High Methoxyl Research Articles

Pectin Microwave Assisted Extraction from Pumpkin Peels: Process Optimization and Chemical-Physical and Rheological Characterization.

Recently, pectin, a versatile polysaccharide with different industrial applications, has gained significant attention as an eco-friendly and functional ingredient. This study investigates pumpkin peels (Cucurbita maxima L., Mantua variety) as a novel source of pectin, using a microwave-assisted extraction method with citric acid-acidified water as solvent. The extraction conditions were optimized using a Design of Experiments approach, considering the solvent-to-solid ratio (SSR), pH, temperature, and extraction time. The optimized conditions (94.8 °C, 5 min, pH 1.5, and 46 mL/g SSR) resulted in a pectin yield of 18.05%. A comprehensive characterization of the extracted pectin was performed, including FT-IR spectroscopy, DSC, TGA, rheological properties, and techno-functional assessments such as water holding capacity and fat binding capacity. The results indicated a high degree of esterification (56.19 ± 0.87%), classifying the pumpkin peels (PP) extract as a high methoxyl pectin. PP pectin demonstrated potential as a stabilizer and emulsifying agent, although its high methoxyl content limits its use as a carrier for targeted bioactive delivery. The findings support the viability of using agricultural by-products to obtain valuable polysaccharides, contributing to waste valorization and sustainable industrial practices.

Structure formation mechanism of pectin-soy protein isolate gels: Unraveling the role of peach pectin fractions.

This study investigated the macro & micro properties of the composite gels formed by soy protein isolate (SPI) and peach pectin fractions: water-soluble pectin (WSP), chelator-soluble pectin (CSP), and sodium carbonate soluble pectin (NSP). Specially, the interaction between pectin fractions and SPI was studied to explain the formation mechanism of the composite gels. WSP, as a high methoxyl pectin, exhibited rich branching (sugar ratio B=3.10). CSP, as a low methoxyl pectin, depicted a high linearity. NSP, with low linearity (sugar ratio A=6.14), contained numerous side chains. Due to the strong interaction between pectin fractions and SPI, the new composites with excellent dense network microstructures were formed, accompanied by increased apparent viscosity, higher G' and G'', and reduced particle size. XRD and FT-IR analysis highlighted the modifications in gel structures. SEM-dispersive X-ray spectroscopy observed elemental distribution and framework composition in pectin-SPI gels. Hydrophobic interaction was the most important chemical force in pectin-SPI binding. Molecular docking results indicated that galacturonic acid in pectin bound more strongly to 7S than to 11S, with tighter hydrogen bonds. Notably, WSP-SPI showed the lowest turbidity, indicating enhanced solubility and particle dispersion, which helped prevent aggregation. CSP-SPI demonstrated the highest G' and G'', ascribing to the high linearity and abundant carboxyl groups in CSP. NSP-SPI showed the highest apparent viscosity and irregular structure. Overall, the texture properties of pectin-SPI gels were driven by pectin's structure properties, which would provide new and valuable information for texture control in gel formulation.

Investigating the matrix effect of high/low methoxyl pectins on typical aroma of apple juice using HS-SPME-GC–MS and NMR analysis

Aroma quality is a key focus for apple juice producers and consumers alike. This study explored how pectin affects aroma release in apple juices. Initially, study selected 14 typical aroma compounds to examine pectin's matrix effects in both model and actual juices. The molecular interactions between pectin and these aromas were analyzed by using Nuclear Magnetic Resonance. Physicochemical analyses revealed that the concentration of pectin retained aroma in cloudy juice was higher. Juices with high methoxyl pectin retained more aroma than those with low methoxyl pectin. The addition of pectin inhibits the release of most volatile substances, such as esters and aldehydes, while promoting the release of alcohols. This is because D-galacturonic acid chemically bonded with esters and aldehydes. Sensory tests showed that pectin addition masked off-flavors and boosted floral notes, also extending the finish of the apple juice. The findings suggest methods and provide theoretical support for improving apple juice aroma by managing pectin levels.

Passion fruit peel-derived low-methoxyl pectin: De-esterification methods and application as a fat substitute in set yogurt

Passion fruit pectin, originally high methoxyl pectin, undergoes substantial conversion into low methoxyl pectin (LMP) through de-esterification. This de-esterification is significance for reducing the application of sugar in food, as calcium ions can replace excessive sugar during gel formation. In this study, LMPs derived from passion fruit pectin were prepared using four methods: low-temperature alkali, room temperature alkali, enzymatic, and dielectric barrier discharge plasma (DBD)-assisted enzyme (DBDE). The de-esterification conditions were optimized, leading to the selection of LMPs with a degree of esterification for the analysis of molecular weight, monosaccharide composition, and gel properties. The results revealed significant differences in the structure and properties of LMPs depending on the de-esterification method applied. The galacturonic acid content of LMPs significantly increased, with LMP from DBDE (LMP-DBDE) exhibiting the highest increase at 47.81 %. Additionally, the molecular weights of LMPs significantly decreased, with LMP-DBDE showing the smallest decrease. LMP-DBDE demonstrated higher apparent viscosity, thermal stability, and gel properties, facilitating the formation of gels. After 21 days of storage, 0.40 % LMP-DBDE yogurt showed no whey separation, significantly extending its shelf life. Therefore, LMP-DBDE exhibits potential as a fat substitute, combining the advantages of LMP with enhanced water-holding capacity, and presenting promising applications in low-fat dairy products.

Fabrication and characterisation of stable ternary complexes based on bovine lactoferrin, pectin and chlorogenic acid

Stable ternary complexes of lactoferrin (LF), high methoxyl pectin (HMP) and chlorogenic acid (CGA) were synthesised and characterised. Soluble LF–HMP complexes were prepared at pH 5, 6 and 7 using established phase diagram. CGA bound to ternary complexes at moderate binding strength (Ka: 103–105 L/M). LF, HMP and CGA interacted via noncovalent interactions like hydrophobic interaction. Ternary complexes showed particle size of 135–462 nm (except for 0.05% CGA at pH 5) and zeta‐potential from −17 to −22 mV. Ternary complexes had superior antioxidant capacity over binary ones (P < 0.05). The ternary complexes may find application in functional beverages.

Influence of Temperature on the Rheological Properties of Selected Mango Products with ‘Saba’ Banana (Musa acuminata x Musa balbisiana BBB Group) Peel Pectin

Saba banana peel pectin (BPP) was applied to mango jelly and mango juice. The rheological characteristics (flow curve, viscosity curve) of mango products at different temperatures (15°C, 25°C, 35°C, 45°C and 55°C) were then evaluated. The rheological data were fitted using the Hershel-Buckley model and the yield stress, consistency index, and flow behavior were identified. Values obtained from BPP mango products were compared to those with commercial low methoxyl pectin (LMP) and high methoxyl pectin (HMP). Results showed that all types of pectin resulted in non-Newtonian mango jelly and mango juice at all temperatures. For both mango jelly and mango juice, the yield stress contributed by BPP was similar to that of HMP. For the consistency, BPP and LMP had same effects on mango jelly while BPP and HMP had the same effects on mango juice at lower temperatures. For the flow behavior, BPP and HMP showed shear thinning effects for most of the temperatures tested.

Efficacy of almond gum for coacervation with whey protein isolate- optimization, functionality and characterization: A comparison with high-methoxyl pectin

Complex coacervates of whey protein isolate (WPI) and two polysaccharides (almond gum (AG) and high methoxyl pectin (HMP)) under the different pHs (2.5–6.0) and biopolymer mass ratios (1:1–6:1) were prepared to achieve the maximum coacervate yield (CY). The optimum pH and mixing ratio to obtain the maximum CY of WPI-AG (75.93 %) and WPI-HMP (53.0 %) coacervates were 4.3 and 2:1, and 3.5 and 3:1, respectively. Although higher serum layers in emulsions stabilized by WPI-AG/HMP coacervates were detected at the 90 °C, remarkable heat stability under processing temperatures was obtained in ex-situ emulsions with both complex coacervates. Significantly more cold-storage and ionic stabilities were observed for emulsions formulated with WPI-AG than WPI-HMP. Peak shifts in FTIR spectra in the WPI-AG coacervate compared to the individual WPI and AG biopolymers revealed strong electrostatic interactions between these biopolymers. The absence of crystalline peaks for AG and HMP in X-ray diffraction (XRD) spectra confirmed the complexation of AG and HMP with WPI. Thermogravimetric and microstructural analyses showed that porous, loose mesh-like WPI-AG coacervates had superior thermal stability and structural integrity compared to WPI-HMP coacervates and individual biopolymers, which evidenced a more gradual weight loss pattern. WPI-AG coacervates would be promising for efficient emulsion-based delivery systems.

The Effect of Different Extraction Conditions on the Physicochemical Properties of Novel High Methoxyl Pectin-like Polysaccharides from Green Bell Pepper (GBP)

Green peppers are massively produced all over the world; however, substantial quantities of peppers are wasted. Functional polysaccharides can be produced from pepper waste. A conventional acid extraction method was used to obtain pectin-like materials from green bell pepper (GBP). A 23 experimental design (two-level factorials with three factors: temperature, pH, and time) was used to study the relationship between the extraction conditions and the measured physicochemical properties. The extracted polysaccharides were further analysed regarding their physicochemical and functional properties. The yields were in the range of (11.6–20.7%) and the highest yield value was extracted at pH 1. The polysaccharides were classified as “pectin-like”, as the galacturonic acid content was lower than 65%. Glucose and galactose were the major neutral sugars, and their relative amounts were dependent on the extraction conditions. The degree of esterification (DE) of the pectin-like extracts was greater than 50% and they were therefore classified as high methoxyl regardless of the extraction conditions. Also, important levels of phenolic materials (32.3–52.9 mg GAE/g) and proteins (1.5–5.4%) were present in the extract and their amounts varied depending on the extraction conditions. The green bell pepper polysaccharides demonstrated antioxidant and emulsifying activities and could also be used adequately to stabilise oil/water emulsion systems. This finding shows that green bell pepper could be used as an alternative source of antioxidants and an emulsifier/stabilising agent, and furthermore, the extraction conditions could be fine-tunned to produce polysaccharides with the desired quality depending on their application.

Extraction and Physicochemical Characterization of Pectin from Noni (Morinda citrifolia) Fruit

Noni (Morinda citrifolia) is a popular plant in Asian countries and has great potential as pectin source for thickening agents in food products. In general, ethanol has been widely used to precipitate pectin, but the proportion can affect the quality of the product. Therefore, this study aimed to characterize the physicochemical properties of pectin from noni fruit. Extraction was performed using 0.1 N HCl at pH 1.5 and heated at 80°C for 15 min, followed by precipitation with different proportions of 96% ethanol including A (1:1), B (1:2), and C (1:3) v/v, while commercial orange pectin was used as a reference. The results showed that all pectin extracted belonged to the high methoxyl category. The FTIR spectra confirmed the presence of important functional groups including OH-hydroxyl, CH3-saturated aliphatic methyl, C=O carbonyl, and -O- cyclic ether. Furthermore, the crystalline and amorphous structures of noni pectin were confirmed by X-ray diffraction observation. The highest yield was achieved using the proportion of 1:3, followed by 1:2, and 1:1 on a wet basis. The MeO and AUA content of sample B (1:2) were relatively similar to those of the reference. Based on extraction results, noni possesses good characteristics and has the potential for commercial pectin production.

Nanosupplements based on protein-polysaccharide coacervates loaded with essential oils: Evaluation of antioxidant and antidiabetic properties

Essential oils (EOs) have demonstrated potential in food products to prevent complications related to diabetes. Nevertheless, the physicochemical characteristics of pure EOs, including high volatility and low chemical stability, face significant challenges when considering their utilization as functional ingredients. Thus, this study aimed to develop nanosupplements based on protein-polysaccharide coacervates loaded with EOs, thyme (THY) and oregano (ORE), and to evaluate their colloidal, antioxidant, and α-glucosidase and α-amylase inhibitory properties following an in vitro gastrointestinal digestion process. First, heat-induced egg white protein nanoparticles (EWPn) were used to encapsulate both EOs as nanocomplexes. Second, the process to obtain nanosupplements involved the electrostatic deposition of high methoxyl pectin (HMP) onto the surface of pre-formed nanocomplexes, resulting in the production of EWPn-THY-HMP and EWPn-ORE-HMP powders through a freeze-drying process. The effects of in vitro digestion on particle size, zeta potential, stability, and bioaccessibility of systems were analyzed. HMP exhibited a slight ability to protect EWPn from gastric digestion, while encapsulation within the EWPn-HMP system prevented the chemical degradation of EOs during gastrointestinal digestion. Subsequently, the antioxidant properties and the inhibitory effects of digested systems on α-glucosidase and α-amylase activities were examined. After in vitro digestion, EWPn-THY-HMP and EWPn-ORE-HMP systems showed higher ABTS+ radical scavenging than pure EOs (around 70% vs. 30%, respectively). Additionally, reducing power activities (expressed as mg of ascorbic acid equivalents-AAE mL−1) of EWPn-THY-HMP and EWPn-ORE-HMP systems were higher (1.6 ± 0.0 mg and 1.8 ± 0.1 mg of AAE mL−1, respectively) compared to pure THY and ORE (approximately 1.5 mg of AAE mL−1 for both) after in vitro digestion. The α-glucosidase inhibitory activity of EOs decreased upon encapsulation within EWPn-HMP system from an IC50 value of 0.3–1.0 μg mL−1, approximately. However, the effect of encapsulation on α-amylase inhibitory activity was EOs-dependent, and it was higher for the EWPn-ORE-HMP system, with an IC50 value of 8.6 ± 0.2 μg mL−1. The results highlight the potential of EOs encapsulation within EWPn-HMP coacervate nanosupplements as a promising strategy to facilitate their incorporation into food matrices while preserving their antioxidant and α-glucosidase and α-amylase inhibitory properties.

High methoxyl pectin grafted onto gallic acid by one- and two-pot redox-pair procedures

The aim of this research was to graft gallic acid (GA) onto high methoxyl pectin (HMP) through the redox-pair of ascorbic acid (Aa) and hydrogen peroxide (H2O2) with one- and two-pot procedures. The effectiveness of the both procedures and the chemical, physical and antioxidant properties of the obtained HMP-GA were evaluated. HMP-GAone-pot (23.3 ± 0.21 mg GA Equivalent (GAE)/g) and HMP-GAtwo-pot (32.3 ± 0.52 mg GAE/g) were best obtained at H2O2/Aa molar ratio-HMP/GA weight ratio of 9.0–0.5 and 16.0–0.5, respectively. The UV–Vis and FT-IR spectra and along with their derivative and thermal gravimetric analyses, revealed differences between HMP-GAone-pot and HMP-GAtwo-pot. The latter exhibited a greater antioxidant capacity than the former in single electron transfer (ET), hydrogen atom transfer (HAT), and ET-HAT mixed assays. The chemical differences can be attributed to side reactions that may have interfered with the grafting reaction. Consequently, HMP-GA, possessing unique antioxidant and prebiotic properties, can be synthesized through redox-pair procedures.

Effects of different solid particle sizes on oat protein isolate and pectin particle-stabilized Pickering emulsions and their use as delivery systems

Oat protein isolate (OPI)/high methoxyl pectin (HMP) complexes (OPP) were prepared to stabilized Pickering emulsions and applied as nutraceutical delivery systems. The different mass ratios and pH changed the interactions between OPI and HMP that caused the different size of OPP. Specifically, smaller particle size of OPP (125.7–297.6 nm) were formed when hydrophobic interactions along with electrostatic forces predominant in OPP (OPI:HMP = 3:1, pH 4, 5). Among these particles, OPP-2 could stabilize Pickering emulsion efficiently through formation of dense interfacial film, which exhibited the highest apparent viscosity and the smallest average droplet size (23.39 μm). Moreover, OPP-2 stabilized Pickering emulsions with superior stability not only exhibited higher encapsulation efficiency of 85.63%, but also could control curcumin release in simulated gastrointestinal fluids to improve curcumin's bioaccessibility. These results verified the possibility of OPP to be a Pickering emulsions stabilizer, and also identified its potential to be a stable delivery system for bioactive compounds.

Ultrasound treatment improved the physicochemical properties of pea protein with pectin ink used for 3D printing

Pectin, as a gelling agent enhancer, is capable of augmenting the strength of plant protein gels; however, their direct blending often results in insignificant crosslinking efficiency. The application of ultrasonication has been found to effectively promote crosslinking interactions between pectin and plant proteins. This study primarily probes into the physicochemical impacts on the pea protein system instigated by ultrasonicated apple pectin (AP), citrus pectin (CP), and high methoxyl pectin (HM) variances. It has been revealed that the incorporation of pectin, subsequent to ultrasonication, ameliorates the textural and rheological traits of the pea protein matrix. Nevertheless, the introduction of high methoxyl pectin excessively enhances these identical properties, rendering it unsuitable for use in food development and three-dimensional (3D) printing technologies. Under an ultrasound power setting of 390 W, the citrus pectin variant outperforms other variants with its superior hardness, elasticity, and viscoelasticity, thereby significantly bolstering the self-supporting capability and malleability of the pea protein system for potential utilization in 3D printing applications. In conclusion, the ultrasonically treated pectin-pea protein amalgam optimizes the physicochemical attributes of the pea protein system, contributing to the stability enhancement of 3D printed products.

Complex coacervate of wheat germ protein/high methoxy pectin in encapsulation of d-limonene

d-limonene is a volatile compound widely used in food flavorings, but it is chemically unstable in the presence of air, light, moisture, and high temperatures. Coacervation is a well-established technique which involves the formation of biopolymer nanocomplexes between negatively charged polysaccharides and positively charged proteins to protect bioactive components. The study shows the effect of pH, protein/polysaccharide ratio and total biopolymer concentration on complex coacervation of defatted wheat germ protein (DWGP) and apple pectin (high methoxyl pectin (HMP)) in the food industry as a carrier and delivery system for d-limonene. DWGP was used for the first time to form coacervate with apple pectin. Turbidity, ζ-potential and particle size of the complex coacervate and their individual biopolymers were examined for preliminary assays of complex coacervation. The optimum condition for DWGP/pectin complex coacervation was found to be at a ratio of 4:1 with a total biopolymer concentration of 1% and a pH of 4.0. The rheological properties of DWGP, pectin, and their coacervate were measured at various pH levels and ratios. The resulting coacervates, used to microencapsulate d-limonene, underwent spray-dried and were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. These findings have the potential to contribute to the development of DWGP/pectin complex coacervates as effective delivery systems for volatile aromas or bioactive compounds.Graphical

Effect of degree of esterification on the stability of high internal phase Pickering emulsions (HIPPEs) fabricated with pectin‐whey protein isolate complexes

SummaryThis study examined the effects of different degree of esterification (DE) on the stability of high internal phase Pickering emulsions (HIPPEs) fabricated using pectin‐whey protein isolate complexes. The modified pectin with different DE was prepared using the alkali de‐esterification method with high methoxyl pectin (HMP). The impact of DE on the conformational changes of pectin and whey protein isolate (WPI) during the complexes formation was examined using Fourier transform infrared spectroscopy (FTIR) and fluorescence spectroscopy. Citrus pectin (CP)–WPI complexes and camellia oil were used to create an emulsion with a self‐supporting structure of 75% internal phase volume. The thermal, centrifugal, storage and freeze–thaw stabilities of CP–WPI stabilised HIPPEs with different DE were evaluated and the results revealed that the low methoxyl pectin (LMP) produced via alkali de‐esterification altered the charge density of pectin. Compared with the untreated pectin, the electrostatic interaction between CP–WPI complexes was enhanced and the stability of CP–WPI stabilised HIPPEs was improved. The study will help to better understand the interaction between CP and WPI, enhance the efficiency of the pectin–protein delivery system and improve the utilisation rate of citrus pectin, which has important guiding significance.

Combining different ionic polysaccharides and pH treatment improved functional properties of soybean protein amyloid fibrils through structural modifications

This paper reported the effects of different ionic polysaccharides (a cationic polysaccharide (chitosan, CTS), an anionic polysaccharide (high methoxyl pectin, HMP), and a neutral polysaccharide (dextran, DEX)) and pHs (2.0, 4.5, 7.0, and 9.0) on the structural and functional properties of soybean protein amyloid fibrils (SAF) under non-covalent interactions. The fluorescence spectroscopy, ζ-potential, surface hydrophobicity (H0), and turbidity analyses revealed that, at any pH, HMP had a greater effect on the structure of SAF than CTS or DEX. Electrostatic and hydrophobic interactions predominated between SAF and HMP. The addition of negatively charged HMP prevented the exposure of hydrophobic groups, the H0 and ζ-potential decreased. Moreover, compared to SAF, the rheological properties of SAF-HMP complexes were enhanced. In particular, at pH 2.0, HMP was crosslinked with SAF and changed the fibrils conformation, the foaming stability of SAF-HMP increased to 100%. Furthermore, at pHs 2.0 and 4.5, strong electrostatic repulsion occurred between CTS and SAF. Therefore, SAF-CTS exhibited the highest emulsifying activity index and emulsifying stability index, which are 58.21 m2/g and 41.76 min, respectively, followed by SAF-HMP. By contrast, DEX had the least influence on the fibrils. These results will give a hand for industrial production of soybean protein amyloid fibrils.

Effect of enzymatic de-esterification and RG-I degradation of high methoxyl pectin (HMP) on sugar-acid gel properties

The influence of RG-I domains on high methoxyl pectin (HMP) sugar-acid gel properties has rarely been reported. In our work, HMP was modified by enzymatic de-esterification and degradation of RG-I domains to compare and analyze the relationship between the structure and final sugar-acid gel properties. The results showed that the degree of esterification (DE) of REP (pectin degraded by rhamnosidase) and GEP (pectin debranched by galactosidase) was the same as that of untreated HMP, whereas the DE of PMEP (pectin de-esterified by pectin methyl esterase) decreased from 59.63 % to 54.69 %. The monosaccharide composition suggested no significant changes in the HG and RG-I structural domains of PMEP. In contrast, the percentage of RG-I structural domains of REP and GEP dropped from 37 % to about 28 %, accompanied by a reduction in the proportion of the RG-I backbones and side chains. The rheological characterization of sugar-acid gels demonstrated an enhanced gel grade for PMEP and a weakened one for REP and GEP. Moreover, we constructed a correlation relationship between the fine structure of pectin and the properties of the sugar-acid gels, confirming the critical contribution of the RG-I region (especially the neutral sugar side chains) to the HMP sugar-acid gels.

Effects of pectin methyl-esterification on intestinal microbiota and its immunomodulatory properties in naive mice

Pectins are dietary fibers that are attributed with several beneficial immunomodulatory effects. Depending on the degree of esterification (DE), pectins can be classified as high methoxyl pectin (HMP) or low methoxyl pectin (LMP).The aim of this study was to investigate the effects of pectin methyl-esterification on intestinal microbiota and its immunomodulatory properties in naive mice.Supplementation of the diet with LMP or HMP induced changes in the composition of the intestinal microbiota in mice toward Bacteroides, which was mainly promoted by HMP. Metabolome analysis of stool samples from pectin-fed mice showed a different effect of the two types of pectin on the levels of short-chain fatty acids and bile acids, which was consistent with highly efficient in vivo fermentation of LMP. Analysis of serum antibody levels showed a significant increase in IgG and IgA levels by both pectins, while FACS analysis revealed a decrease of infiltrating inflammatory cells in the intestinal lamina propria by HMP.Our study revealed that the structural properties of the investigated pectins determine fermentability, effects on microbial composition, metabolite production, and modulation of immune responses. Consumption of HMP preferentially altered the gut microbiota and suppressed pro-inflammatory immune responses, suggesting a beneficial role in inflammatory diseases.

Enhancing pectin extraction from orange peel through citric acid-assisted optimization based on a dual response

Pectin is widely used in several products in the industry. Conventionally, strong and harmful acids are used for its extraction. This study optimized the extraction of orange peel's pectin using citric acid, considering yield and degree of esterification (DE) as response variables. Proximal analyses were performed, and the samples were subjected to a Box-Behnken design on three central points, considering as variables the temperature, time, and pH. The results of proximate analyses of the orange peels revealed 11.76 % moisture content, 87.26 % volatiles, 0.09 % ash, 50.45 % soluble carbohydrates, 70.60 % total carbohydrates, 0.89 % fixed carbon, 5.35 % lipids, and 36.75 mg GAE/g of phenolic compounds. The resulting second-order polynomial model described the relation of the input and output variables related to each other. The best performance to obtain a higher yield (18.18 %) of high methoxyl pectin (DE 50 %) was set at 100 °C/30 min/pH 2.48. Pectin showed antioxidant properties by ABTS and DPPH assays and similar thermal properties to the commercial polymer. Its equivalent weight was 1219.51 mol/g, and the methoxyl and anhydrouronic acid were 2.23 and 67.10 %, respectively. Hence, pectin extraction with citric acid results in a high-quality polymer and could be used as a gelling agent, stabilizer, or texturizer in food products.

Production of milk-based drink enriched by dietary fiber using carrot pomace: Physicochemical and organoleptic properties during storage

The utilization of fruit and vegetable wastes in the production of functional dairy beverages is one of the effective ways to enhance fiber intake in a diet. In this study, the production of milk-based drinks containing carrot pomace (CP), as a dietary fiber source, was evaluated. CP was added into low-fat sterilized milk to create 2, 4, and 6 % (w/w) CP-fortified milk drink using high methoxyl pectin (0, 0.05, 0.1, and 0.15 % w/w) as a stabilizer. Our results implied that CP altered the color of milk, making it darker and more red/yellow, increased its apparent viscosity from 11.6 to 16.15 m Pa.s, acidity (from 0.17 to 0.19 %), soluble solids (from 8.25 to 9.90° BX), and promoted sedimentation, while, significantly reduced negative charges from −42.45 to −21.45 mV. It observed that 0.1 % of pectin has the potential to stabilize the carrot pomace-milk drink and reduce the sedimentation of particles, which made the drinks a vehicle for delivering a higher level of dietary fiber and phytochemicals (carotenoids and vitamins). Afterward, the effect of pectin (0 and 0.1 %) on drink stability containing CP (4 %) during 8 days of cold storage was investigated at regular intervals. No significant changes were observed in the physicochemical properties of treatments, concerning the acidity, turbidity, color, physical stability, and ζ-potential over time. The results indicated that a reversible phase separation occurred in the beverage samples, induced by decreased ζ-potential during the period. Also, a slight loss in total carotenoid content of samples from 31.20 to 23.18 mg ß-carotene l −1 was found with the prolonged storage time. Sensory analysis revealed a similar consumer preference in terms of sensory attributes (color, flavor, aroma, and mouthfeel) for both treatments. Therefore, producing a stable functional milk drink containing 4 % CP could be feasible and applicable in food industry.