Carrageenan Concentration Research Articles

Carrageenan-based Film Utilization for Eco-friendly Tea Bag

This study addresses concerns related to potential health risks associated with chlorine residues in traditional tea bags, which exhibit resistance to decomposition in soil. Consequently, the study utilized carrageenan, derived from <i>Eucheuma cottonii</i> seaweed, as a coating material for edible film. This research explores the impact of carrageenan concentration and drying temperature on the performance of tea bags. This study applied the randomized complete block design to analyze the impact of three carrageenan concentrations (1%, 3%, and 5%) at three different drying temperatures (80ºC, 85ºC, and 90ºC) on carrageenan-based film. The investigation comprehensively evaluates the compliance of the carrageenan-based film with commercial-grade quality standards through critical factors such as thickness, solubility, mechanical strength and hedonic analysis. The findings indicate that the most effective carrageenan-based edible film can be produced at a concentration of 3% and a drying temperature of 90°C, highlighting its potential as an eco-friendly alternative in tea bag production.

The Effect of Different Bases of Vegetable and Carrageenan Concentrations on The Quality of The Mix Vegetable Leather of Lettuce and Mustars Greens

The benefits of each vegetable are different, one vegetable cannot be substituted for another. Vegetable processing in Indonesia is still very limited to sautéed, boiled, steamed or eaten directly, meaning that people's interest in vegetable consumption is still relatively low. However, increasing public awareness of the use of vegetables encourages variations in vegetable processing. One of the processing that can be applied to vegetables is manufacturing mix vegetable leather. Vegetable leather is a processed product derived from crushed and dried vegetables. The diverse benefits of each vegetable encourage its creationmix vegetable leather orvegetable leather which uses more than 1 vegetable as the basic ingredient. Mustard greens and lettuce are vegetables with high production in Indonesia. Apart from that, the crude fiber from mustard greens is 51.07%, while lettuce contains 50.7% crude fiber. The purpose of this study is to obtain the effect of vegetable basis and carrageenan concentration variance on mix vegetable leather of lettuce and mustard greens. The increase of people awareness of vegetable utilization drives to variate the vegetable processing. Each vegetable has its own unique benefits thus they could not be easily subtituted and mixed. This study used RAL with two factors, those are variety of vegetable basis between lettuce and mustard greens (30,50,100) and carrageenan consentration (1% and 1,5%). The chemical respond in this study covers moisture content, ash content, and crude fiber, while the organoleptic respond covers color, aroma, flavor, and texture. The best treatment is found on A1B1, that has 30 g for vegetable basis and 1% of carrageenan consentration with 13,31 % moisture content, 12,29% ash content, 8,24% crude fiber, 3,7 score in color and 2,05 color quality; aroma 3.23 and aroma quality 2.80; taste 3.40 and taste quality 3.06; and texture 3.46 and texture quality 3.73.

Hydrothermal extraction and thorough characterization of carrageenans and proteins from Gigartina pistillata

Carrageenan, an interesting biopolymer from red seaweed, possesses a myriad of applications in food, nutraceutical, or pharmaceutical industries. Although its conventional extraction used to be performed with alkaline solvents, water extraction under subcritical conditions is an alternative eco-friendly technique that has gained popularity in recent years. This work evaluates the recovery and characterization of carrageenan and proteins from Gigartina pistillata. The highest number of proteins was identified at the lowest processing tempeartures. Extracted carrageenan exhibits molecular weights greater than 500 kDa and good rheological behaviour, with interest for food applications and for the formulation of hydrogels when mixed with KCl. The carrageenans and carrageenan hydrogels presented interesting properties such as good thermal stability until 170 °C (TGA-DTG) and show characteristic bands of kappa/iota carrageenans in FTIR studies. Greater cell viability than 70% were achieved on NIH/3T3 fibroblast at carrageenan concentrations of 0.05 and 0.025%, whereas carrageenan extracted at 160 °C (concentration of 0.025%) displays a lower inflammatory action than other samples. In this sense, in this work the eco-friendlier extracted carrageenan was thoroughly characterized and its potentiality to be used in the biomedical field was evaluated.

Aplikasi Edible Coating dari Lidah Buaya dan Karagenan untuk Memperpanjang Umur Simpan Buah Tomat (Lycopersicum esculentum Mill.)

Tomato fruit (Lycopersicum esculentum Mill.) is a food material with a high water content so it is easy to decompose. This shows that efforts to prevent reduction in food quality can be developed in the form of edible coating from aloe vera gel with concentration of 0%, 30%, 40%, and 50%, and carrageenan with concentration of 1%, 2%, and 3%. The aims of this research were to determine the concentration of aloe vera gel and carrageenan based on the characteristics of edible film and to determine the effect of edible coating and storage time on the quality of tomato. The first stage of this research is making edible film based on analysis parameters such as water vapor transmission rate (WVTR), tensile strength, elongation, and thickness. The selected concentration used in the second stage of this research for making edible coating was 40% of aloe vera gel and 3% of carrageenan. The selected concentration has a WVTR value of 1.758±0.20 g.mm/m2.hour, tensile strength value of 0.248±0.00 N/cm2, elongation value of 25.164±0.10%, and thickness value of 0.074±0.00 mm. Tomato samples coated with edible coating and control tomatoes is stored for 9 days at room temperature (24-25oC and 65–70% relative humidity aproximately) and samples are analyzed every 3 days based on analysis parameters such as vitamin C content, weight loss, hardness level, pH, ohue, lycopene content, and total dissolved solids value. The application of edible coating and storage time can inhibit the decrease of vitamin C levels, lycopene levels, weight loss, hardness, also can inhibit the increase in pH value and total dissolved solids value. Meanwhile, the change in color (hue) of tomato is not affect by the use of edible coating. Keywords: aloe vera, carrageenan, edible coating, storage time, tomato

Potensi Bunga Anggrek Cymbidium Golden Boy sebagai Sumber Antioksidan dan Aplikasinya pada Flower Leather

Orchid flowers are believed to be an antioxidant source, however, the antioxidant activity of the Cymbidium Golden Boy (CGB) orchid has not been identified. The antioxidant potential can be applied to flower leather products, and a main reason behind the idea is the valorization of agricultural waste. The aim of this research is to study phenol content and antioxidant capacity of ethanol extracts of CGB orchid petals. Additionally, this study aimed to determine the best formulation for flower leather products with a combination of carrageenan and gum arabic based on organoleptic acceptance. This research was conducted by extracting CGB orchid flowers using ethanol, and total phenol and antioxidant activity of the extracts were determined. Moreover, the flower leather products were mad from CGB orchid flowers as the raw material, accroding to a Factorial Randomized Block Design using two factors as follows: carrageenan concentration (0, 0.3, 0.5, and 0.7%) and gum arabic concentration (0.9, 1.2, and 1.5%). Flower leather samples were analyzed for moisture content, tensile strength, total dissolved solid, color intensity, and sensory. The ethanol extract of CGB orchid flowers showed antioxidant capacity up to 23.88 ppm and high phenolic content which is equal to 15.32 mg GAE/g. The differences between carrageenan and arabic gum concentration showed significant effect on water content and dissolve solid, but they did not affect on tensile strength and color intensity. The best treatment of flower leather according to panelist evaluation was those prepared from carrageenan 0.5% and arabic gum 0.9%, reaching tensile strength 4.86 N, brightness level (L) 40.1, (a+) +5.7, (+b) 23.7, water content 19.18%, aroma score 3.76 (slight flowery), taste 4.84 (pleasant), and texture 4.56 (approaching chewiness).

Ozonation Treatment, Edible Coating Carrageenan, and Temperature Variation on The Quality of Fresh-Cut Pineapple During Storage

Fresh-cut pineapples are increasingly popular in Indonesia, but it damage easily due to contamination of pathogenic microorganisms, resulting in a short shelf life. This research aims to examine the effect of applying ozone and edible carrageenan coating on the quality of fresh-cut pineapple stored at low temperatures. The experiment used factorial completely randomized design. The first factor was concentration of carrageenan and the second factor was storage temperature. Based on the lowest TPC (total plate count) value from a preliminary research, the experiment was conducted with soaking time of 60 s. Results showed that weight loss, hardness, and TDS values was respectively 2.24 %; 13.03 °Brix; 11.42 kgf, and tended to increase until the last day of storage. The best results was found at 2.5% carrageenan coating and 5 °C. Results from the organoleptic test, however, found the highest score of 4.41 was collected from 1.5% carrageenan coating and 5 °C. It can be concluded that the combination of soaking in ozonized water for 60 s, immersing the fruit in a 2.5% edible coating carrageenan solution stored at 5 °C can maintain the quality of the fruit and increase the shelf life of fresh-cut pineapple compared to controls that were not given any treatment. Keywords: Drying, Physical Quality, Temperature, Tomatoes, Tween 80.

Characteristics of Fruit Leather with Proportion of Carica Puree (Carica pubescens) : Lime Juice (Citrus aurantifolia) and Carrageenan and Their Shelf Life Estimation

Fruit leather is a delectable treat crafted from pureed and dehydrated fruit. Carica fruit (Carica pubescens) contains fiber and pectin, which are requirements for making fruit leather. Lime (Citrus aurantifolia) was added as an acid in the gel formation. The addition of carrageenan is expected to improve the plasticity of fruit leather. One of the qualities of fruit leather is determined by its shelf life. This study seeks to assess the physicochemical and organoleptic attributes of carica and lime fruit leather, as well as to analyze the estimation of shelf life resulting from the optimal treatment. Factorial completely randomized design (CRD) with two factors was utilized in the study. Factor I involved the ratio of carica puree to lime juice (95:5, 90:10, 85:15), while factor II consisted of different carrageenan concentrations (0,3%, 0,6%, 0,9%) with two replications. The results were documented in English. The data was subjected to analysis of variance (ANOVA) followed by Duncan's New Multiple Range Test (DNMRT) at a significance level of 5%. The most effective treatment was found to be a blend of 95% carica puree to 5% lime juice, combined with 0.9% carrageenan. The test results revealed a moisture content of 15,33%, crude fiber content of 2,55%, pH level of 4.65, tensile strength of 4,45 N, vitamin C concentration of 12,20 mg/100g, antioxidant activity of 25,23%, color intensity of 3,24 (neutral), aroma profile of 3,04 (neutral), taste rating of 4,00 (like), texture score of 3,12 (neutral), total dietary fiber content of 4,45%, and an estimated shelf life of 70 days at 10⁰C (under refrigeration), 10 days at 30⁰C (at room temperature), and 3 days at 50⁰C.

Effect of κ-carrageenan on the quality of crayfish surimi gels

The demand for crayfish surimi products has grown recently due to its high protein content. This study examined the effects of varying κ-carrageenan (CAR) and crayfish surimi (CSM) concentrations on the gelling properties of CAR-CSM composite gel and its intrinsic formation process. Our findings demonstrated that with the increasing concentration of carrageenan, the quality of CAR-CSM exhibited rising trend followed by subsequently fall. Based on the textural qualities, the highest quality CAR-CSM was achieved at 0.3% carrageenan addition. With the exception of chewiness, and the cooking loss of the gel system was 1.62%, whiteness was 82.35%, and the percentage of β-sheets increased to 57.18%. Further increase in CAR (0.4–0.5%) addition resulted in internal build-up of LCAR-CSM, conversion of intermolecular forces into disulfide bonds and gel breakage. This study exudes timely recommendations for extending the CAR application for the continuous development of crayfish surimi and its derivatives and its overall economic worth.

Karakteristik Mutu Selai Lembaran Pedada (Sonneratia caseoloris) dengan Variasi Konsentrasi Agar-agar dan Karagenan sebagai Texturizer

Sheet jam is a modification of semi-solid jam products into sheets that are dense, practical and not too sticky. This research aims to characterize the effect of adding jelly or carrageenan on the physical, chemical and organoleptic properties of pedada fruit sheet jam. This research consisted of 2 treatments, namely the type of texturizer (jelly and carrageenan) and the concentration of the texturizer (1.5%, 2.25%, 3.0%). Analysis of yield, physical (texture), chemical (water content, fiber, protein, vitamin C, total dissolved solids), organoleptic tests (color, aroma, texture, taste, stickiness and overall), determining the best treatment as well as income and profit analysis are carried out on all sheet jam samples. Analysis of the best treatment using the De Garmo method states that the best sheet jam is found in the treatment with the addition of 1.5% carrageenan concentration, with a yield value of 56.31%, texture 2.32 mm, water content 26.08%, fiber content 0.82%, protein content 5.35%, vitamin C content 0.36% and total dissolved solids 29.70%. Organoleptic tests on color, aroma, texture, taste, stickiness and overall showed values of 4.20%, 3.85%, 3.85%, 3.85%, 3.70% and 4.25%. The results of the income and profit analysis of sheet jam for the best treatment show that with a total cost of Rp. 2,462,907 can generate income of Rp. 3,210,000 with a profit in one month of production of Rp. 747,093

The Effect of Carrageenan Concentration on the Physical, Chemical Characteristics and Preference Levels of Watermelon Albedo and Red Dragon Fruit Sheet Jam

This study aimed of this study was to find out how carrageenan affected the physical, chemical, and consumer preference characteristics of an albedo sheet jam combination made from red dragon fruit and watermelon. Four amounts of carrageenan addition— 0%, 1%, 1.5%, and 2%; three repeatations; and a one-factor Completely Randomized Design (CRD)—were employed in this investigation. Analysis. The sheet jam's texture, color, water content, total dissolved solids, reducing sugars, antioxidant activity, Vitamin C concentration, and hedonic tests were all examined after that. The SPSS program is used in statistical data processing to perform one-way analysis (one-way ANOVA). Using the Duncan approach, more study was conducted to determine the variations between treatments. The hedonic test was used to identify the chosen sheet jam formulation, which also included the inclusion of 1% carrageenan concentration, and the following quality test findings were obtained: Lightness (L) 20.19, redness (a*) 7.11, yellowness (b*) -1.87, texture 652.15 N/mm2, water content 18.28% wb, total dissolved solids 21.29% 0 brix, reducing sugars 46.35%, antioxidant activity of RSA 19.32%, and vitamin C 9.14 mg/100 g.

Composite hydrogels formed from okara cellulose nanofibers and carrageenan: Fabrication and characterization

Currently, there is great interest in converting edible agro-waste, such as okara from soybean production, into value-added products. For this study, we focus on fabricating composite hydrogels from okara cellulose nanofibers (CNFs) and carrageenan (CA). We also examined the effects of TEMPO oxidation of the okara CNFs, as well as CA concentration, on the microstructure and physicochemical properties of the composite hydrogels. The water holding capacity, oil holding capacity, surface tension, gel strength, and viscoelasticity of the composite microgels increased with increasing CA concentration, and it was found that the highest values were obtained for TC-CA2 hydrogel: contact angle = 43.6° and surface tension = 45.12 mN/m, which was attributed to the formation of a more regular and dense three-dimensional gel network. All the CNF-CA microgels had highly anionic ζ-potential values (−38.8 to −50.1 mV), with the magnitude of the negative charge increasing with TEMPO oxidation and carrageenan concentration. These results suggest there would be strong electrostatic repulsion between the composite hydrogels. The composite microgels produced in our work may be useful functional materials for utilization within the food industry, thereby converting a waste product into a valuable commodity.

Carrageenan-Induced Acute Inflammation on Back-Skin of Mice: Histopathological Features, Number of Inflammatory Cells, and Expression of COX-2, COX-1, and IL-6

Carrageenan is a sulfated polysaccharide obtained from red seaweed (Rhodophyceae) and can trigger inflammatory activation in both humans and laboratory animals. This study aimed to investigate the expression of cyclooxygenase-2 (COX-2), cyclooxygenase-1 (COX-1), and interleukin-6 (IL-6) and the number of inflammatory cells (neutrophil) involved in a carrageenan-induced acute inflammatory model in the back skin of mice. Paraffin blocks from the back skin of female Swiss mice aged 8 weeks were used in this study. The back-skins of 4 groups of 5 mice in each group were subcutaneously injected with 1%, 2%, and 4% carrageenan powder in 0.9% buffer saline and 0.9% buffer saline as control. Skin samples on paraffin blocks were taken 6 hours after carrageenan injection. Furthermore, paraffin blocks were stained with hematoxylin-eosin (HE) to count the number of inflammatory cells. Immunohistochemistry staining using anti-COX-2, COX-1, and IL-6 antibodies was performed to determine the role of inflammatory mediators. The results showed that the number of inflammatory cells (neutrophils) increased significantly following an increase in carrageenan concentrations. The COX-2, COX-1, and IL-6 expressed by inflammatory cells increased significantly at carrageenan concentrations of 1% to 4%. Histopathological features supported the results obtained from the calculation of the number of inflammatory cells and the expression of COX-2, COX-1, and IL-6. The inflammatory markers consisting of COX-2, COX-1, and IL-6 were expressed on the back skin of mice at 6 hours post-injection with 1% to 4% carrageenan. It can be concluded that carrageenan can be used for an acute inflammatory model of the back skin of a mouse. This inflammation model is intended to facilitate the evaluation or measurement of therapeutic and inflammatory responses when test substances are administered topically or transdermal.

Co-Delivery System of Vitamin B12 and Vitamin E Using a Binary W/O/W Emulsion Based on Soybean Isolate Protein-Xanthan Gum/Carrageenan: Emulsification Properties, Rheological Properties, Structure, Stability, and Digestive Characteristics.

In this study, the soybean protein isolate (SPI)-xanthan gum (XG) or carrageenan (CA) W/O/W emulsions for the co-delivery of vitamin B12 and vitamin E were prepared. The effects of XG and CA concentrations on the physicochemical properties and digestive characteristics of the emulsions were also investigated. The addition of XG and CA improved the SPI aggregation and increased its electrostatic repulsion so that more SPI was adsorbed at the phase interface. The emulsifying activity index and emulsifying stability index increased to 24.09 (XG 0.4%) and 14.00 (CA 0.5%) and 151.08 (XG 0.4%) and 135.34 (CA 0.5%), respectively. The adsorbed protein content increased to 88.90% (XG 0.4%) and 88.23% (CA 0.5%), respectively. Moreover, the encapsulation efficiencies of vitamin B12 and vitamin E were increased to 86.72% (XG 0.4%) and 86.47 (CA 0.5%) and 86.31% (XG 0.4%) and 85.78% (CA 0.5%), respectively. The bioaccessibility of vitamin B12 and vitamin E increased to 73.53% (XG 0.4%) and 71.32% (CA 0.5%) and 68.86% (XG 0.4%) and 68.74% (CA 0.5%). The best properties of the emulsions were obtained at a 0.4% concentration of XG and 0.5% of CA. This study offers a novel system for delivering bioactive substances, which is favorable for the advancement of food with delivery capability in food processing.

Effect of carrageenan addition on the characteristic of chitosan-based bioplastic

Synthetic plastic is a product that widely used in daily life. However, the use of plastic has a negative impact that is very difficult to decompose by nature, so it is necessary to find other alternatives by switching to bioplastics. Chitosan is a polysaccharide that can be used as raw material for bioplastics because of its good plastic-forming ability. On the other hand, it has poor elasticity so it is necessary to add carrageenan which can improve the mechanical properties of bioplastics. The purpose of this research is to determine the characteristics of bioplastics made from a mixture of chitosan and carrageenan. The concentration of chitosan used was 2%, glycerol was 0.5%, and carrageenan concentrations were varied from 0%, 0.25%, 0.5%, 0.75%, and 1%. Characteristic tests carried out were film thickness, density, moisture content, solubility, tensile strength, elongation, FTIR, and antibacterial activity. The result showed that the addition of 0.5% of carrageenan resulted in better bioplastic with film thickness of 0.06 mm, density of 0.85 g/cm3, water content of 17.27%, solubility of 36.89%, the tensile strength of 13.72 mPa, the elongation of 46.03%, inhibition zone of the antibacterial activity of 2.66 mm and a new group is formed in the FTIR test.

Utilization of pineapple cobs and peels for fruit leather processing

Pineapple cobs and peels are agricultural waste that have not been utilized optimally, but still have a high nutritional content including carbohydrates and proteins, and contain phenolic compounds and flavonoids. Efforts to utilize the waste of pineapple cob and peels by processing it into fruit leather to increase its economic value. The purpose of this study was to determine the effect of the proportion of cobs: pineapple peel and the addition of carrageenan on product quality, and to determine the best treatment to produce fruit leather with good characteristics and be liked by the panelists. This study used a completely randomized design (CRD) with a two-factor factorial pattern with two replications. Factor I was the proportion of tubers: pineapple peels (w/w) 60:40, 50:50, and 40:60. Factor II was carrageenan concentration of 0.6%, 0.8% and 1%. Based on the results of the study, the best treatment was the proportion of cobss: pineapple peels 50:50 (w/w) with a carrageenan concentration of 1% which produced fruit leather with a water content of 16.26%, reducing sugar content of 24.83%, vitamin C content of 15 .37 mg/100g, antioxidant activity 27.37%, crude fiber content 3.08%, and tensile strength 3.02 N.

PH and Sugar Content of Honey Pineapple Jam (Ananas comosus L Merr) with Addition of Carrageenan

This study aims to evaluate the effect of adding carrageenan to the pH value and sugar content of honey pineapple jam. Honey pineapple (Ananas comosus L. Merr) was used as the main ingredient with the addition of carrageenan at concentrations of 0%, 0.2%, 0.6%, and 1%. The method used is a completely randomized design (CRD) with one factor and three replications. The results showed that the addition of carrageenan significantly (P<0.05) affected the sugar content in pineapple jam. The higher the carrageenan concentration, the lower the sugar content in pineapple jam. However, the addition of carrageenan had no significant effect (P>0.05) on the pH of pineapple jam. Carrageenan acts as a thickener and water binder in jam but does not substantially change the level of acidity (pH). Keywords: carrageenan, sugar content, honey pineapple jam, and pH

Chemical and Organoleptic Properties of Dragon Fruit Gummy Candy and Apple Snail Collagen Extract with Carrageenan Addition

Gummy candy is a soft confectionery crafted from fruit juice, sugar, and gelling agents, known for its chewy texture. The utilization of dragon fruit juice enhances its nutritional value due to its antioxidant properties, phenolic compounds, and vitamin C content. Additionally, it aims to diversify products derived from dragon fruit. Meanwhile, the utilization of collagen from apple snails seeks to boost the economic value of these snails and provide an alternative source of collagen raw material. In this study, the gummy candy uses carrageenan as a hydrocolloid material to establish the chewy texture. This study's primary objective is to determine the optimal combination involving the proportion of dragon fruit juice, apple snail collagen extract, and carrageenan concentration for producing high-quality gummy candy. The research employed a Completely Randomized Design (CRD) with a two-factor factorial pattern and two replications. The first factor was the proportion of dragon fruit juice to apple snail collagen (70:30, 75:25, and 80:20), while the second factor was the carrageenan concentration (3%, 5%, and 7% w/w). Observational data were analyzed using Analysis of Variance (ANOVA), and if interactions were observed, they were further assessed with Tukey's test at a significance level of 5%. The treatment combination of a 75:25 proportion of dragon fruit juice to apple snail collagen and a 7% carrageenan concentration proved to be the most effective, yielding gummy candy with a moisture content of 13.21%, ash content of 0.95%, and organoleptic evaluation scores for aroma, taste, color, and texture of 3.25, 3.4, 3.4, and 3.7.

Characteristics of Margarine Produced from Palm Stearin and Tilapia (Oreochromis niloticus) Oil with Carrageenan as Emulsifier

One of the tilapia waste produced is offal. The content contained in the innards of tilapia contains a lot of fat which can be used as raw material for making fish oil. Fish oil plays an important role in health because it contains a source of omega 3. The application of fish oil into margarine can be used in the manufacture of bakery products. Making margarine requires an emulsion stability, which functions so that oil and water can mix. One of the emulsion stability that can be used is carrageenan. The purpose of this study was to determine the effect of using carrageenan on the stability of the emulsion on the physical properties of margarine and to determine the best concentration. This study used a completely randomized design (CRD), using one factor, namely the carrageenan concentration of 0.1; 0.2 and 0.3. The test parameters observed were water content test, spreadability test, texture test, melting point slip test, emulsion stability and hedonic test. The result shows that carrageenan plays a significant role as an emulsifier agent for the tilapia oil based margarine as it enhances the physical chracteristics of margarine. The best test results at a concentration of 0.3% with a water content value of 14.64%. The results for the basting power were 3.93%, while the slip melting point test was 33.80ᵒC, the stability test results were 93.07%, the hedonic test was 7.37 < µ < 7.76. The research suggests that there should be further analysis of margarine shelf-life time and fatty acid composition.

Characterization of Seaweed Caragenan Eucheuma cottonii and Its Aplication as Edible coating

Seaweed E. cottonii is carragaenophytes or carrageenan-producing plant. Carrageenan has a functions stabilizer, thickener and gel former, so it can be used as edible coating that can maintain fish quality. Tuna has nutritional content per 100 grams such protein around 25-26.2%; water 69.40%; fat 1.50%; and carbohydrates 0.03%. Tuna filets quickly decompose if proper handling is not carried out, it is necessary to apply edible coating because this edible coating can protect the product from air contamination and can prevent microbial growth. This study aims to determine the effect of extraction time characteristics of carrageenan and the appropriate concentration of carrageenan for edilbe coating tuna filet. The extraction process was carried out by heating dried seaweed samples with 8% KOH solution for 1 hour, 2 hours and 3 hours at a temperature of 50˚C. The best characteristics of carrageenan resulted from 2 hours of extraction time with 40% yield, 14.95% water content, 63 dPas viscosity and 12.396 ppm sulfate content. The best carrageenan was applied as edible coating on tuna filets with 3 concentrations, namely 1.5%, 2% and 2.5%, each of which was added with 2 mL of glycerol. Based on the Total Plate Count (TPC), it was found that a carrageenan concentration of 2.5% could prevent bacterial growth in the sample as indicated by the TPC number obtained at 2.7×106, which was lower than the control, which was 1.7×107.

Native hybrid carrageenans from Sarcopeltis skottsbergii and Sarcothalia crispata: The role of counterions on their gelling properties

Carrageenans are red seaweed polysaccharides of great importance as gelling agents in the food texture market. The hybrid kappa/iota-carrageenan is extracted from certain cold-water species and its unique properties have given rise to growing demand for this biopolymer. Gelation of these polysaccharides is affected by the valency and, sometimes, the identity of counterions. The main objectives of this work were to investigate the role of potassium and calcium ions on the gelation of the native hybrid carrageenans from Sarcopeltis skottsbergii and Sarcothalia crispata from the South American Atlantic coast, and to optimize the structural properties of these gels. Response surface methodology was used to analyze the effects of carrageenan concentration, salt concentration, and KCl:CaCl2 ratio, on the rheology, texture, syneresis after 50 % deformation, and color of these gels. Both native carrageenans presented high extraction yield (42.73 ± 0.20 g/100 g for S. skottsbergii and 20.43 ± 7.64 g/100 g for S. crispata) and formed either weak or strong gels upon the addition of salt. Carrageenan and salt concentrations increased gel strength, but also increased turbidity. Moreover, KCl fraction also increased gel strength, attributed to the predominance of the kappa diad in these carrageenans, whose gelation is favored by potassium ions. All samples showed syneresis after deformation, being minimized with higher carrageenan and salt contents. Optimal compositions predicted by the selected models to maximize gel strength and minimize syneresis and haze, were 1.13 % carrageenan, 0.39 M salt and a proportion of 0.85 KCl for S. skottsbergii, and 1.16 % carrageenan, 0.36 M salt and a proportion of 0.85 KCl for S. crispata. Predicted responses for these optimal compositions were in accordance with the observed responses. Considering the worldwide growing demand for kappa/iota-carrageenan in the food industry, S. skottsbergii and S. crispata from the South Atlantic represent a potential source of these biopolymers.