Characteristics of sago and pectin edible film with the addition of chitosan and its use in hard candy wrappers

Biodegradable packaging is currently indispensable to reducing the use of plastics. The edible film is a type of food packaging that is safe, biodegradable, and environmentally friendly. This study aims to determine the characteristics of edible films of sago and pectin with different concentrations of chitosan. Comparison of sago and pectin (2:1) with 0.2%, 0.4%, 0.6%, and 0.8% of chitosan concentrations and 1% w/w and 1% glycerol b/v in each treatment. Observations were made on the solubility of the film, thickness, elongation, tensile strength, and color. Statistical analysis showed that the concentration of chitosan affected the thickness and color of the edible film but not elongation, tensile strength, and solubility. The best treatment was found at a concentration of 1% chitosan resulting in a film thickness of 0.115 mm, yellowish white color with a value of 6, a solubility of 98.80%, elongation of 5.75%, and tensile strength of 24.84 KPa. Edible film as a hard candy wrapper can reduce hygroscopic properties by 7.58% per hour.


Introduction
Edible film or edible coatings applied to food products as wrappers or coatings can extend the shelf life and can be consumed together with food.The use of edible film is currently a serious concern Because the many losses associated with plastic film or synthetic packaging have the effect of being able to damage the environment [1].Edible film has gained popularity in the scientific world and attracted the attention of authorities and consumers who care about environmental protection [2].Edible Film contains easily soluble materials, especially those containing microorganisms, and can be considered as living ecosystems that selectively allow the exchange of respiration gases (e.g.oxygen, carbon dioxide, and ethylene) between food and the atmosphere, reducing or preventing the loss of moisture and aroma or protect against unwanted microorganisms [3].The use of edible film can coat food completely or can be applied between food components [4].The materials used for the production of edible film are biopolymers, proteins, lipids, or composites that are faster and easier to degrade compared to plastic materials [5].The edible film is usually obtained from food-able materials and then applied using coating or wrapping directly on the surface of the food [6][7][8].The use of films for the preservation of foods such as wax dates back to the 12th century in China, used to delay the loss of moisture from fruits.
Sixteen centuries ago, the first edible film made from soy milk was used in Japan to preserve fruits and to obtain a shiny surface [9,10].
Among the many roles played by edible film, the physical protection [11] of the edible film can be categorized according to the class of its constituent materials.Hydrocolloids (polysaccharides and proteins) and lipids are the most widely used materials.Among other things, polysaccharides are the easiest to buy and are more suitable for forming films or coatings.The presence of a large number of hydroxyl groups and hydrogen bonds favors the formation of a film.Different properties can be observed between films and coatings made of negatively charged g um (i.e., alginate, pectin, or carboxymethyl cellulose) [7].
The proteins used for the edible film are mostly of animal origin (gelatin, casein, whey protein, collagen, or egg albumin).However, vegetable proteins (e.g., corn, soybeans, wheat, cottonseed, peanuts, and rice) are also preferred and fit a vegetarian diet.Protein denaturation using heat or pH adjustment, followed by a conglomeration of peptide chains through new intermolecular interactions [12].This type of film is suitable mainly for meat products, due to its affinity for hydrophilic surfaces [13][14][15].Lipids (glycerol, palmitic acid) cannot form a cohesive film, so combined with hydrocolloids such as polysaccharides to obtain an optimal water vapor barrier [16].
The integration of different additives (i.e., probiotic microorganisms but also organic acids [17], essential oils [18], plant extracts [19], and compound antibacterial [20] biodegradable chitosan, has antimicrobial and antioxidant activity [21] into edible film has benefits for food products.Edible film from agricultural by-products such as nutmeg flesh as a source of pectin combined with tapioca with the addition of palmitic acid which can increase tensile and elongation strength and reduce the transmission rate of water vapor [22], peach peel combined with hydroxypropyl methylcellulose (HPMC) as a binder and micro-cellulose / nanofiber l (CMNF) as a filler.Can increase permeability to moisture (from 0.9 to 5.6 g mm kPa −1 h −1 m −2 ) and extensibility (from 10 to 17%) but reduced mechanical resistance (67-2 MPa) and stiffness (1.8 GPa -18 MPa) prove the plasticization effect of peach pulp in the HPMC matrix, which is amplified by CMNF [23].
Advances in technology and increasing consumer awareness of the relationship between eating habits and health prompted researchers to race to research edible film and its application to food products.One of the main challenges that must be faced to achieve wider industrial applications is to obtain the perfect combination of ingredients, technologies, and benefits for health, tailored to specific foods and consumer needs, as well as at a low cost and acceptable to consumers.In this study, sago and pectin were used as the main ingredients because they are natural ingredients and are local products that are available and easy to obtain, cheap and affordable, and available at any time needed.While the additional ingredients used are chitosan and glycerol.It is expected that the addition of chitosan in various concentrations in addition to improving the physical properties of edible film can also protect wrapped candy because it has antimicrobial and antioxidant activity.The use of glycerol as a plasticizer is quite an important component in the manufacture of edible film because it is needed to overcome the fragile nature of the film caused by extensive intermolecular forces and increase flexibility and extensibility.The addition of CaCl2 to pectin can form cross-bonds with pectin, increase the strength of the film and make it more resistant to physical damage, and can help increase resistance to oxygen, carbon dioxide, and moisture, thus maintaining the quality of packaged food products to help extend the shelf life of packaged food products.The purpose of this study was to study the Edible Characteristics of Sago and Pectin Composite Film with the Addition of Chitosan in various concentrations and their application to hard candy as wrappers.

Time and place
The research is conducted at the laboratory of the Center for the Study of Agricultural Technology (BPTP) of North Sulawesi from February to June 2022 and edible film analysis at the Agricultural Technology Laboratory of Gajah Mada University Yogjakarta.

The procedure of hard candy
Weighing materials Glucose 80 grams, Sucrose 20 grams, KCl 0.6 grams, and ginger extract 5 ml.Mixing Sucrose and Glucose in a beaker glass, and then heating in a hot plate keep stirring with a magnetic stirrer until the sugar dissolves completely.And then 5 ml ginger extract was added and KCl 0.6 gram.After everything was mixed, the heating and stirring continues until 130-140°C.Candy tested in cold water, if candy is hard continued with printing in Candy mold silicone.Then leave at room temperature until hardened.Wrapped candy with edible film + candy wrappers.

Result and discussion
The characteristics of the resulting edible film are strongly influenced by the type and properties of the material used.Sago and pectin are polysaccharides that are hydropolyc, so the edible film produced has a large moisture permeability, it is hoped that the addition of chitosan can help reduce water vapor permeability and improve physical and mechanical properties that can match plastic film [7].
The results of edible film analysis of a mixture of sago and pectin with the addition of chitosan in various concentrations can be seen in Table 1.The results of statistical analysis showed that the chitosan concentration treatment had a noticeable effect on thickness and color but had no real effect on elongation, tensile strength, and solubility of the α level of 0.05%.
The color of the edible film is influenced by the material used, especially chitosan which has a yellowish-white color that causes the edible film produced to be cream or yellowish-white, and when using the RHS Colour Chart tool the colors are light yellow and Pale yellow.The same notation on columns was no difference.

The thickness of edible film
The resulting film thickness ranges from 0.0850 -0.1150 mm.The highest level was obtained at a chitosan concentration of 1% which was 0.1150 mm while the lowest was in the Control.In Figure 2 it can be seen that the higher the chitosan concentration the thicker the edible film produced.The higher the concentration of chitosan added, the greater the number of edible film-forming components so the thicker the film produced.The thickness of the film is affected by the number of solids in the filmforming solution and the printing thickness [21].This result is in line with the results of research (23) on the use of chitosan as an ingredient for making the edible film from yellow sweet potato starch that the higher the concentration of chitosan added will cause an increase in the thickness value of the resulting edible film.

The elongasi of edible film
The percentage of elongation is the change in the maximum length that the film undergoes at the time of the breaking tension strength test at the time of the film tearing [24].The extension of the edible film ranges from 5.27 -5.75 percent (Figure 3).The results of statistical analysis showed that chitosan concentration had no real effect on film elongation, but the control showed a noticeable difference.This means that chitosan concentrations of up to 1% have not had a noticeable effect on the prolongation properties of the film.The absence of differences with chitosan treatment is due to the physical properties of chitosan having a fairly high viscosity of 309 cps (22) which can affect the percent extension of edible film produced.

Tensile strength of edible film
The fractured tension strength property is an important mechanical property to measure on edible film and expresses the maximum force required to break or tear the film (23).The resulting breaking strength ranges from 23.67 -24.84 KPa.The higher the concentration of chitosan added, the strength of the resulting breaking film tends to increase.However, the results of the fingerprint analysis showed that the addition of chitosan concentration had no effect (α 0.05) on tensile strength edible film.This is because the higher the added concentration can increase the strength between molecular chains in the film matrix through the formation of pectin interactions with CaCl2, sago, glycerol, and chitosan to be stronger, more compact, and more flexible.The mechanical properties of the film depend on the filmforming material, especially the structural cohesion properties are the result of the polymer's ability to form strong molecular bonds [7].

Solubility of the edible film
The solubility of edible film in water indicates the application of the resulting film.The results of the analysis (Table 1), showed that the solubility of the film between chitosan concentrations had no real effect The highest film solubility was obtained without the addition of Chitosan (Control) which was 98.89 and the addition of chitosan 1% which was 98.80.This is because chitosan, which is not easily soluble in water, causes a lower level of solubility.In addition, chitosan is a product of the chitin deacetylation process, which has unique properties, since this polymer has a positively charged amino group, while other polysaccharides such as sago and pectin are generally neutral or negatively charged so that they dissolve faster.Therefore, chitosan can be used as a source of natural material, because chitosan is a natural polymer that can be biodegraded and adsorbed [21].

Application of edible film on ginger hard candy
Hard candy produced before packaging with edible film and synthetic plastic packaging is first measured water content to determine whether the water content produced meets applicable industry standards, namely a maximum of 7.5% and can predict the duration of storage.Based on the state of snacking survey (2020), shows that there has been an increase in snack consumption in Indonesia during the pandemic by 60%.This has encouraged the emergence of innovations in various types of snacks such as chips, extrusion products, and various types of sweets.
Candy is a product that retains its shape for a long period and is expected not to be chemically or microbiologically affected before consumption.Based on its texture, hard candy is classified as a noncrystalline (amorphous) candy known as without form [27].The characteristics of the product largely depend on the formulation of the manufacturer.Moisture content measurement aims to determine the moisture content of the product produced by various treatments so that the durability of the product can be estimated.The water content of food ingredients greatly affects the quality of these foodstuffs.The high water content will make it easy for bacteria, fungi, and other microbes to multiply, resulting in chemical changes [28].Meanwhile, the low water content can prevent the emergence of microorganisms and physiochemical reactions so that materials can last longer [29].
In Figure 6, it can be seen that there is an increase in the moisture content of soft candy during 2 months of storage.The highest increase in moisture content in hard candy coated by the edible film.This is because the use of edible film as a wrapper is generally used as a permanent coating as a moisture barrier between food and the environment.Films or coatings made of polysaccharides (sago and pectin) and proteins are hydrophilic, so they have a high water vapor permeability (30).
The initial level before treatment averaged 2.17 %.With the presentation of 2.17% water content, it has low water content and has met the requirements of the Indonesian National Standard in 2008 (SNI 3547.2-2008) for Hard candy, namely the maximum moisture content is 7.5% It can be seen that the highest percentage of moisture content in the use of edible film is 3.12%.Analysis of the resulting moisture content for all treatments showed no noticeable difference until 8 weeks of storage.Except those that use edible film wrappers singularly.This is due to the candy wrapper using the same, namely OPP plastic.3.5.2.Hygroscopic properties.This hygroscopic property in sucrose is due to the presence of free and reactive polyhydroxy groups capable of binding hydrogen to water (32).Simple sugars have different hygroscopic properties, as they are affected by relative humidity (RH) and ambient temperature.Sucrose has stronger hygroscopic properties than other sugars, so it can bind water more strongly.In hygroscopic tests that have been carried out on several hard candy samples, the sample melts after being allowed to stand for 30 minutes at room temperature.Hard candy coated with edible film has not melted and does not show any deformation (Figure 7).This indicates that edible film can protect hard candy from the influence of humidity and ambient temperature.However, for long-term storage, special plastic packaging of sweets is needed as secondary packaging to protect them at the time of storage and transportation.Hard candy requires good packaging and storage space at an appropriate temperature.Edible packaging films in general have not been able to completely replace conventional packaging but to improve the efficiency of food preservation can be further improved by using edible primary packaging along with inedible packaging as secondary packaging to enhance additional protection from the atmosphere and prevent contamination from microorganisms or contamination of other foreign objects.

Conclusions and suggestions
The results of statistical analysis show that chitosan concentration has a noticeable effect on the thickness and color of the edible film, but it has no noticeable effect on elongation, tensile strength, and solubility at a level of α 0.05%.However, when compared to dick (without the addition of chitosan), there is an increase in the value of elongation, tensile strength, and solubility with different concentrations of chitosan.The best treatment was found at a chitosan concentration of 1% resulting in a film thickness of 0.115 mm, a yellowish-white color with a value of 6, a solubility of 98.80%, an elongation of 5.75%, and a tensile strength of 24.84 KPa.Edible film as a hard candy wrapper can maintain moisture content and reduce hygroscopic properties by 7.58% per hour.Edible Film as edible packaging in general has not been able to completely replace conventional packaging but to improve the efficiency of food preservation can be further improved by using edible primary packaging along with secondary packaging to increase additional protection from the atmosphere, preventing contamination from microorganisms and foreign objects and facilitating transportation.

Figure 1 .
Figure 1.Flowchart the procedure of the edible film.

Figure 2 .
Figure 2. Histogram effect of addition of chitosan concentration on edible film thickness.

Figure 3 .
Figure 3.The effect of the addition of chitosan concentration on edible film elongation.

6 Figure 4 .
Figure 4. Histogram effect of chitosan concentration on tensile strength edible film.

Figure 5 .
Figure 5. Histogram effect of chitosan concentration on the solubility of edible film.

Figure 6 .
Figure 6.Effect of Candy storage on the moisture content of hard candy.

Table 1 .
The characteristics of edible film with the addition of different concentrations of chitosan.