MINISTRY OF EDUCATION AND TRAININGHO CHI MINH CITY UNIVERSITY OF TECHNOLOGY AND EDUCATION GRADUATION THESIS MAJOR: FOOD TECHNOLOGY INSTRUCTOR: NGUYEN VINH TIEN NGO THI MINH NGUYENTHE IMP
INTRODUCTION
Posing the problem
Many plant species serve dual purposes in medicine and food, leveraging their biochemical and physicochemical properties for traditional medicinal applications and enhancing their commercial value as food products In Vietnam, plants like ginger, mint, perilla, and grass jelly are renowned for their nutritional benefits and health-promoting properties Notably, the Catunaregam spinosa plant has been traditionally utilized for its medicinal qualities and is now being processed into a jelly form, becoming a popular dessert in Northern Vietnam However, jelly products made from C spinosa remain relatively novel and underdeveloped compared to traditional grass jelly offerings in the region.
Catunaregam spinosa is a plant usually grown in Asia, such as India, Nepal, and South
China and is especially grown in the northern countryside of Vietnam In Vietnam,
Catunaregam spinosa is being studied for its therapeutic properties, with research highlighting its antioxidative, anti-hyperglycaemic, hepatoprotective, anti-inflammatory, and antibacterial effects, as noted by Timalsina et al However, there is still limited information available regarding the pectin structures found in the leaves of C spinosa.
Pectin, a complex blend of polysaccharides, serves as a natural gelling agent sourced from higher plants and is extensively utilized in food technology The gelling properties of pectin derived from Catunaregam spinosa leaves have facilitated the development of C spinosa jelly However, the low pectin content in these leaves leads to a weak gel structure, resulting in several structural shortcomings in the jelly product.
Jelly is a classic summer dessert that is perfect for hot days, offering a refreshing treat With a wide range of flavorings available on the market, jelly products provide numerous options to satisfy different tastes.
The goal of incorporating texture additives in jelly production is to enhance its structure while maintaining its flavor, color, and aroma By analyzing market trends and utilizing optimal ratios of these additives, manufacturers can create innovative herbal jelly alternatives that appeal to consumers.
2 consequence, our group established the investigation topic “The impact of food additives on qualities of gels from Catunaregam spinosa leaves extract”.
Research objectives
The experiment aimed to identify the optimal additive concentrations that contribute to the formation of jelly products Pectin was extracted from C spinosa leaves to analyze its properties By comparing jelly samples enhanced with various additives—agar, gelatin, xanthan gum, and carrageenan—to those made using the traditional method with only Ca(OH)2, the study facilitated the selection of suitable additives for improved jelly formulation.
Sugar is added to jelly to enhance its flavor and sensory appeal By utilizing sensory approaches, it is possible to identify the ideal type of structural additives and sugar content that align with consumer preferences This research offers valuable recommendations for creating technological innovations in jelly product development.
Research object and scope
- The Catunaregam spinosa leaves powder from Catunaregam spinosa leaves in
Tam Đao, Viet Nam from Bach Hoa Xanh, Ha Noi
- Ca(OH)2: commercial calcium hydroxide powder
- Agar powder from Platapiantong brand company, Thailand
- Gelatine powder from ST FOOD company, Thailand
- Xanthan gum powder: commercial xanthan gum
- Carrageenan powder from Mioka Biosystems Corporation, Philippines
- Sugar from TTC – Bien Hoa Join Stock Company
In this study, the Catunaregam spinosa jelly with additives was evaluated for its hardness, deformation, syneresis, pectin characteristic and sensory test with descriptive test and hedonic test.
Research content
The main contents of the research article on evaluating the ability of additives to create structure for jelly products include:
- Determining the pectin content in the Catunaregam spinosa leaves powder
- Investigate the gelling-forming ability of food additives with different concentrations for Catunaregam spinosa jelly
- Survey the influence of additives on the syneresis of the product
- Comparing and selecting the suitable formulas based on sensory tests.
Scientific and practical values
- The utilization of a gelling agent-supplemented jelly production process serves as a valuable reference for scientific research
- The development of an unprecedented jelly product from a traditional method, incorporating a gelling agent to enhance the jelly's texture and make it suitable for consumer preferences
- This study can be served as a reference for research on gelling agent-supplemented jellies and traditional Asian jelly products
- The result of this research contributes technological parameters for further research on the addition of food additives to novel jelly products
- The production technique of this jelly product can contribute to the research and development of food products from Catunaregam spinosa leaves.
Report layout
LITERATURE REVIEW
Catunaregam spinosa powder
2.1.1 Introduction of Catunaregam spinosa powder
Catunaregam spinosa (Thunb.) Tirveng, a thorny shrub from the Rubiaceae family, is found at elevations up to 4000 feet The powder is derived from its dried and ground leaves.
In Viet Nam, this species has many Vietnamese names such as: “găng trắng”, “găng tu hú”, “găng trâu”, “găng gai” that has been shown in [1]
TABLE 2.1 TAXONOMY OF C ATUNAREGAM SPINOSA
Species Catunaregam spinosa (Thunb.) Tirveng.
Fig 2.1 Catunaregam spinosa leaves and Catunaregam spinosa powder
TABLE 2.2 SYNONYM OF C ATUNAREGAM SPINOSA
Gardenia stipularis Rottler Genipa dumetorum (Retz.) Baill
Posoqueria dumetorum (Retz.) Willd ex Roxb
Randia uniflora Regel Solena dumetorum (Retz.) D.Dietr
Xeromphis retzii Raf Distinguishing natural features
C spinosa features simple, shiny, and pubescent leaves that are bright green on the upper side and paler below These leaves are ovate or spatulate, measuring 4 to 6 cm in length and 2 to 3 cm in width, with a petiole length of 4 mm The leaf blade is characterized by its ovate or spatulate shape and an acute apex.
The tree features apiculate leaves with an attenuate base and entire margins, characterized by reticulate venation and a prominent midrib Its solitary, nearly sessile flowers are pale white in color The fruit, which has yellow flesh, is spherical or ovoid, measuring 2.5 to 4 cm in length and width, and consists of two compartments The numerous seeds are approximately 5 mm long and 3 to 4 mm wide, displaying a rounded dorsal edge and flat, smooth sides, with a light black coloration This tree typically blooms between March and July, as identified by Lợi.
Catunaregam spinosa is a small tree or deciduous shrub, reaching heights of up to 5 meters, characterized by its sharp, straight spines This plant is indigenous to regions including India, Nepal, Bangladesh, South China, and the African subcontinent, thriving in semitropical and subtropical tidelands For centuries, it has been utilized in Ayurvedic and Siddha medicine to address various ailments, with its fruits, roots, and leaves also playing a role in traditional Chinese medicine In Vietnam, Catunaregam spinosa is commonly found in provinces such as Son La, Lang Son, Quang Ninh, Hai Phong, Phu Tho, Vinh Phuc, Thanh Hoa, Nghe An, Thua Thien - Hue, Da Nang, and Dong Nai.
The plant is utilized in both medicinal and culinary applications, with its roots, leaves, fruits, and stems being harvested in the fall and winter These parts can be preserved in fresh or dried forms, with dried fruits often processed into pharmaceutical products Additionally, fresh leaves are dried and crushed to extract mucus, which is used in food for refreshing purposes.
C spinosa fruit contains 74.1% water, 0.2% ether, 0.9% protein, 5.5% sugar, 17.7% carbohydrates, 4.43% fiber, acids (citric acid) 0.3%, and tannin 1.6% In addition, there are pectin, mucus and tartaric acid Triterpene saponins are present in fresh fruit with a content of 2 - 3% and dry fruit 10% When hydrolyzed, saponin produces oleanolic acid and the sugars are glucose, fructose, xylose and glucuronic acid There are also 1 – keto – 3α – hydroxyolean (II) β and α amyrin, β sitosterol and oleanolic acid Theseeds of C spinosa contain 1.5% fat, 14.2% protein, seed mucilage, seed resin, 1.4% organic acids and a small amount of unidentified alkaloids The bark of the C spinosa tree contains scopoletin, D- manitol and a mixture of saponins that when hydrolyzed give the sugars glucose, xylose, rhamnose, and two sapogenins, randialic A and randialic B acids The roots also contain scopoletin, D – manitol that has been confirmed by Bích et al [3]
C spinosa is a versatile plant whose various parts, including fruits, stem bark, leaves, and seeds, have been utilized in traditional medicine and as food The juice extracted from these components is commonly used to treat ailments such as anthelmintics, tonics, piles, and flatulence Consuming this juice on an empty stomach is believed to enhance the body's defense mechanisms and promote longevity Additionally, C spinosa is recognized for its effectiveness in treating ulcers, inflammation, tumors, wounds, and skin diseases Moreover, it serves as a nutritious vegetable, rich in vitamins and minerals, contributing to improved dietary habits.
Pectin
Pectin is a natural, high molecular weight polysaccharide that is anionic, biocompatible, and non-toxic, derived from the cell walls of higher plants Its structure primarily consists of three well-characterized motifs: rhamnogalacturonan I (RG I), rhamnogalacturonan II (RG II), and homogalacturonan (HG) The HG backbone is formed by α-1,4-linked D-galacturonic acid units, while RG I features a branched structure rich in neutral sugars such as mannose, galactose, and arabinose, with side chains of α-1,2-linked L-rhamnopyranose RG II, also based on an HG backbone, represents a conserved branching domain of pectin that has been extensively studied by researchers like Chen et al.
Due to its natural tendency to form aqueous gels, pectin is known as a functional ingredient, gelling/thickening agent, and stabilizer in food manufacturing It has been used
Pectin, a versatile biopolymer, is widely used in confections, fermented dairy products, jams, jellies, fruit preparations, fruit drink concentrates, and fruit juice Its remarkable gelling properties, excellent biocompatibility, non-toxicity, and biodegradability position it as a promising material for applications in the pharmaceutical, health, and cosmetic industries However, research by Chen et al [4] indicates that pectin may have inherent disadvantages when utilized in specific contexts.
Pectins are categorized by their degree of esterification (DE), which is determined by the percentage of carboxyl groups esterified with methanol High-methoxyl pectins (HM-pectins) have a DE greater than 50%, while low-methoxyl pectins (LM-pectins) have a DE of less than 50%.
Low Methoxyl Pectins: When divalent cations exist, which is particularly calcium,
LMPs (Low Methoxy Pectins) can form gels due to the development of intermolecular connection zones between homogalacturonic regions of various chains, often referred to as the "egg box" binding mechanism The ability of LMPs to gel increases as the level of methylation decreases Additionally, low calcium levels make LMPs with a blockwise distribution of free carboxyl groups highly sensitive While acetyl groups contribute to the stabilizing properties of pectin emulsions, they also hinder gel formation with calcium ions, as noted by Bagal‐Kestwal et al [6].
High Methoxyl Pectins (HMPs) have a low degree of dimerization when binding with calcium due to insufficient carboxylate groups When the methoxyl esterified content exceeds 50%, calcium ions interact but do not form gels At a pH of around 3.0, HMPs, typically around 67% in content, create gels through hydrophobic interactions and hydrogen bonding, which reduce electrostatic repulsions among sugars and acids.
The physical characteristics of pectin are primarily influenced by its structure as a linear polyanion (polycarboxylate) Pectins dissolve at temperatures exceeding that of pure water but become insoluble and form gels in aqueous solutions at the same temperature Factors such as molecular weight, degree of esterification (DE), concentration, pH, and the presence of counterions significantly impact the viscosity of pectin solutions, paralleling their effects on solubility.
To assess the potential for pectin to gel, it is essential to consider various factors such as pH, temperature, sugar concentration, cation type and concentration, as well as additional variables Key characteristics influencing gel formation include heterogeneity, the presence of acetate esters, degree of amidation (DA), degree of esterification (DE), and molecular weight, as outlined by Bagal-Kestwal et al [6].
In aqueous solutions, pectin undergoes depolymerization and deesterification, with optimal stability occurring around a pH of 4 However, both processes can take place at pH levels above and below 4, with deesterification occurring at a faster rate than depolymerization According to BeMiller (1986), the presence of solutes can reduce the rates of these reactions by decreasing water activity.
Pectin has gained popularity as an emulsifier in various food applications, particularly in creating the jelly-like consistency of jams and marmalades while reducing syneresis It is often a key ingredient in gelling sugar for home use, where it is mixed with sugar and citric acid High Methoxy Pectins (HMPs) are ideal for traditional jams with high sugar content, while amidated pectins and Low Methoxy Pectins (LMPs) suit products with lower sugar levels In confectionery, pectin contributes to the gel structure and enhances flavor release Additionally, it serves as a fat substitute in baked goods, improves mouthfeel and stability in juice-based drinks, and stabilizes acidic protein beverages Pectin also enhances whey protein functionality and maintains casein colloid stability As a source of dietary fiber, pectin is commonly found in desserts and dessert fillings, with typical usage levels ranging from 0.5% to 1.0%, similar to the pectin content in fresh fruit.
Calcium hydroxide solution (Ca(OH) 2 )
2.3.1 Introduction of calcium hydroxide solution
Calcium hydroxide (Ca(OH)2) is a soft white powder commonly utilized as a raw material in the chemical industry This compound is produced by combining calcium oxide with water and consists of two hydroxide ions (OH−) for every calcium ion (Ca2+).
10 ionic, with aqueous and electrolytic dissociations both producing calcium ions and hydroxide ions, which is provided by [7]
Calcium hydroxide (Ca(OH)₂), commonly known as lime water or milk of lime, is a saturated solution formed when calcium oxide (CaO) is mixed with water This inorganic compound appears as a colorless crystal or white powder and is also referred to by various names, including pickling lime, cal, builders' lime, hydrated lime, and caustic lime.
Calcium hydroxide (Ca(OH)2) is produced by dissolving calcium oxide (CaO) powder in water, creating a milky white solution After allowing the mixture to stand for 1 to 2 hours, a clear layer of Ca(OH)2 solution forms in the middle, with scum on the surface and sediment at the bottom This alkaline, slushy layer is utilized in the food industry, with the quantity of solution varying based on the specific food type.
2.3.2 Properties of calcium hydroxide solution
Calcium hydroxide appears as a white powder with a slight bitter taste It is soluble in water, only slightly soluble in boiling water, and partially insoluble in 95% ethanol and diethyl ether It dissolves in diluted hydrochloric, nitric, and acetic acids, and also absorbs carbon dioxide from the air.
Calcium hydroxide's solubility in water diminishes as the temperature rises, with a solubility of just 1.73 g/L at 20°C, resulting in a basic solution When it reacts with acids, calcium hydroxide produces salts, and when it interacts with carbon dioxide, it forms calcium carbonate.
Calcium hydroxide solution, with a pH of approximately 12.4, is classified as a base due to its pH level exceeding 7 This elevated pH makes calcium hydroxide an ideal option for various industrial applications that require an alkaline solution.
Calcium hydroxide solution serves as an effective flocculant, facilitating the clumping and settling of suspended particles in liquids through a process known as flocculation This method is essential in water and wastewater treatment, aiding in the removal of impurities like suspended solids, bacteria, and algae Additionally, calcium hydroxide solution is utilized in the food industry as a thickener, enhancing the consistency of products such as soups, sauces, and paints.
2.3.3 Application of calcium hydroxide solution
Application of calcium hydroxide in food are provided in [9]
Calcium hydroxide solution plays a crucial role in traditional dessert preparation by soaking sticky rice, resulting in a supple texture and a beautiful shine It also neutralizes the sourness of phrynium leaves, enhancing the cake's unique flavor Additionally, this solution is mixed into the dough, contributing to a softer consistency and a brighter color in the final product.
Calcium hydroxide solution plays a crucial role in the candied fruit-making process by neutralizing sour flavors, resulting in a clearer appearance and extended shelf life Additionally, it is used to treat lotus flowers, effectively eliminating bitterness and maintaining the crisp texture of the petals.
Pickling lime: Calcium hydroxide solution is used in the pickling procedure Pectin becomes stiffer during the pickling process when calcium attaches to maintain the crunch of pickles
Calcium hydroxide solution is an effective method for soaking fruits and vegetables prior to processing, as it helps eliminate dirt and bacteria while preserving freshness Additionally, this solution is beneficial for chicken, as it removes any fishy odor and enhances the meat's tenderness and chewiness.
Soaking corn kernels in a calcium hydroxide solution simplifies the process of converting maize into flour while also releasing essential nutrients like niacin.
Certain types of sugar are refined using calcium hydroxide through a process known as carbonatation, which involves mixing untreated sugar solutions with calcium hydroxide This method improves the stability of the sugar and effectively removes contaminants, resulting in a purer product.
Calcium hydroxide serves multiple purposes in food production, acting as a buffer, neutralizer, and curing agent in products like beer, cheese, and cocoa Additionally, it is utilized in the creation of food additives, advanced biomaterials such as hydroxyapatite (HA), and nutritional supplements for livestock, including vitamin C phosphate, calcium naphthenate, calcium lactate, and calcium citrate Its unique properties allow it to effectively alter pH levels and facilitate coagulation, making it valuable in various medicinal applications.
Agar
Agar, a hydrocolloid first discovered in Japan during the mid-17th century, forms a gel at temperatures between 32 and 43 °C and remains stable, not melting below 85 °C It is soluble in boiling water, producing a clear aqueous solution at a concentration of 1.5% (w/v) This definition is recognized by both the US Pharmacopeia and the Food Chemicals Codex, as noted by Nussinovitch & Nussinovitch (1997).
Agar yield refers to the percentage of dried weight of algae extracted as crude agar, with seaweeds typically yielding between 20% and 30% However, some reports indicate abnormally high agar yields exceeding 50%, which may be attributed to contamination from floridean starch extracted alongside the agar.
Agar extract contains two main types of polysaccharides: agaropectin, an ionic polysaccharide that does not gel, and agarose, the gelling component that is largely sulfate-free In commercial agar production, agaropectin is typically discarded due to its minimal commercial application, despite containing about 2% sulfate The concentration of agarose in agar-bearing seaweeds ranges from 50% to 90% Agarose and agaropectin can be separated using quaternary ammonium salts or by acetylating the polymer in chloroform, resulting in soluble agarose acetate and insoluble agaropectin acetate Agarose consists of four basic sugar units: D-galactose, L-galactose, 3,6-anhydro-L-galactose, and D-xylose, and features a linear structure without branching In contrast, agaropectin's fundamental sugar units include pyruvic acid, galactose sulfate, D-xylose, L-galactose, and 3,6-anhydro-L-galactose.
Agar can dissolve completely in boiling water, but it can also be fully dissolved in cold water by soaking it overnight, especially when in forms like bars, strings, or flakes A brief soak of just a few minutes can enhance the dissolving process, even with the soluble variety of agar It's essential to maintain a neutral pH during soaking and boiling for optimal results.
Agar's physical properties, including gel strength, syneresis, viscosity, and melting temperatures, alongside its chemical characteristics such as sulfate content and 3,6-anhydrogalactose levels, are crucial for determining its quality The configuration and quantity of sulfate groups, along with the percentage of 3,6-anhydrogalactose in the phycocolloid, significantly influence the gel's characteristics and the proportions of algal components.
Research indicates that higher agar concentrations lead to increased setting and gelation temperatures of agarose Additionally, the firmness of the gel correlates with the sol's setting point at a consistent temperature As the methoxyl content rises, agarose gels form at elevated temperatures Furthermore, agarose gelation temperature rises more gradually with slower cooling rates, as noted by Nussinovitch & Nussinovitch (1997).
Factors affecting yield and quality of agar are listed in [11]
- Season: Agar production was higher in summer (temperature region) and rainy season (tropical region) compared to winter (temperature region) and dry season (tropical region), respectively
- Salinity: Agar production was higher at high (>40 ppt) or low salinity (