Sensory characteristics of catfish bone flavor enhancer with addition of aromatic citronella (Cymbopogon nardus) extracted with various temperatures and maltodextrin concentration

Fish waste processing is one way to support the development of fishery products and environmental sustainability. Catfish bone powder has an unpleasant aroma. Unpleasant aroma could be reduced by adding spices such as aromatic citronella. This study aims to determine the effect of citronella extract in catfish bone flavor enchancer powder. Experimental design in this study used completely randomized design (CRD) with two factors, variations in temperature differences and maltodextrin concentration. The temperature variations used were 70°C and 80°C and maltodextrin 10% and 15%. The analysis conducted included hedonic characteristics consist of flavor, color, aroma, and texture. Statistical analysis was performed with two-way ANOVA and continued with DMRT (Duncan’s Multiple Range Test) test at the significance level α = 5%. Hedonic test showed that texture analysis ranged from 2.92-3.25, aroma 3.06-3.14, color 2.86-3.31, flavor 3.00-3.14. Adding aromatic citronella increase color and texture hedonic valuation significantly.


Introduction
Indonesia has both water and land, with almost 70% of its territory consisting of water.Fisheries have great potential as a source of protein for the people of Indonesia.The high protein content and low fat content in fish make it a food that is often used as a meal in the community.In addition to marine products, fish are also obtained from ponds.One variety of freshwater fish that is often used as a meal by the Indonesian population is catfish [1].
In 2021, catfish aquaculture production in Indonesia reached 347,511.48tons [2].High amount of production is related to the level of Indonesian people's liking for catfish.This type of fish is generally consumed in simple processed forms such as fried or steamed.Catfish contain carotenoid pigments, vitamin A, phosphorus, calcium, iron, vitamin B1, vitamin B6, vitamin B12, and have abundant amino acid content such as leucine and lysine [3].Unlike other scaly fish, catfish do not require special water requirements to be able to live and survive.Because of its formidable ability, many people choose to cultivate catfish [4].
Fish waste processing is one way to support the development of fishery products and environmental sustainability.High demand for catfish increase the supply abundantly.However, mass production of catfish in the home industry affect the huge amount of waste such as fish bones [1].Fish bones contains calcium that could be utilized in the food industry.Catfish bones flour contains 13.48% calcium.Fortification of fish bones flour increase nutrition of functional foods, lengthen shelf life and storage ability of fish bone [5].
Fish bone flour has short durability and will causes damage to the flavour as well as changes in the odor of the product.Organoleptic parameter will affected by the occurrence of clumps in the powder during storage.Catfish bone powder has an unpleasant aroma.Reducing the unpleasant aroma could be done by adding spices such as citronella.Citronella is used as a solution to reduce unpleasant odors and it has benefits for the body, such as improving perspiration, mucus solvent, mouthwash, and increased body temperature.Citronella contains essential oils that have phenolic compounds, and flavonoids that are included in antioxidants [6].The nature of essential oils is volatile, as they have a low boiling point, and natural ingredients that have effectiveness as antibacterials [7].
Drying process in the form of foam mat drying accelerate the process of water evaporation and occurs at low temperatures [8].The advantages of the foam mat drying method are that the process is relatively simple and economical.Drying process is done at temperature of 50°C-80°C therefore the color, taste, nutrients and other nutrients could be maintained [9].
Maltodextrin as encapsulating material has ability to protect food components, including antioxidant activity, and has a strong binding ability to the encapsulated compound.Capsule layers containing maltodextrin can protect sensitive ingredients such as antioxidant ingredients, flavor ingredients, vitamins, colorants, and other nutritional ingredients [10].Maltodextrin is an additive that can be used as a filling agent [11].The selection of maltodextrin as an encapsulant material is due to the use of maltodextrin including as a sugar substitute to reduce sweetness in foods or beverages, as a stabilizer, thickener, and coagulating agent in foods.Maltodextrin is often used as an additional component in spray drying processes, as a carrier for non-caloric sweeteners, spices, vitamins, or minerals in powder form [12].
Sensory characeristics of food is crucial to predict the product positioning in the market.Investigating consumer acceptance can be carried out by sensory analysis.This study established scientific measurement to identify, analysis and interpret product attributes using human senses, as affected by functional ingredients, different temperature and maltodextrin concentration been used.Thus, this study aims to investigate the sensory characteristics of flavoring powder from catfish bones with the addition of citronella and processed with various temperature and maltodextrin concentration.

Place and location of research
This research was conducted in March-May 2023, at the Ahmad Dahlan University Food Technology Laboratory located at Jl. Ringroad Selatan, Tamanan, Bantul, Yogyakarta.
Hedonic tests on flavored powder from fish bones with citronella extract were conducted on 36 untrained panelists using 4 levels of numeric scale (dislike, very dislike, like and very like).Panelists ranged in age from 20 to 22 years.Panelists are expected to be able to assess the parameters of taste, aroma, color, and texture.One-way ANOVA followed by Duncan Multiple Range Test at the confidence level of 95% was carried out to analyze the result statistically.

Experiment design
This study used experimental research with a completely randomized design (CRD) research design with factorial consisting of two factors, namely the use of maltodextrin and drying temperature.Factor I: Maltodextrin concentration consists of 2 levels, namely: M1 = 10 M2 = 15 Factor II: Drying temperature consists of 2 levels, namely: A1 = 70°C A2 = 80°C

Results and discussions
Panelists used were untrained panelists with healthy senses of smell, taste and sight.Sensory test characteristics assessed were texture, color, aroma, and taste, conducted on 36 panelists using hedonic scores (dislike, very dislike, like and very like) with a numeric scale (1,2,3 and 4).The results of the organoleptic test on citronella and catfish bone extract flavor powder can be seen in Table 1.

Texture
Food texture is the result of a tactile response to physical stimuli when the oral cavity contacted with food [13].Texture determining the quality of food ingredients.Results of statistical tests on sensory of the texture preference score showed significant effect of temperature anda maltodextrin concentration on flavour enhancer with citronella extract and catfish bones at a significant level of 5% (Figure 1).Average score on texture ranged from 1-4, the average value obtained ranged from 2.92-3.25.Lowest hedonic texture was sample A2 with an average score of 2.92, temperature treatment of 80°C without addition of maltodextrin.Meanwhile, the highest texture of hedonic score was obtained in M2A2 with an average of 3.25, temperature treatment of 80°C and 15% maltodextrin.This shows that the treatment of the use of maltodextrin addition and different temperatures had significant effect on the hedonic value  [14] showed regarding dragon fruit peel powder drink, this study has an average value of texture organoleptic test ranging from 3.80-4.00.

Figure 1. Texture hedonic analysis
The organoleptic value in the texture test stated that the panelists liked the texture of the citronella and catfish bone extract flavor powder.The effect of liking the texture of the flavor powder is possible due to the addition of ingredients such as maltodextrin which can increase the total solids in the flavor powder of citronella extract and catfish bones.This is reinforced by Umah (2021) [15] which states that adding components to the process of making flavor from carbohydrate-containing vanamei shrimp head extract powder can increase the overall mass of the product.The higher amount of total solids produced after drying at a certain rate, the higher the rate of water evaporation resulted.

Aroma
Aroma plays significant role in sensory analysis.Panelists rely on their sense of smell to assess the aroma of food products.If the product has an unpleasant aroma, the taste buds of the panelists may be affected and the score of aroma hedonic assessment might decrease.Aroma of food ingredients greatly affects the taste of the food produced.Aroma testing is very important in industry to provide a quick assessment, whether the product is liked or not [16].
Statistical analysis showed insignificant effect of temperatures and maltodextrin concentration to aroma hedonic score of catfish bones flavor powder with addition of citronella extract (Figure 2).Average value of the hedonic score on aroma ranged from 3.06-3.11.Temperature of 70°C and 10% of maltodextrin caused lowest hedonic score on aroma (3.06).Meanwhile, highest value of hedonic score on aroma was obtained in the M2A1 treatment (3.14), with the use of 70°C temperature and 15% maltodextrin.This score was in accordance with research regarding citronella powder that showed aromatic value of hedonic sensory analysis varied from 2.55-4.36[17].

Figure 2. Aroma hedonic analysis
Sensory analysis value stated that all panelists liked the aroma of flavour enhancer with citronella extract and catfish bones due to the presence of citronella extract and the use of other spices such as shallots, garlic salt and pepper, which can strengthen the aroma of the flavor powder.This result reinforced a statement that showed the difference in aroma caused by the mixing of chicken liver flour with spices such as onions and garlic, increasing the saltiness of the product [18].

Color
Color affect the first impression consumers while determines the quality and acceptability of food.Color indicates chemical changes in food, such as browning and caramelization reactions [16].Statistical analysis of hedonic sensory scores showed significant effect of temperature and maltodextrin concentration on color of catfish bone powder with addition of citronella extract, at significant level of 5% (Figure 3).Average value of the color hedonic score ranged from 2.86-3.14.Lowest color hedonic score value obtained in the A2 treatment (2.86), with the use of 80 °C temperature without the addition of maltodextrin.Meanwhile the highest color hedonic score was M2A2 (3.14), with the use of 80 °C temperature and 15% maltodextrin.This study was in accordance with the research [17] regarding kitchen citronella powder that showed color hedonic score ranged from 3.20-4.12.

Figure 3. Color hedonic analysis
Sensory value on color test stated that the panelists liked the color of flavour enhancer with the addition of citronella extract and catfish bones.The liking score was obtained due to the yellowish brown color affected by temperature and maltodextrin of the flavor enhancer with citronella and catfish bone powder.This result was in accordance with the opinion of [18] that stated the change in color to brown is due to the formation of brown pigments in the Maillard reaction during the drying of catfish bones into flavor powder.Maillard reaction arises due to chemical reaction between free amino acids from proteins and reducing sugar groups, resulting in pigment formation.

Taste
Taste is one of the parameters in the hedonic test that utilizes the tongue as a sense of taste and an an influential parameter in determining consumer expectations of a food product.Typically, taste-activecomponents are non-volatile compounds such as free amino acids, nucleotides, sugars, mineral salts, organic bases, organic acids, and inorganic compounds [19].
Statistical analysis on taste sensory hedonic scores showed insignificant effect of temperature and maltodextrin on taste of flavor enhancer with citronella extract and catfish bones (Figure 4).Average value of the hedonic score on taste ranged from 3.00-3.14.Lowest hedonic score on taste was obtained in treatment A1 (3.00) with the use of 70 °C temperature without the addition of maltodesktrin.Meanwhile, the highest score of hedonic score in taste was obtained in the M2A1 (3.14), with the use of 70 ° C temperature and 15% maltodextrin.This result showed that maltodextrin addition and different temperature variations did not have significant effect on the hedonic value.This study was in accordance with research regarding citronella instant powder drinks resulted in hedonic taste score ranged from 2.52-4.3.04 [19].Sensory analysis stated that all panelists liked the taste of flavor enhancer with citronella extract and catfish bones.This result might be affected by the presence of citronella extract and the use of other spices such as shallots, garlic, salt and pepper, which strengthening the taste of the flavor enhancer.This is in accordance with [20] that the change in taste was due to the formation of amino acid in the Maillard reaction during the drying of fish bones into flavor powder.Maillard reaction arises due to a chemical reaction between free amino acids from proteins and reducing sugar groups, resulting in flavor formation.

Conclusion
Maltodextrin concentration and drying temperatures gave significant effect of hedonic level on texture and color parameters.All sensory characteristics were favored by the panelists.Adding aromatic citronella increase color and texture of hedonic valuation significantly.