Low-methoxyl pectin stabilizes low-fat set yoghurt and improves their physicochemical properties, rheology, microstructure and sensory liking

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.

An in-depth review: Unraveling the extraction, structure, bio-functionalities, target molecules, and applications of pectic polysaccharides

Pectic polysaccharides have long been a challenging subject of research in the field of macromolecular science, given their complex structures and wide range of biological effects. However, the extensive exploration of pectic polysaccharides has been limited due to the intricacy of their structures. In this comprehensive review, we aim to provide a thorough summary of the existing knowledge on pectic polysaccharides, with a particular focus on aspects such as classification, extraction methodologies, structural analysis, elucidation of biological activities, and exploration of target molecules and signaling pathways. By conducting a comprehensive analysis of existing literature and research achievements, we strive to establish a comprehensive and systematic framework that can serve as a reference and guide for further investigations into pectic polysaccharides. Furthermore, this review delves into the applications of pectic polysaccharides beyond their fundamental attributes and characteristics, exploring their potential in fields such as materials, food, and pharmaceuticals. We pay special attention to the promising opportunities for pectic polysaccharides in the pharmaceutical domain and provide an overview of related drug development research. The aim of this review is to facilitate a holistic understanding of pectic polysaccharides by incorporating multifaceted research, providing valuable insights for further in-depth investigations into this significant polymer.

Grape pomace high-methoxyl pectin: A new prebiotic stabilizer for low-fat synbiotic yogurt gels - Optimization and characterization

High-methoxyl pectin (HMP, 72.5 % esterification degree and galacturonic acid content of 67.9 %) was extracted from grape pomace using a sequential ultrasound-microwave extraction. The extracted HMP was used to develop low-fat synbiotic set yogurts containing probiotic cells. Higher grape pomace pectin (GPP) concentrations (0.5-2 %) increased the probiotic bacterial population of Lactobacillus acidophilus LA-5 and Bifidobacterium bifidum BB-12. Higher cell viability was observed for L. acidophilus LA-5 compared to B. bifidum BB-12. A response surface optimization showed that the presence of 8.08 Log CFU mL-1L. acidophilus LA-5 and 1.88 % HMP experimentally resulted in the best probiotic viability (10.83 ± 0.11 Log CFU mL-1), overall acceptability (8.03 ± 0.06), and pH (4.25 ± 0.05) values. Compared to pectin-free probiotic yogurts, the optimal yogurt gels presented higher probiotic survivability, lower syneresis, and superior storage-dependent sensory attributes during 21 days of storage. However, a 14-day storage period was generally deemed suitable. The GPP-containing yogurt compared to the pectin-free sample exhibited higher colloidal stability with a larger particle size (433.8 nm vs. 272.5 nm) and lower zeta potential (-20.4 mV vs. -10.6 mV). Field emission-scanning electron (FE-SEM) and fluorescent (FLM) microscopy images confirmed a denser microstructure for GPP-enriched yogurts. The chemical interactions in the yogurt were not affected by enriching with GPP as investigated by FTIR, whereas the steady and dynamic rheological properties were significantly improved. GPP-enriched yogurt had a firmer gel structure with a larger linear region and lower G' compared to the control, indicating a semi-solid state. The GPP as a multi-functional prebiotic ingredient would be promising in designing healthier food products.

Role and influence mechanism of different concentration of hyaluronic acid on physicochemical and organoleptic properties of yogurt

Hyaluronic acid (HA) has been approved to be added to milk and other dairy products, it has highly water-binding ability which can combine with a large number of water molecules through intramolecular hydrogen bonding to form high viscous gels. In addition, HA is one of the prebiotics, can provide health benefits like anti-aging, anti-inflammatory, angiogenic, is a potential additive for enhancing the quality of yogurt. Therefore, the aim of this study was to evaluate the effect of 0%, 0.02%, 0.05%, 0.1%, 0.25% and 0.5% HA on rheological properties, functional properties, thermal stability, protein stability, protein structure and protein fractions of yogurt. The addition of HA, storage modulus (G') is always larger than loss modulus (G'') in all the samples, which is a typical characteristic of gel networks, and the microstructures of the yogurt samples showed a continuous and more homogeneous spatial network structure. Overall, the higher concentration (0.5%) had positive effect on the yogurt characteristics, like higher WHC, foam stability, microstructure, and texture. In contrast, the 0.1% concentration HA lead to a very abnormal results, it had a negative effect on yogurt including water-holding capacity, texture, and protein stability, suggesting structural destabilization and disruption of inter-aggregation before protein. These findings provide a valuable fundamental data for commercialized HA adding yogurt development and quality control processes.

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.

Optimizing Skim Milk Yogurt Properties: Combined Impact of Trans-glutaminase and Protein-Glutaminase

The lack of fat in yogurt can lead to alterations in taste and whey separation, reducing consumer acceptance. In this study, the feasibility of enhancing the quality of skim milk yogurt through a combination of transglutaminase (TG) and protein-glutaminase (PG) was investigated. The combination of TG and PG resulted in simultaneous cross-linking and deamidated of casein micelles, with PG deamidation taking priority over TG cross-linking, leading to higher solubility and lower turbidity of milk proteins compared with TG alone. When 0.06 U/mL TG and 0.03 U/mL PG were added, firmness and viscosity indexes significantly increased by 38.26 and 78.59%, respectively as compared with the control. Microscopic images revealed increased cross-linking with casein and filling of cavities by smaller sub-micelles in the combination of TG and PG treatment. Furthermore, the combination of TG and PG resolved issues of rough taste and whey separation, leading to improved overall liking. This study highlights the benefits of using both enzymes in dairy production and has important implication for future research.

The properties of the rice resistant starch processing and its application in skimmed yogurt

Extrusion is typically employed to prepare resistant starch (RS). However, the process is complicated. In this study, the effects of twin-screw extrusion on the crystallinity, thermal properties, and functional properties of starch formed in different extrusion zones were investigated. The effects of this process on the rheological properties and microstructure of RS-added skimmed yogurt were also studied. According to the results, the RS content increased from 7.40 % in the raw material to 33.79 % in the extrudate. The A-type crystal structure of the starch was not observed. The dissociation temperature of the extruded starch ranged from 87.76 °C to 100.94 °C. The glycemic index (GI) of skimmed yogurt fortified with 0.4 % RS was 48.7, and the viscosity was also improved. The microstructure exhibited a uniform network of the starch-protein structure. The findings may serve as a theoretical basis for the application of RS in the food industry.

Evaluation of lupine seeds (Lupinus albus L.) neutral extract as a texture improver in low-fat yogurt production

Aqueous lupine seeds (Lupinus albus L.) extracts were evaluated as a natural fat substitute in low-fat yogurt production. Thus, the chemical composition, particle size, molecular weight, total phenolic (TPC), and total flavonoids (TFC) of the selected extract were estimated. Also, the antimicrobial activity and antioxidant capacity of selected extract were investigated. Yogurt with neutral lupine extract (NeLP) had the highest all sensorial attributes compared to other extracts. Also, the incorporation of NeLP during low-fat yogurt processing increased the solid content, and viscosity, as well as improved the textural profile and sensorial attributes without any negative effect on the yogurt's color. SEM micrographs of NeLP-yogurt microstructure showed a matrix characterized by large fused casein micelles clusters with comparatively lower porosity compared to control yogurt (without NeLP). The chemical composition of NeLP indicated that the major sugar constituents are glucose and galactose with different molar fractions. The molecular weight of NeLP is 460.5 kDa with a particle size of 1519.9 nm. Also, IC50 of NeLP is 0.589 mg/ml, while TPC and TFC are 7.17, and 0.0137 g/100 g sample, respectively. Hence, lupine neutral extract (0.25%) could be used as a fat replacer or texture improver ingredient in such low-fat yogurt which led to improved its characteristics without any negative defect during 7 days at 5 °C.

Effect of exopolysaccharides yield and addition concentration of Lactobacillus helveticus on the processing characteristics of fermented milk and its mechanism

Exopolysaccharides (EPS) yield and added concentration of lactic acid bacteria can greatly affect the processing characteristics of fermented milk. In order to investigate the effects and mechanisms of EPS yield and added concentration on fermented milk, researchers extracted EPS from 50 strains of Lactobacillus helvedicus (L. helvedicus) and selected the two strains with the largest difference in EPS yield (L. helvedicus LH18 and L. helvetigus LH33) for subsequent experiments. The physicochemical properties of EPS-LH18 and EPS-LH33 were analyzed. The gel characteristics and protein conformation of fermented milk were studied by means of texture analyzer, rheometer, scanning electron microscopy, nuclear magnetic resonance machine, fluorescence spectrophotometer and circular dichroism. The results indicate that the monosaccharide compositions of EPS-LH18 and EPS-LH33 are the same and have good thermal stability. The texture and rheological properties of L. helveticus LH18 fermented milk are significantly superior to other fermented milk. The reason is that L. helveticus LH18 EPS has the highest yield, which leads to a denser gel structure, lower surface hydrophobicity and free sulfhydryl content of its fermented milk. According to circular dichroism analysis, β- sheet and random coil are the internal factors leading to the difference in fermented milk gel. In addition, the fermented milk improved even more favorably as the concentration of the two EPS additions increased. As described above, L. helveticus LH18 has the potential to be an excellent yogurt starter, and both of the above EPS can be used as probiotic stabilizer alternatives for fermented dairy products.

Effect of protein-glutaminase on the texture, rheology, microstructure and sensory properties of skimmed set-type yoghurt

The effects of enzymatic deamidation by protein-glutaminase (PG) on the texture, rheology, microstructure, and sensory properties of skimmed set-type yoghurt were studied. The proportion of small-particle size milk protein micelles (10-50 nm) increased significantly from 0 to 99.39% after PG deamidation. Cryo-SEM results revealed that PG-treated yoghurt had a denser and less open 3D structure. PG was effective at inhibiting post-acidification during storage at 4 ℃. The water holding capacity of PG-treated yoghurt (0.12 U·mL-1) increased by more than 15%. The fluidity and viscosity of yoghurt were significantly improved with increasing PG dose. Sensory evaluation revealed that PG (0.06 U·mL-1) significantly improved the smoothness and creaminess of skimmed set-type yoghurt, which corresponded to the pastiness in texture. In summary, PG can effectively address the problems of post-acidification, gel fracture, and flavors change in skimmed set-type yoghurt, providing new applications for PG in the food industry.

Recent Advances in the Extraction of Pectin from Various Sources and Industrial Applications

Pectin is a structural polysaccharide present in plants that primarily consists of galacturonic acid units. This Review discusses the chemistry of pectin, including its composition and molecular weight. Pectin is conventionally extracted from agricultural waste (fruit and vegetable peels) using an acidic or basic aqueous medium at high temperatures. These processes are time- and energy-consuming and also result in severe environmental problems due to the production of acidic effluents and equipment corrosion. As pectin usage is increasing in food industries for developing different products and it is also used as an excipient in pharmaceutical products, better extraction procedures are required to maximize the yield and purity. The Review encompasses various alternate green approaches for the extraction of pectin, including traditional acid extraction and various emerging technologies such as deep eutectic solvent-based extraction, enzyme-assisted extraction, subcritical fluid extraction, ultrasound-assisted extraction, and microwave-based extraction, and evaluates the yield and physicochemical characteristics of the extracted pectin. This work aims to provide a platform for attracting more thorough research focused on the engineering of novel and more efficient green methods for the extraction of pectin and its utilization for various biotechnological purposes.

Production and functional evaluation of nonfat dry milk with whey proteins as fibrils

Commercial manufacturing of dairy products involves the addition of dairy ingredients (such as nonfat dry milk and milk protein concentrates), as well as nondairy additives (such as gums, stabilizers, emulsifiers, and texture modifiers) to get the best product appearance, maintain the product quality, and extend shelf life. Though these nondairy additives are not harmful, consumers do not prefer them in dairy food formulations. Therefore, the dairy industry is working on improving the inherent functionality of dairy ingredients using different processes. Recently, fibrillation emerged as a new technique to convert globular proteins such as whey proteins into fibrils, which provide enhanced viscosity, foaming, and emulsification capacity. Therefore, skim milk was subjected to microfiltration followed by ultrafiltration of microfiltration permeate to fractionate whey proteins. Then, whey proteins were selectively fibrillated and mixed back with other streams of microfiltration and ultrafiltration to get fibrillated skim milk. Fibrillated skim milk was spray-dried to get fibrillated nonfat dry milk (NDM). Visible whey protein fibrils were observed in reconstituted fibrillated NDM, which showed survival of fibrils in fibrillated NDM. Fibrillated NDM showed significantly higher viscosity than control NDM. Fibrillated NDM also showed higher emulsification capacity, foaming capacity, and stability than the control NDM but lower gel strength. Considering the improved functionality of fibrillated NDM, they can be used in product formulations such as ice cream mix, where the thickening of a solution, good emulsification, and foaming properties are required.

Black garlic particles as a natural pigment and emulsifier in a Pickering emulsion based low fat innovative mayonnaise: Improved rheology and bioactivity

Black garlic is rich in brown pigments and Maillard reaction products are known for antioxidant activity and health promoting effects. In the present investigation, we report a facile strategy for fabricating low-fat innovative mayonnaise (IM) using black garlic particles (BGP) as a natural pigment, and a functional ingredient. Whey protein concentrate and high methoxyl pectin at optimized concentrations were utilized for fabricating an IM which served as a control. IM5 and IM10 were ternary composites constituting whey protein, high methoxyl pectin along with BGP (@5 and 10% respectively). The formulation IM10 (BGP @10%) showed high firmness and low spreadability quotient, hence IM5 was taken forward for fabrication for two more variants namely IM-J (using low methoxyl pectin (LMP) from jackfruit peels) and IM-C (LMP from citrus). The effect of BGP and LMP on the functional quality of IM was confirmed through zeta potential, antioxidant activity, textural, rheological, and microscopic evaluation. Fluorescence microscopy confirmed the presence of solid particles over the fat phase of IM, while interaction of pectin and whey proteins was demonstrated through fluorescence emission spectroscopy which clearly displayed stabilization of IM through the formation of Pickering emulsion. Pronounced difference in color and flavor score with BGP established high sensory scores in IM5, IM-J, and IM-C. Rheology supported the stabilizing effects of LMP in IM-J and IM-C in terms of speedy recovery of thixotropy, with recovering storage modulus (G'). Enhanced viscosity of IM-C and IM-J further corroborated the dual effect of LMP and BGP in improving emulsifying and functional quality of IM. Enhanced oxidative stability of IM was established by reduced peroxide and Totox values. Overall our results suggest the promising applications of black garlic as functional ingredient in protein and pectin based Pickering emulsions.

Application of natural and modified additives in yogurt formulation: types, production, and rheological and nutraceutical benefits

Yogurt, a popular fermented dairy product, is of different types and known for its nutritional and nutraceutical benefits. However, incorporating additives into yogurt has been adopted to improve its functionality and nutraceutical properties. Additives incorporated in yogurt may be natural or modified. The incorporation of diverse natural additives in yogurt formulation, such as moringa, date palm, grape seeds and argel leaf extracts, cornelian cherry paste, mulberry fruit and leaf powder, lentil flour, different types of fibers, lemongrass and spearmint essential oils, and honey, has been reported. Similarly, modified additives, such as β-glucan, pectin, inulin, sodium alginate, and gelatin, are also added to enhance the physicochemical, textural, sensory, and rheological properties of yogurt. Although additives are traditionally added for their technological impact on the yogurt, studies have shown that they influence the nutritional and nutraceutical properties of yogurt, when added. Hence, yogurts enriched with functional additives, especially natural additives, have been reported to possess an improved nutritional quality and impart several health benefits to consumers. These benefits include reducing the risk of cardiovascular disease, cancer, osteoporosis, oxidative stress, and hyperglycemia. This current review highlights the common types of yogurt, the production process, and the rheological and nutraceutical benefits of incorporating natural and modified additives into yogurt.

Effect of atmospheric cold plasma treatment on acid gelation properties of skim milk: Rheology and textural studies

Cold plasma processing is a non-thermal food processing technique that has been shown to improve the gelling properties of plant proteins by altering their structure through oxidation and crosslinking. This study aimed to investigate the effects of cold plasma treatment on the rheological properties of skim milk under different conditions, focusing on the impact of feed gas and treatment time on skim milk's sulfhydryl content, flow properties, and acid gelling behavior. Results showed that free sulfhydryl content decreased with treatment time, with a notable reduction observed after 2 min of N2-O2 plasma treatment. Skim milk treated with N2 plasma experienced a more gradual decrease in free SH content. Cold plasma increased skim milk viscosity over time. N2-O2 plasma treatment significantly affected G'40 and G'4 storage moduli, with an increase observed after 2 min of exposure but no change beyond that time. Acid gels' greenness (a* value) decreased with increasing treatment time compared to the control. Acid gel firmness of milk treated with N2-O2 plasma for 1 min significantly increased from 1.804 N to 1.912 N, and further to 2.072 N after 2 min of treatment. However, longer exposure times led to lower firmness in gels. N2 plasma treatment also significantly impacted acid gel firmness. Syneresis in acid gels decreased from 63.4 % to 57.7 % and 58.7 % after 1 and 2 min of N2-O2 plasma treatment, respectively, but increased to about 70 % after 4 min. Acid gels made from milk treated with N2 plasma experienced considerably less syneresis. The cold plasma treatment under different conditions significantly affected the properties of skim milk, with various impacts on sulfhydryl content, flow properties, and acid gelling behavior. These findings demonstrate the potential applications of cold plasma processing in the food industry to improve product properties.

Stability and flavor of set yogurt fortified with Tremella fuciformis polysaccharide during cold storage

Tremella fuciformis is an edible and medicinal fungus containing excellent nutritional value. T. fuciformis polysaccharide (TFP) is the important bioactive ingredients of T. fuciformis, which has gained great attention. The aim of this study was to investigate the effect of TFP on the stability and flavor of set yogurt. Our results revealed that the addition of 0.1% TFP had a positive effect on improving the stability of set yogurt including the water holding capacity, texture, rheological properties and microstructure at the cold storage period of 1, 7, 14 and 21 days. It is remarkable that the hardness, gumminess and chewiness of the set yogurt were significantly improved by the addition of TFP during the cold storage. Moreover, the set yogurt containing TFP was able to maintain better stability in the three intervals thixotropy test. In particular, the addition of 0.1% TFP had no adverse effects on the flavor of set yogurt, including sourness, sweetness, umami, bitterness, richness and saltiness. These data suggested that TFP can be used as a natural potential stabilizer for the set yogurt.

Microwave-assisted valorization and characterization of Citrus limetta peel waste into pectin as a perspective food additive

Machine learning techniques were employed to evaluate the effect of process parameters viz. microwave power (100 W, 300 W, 600 W); pH (1, 1.5, 2); and microwave time (the 60 s, 120 s, 180 s) on the pectin yield from Citrus limetta peel. A fourth-order polynomial function of 66.60 scales was used by the Support Vector Regression (SVR) model at an epsilon (ε) value of 0.003. The co-efficient of determination (R2) and root mean square error-values for training data and test data were 0.984; 0.77 and 0.993; 0.66 respectively. At optimized conditions, microwave power 600 W, pH 1, and time 180 s the best yield of 32.75% was obtained. The integrity of pectin skeletal was confirmed with FTIR and 1H NMR spectrums. The physicochemical analysis revealed that CLP is a high-methoxyl pectin (HMP) with a 63.20 ± 0.88% degree of esterification, 798.45 ± 26.15 equivalent weight, 8.06 ± 0.62% methoxyl content, 67.93 ± 3.36 AUA content, 6.27 ± 0.27 g water/g pectin WHC, 2.68 ± 0.20 g oil/g pectin OHC, low moisture, ash and protein content of 6.85 ± 0.10%, 3.87 ± 0.10% and 2.61 ± 0.06% respectively, which can be utilized as a food additive. Therefore, pectin extraction from Citrus limetta peel using a greener technique like MAE is an eco-friendly, time-saving approach to transform waste into a versatile food additive.

Dietary fiber modification: structure, physicochemical properties, bioactivities, and application-a review

There is increasing attention on the modification of dietary fiber (DF), since its effective improvement on properties and functions of DF. Modification of DF can change their structure and functions to enhance their bioactivities, and endow them with huge application potential in the field of food and nutrition. Here, we classified and explained the different modification methods of DF, especially dietary polysaccharides. Different modification methods exert variable effects on the chemical structure of DF such as molecular weight, monosaccharide composition, functional groups, chain structure, and conformation. Moreover, we have discussed the change in physicochemical properties and biological activities of DF, resulting from alterations in the chemical structure of DF, along with a few applications of modified DF. Finally, we have summarized the modified effects of DF. This review will provide a foundation for further studies on DF modification and promote the future application of DF in food products.

Impact of Apple Pomace Powder on the Bioactivity, and the Sensory and Textural Characteristics of Yogurt

This study focused on the development of a yogurt with an improved structure, texture and antioxidant activity level, by using apple pomace (AP) powder that was obtained in large quantities during the production of juices. The objective was to determine the sensory, physicochemical, textural and antioxidant characteristics of yogurt with the addition of AP powder (0.2-1.0%), during its shelf life. The physicochemical composition of AP was determined as follows: dietary fibers-62.73%, including pectin-23.12%; and the content of the antioxidant compounds in AP-total polyphenols (728.8 mg GAE/100 g DW), flavonoids (246.5 mg QE/100 g DW), tannins (63.54 mg TAE/100 g DW), carotenoids (4.93 mg/100 g DW) and the ability to inhibit the free radical (2433 µmol TE/100 g DW). AP addition reduces the yogurt fermentation time. The increase in the total dietary fiber content of up to 0.63% and in the insoluble fiber of up to 0.14% was attested in this study, as well as a significant increase in antioxidant activity, which correlated to the AP content. The addition of AP improved the textural properties of the yogurt during storage (20 days) and led to a significant reduction in syneresis. The influence of the AP content and the storage period on the textural characteristics and the overall acceptability of the yogurt samples were analyzed by the mutual information method. The AP content greatly influenced the yogurt's quality, with the information analysis value for the overall acceptability being 0.965 bits. The analysis of the sensory and textural parameters of the yogurt during storage (1-20 days) demonstrated that samples with AP in proportions of 0.6-0.8% were evaluated with the highest score.

Fortification of milk-based yogurt with protein hydrolysates from brewers' spent grain: Evaluation on microstructural properties, lactic acid bacteria profile, lactic acid forming capability and its physical behavior

Current study aimed to evaluate the utilization of protein from brewers' spent grain (BSGP) on microstructural formation as well as rheological behavior, acidity and lactic acid bacteria (LAB) profile during the refrigerated storage. Three different BSGPs were provided including BSGP-C (extracted without enzymatic hydrolysis), BSGP-P (with protease), and BSGP-PF (with protease co-incubated with flavourzyme). The results demonstrated that BSGPs improved lactic acid forming capability in yogurt production to a higher level than milk-protein based enrichment. BSGPs improved the growth and survival of lactic acid bacteria (LAB), particularly BSGP-P in improving the survival rate of L. bulgaricus. Confocal laser scanning microscopy showed that BSGP-P generated a denser, softer and more homogenous surface appearance as well as showed the tendency to form more compact networks; had a weaker initial gel forming, increased and preserved the consistency of the yogurt during the storage. In conclusion, BSGPs in yogurt improved and preserved the textural properties, consistency, acidity and lactic acid bacteria.

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Protease-extracted preserve the flow behavior of yogurt

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Protease-extracted soften the microstructural surface of the matrices

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BSG protein-rich extracts improve the survival of lactic acid bacteria

Modification and application of highly active alkaline pectin lyase

Alkaline pectate lyase has developmental prospects in the textile, pulp, paper, and food industries. In this study, we selected BacPelA, the pectin lyase with the highest expression activity from Bacillus clausii, modified and expressed in Escherichia coli BL21(DE3). Through fragment replacement, the catalytic activity of the enzyme was significantly improved. The optimum pH and temperature of the modified pectin lyase (PGLA-rep4) were 11.0 and 70 °C, respectively. It also exhibited a superior ability to cleave methylated pectin. The enzyme activity of PGLA-rep4, measured at 235 nm with 0.2% apple pectin as the substrate, was 554.0 U/mL, and the specific enzyme activity after purification using a nickel column was 822.9 U/mg. After approximately 20 ns of molecular dynamics simulation, the structure of the pectin lyase PGLA-rep4 tended to be stable. The root mean square fluctuation (RMSF) values at the key catalytically active site, LYS168, were higher than those of the wildtype PGLA. In addition, PGLA-rep4 was relatively stable in the presence of metal ions. PGLA-rep4 has good enzymatic properties and activities and maintains a high pH and temperature. This study provides a successful strategy for enhancing the catalytic activity of PGLA-rep4, making it the ultimate candidate for degumming and various uses in the pulp, paper, and textile industries.

Current Advancements in Pectin: Extraction, Properties and Multifunctional Applications

Pectin is a heterogeneous hydrocolloid present in the primary cell wall and middle lamella in all dicotyledonous plants, more commonly in the outer fruit coat or peel as compared to the inner matrix. Presently, citrus fruits and apple fruits are the main sources for commercial extraction of pectin, but ongoing research on pectin extraction from alternate fruit sources and fruit wastes from processing industries will be of great help in waste product reduction and enhancing the production of pectin. Pectin shows multifunctional applications including in the food industry, the health and pharmaceutical sector, and in packaging regimes. Pectin is commonly utilized in the food industry as an additive in foods such as jams, jellies, low calorie foods, stabilizing acidified milk products, thickener and emulsifier. Pectin is widely used in the pharmaceutical industry for the preparation of medicines that reduce blood cholesterol level and cure gastrointestinal disorders, as well as in cancer treatment. Pectin also finds use in numerous other industries, such as in the preparation of edible films and coatings, paper substitutes and foams. Due to these varied uses of pectin in different applications, there is a great necessity to explore other non-conventional sources or modify existing sources to obtain pectin with desired quality attributes to some extent by rational modifications of pectin with chemical and enzymatic treatments.

Lignocellulose, dietary fibre, inulin and their potential application in food

In recent years, due to food insecurity, lignocellulose, dietary fibre as well as inulin have received wider attention owing to their abundance and being relatively low-cost indigestible polysaccharides. Since the recognition, acceptance of the consumption and utilization of these polysaccharides, as well as their attraction in science and industry has grown tremendously. There have been further researches carried out to ascertain the fact that people who consume or utilize these polysaccharides have low exposure to some fatal life-threatening illnesses. Rich sources of indigestible polysaccharides such as vegetables, cereals, fruits and nuts are beneficial to good health as consuming them reduce the occurrence of degenerating diseases such as colon cancer, heart disease, diabetes, etc. Despite these increasing facts depicting their advantages in the state of human health, their intake and utilization still fall below the acceptable limit and the knowledge of how they work in the human body are minimal with their explicit actions not easily shown. Hence, this review gives a better understanding of the significance of lignocellulose, dietary fibre and inulin, their functions, classifications, types and applications in the food industry, thereby exposing their various uses as these polycarbohydrates were considered a waste before now.

Tremella fuciformis polysaccharides as a fat substitute on the rheological, texture and sensory attributes of low-fat yogurt

The potential of Tremella fuciformis polysaccharides (TFPS) as a fat substitute in low-fat yogurt was evaluated in this study. The effects of adding different concentrations of TFPS solution on the physical and chemical properties, texture, rheology, microstructure and sensory properties of low-fat yogurt were evaluated. Compared with control, the addition of TFPS not only increased the solid content and water holding capacity of yogurt, but also reduced syneresis losses in low-fat yogurt. In fact, the addition of TFPS did not affect the color of yogurt but had a positive effect on the texture and sensory of yogurt. In terms of rheology, all low-yogurt samples exhibited rheological to the weak gel-like structures (G' > G″), and the storage modulus and loss modulus of the yogurt added with TFPS were higher than those of the low-fat yogurt control group. Compared with the low-fat yogurt control group, yogurt added TFPS makes the cross-linking of polysaccharides and casein more compact. In conclusion, TFPS has potential as a fat substitute in dairy products.

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TFPS with Medicine Food Homology can be used as a fat substitute for low-fat yogurt.

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TFPS significantly improved the physical and chemical properties of low-fat yogurt.

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0.025% TFPS in low-fat yoghurt was most acceptable in the sensory score.

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Polysaccharide-protein interactions enhanced protein network structure.

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TFPS improved overall organoleptic quality of low-fat yogurt.

Effects of Commercial Polysaccharides Stabilizers with Different Charges on Textural, Rheological, and Microstructural Characteristics of Set Yoghurts

The study investigated the preparation of set yoghurts by adding three common commercial polysaccharide stabilizers, namely sodium alginate (SA), gellan gum (GG), and konjac gum (KGM), in milk fermentation to evaluate their effects on the texture, rheology, and microstructure of set yoghurts. The physicochemical properties, water-holding capacity (WHC), texture, low-field nuclear magnetic resonance (LF-NMR), rheology, and microstructure of set yoghurts added with different kinds and quantities of polysaccharides were compared and analyzed. The results showed that the set yoghurts added with anionic polysaccharide GG had more obvious effects on improving WHC, firmness, and rheological properties compared with the set yoghurt added with KGM and SA. The firmness of set yoghurts with 0.02% (w/v) GG increased from 1.17 N to 1.32 N, which significantly improved the gel structure. The transverse relaxation time (T2) of set yoghurts added with GG was the closest to that of the control. Compared with the set yoghurts added with 0.02% SA and KGM, the free water area (A23) of the one added with 0.02% GG decreased most significantly. Moreover, all samples showed shear-thinning behavior, and the apparent elastic and viscous modulus (G', G″) increased with the increase of GG concentration. The G' and G″ of set yoghurts with 0.005% SA and KGM were higher than those in the control, decreased when adding 0.010%, and then increased with the increase of SA and KGM. Additionally, the microscopic observation demonstrated that the addition of GG in set yoghurts significantly promoted the formation of larger protein clusters and showed a tighter and more uniform protein network comparing with the other two polysaccharides (SA, KGM).

Valorization of citrus peel waste for the sustainable production of value-added products

Globally the generation and mismanagement of waste from fruit processing and post-harvest impose a severe burden on waste management strategies along with environmental pollution, health hazards. Citrus waste is one of such worrying fruit waste, which is rich in several value-added chemicals, including pectin. Pectin is a prebiotic polysaccharide possessing a multitude of health benefits. Citrus pectin has excellent gelling, thickening, water holding capacity, and encapsulating properties, which pave its functionality in versatile industrial fields including food processing and preservation, drug and therapeutic agents, cosmetics, and personal care products. The utilization of citrus wastes to derive valuable bioproducts can offer an effective approach towards sustainable waste management. With the ever-increasing demand, several strategies have been devised to increase the efficiency of pectin recovery from citrus waste. This review article discusses the sources, effect, and technology-mediated valorization of citrus waste, the functional and nutritive application of pectin along with its socio-economic and environmental perspective.

Pilot-scale production of exopolysaccharide from Leuconostoc pseudomesenteroides XG5 and its application in set yogurt

Exopolysaccharide from Leuconostoc pseudomesenteroides XG5 (XG5 EPS) is a linear dextran that is built by glucose units via α-1,6 glycosidic bond. The primary objective of this study was to investigate the yield of XG5 EPS and its application in set yogurt. In laboratory scale, the culture conditions of XG5 EPS production were optimized using the L9 (3³) orthogonal test. Here, the optimized yield of XG5 EPS was 26.02 g/L under the conditions of 100 g/L sucrose, initial pH 7.0, 25°C incubation, and 100 rpm for 36 h in a shaking flask. Based on the optimized parameters of laboratory scale, a pilot fed-batch fermentation was performed in a 50-L bioreactor with an adjusted agitation speed of 20 rpm. The XG5 EPS yield reached 40.07 g/L in fed-batch fermentation, which was 54% higher than that achieved in laboratory scale. In addition, XG5 EPS was added into set yogurt to investigate its effect on the stability of set yogurt. Our data demonstrated that the XG5 EPS improved the water-holding capacity, texture profile, and viscosity of set yogurt during cold storage compared with the controls. In particular, addition of 0.5% XG5 EPS increased the structure of 3-dimensional network of set yogurt, which eventually improved the physical stability of the set yogurt. Overall, this study provided new insights for exploring the pilot scale production and application of dextran.

The Extraction, Functionalities and Applications of Plant Polysaccharides in Fermented Foods: A Review

Plant polysaccharides, as prebiotics, fat substitutes, stabilizers, thickeners, gelling agents, thickeners and emulsifiers, have been immensely studied for improving the texture, taste and stability of fermented foods. However, their biological activities in fermented foods are not yet properly addressed in the literature. This review summarizes the classification, chemical structure, extraction and purification methods of plant polysaccharides, investigates their functionalities in fermented foods, especially the biological activities and health benefits. This review may provide references for the development of innovative fermented foods containing plant polysaccharides that are beneficial to health.

Effects of mulberry pomace on physicochemical and textural properties of stirred-type flavored yogurt

Adding functional ingredients is an important method to develop functional dairy products. Mulberry pomace (MPo), a byproduct of mulberry fruit processing, is rich in phenolic compounds and anthocyanins and can be served as the functional ingredient in functional dairy products. The aim of this work was to prepare a functional flavored yogurt by incorporating MPo into stirred yogurt and to investigate the effects of MPo on the physicochemical and textural properties of the product during cold storage. We supplemented MPo powder up to 3% (wt/wt) in fermented milk, and the changes in color, pH, titratable acidity (TA), total phenol content (TPC), total anthocyanin content (TAC), water-holding capacity, rheological behavior, texture, and microstructure of the functional flavored yogurt were monitored during storage under 4°C for 28 d. The MPo powder brought a pink to dark red color to the yogurt, decreased the lightness (L*) and yellow-blue color (b*) values, increased the red-green color (a*) values, decreased the pH value, and increased the contents of TA, TPC, and TAC in a dose-dependent manner. The addition of MPo at 1%, 2%, and 3% (wt/wt) significantly increased water-holding capacity, consistency, viscosity, and viscosity index, and reduced firmness of yogurt samples. Supplementation of MPo significantly reduced the pore spaces and channels inside the samples and improved microstructure of the functional yogurt. During the 28 d of cold storage, MPo-fortified yogurt samples kept relatively constant color, although their L*, a*, and b* showed a decreasing tendency. The pH of all yogurt samples gradually decreased with increasing of TA. Interestingly, TPC and TAC contents and the texture parameters of MPo-fortified yogurt increased gradually and continuously during the 28 d of cold storage. Mulberry pomace is beneficial to improve the physicochemical and textural properties of yogurt and has the potential as a natural stabilizer to be used in functional yogurt rich in phytochemicals.

Bioactive compounds and techno-functional properties of high-fiber co-products of the cacao agro-industrial chain

The cacao shell (CS) and cacao pod husk (CPH), two of the most promising high-fiber co-products of the cacao agro-industrial chain, were evaluated to determine their potential incorporation into food products. This research determined bioactive compounds and techno-functional properties of CS and CPH, and was evaluated the enzymatic inactivation by thermal treatments in CPH. We found that CS is rich in protein, lipids, dietary fiber (48.1 ± 0.3 g 100 gdw -1), and antioxidant molecules such as epicatechin (1.10 ± 0.02 mg g-1) and isoquercetin (1.04 ± 0.09 mg g-1). Moreover, in CS a positive effect of hydration mechanism occur; in fact, it was observed a reduction of Lightness (L∗) value and a remarkable color difference (ΔE∗,18.8 ± 0.7) (CIEL∗a∗b∗ color space), between hydrated and dry CS samples; so, it could be used as a potential natural colorant in foods. CPH resulted equally rich in dietary fiber (35.3-37.4%) and flavonoids (2.9 ± 0.1 mg RE g-1); in this co-product, the rapid enzymatic inactivation by thermal treatments was essential to obtain the highest antioxidant activity and polyphenols content; regarding the techno-functional properties, it was found that CPH flour had high hydration capacity, so CPH can use it as a replacement for emulsifiers or water holding additives while incorporating the fiber and abundantly found antioxidants.

Dietary pectic substances enhance gut health by its polycomponent: A review

Pectic substances, one of the cell wall polysaccharides, exist widespread in vegetables and fruits. A surge of recent research has revealed that pectic substances can inhibit gut inflammation and relieve inflammatory bowel disease symptoms. However, physiological functions of pectins are strongly structure dependent. Pectic substances are essentially heteropolysaccharides composed of homogalacturonan and rhamnogalacturonan backbones substituted by various neutral sugar sidechains. Subtle changes in the architecture of pectic substances may remarkably influence the nutritional function of gut microbiota and the host homeostasis of immune system. In this context, developing a structure-function understanding of how pectic substances have an impact on an inflammatory bowel is of primary importance for diet therapy and new drugs. Therefore, the present review has summarized the polycomponent nature of pectic substances, the activities of different pectic polymers, the effects of molecular characteristics and the underlying mechanisms of pectic substances. The immunomodulated property of pectic substances depends on not only the chemical composition but also the physical structure characteristics, such as molecular weight (M_w ) and chain conformation. The potential mechanisms by which pectic substances exert their protective effects are mainly reversing the disordered gut microbiota, regulating immune cells, enhancing barrier function, and inhibiting pathogen adhesion. The manipulation of pectic substances on gut health is sophisticated, and the link between structural specificity of pectins and selective regulation needs further exploration.