible coating (A1B1) or control at cold temperatures showed the highest weight loss percentage of 26.08%.Red pepper samples coated with edible coating with 100 g sago starch concentration and 10% glycerol addition (A2B1) were lower, namely 21.26%.In comparison, the coated red pepper with an edible coating with a concentration of 200 g of sago starch and the addition of 10% glycerol (A3B1) showed the lowest percentage of weight loss, which was 16.72%.The average percentage of red pepper weight loss shows that the concentration of sago starch in the edible coating  Based on research data, the weight loss of red peppers at room temperature shown in Figure 2 shows that red peppers experienced a decrease in fruit weight during storage at room temperature.Red pepper samples without applying sago starch edible coating had a higher percentage value than those with sago starch edible coating.On the fifth day of storage, red pepper samples without the application of edible coating or control (A1B2) began to increase, where the weight loss percentage reached 15.31% until the last day of storage reached 34.48%.In contrast, the red pepper sample that applied edible coating with a concentration of 200 g of sago starch and 10% glycerol (A3B2) had the lowest weight loss percentage until the last day of storage was 29.32%.However, the red pepper sample that applied edible coating with a concentration of 100 g of sago starch and 10% glycerol (A2B2) had the highest percentage value at the end of storage (day 16), which was 39.90%.This was due to one of the samples experiencing damage.Damage to the sample coated with sago starch edible coating with a concentration of 100 grams (A2B2) was indicated by the growth of mold on the stems of the red peppers, causing the stalks to begin to rot and the flesh of the red peppers to become soft.The growth of mold on red peppers is generally influenced by storage temperature, where mold grows between 25 ˚C -30 ˚C.Room temperature with relatively high humidity can trigger mold growth where water vapor condenses on the surface of red peppers.Widaningrum et al. (2016) stated that mold growth is generally influenced by storage temperature and humidity.[6] Research data shows that storage temperature and duration greatly influence the decrease or increase in weight loss in red peppers.Samples stored at room temperature experienced a much higher shrinkage in fruit weight than cold temperatures.In addition, peppers stored at room temperature experience faster wrinkling of the fruit skin than cold temperature storage and in addition, based on the data obtained shows that the concentration of sago starch as a primary ingredient for edible coatings has an effect on the change in weight loss of red peppers during storage.The results showed that among the three concentrations of edible coating treatments, both cold and room temperature storage, the lowest percentage of fruit weight loss was sample A3 (200 g sago starch concentration with the addition of 10% glycerol).This shows that the concentration of sago starch in the manufacture of edible coatings can reduce the rate of respiration in red peppers so that they can inhibit the loss of water content in red pepper fruit tissue.Other, the application of an edible coating on red peppers acts as a barrier against water vapor, gas, and other dissolved substances.Samples of red peppers with a concentration of 200 g of sago starch with the addition of 10% glycerol (A3) are effective because they can reduce or prevent fruit weight loss.Based on the results of the analysis of variance (ANOVA) using IBM SPSS in table 2, the weight loss percentage data shows a significance result where the p-value is smaller than the 0.05 (5%) significance level, then proceed with a follow-up test (Duncan's test) .Based on the Duncan test conducted, the data showed that the sago starch edible coating treatment significantly affected the percentage of red pepper weight loss during storage.

Fruit Color
Observation of color changes in red peppers is done by displaying the measurement results of the *L value, *a value, and *b value.Data for each sample was carried out at three points, namely the top, middle, and bottom of the peppers, to produce an average value for each sample.The *L value indicates the brightness level of red peppers during storage.Following are the results of the analysis of color changes (Value *L) on red peppers at cold temperatures during storage: Based on data from color analysis (*L value) of red pepper during storage, it shows that red pepper samples display fluctuating data.The brightness level of red pepper samples obtained at each point varies.However, based on the average brightness level of the fruit (L value), it shows that the sample with the highest L value, namely the red pepper sample coated with an edible coating with 100 g sago starch concentration and 10% glycerol addition (A2B1) has a higher brightness value than the white pepper treatment.Meanwhile, the sample with the lowest L value was the red pepper sample coated with an edible coating with a concentration of 200 g of sago starch and the addition of 10% glycerol (A3B1).The difference in the value of fruit brightness (L value) on red peppers did not show a significant difference.A decrease in the *L value occurs, causing the color of the peppers to darken.The decrease in *L value occurs due to the degradation of amino acids, causing the product's color to appear dark.Angga (2007) states that the *L value indicates the brightness level of the fruit; the higher the *L value, the higher the fruit's brightness level.[7]  Based on the results of analysis of variance (ANOVA) using IBM SPSS in table 4, the color change data (*L value) shows insignificant results, which shows the number p-value is more significant than the significance level of 5% (0.05).This shows that the sago starch edible coating treatment had no significant effect on the brightness level of red peppers (*L value).The differences and similarities in the notations behind the numbers in table 4 show that there are fundamental differences and not actual differences in the treatment with the length of storage of red peppers.Based on data from color analysis (value *a) on red pepper samples without being coated with sago starch, edible coating decreased during storage at cold and room temperatures.It shows that red peppers without edible coating (A1) cannot maintain the color of red peppers stored at room temperature and cold temperatures, and in contrast, coated red pepper sample with an edible coating with a concentration of sago starch 100 g (A2) and a sample of red peppers coated with an edible coating with a concentration of sago starch 200 g (A3) which experienced an increase in *a value during storage both at room temperature and at cold temperatures.It shows that red peppers retain their color quality.
The color intensity of the red pepper samples coated with sago starch edible coating, both at a concentration of 100 g and 200 g of sago starch, showed an increasingly reddish color indicating that the red peppers were undergoing a fruit ripening process.In contrast to the sample without edible coating (control), the *a value decreased.The increasing intensity of the red color in red peppers indicates that the carotenoid pigments in red peppers have gradually increased.Kurniawan (2020) stated that red peppers' red discoloration occurs due to pigmentation degradation in the fruit skin, especially chlorophyll and carotenoid pigments.[8]  Based on the analysis of variance (ANOVA) using IBM SPSS in table 6, the color change data (value *a) shows insignificant results, which shows the p-value is more significant than the 5% significance level.It shows that the sago starch edible coating treatment had no significant effect during storage.The notation equation behind the numbers in Table 6 shows that the edible coating treatment has no significant effect on the color change (value *a) on red peppers at cold and room temperatures during storage.Based on the color analysis data (value * b) in the red pepper samples listed in Table 7, it shows that the samples with the three treatments stored at cold temperatures at the start of storage had a positive value indicating that the samples tended to turn yellow, in contrast to the samples stored at room temperature at the beginning of storage it has shown a negative value on the aromatization value of *b which indicates that the red pepper samples tend to turn blue.At the end of storage, changes in color *b values in the six treatments indicated that all samples experienced a decrease in *b values towards the negative, which indicated that the blue color component in red peppers was a more prominent color.The main blue color index indicates that red peppers contain anthocyanin pigments.Based on data from color analysis (°Hue) in red pepper samples listed in Table 9, it shows that the average °Hue values in red pepper samples with three different treatments tended to be the same both at cold and room temperature storage, where paprika samples Red without being coated with sago starch edible coating (A1B1) had a higher °Hue value than samples coated with edible coating with a concentration of 100 g sago starch (A2B1) and samples coated with an edible coating with a concentration of 200 g sago starch (A3B1).Then the samples stored at room temperature were coated with an edible coating with a concentration of 200 g sago starch (A3B2), showed the highest average value compared to samples without being coated with an edible coating of sago starch (A1B2), and samples coated with an edible coating with a concentration of 100 g of sago starch.(A2B2).The decrease in the °Hue value in the red pepper samples occurred due to the ripening process of the fruit.The red color in red peppers is produced by carotenoid pigments, while anthocyanin pigments produce purple in red peppers.Carotenoid and anthocyanin pigments have antioxidant properties which are found in red peppers.Puspita et al. (2018) stated that in addition to containing carotenoid pigments, which give red pigment to red peppers, red peppers also contain flavonoid pigments in the form of anthocyanin pigments as natural pigments that can dissolve in water.Anthocyanin pigments play a role in giving purple and blue pigments to red peppers.[9]  Based on the analysis of variance (ANOVA) using IBM SPSS in Table 10, the color change data (°Hue) of red bell peppers showed significant results on day one and day five, where the p-value was lower than the significance level of 5%.On the 11th and 16th days, the p-value is more significant than the 5% significance level.The differences and similarities in the notations behind the numbers in Table 10 show that the treatment has a significant and no significant effect on the color change (°Hue) of the peppers during storage of red peppers at cold temperatures or room temperature.

Fruit hardness
Data on the results of hardness measurements of red peppers during storage at cold temperatures is shown in the bar chart below: Based on the graph of the hardness of red peppers stored at cold temperatures in Figure 3, it shows that the hardness of red peppers in red pepper samples without being coated with sago starch edible coating (A1B1) decreased by 24.1% at the end of storage on the 16th day with an average hardness level of 0.026 N. In contrast, red pepper samples coated with edible coating with a concentration of 100 g sago starch (A2B1) were able to maintain their hardness at the end of storage, which had an average hardness level of 0.032 N and red pepper samples coated with edible coating with a concentration of  10.5% so that it has an average hardness level of 0.037 N. It shows that samples coated with an edible coating with a concentration of 100 g sago starch (A2B1) could maintain the hardness level of red peppers during storage, and among three samples without edible coating (A1B1), there was a decrease in the highest level of hardness indicated that the fruit experienced significant softening during storage.
The decrease in hardness in the samples without being coated with an edible coating which was stored at cold temperatures, indicated that the samples began to experience softening of the fruit flesh.The softening of red peppers is due to the reshuffling of the cell wall, which is a series of fruit ripening processes.Kusumiyati et al. (2018) stated that fruit softening occurs due to the breakdown of polysaccharides and cell wall compounds from protopectin to pectin, which occurs as part of the fruit ripening process.The enzymes pectinase and cellulase accelerate the process of breaking down the protection.[10] Figure 4. Graph of hardness level (newtons) of red bell peppers at room temperature Red bell peppers stored at room temperature tend to soften faster than samples stored at cold temperatures.The average hardness value of red peppers shows that samples without being coated with sago starch edible coating (A1B2) have a hardness level of 0.021 N, experiencing a drastic decrease of 42.3%.Meanwhile, samples coated with edible coating with sago starch concentration of 200 g had a higher hardness level than the three treatments which were stored at room temperature, which was 0.033 N, with a relatively low decrease of 11.4%.Based on data on the average hardness level of red peppers at cold temperature storage and room temperature, it shows that storage at room temperature cannot reduce respiration and transpiration rates in fruit as part of the metabolic process thus accelerating softening of red bell pepper.Based on Figure 5 shows the average value of total dissolved solids (TPT) at the beginning of storage was 8.6°Brix, and the average value of total dissolved solids (TPT) on the last day of storage (day 16) was 10.2°Brix at the three different concentrations.different cold temperature storage.This indicates that there was an increase in the value of total dissolved solids during storage.The three different types of samples, namely samples without edible coating (A1B1), samples coated with edible coating with 100 g sago starch concentration (A2B1), and samples coated with edible coating with 200 g sago starch concentration (A3B1) tended to experience an increase in total value.dissolved solids (TPT) during storage.An increase in the total dissolved solids (TPT) value indicates the ripening of the fruit.Angelia (2017), states that the more ripe a fruit is, the higher the total dissolved solids (TPT) value will be, and vice versa, the total dissolved solids in the fruit decreases with increasing fruit acidity.In addition, an increase in the total dissolved solids value indicates that the more sugar content (glucose and fructose) contained in red peppers.Glucose and fructose compounds produced from the hydrolysis of carbohydrates.[11] Figure 6.Graph of total dissolved solids of red bell peppers at room temperature.Based on the graph in Figure 8, it shows that the total dissolved solids (TPT) value during 16 days of storage experienced a fluctuating increase where there was a decrease in the TPT value but it could increase again.Based on the average total dissolved solids (TPT) value, red pepper samples without sago starch edible coating (A1B2) had the highest total dissolved solids compared to other treatments, namely 9.6°Brix.Meanwhile, the sample coated with 100 g sago starch edible coating (A3B2) had the lowest total dissolved solids value of 9.2°Brix.When compared between the two storage temperatures, the average total dissolved solids in red pepper samples stored at room temperature (B2) was 9.4°Brix higher than samples stored at cold temperatures (B1) with an average value of 9.2° Brix.0,351 0,627 0,209 0,893 Based on the results of analysis of variance (ANOVA) using IBM SPSS in Table 12, the total dissolved solids (TPT) data on red peppers showed that treatment and storage temperature had no significant effect on the total dissolved solids (TPT) value of red peppers because the significance value was more significant than the level Duncan's test 5% (0.05).

Conclusion
Edible coating treatment with 200 g sago starch concentration and adding 10% glycerol in cold storage (A3B1) is the best treatment for maintaining the quality of red peppers during storage.The effect of sago starch concentration as an essential ingredient for making edible coatings does not significantly affect color changes, including the level of brightness (*L value), chromatic values of a mixture of red and green (value *a), chromatic values of a mixture of yellow and blue (value *b).and identification of the color (°Hue) and total dissolved solids (TPT) of red peppers, but significantly affect the percentage of weight loss and hardness of red peppers during storage.

Figure 1 .
Figure 1.Graph of red bell pepper weight loss at cold temperatures.

Figure 2 .
Figure 2. Graph of weight loss of red bell peppers at room temperature.

Figure 3 .
Figure 3. Graph of hardness (newtons) of red bell peppers at cold temperatures.

Figure 5 .
Figure 5. Graph of total dissolved solids (°Brix) of red bell peppers at cold temperatures.

Table 1 .
Formulation of sago starch edible coating 3.3.4.Storage of Red BellPeppers.Storage of red peppers after applying sago starch edible coating is as follows: Coated red peppers and uncoated red peppers (control) were stored at two temperature treatments, cold temperature ±10˚C and room temperature ±27 ˚C.The sample was stored for 16 days.3.3.5.Observation Parameter.The parameters of the observations was weight loss, color, hardness and total dissolved solids measured on the first, fifth, eleven, and 16 th days with two repetitions.3.3.6.Data analysis.The data collected were analyzed using ANOVA (Analysis of Variance) with two repeats.The analysis was continued with Duncan Multiple Range Test (DMRT) to determine the difference between treatments, indicated by lowercase letters behind the numbers.The same letter indicated that the treatments were not significantly different, while different letters indicated a significant difference.The data were processed using Microsoft Excel 2016 and IBM SPSS Statistics software.

Table 2 .
DMRT (Duncan) test results for red bell pepper weight loss to edible coating treatment during storage Note: The numbers followed by the same lowercase letter in the same column are not significantly different according to the Duncan test at the level of 0.05 (5%).

Table 3 .
Results of brightness level analysis (Value *L) of red bell peppers

Table 4 .
DMRT Test Results (Duncan) *L value on red bell pepper color for edible coating treatment during storage Note: The numbers followed by the same lowercase letter in the same column are not significantly different according to the Duncan test at the level of 0.05 (5%).

Table 5 .
Results of color analysis (Value *a) of red bell peppers

Table 6 .
DMRT test results (Duncan) Value *a on the color of red bell peppers for the edible coating treatment during storage Note: The numbers followed by the same lowercase letter in the same column are not significantly different according to the Duncan test at the level of 0.05 (5%).

Table 7 .
Results of color analysis (Value *b) of red bell peppers

Table 8 .
DMRT Test Results (Duncan) *b value on the color of red bell peppers for the edible coating treatment during storage Note: The numbers followed by the same lowercase letter in the same column are not significantly different according to the Duncan test at the level of 0.05 (5%).

Table 9 .
Results of color analysis (°Hue) of red bell peppers during storage

Table 10 .
DMRT (Duncan) test results for red bell pepper color (°Hue) on edible coating treatment during storage

Table 11 .
DMRT (Duncan) test results for the hardness of red bell peppers against edible coating treatment during storage The numbers followed by the same lowercase letter in the same column are not significantly different according to the Duncan test at the level of 0.05 (5%).Total dissolved solids (TPT) in foodstuffs such as red peppers show the tannin or latex content, the sweetness of the fruit, and the content of fructose, glucose, and sucrose.The results of TPT of red peppers during cold temperature storage are shown in the chart below:

Table 12 .
DMRT (Duncan) test results for red bell pepper total dissolved solids (TPT) on edible coating treatment during storage