Effects of high hydrostatic pressure and superfine grinding treatment on physicochemical/ functional properties of pear pomace and chemical composition of its soluble dietary fibre

Effects of modification methods on the structural characteristics and functional properties of dietary fiber from cucumber

Cucumbers produce by-products such as cucumber pomace during processing and most of them are discarded without being utilized. To effectively utilize the waste, cucumber pomace is used to extract both insoluble and soluble dietary fibers (DFs) using compound enzyme method (ME), High pressure processing assisted ME (HPP-ME), and dynamic high-pressure microfluidization-assisted ME (DHPM-ME). The results showed that DHPM-ME improved the extraction rate of soluble DFs most effectively, increasing it from 1.74 % to 4.08 %. The modified DFs exhibited enhanced hydration properties and functional properties after HPP-ME- and DHPM-ME-mediated auxiliary treatment. Additionally, the modified DFs exhibited improved thermal stability, increased absorption peaks in the infrared spectra, decreased crystallinity, improved glucose and cholesterol adsorption ability, and delayed glucose adsorption. The cucumber pomace-derived modified DFs can be used as a functional food additive in bakery, meat, dairy products, and beverages, and their effective use can further enhance the economic benefits.

Advancements in modifying insoluble dietary fiber: Exploring the microstructure, physicochemical properties, biological activity, and applications in food industry-A review

Recent research has primarily focused on strategies for modifying insoluble dietary fiber (IDF) to enhance its performance and functionality. IDF is obtained from various inexpensive sources and can be manipulated to alter its biological effects, making it possible to revolutionize food processing and nutrition. In this review, multiple IDF modification techniques are thoroughly examined and discussed, with particular emphasis on the resulting changes in the physicochemical properties, biological activities, and microstructure of the fiber. An extensive overview of the practical applications of modified IDF in food processing is provided. Our study aims to raise awareness about the vast possibilities presented by modified IDF and encourage further exploration and utilization of this field in the realm of food production.

How lignocellulose degradation can promote the quality and function of dietary fiber from bamboo shoot residue by Inonotus obliquus fermentation

Lignocellulose constitutes the primary component of dietary fiber. We assessed how fermenting bamboo shoot residue with the medicinal white-rot fungus Inonotus obliquus affected the yield, composition, and functional attributes of dietary fiber by altering bamboo shoot residue lignocellulose's spatial structure and composition. I. obliquus secretes lignocellulolytic enzymes, which effectively enhance the degradation of holocellulose and lignin by 87.8% and 25.5%, respectively. Fermentation led to a more porous structure and reduced crystallinity. The yield of soluble dietary fiber increased from 5.1 g/100 g raw BSR to 7.1 g/100 g 9-day-fermented bamboo shoot residue. The total soluble sugar content of dietary fiber significantly increased from 9.2% to 13.8%, which improved the hydration, oil holding capacity, in vitro cholesterol, sodium cholate, and nitrite adsorption properties of dietary fiber from bamboo shoot residue. These findings confirm that I. obliquus biotransformation is promising for enhancing dietary fiber yield and quality.

Synergistic effect of bath-ultrasonication and heating treatments on two-steps treatment of brewers' spent grain

The study aimed to evaluate the chemical composition, antioxidant activity and techno-functionality of brewers' spent grain (BSG) treated with two-steps treatment involving 5, 15, and 25 min bath-ultrasonication (USB) continued with autoclave (AH) at 90, 110, and 130 °C and/or water-bath (CWH) at 80, 90, and 100 °C. The two-steps treatments slightly affected the water- and oil-holding capacity and extractable fat content. Most of the two-steps treatments increased the amount of flavan-3-ols and phenolic acids, up to 4 times higher compared to its control. The two-steps treatment involving CWH had no significant (p > 0.05) impact on fat content, antioxidants and techo-functionality of BSG. Up to 15 min USB increased the poly-unsaturated fatty acids and lowered the amount of saturated fatty acids. In conclusion, the two-steps treatment consists of USB (up to 15 min) continued with AH and CWH increased the amount of nutritional-related chemical composition such as UFA and phenolic acids as well as antioxidant activity of BSG.

Characterization of the Structure and Physicochemical Properties of Soluble Dietary Fiber from Peanut Shells Prepared by Pulsed Electric Fields with Three-Phase Partitioning

This study evaluated the impact of pulsed electric fields (PEFs) combined with three-phase partitioning (TPP) extraction methods on the physicochemical properties, functional properties, and structural characterization of the soluble dietary fiber (SDF) derived from peanut shells (PS). The findings of this study indicated that the application of a PEF-TPP treatment leads to a notable improvement in both the extraction yield and purity of SDF. Consequently, the PEF-TPP treatment resulted in the formation of more intricate and permeable structures, a decrease in molecular weight, and an increase in thermal stability compared to SDFs without TPP treatment. An analysis revealed that the PEF-TPP method resulted in an increase in the levels of arabinose and galacturonic acid, leading to enhanced antioxidant capacities. Specifically, the IC50 values were lower in SDFs which underwent PEF-TPP (4.42 for DPPH and 5.07 mg/mL for ABTS) compared to those precipitated with 40% alcohol (5.54 mg/mL for DPPH, 5.56 mg/mL for ABTS) and PEF75 (6.60 mg/mL for DPPH, 7.61 mg/mL for ABTS), respectively. Notably, the SDFs which underwent PEF-TPP demonstrated the highest water- and oil-holding capacity, swelling capacity, emulsifying activity, emulsion stability, glucose adsorption, pancreatic lipase inhibition, cholesterol adsorption, nitric ion adsorption capacity, and the least gelation concentration. Based on the synthesis scores obtained through PCA (0.536 > -0.030 > -0.33), which indicated that SDFs which underwent PEF-TPP exhibited the highest level of quality, the findings indicate that PEF-TPP exhibits potential and promise as a method for preparing SDFs.

Effect of physical treatments on the functional and structural features of soluble dietary fiber from soybean dregs

BACKGROUND

In this research, the effects caused by ultrafine grinding (U), high-temperature cooking (HTC), microwave (M) and combined treatment (U-HTC, U-M) were evaluated on the functional properties and structural characteristics of soluble dietary fiber (SDF) obtained from soybean dregs.

RESULTS

Physical treatments could increase the extraction yield of SDF and improve the functional properties of SDF. The highest extraction yield (277.15 ± 5.87 g kg-1 based on the weight of soybean dregs) and purity (863.37 ± 5.15 g kg-1 based on the extract weight) of SDF was found in the sample by U-M treatment. U-HTC and U-M combined treatments significantly improved the water solubility and oil holding capacity of SDF. U-M treatment significantly increased the ability of SDF to adsorb cholesterol and perform cationic exchange; compared to the control, these abilities were increased by 138.46% and 10.38%, respectively. At pH 2.0, the nitrite ion adsorption capacity (NIAC) of SDF obtained by U-M combined treatment was 184.55 μg g-1 , which was significantly higher by 32.10% compared with that of the control. The results obtained by X-ray diffraction and scanning electron microscopy showed that the structure of SDF generated from soybean dregs became coarser and more porous, and the crystallinity decreased after physical treatments.

CONCLUSION

Combined physical treatment is an effective way to improve the extracted yield and functional properties of SDF from soybean dregs. © 2023 Society of Chemical Industry.

Effects of extraction methods on the structure and functional properties of soluble dietary fiber from blue honeysuckle (Lonicera caerulea L.) berry

The work within this study aimed to investigate and compare the effects of compound enzyme extraction (CE), ultrasonic chemical extraction (UC) and combined fermentation extraction (CF) on the physicochemical properties, microstructure, and functional properties of soluble dietary fiber (SDF) extracted from blue honeysuckle berries. The results showed that CE-SDF had higher crystallinity (32.41%). UC-SDF had the highest yield (13.32 ± 0.80 g/100 g). CF-SDF had the maximum inhibition of α-amylase (50.82 ± 0.76%) and α-glucosidase (54.87 ± 1.25%). The in vitro hypoglycemic activity of the three SDFs was observed in the order of CF > CE > UC. Meanwhile, the purity of SDF had a strong positive correlation with its antioxidant and in vitro hypoglycemic capacities. The crystallinity of SDF was found to be positively correlated with its molecular weight and thermal properties. Additionally, the sugar composition of SDF was found to be an important factor affecting its biological activity.

Effects of high-pressure processing on the physicochemical and adsorption properties, structural characteristics, and dietary fiber content of kelp (Laminaria japonica)

To investigate the effects of high-pressure processing (HPP) on the physicochemical and adsorption properties and structural characteristics of kelp, kelp slice (KS) and kelp powder (KP) were treated under different pressures (300, 450, and 600 MPa) for 5 and 10 min. Compared to untreated KP, HPP-treated KP yielded a 1.31-fold increase in water holding capacity (600 MPa/5 min), a 0.12-fold increase in swelling capacity (450 MPa/10 min), a 1.33-fold increase in oil holding capacity (600 MPa/10 min), a 10-fold increase in glucose adsorption capacity (450 MPa/10 min), and a 0.22-fold increase in cholesterol adsorption capacity (163.1 mg/g DW at 450 MPa/10 min), and exhibited good Cd (Ⅱ) adsorption capacity when its concentration was 10 mmol/L in the small intestine. The physicochemical properties of HPP-treated KS were not improved due to its low specific surface area. In addition, HPP treatment efficiently reduced the particle size of KP and increased its total and soluble dietary fiber content by 17% and 63% at 600 MPa/10 min, respectively. Scanning electron microscope micrographs demonstrated that the surface of HPP-treated KP was rough and porous, and the specific surface area increased with increasing pressure and processing time. To conclude, the results obtained in the present study suggest that HPP is a promising processing method for improving the functionality and structural characteristics of KP and provide a theoretical basis for the utilization of HPP-treated KP as a fiber-rich ingredient in the functional food industry.

Preparation and characterization of soluble dietary fiber from tiger nut residues, showing enhanced antioxidant activity and metal-ion-binding properties

To improve the utilization of soluble dietary fiber (SDF) from tiger nut residues, the response surface methodology was used to optimize the conditions of superfine grinding to produce SDF with antioxidant and metal-ion-binding properties. The yield was increased (30.56%) and the average particle diameter of SDF was decreased (D50: 32.80 μm) under the optimal conditions (a proportion of grinding medium of 100%, a feeding mass of 0.90 kg, a grinding time of 20 min, and a moisture content of 8.00%). In addition, superfine grinding substantially modified the surface morphology and increased the SDF content and the proportion of monosaccharides by decreasing the molecular weight. Moreover, superfine grinding remarkably enhanced the in vitro antioxidant activities (ABTS+, DPPḤ, and ·OH) of the SDF, which also exhibited favorable metal-ion-binding properties (Ca2+, Zn2+, and Co2+). These results suggest that superfine grinding can be used as a technique to modify dietary fiber to manufacture functional SDF.

Relationship between Physicochemical, Techno-Functional and Health-Promoting Properties of Fiber-Rich Fruit and Vegetable By-Products and Their Enhancement by Emerging Technologies

The preparation and processing of fruits and vegetables produce high amounts of underutilized fractions, such as pomace and peel, which present a risk to the environment but constitute a valuable source of dietary fiber (DF) and bioactive compounds. The utilization of these fiber-rich products as functional food ingredients demands the application of treatments to improve their techno-functional properties, such as oil and water binding, and health-related properties, such as fermentability, adsorption, and retardation capacities of glucose, cholesterol, and bile acids. The enhancement of health-promoting properties is strongly connected with certain structural and techno-functional characteristics, such as the soluble DF content, presence of hydrophobic groups, and viscosity. Novel physical, environmentally friendly technologies, such as ultrasound (US), high-pressure processing (HPP), extrusion, and microwave, have been found to have higher potential than chemical and comminution techniques in causing desirable structural alterations of the DF network that lead to the improvement of techno-functionality and health promotion. The application of enzymes was related to higher soluble DF content, which might be associated with improved DF properties. Combined physical and enzymatic treatments can aid solubilization and modifications, but their benefit needs to be evaluated for each DF source and the desired outcome.

Antioxidants in Fruit Fractions of Mediterranean Ancient Pear Cultivars

BACKGROUND

The genetic diversity of Sardinian pear germplasm has received limited attention regarding its chemical composition. Understanding this composition can aid in the setting up of resilient, extensive groves that offer multiple products and ecosystem services. This research aimed at investigating the antioxidant properties and phenolic compounds of ancient pear cultivars grown extensively in Sardinia (Italy); Methods: the cultivars Buttiru, Camusina, Spadona, and Coscia (as a reference) were compared. Fruit samples were manually peeled and cut. Their flesh, peel, core, and peduncle were frozen separately, lyophilized, and milled before being analysed; Results: The content of total phenolics (TotP), total flavonoids (TotF), condensed tannins (CT), and antioxidant capacity in each fruit part varied significantly among the cultivars. The TotP content was high in the peduncle (42.2-58.8 g GAE kg^-1 DM) and low in flesh (6.4-17.7 g GAE kg^-1 DM); Conclusions: the highest values of antioxidant capacity, TotP, NTP, TotF, and CT were found in the flesh of the cultivar Buttiru and in the peel of the cultivar Camusina. Chlorogenic acid was the major individual phenolic compound in peel, flesh and core, whereas arbutin was mostly present in the peduncle. Results can contribute to revise target exploitations of underutilized ancient pear cultivars.

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.

Characterization of the structural, physicochemical, and functional properties of soluble dietary fibers obtained from the peanut shell using different extraction methods

Objective

To propose a possible solution for a peanut by-product, peanut shell (PS), this study evaluated the effects of different methods, including enzymatic extraction (E-SDF), microwave extraction (M-SDF), and pulsed electric field extraction (PEF-SDF), on the characterization of soluble dietary fibers (SDFs) from PS.

Methods

We determined the physicochemical properties, including water- and oil-holding capacities (WHC and OHC), emulsifying properties, rheological properties, functional properties, including pancreatic lipase activity inhibition (PRAI), glucose and cholesterol adsorption capacities (GAC and CAC), and the structural properties of SDFs.

Results

The results showed that PEF-SDF possessed the highest WHC, OHC, and emulsifying properties. M-SDF and PEF-SDF appeared to have more complex and porous structures, and they showed small molecular weights. Notably, PEF-SDF showed the strongest capacities in CAC, GAC, and PRAI.

Conclusions

The results indicate that PEF-SDF is a potential SDF preparation method for a promising dietary fiber (DF) source, PS.

Comparison of physicochemical and in vitro hypoglycemic activity of bamboo shoot dietary fibers from different regions of Yunnan

In this study, the physicochemical properties, thermal characteristics, and in vitro hypoglycemic activity of dietary fibers extracted from four bamboo shoots were characterized and compared. The results showed that Dendrocalamus brandisii Munro (C-BSDF) had the highest dietary fiber content (6.1%) and the smallest particle size (222.21 μm). SEM observations found that C-BSDF exhibited a loose and porous microstructure, while FTIR and XRD confirmed that C-BSDF had a higher degree of decomposition of insoluble dietary fiber components and the highest crystallinity, resulting in a better microstructure. Furthermore, C-BSDF exhibited excellent physiochemical properties with the highest water hold capacity, water swelling capacity, and preferable oil holding capacity. Thermal analysis showed that C-BSDF had the lowest mass loss (64.25%) and the highest denaturation temperature (114.03°C). The hypoglycemic activity of dietary fibers from bamboo shoots were examined in vitro and followed this order of activity: C-BSDF>D-BSDF>A-BSDF>B-BSDF. The inhibition ratios of GAC, GDRI and α-amylase activity of C-BSDF were 21.57 mmol/g, 24.1, and 23.34%, respectively. In short, C-BSDF display excellent physicochemical and functional properties due to its high soluble dietary fiber content, small particle size with a high specific surface area, and loose microstructure. Thus, D. brandisii Munro can be considered a promising new source of dietary fiber for hypoglycemic health products.

Improving the function of pickle insoluble dietary fiber by coupling enzymatic hydrolysis with HHP treatment

In order to improve the function of insoluble dietary fiber (IDF) extracted from pickle, the coupled enzymatic hydrolysis and high hydrostatic pressure treatment method (EHHP) was used to modify its structure. Compared with the unmodified IDF (U-IDF), analysis of the particle size dispersion, bulk density, surface structure monosaccharide composition, microstructure, thermodynamic properties showed that the modified IDF (EHHP-IDF) has a looser and more porous structure, reduced particle size, bulk density, crystal strength and thermal stability, and increased xylose and galactose content. Due to the special looser microstructure, EHHP-IDF has showed the notable capacity of absorption of oil, glucose, nitrite, cholesterol as well as Pb2+. Collectively, these results show that EHHP has good potential use as an ideal modification method to improve the function of IDF, and a novel functional ingredient of EHHP-IDF which could be used in future food processing was obtained in this study.

Structure, Physicochemical Property, and Functional Activity of Dietary Fiber Obtained from Pear Fruit Pomace (Pyrus ussuriensis Maxim) via Different Extraction Methods

In this study, soluble dietary fiber (SDF) and insoluble dietary fiber (IDF) were extracted from Pyrus ussuriensis Maxim pomace via three methods including enzymic extraction (EE), microwave-assisted enzymatic extraction (MEE), and three-phase partitioning (TPP). The effects of different extraction methods on the structure, physicochemical property, and functional activity of the extracted dietary fiber were evaluated. The results showed that different extraction methods had significant effects on the extraction yield, molecular weight distribution, thermal stability, antioxidant activity, and hypoglycemic activity in vitro, but resulted in no difference in the structure and composition of functional groups. It is noteworthy that SDF extracted by TPP has a more complex and porous structure, lower molecular weight, and higher thermal stability, as well as better physicochemical properties and in vitro hypoglycemic activity. IDF extracted by MEE showed the greatest water and oil holding capacity; the highest adsorption capacity for glucose, cholesterol, and nitrite ion; as well as the strongest inhibitory activity on α-amylase. These results suggest that PUP may be a source of cheap natural dietary fiber.

Modification of Artichoke Dietary Fiber by Superfine Grinding and High-Pressure Homogenization and Its Protection against Cadmium Poisoning in Rats

This study was carried out to investigate the effects of superfine grinding (SP) and high-pressure homogenization (HPH) on the structural and physicochemical properties of artichoke dietary fiber (ADF), as well as the protective effects against cadmium poisoning in rats. The structural characteristics and physicochemical properties of ADF, HPH-ADF (ADF treated by HPH) and CM-ADF (ADF treated by SP and HPH) were determined, and cadmium chloride (CdCl2) was induced by exposing rats for 7 weeks. The amounts of creatinine and urea; the activities of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in serum; the quantity of red blood cells, hemoglobin, white blood cells and neutrophil proportion in blood samples; and the activity of glutathione peroxidase (GSH-Px) in liver tissue were analyzed. Hematoxylin-eosin (HE) staining was performed to analyze the tissue structure and pathology of the liver and testis. The results showed that ADF subjected to HPH and SP-HPH exhibited increased content of soluble dietary fiber (SDF) (p < 0.05). HPH and SP-HPH treatments increased oil-holding capacity (OHC), total negative charge (TNC) and heavy metal adsorption capacity (p < 0.05). The CdCl2 intervention led to a significant increase in AST, ALT, creatinine, urea, neutrophil proportion and white blood cell count, as well as a significant decrease in GSH-Px activity, red blood cell count and hemoglobin (HGB) (p < 0.05). In rats fed with ADF, HPH-ADF and CM-ADF significantly reduced creatinine, urea amounts, ALT, AST activity in serum, leukocyte count and the neutrophil ratio in blood and increased GSH-Px activity in the liver, in addition to increasing the erythrocyte count and hemoglobin count in blood (p < 0.05). H&E staining results showed that steatosis in the liver was significantly reduced, whereas testicular tissue edema was improved. These results indicate that ADF exhibited positive activity against cadmium poisoning in rats and that CM-ADF had a better protective effect than ADF and HPH-ADF. ADF has specific potential to be used in health foods or therapeutic drugs, providing a reference for the development and utilization of artichoke waste.

Alteration in dough volume and gluten network of lychee pulp pomace bread base on mixture design dominated by particle size

The reducing flavor of whole grain bread has been constantly affecting the consumption desire of a significant proportion of consumers. The study presents the use of lychee pulp pomace (LPP) powder to replace certain proportion of wheat flour and produce wheat bread with better quality, while having minimal effects on the volume and improving the nutritional quality. Distinct particle sizes (60-400 µm) of LPP powder were obtained by superfine or ordinary grinding. Effect of different additive proportions (7-19%) of LPP powder on bread dough quality were studied by constrained mixture designs. The volume of fermented doughs subsequently decreased after adding LPP powder. However, LPP powders with smaller particle sizes were able to minimize this effect due to its higher water-holding capacity. The analyses of gluten network showed that smaller particle sizes of LPP powder resulted in a decrease in surface hydrophobicity and increase in the elasticity and stability of gluten network. Finally, optimum mixture formula was composed of 16% LPP powder with 60 µm particle size and 15% water. The study illustrated the potential to make high-quality bread with small particle size of LPP powder. PRACTICAL APPLICATION: The addition of dietary fiber to wheat flour can adversely affect the dough volume and reduce the dough quality. By reducing the particle size of lychee pulp pomace powder, this adverse effect could be minimized while increasing the content of dietary fiber and bound phenolics in the dough. This provides data for the production of high-quality lychee dough bread.

Anti-inflammatory and intestinal microbiota modulation properties of high hydrostatic pressure treated cyanidin-3-glucoside and blueberry pectin complexes on dextran sodium sulfate-induced ulcerative colitis mice

This study investigated the anti-inflammatory effects of cyanidin-3-glucoside (C3G) and blueberry pectin (BP) complexes on mice with dextran sodium sulfate (DSS)-induced colitis before and after high hydrostatic pressure (HHP) treatment. Real-time polymerase chain reaction (RT-PCR), western blotting, and 16S rDNA sequencing were used to study the expression of inflammation-related factors, activation of signal pathway-related proteins, and changes in the intestinal flora in ulcerative colitis (UC) mice. The results showed that HHP-treated C3G-BP complexes significantly relieved diarrhea and blood loss in the stool of UC mice and alleviated colon shortening. The potential mechanism of action involved reduction in intestinal oxidative stress mRNA expression of pro-inflammatory factors, improvement in anti-inflammatory factor levels, inhibition of the NF-κB signaling pathway, increased protein levels of Bcl-2/Bax and caspase-3/cleaved caspase-3 genes, and improved gut microbiota composition. Compared with other experimental groups, the HHP-treated C3G-BP complexes group exhibited the best anti-inflammatory effect on DSS-induced UC mice. The results may provide new ideas for using C3G-BP complexes for treating UC and help develop better processing methods.

Effect of Pretreatment and High Hydrostatic Pressure on Soluble Dietary Fiber in Lotus Root Residues

High hydrostatic pressure (HHP) can enhance the physicochemical properties of soluble dietary fiber (SDF) from fruit and vegetable residues including hydration properties, emulsibility, and rheological properties, while the pretreatment methods such as solid-water suspension status are ignored all along. Here, three groups of lotus root residue (LRR) for HHP treatment (400 MPa, 15 min) were prepared: the fresh lotus root residue (FLRR), FLRR mixed with water (FLRR + W), and dried FLRR suspended in water at the same solid/water level with FLRR + W (DLRR + W). As a control, non-HHP-treated FLRR was tested. Results showed that FLRR + W obtained the highest SDF yield and presented a honeycomb structure which was not observed in other LRR samples. In addition, properties of SDF extract from FLRR + W changed most significantly, including not only the enhancement of SDF yield, the improvement of hydration properties, and the reduction of molecular weight but also the increase of thermal and rheological stability. Principal component analysis (PCA) profile illustrated that the difference of LRR-water system contributed 27.6% to the SDF physicochemical changes, and SDF from DLRR + W distinguished it from the other samples with mannose, ribose, and glucuronic acid, indicating that the drying procedure also played a role in the HHP treatment focusing on the sugar constitution. Therefore, the solid-water suspension status is a noteworthy issue before HHP treatment aiming at SDF modification.

Characterization of Berry Pomace Powders as Dietary Fiber-Rich Food Ingredients with Functional Properties

This study aimed to evaluate and compare the dried pomace powder of cranberries, lingonberries, sea buckthorns, and black currants as potential food ingredients with functional properties. The composition and several physicochemical and adsorption properties associated with their functionality were investigated. Tested berry pomace powders were rich in dietary soluble fiber (4.92–12.74 g/100 g DM) and insoluble fiber (40.95–65.36 g/100 g DM). The highest level of total phenolics was observed in the black currant pomace (11.09 GAE/g DM), whereas the sea buckthorn pomace revealed the highest protein concentration (21.09 g/100 g DM). All the berry pomace powders that were tested exhibited good water-holding capacity (2.78–4.24 g/g) and swelling capacity (4.99–9.98 mL/g), and poor oil-binding capacity (1.09–1.57 g/g). The strongest hypoglycemic properties were observed for the lingonberry and black currant pomace powders. The berry pomace powders presented effective in vitro hypolipidemic properties. The cholesterol-binding capacities ranged from 21.11 to 23.13 mg/g. The black currant and cranberry pomace powders demonstrated higher sodium-cholate-binding capacity than those of the lingonberry and sea buckthorn pomace powders. This study shows promising results that the powders of tested berry pomace could be used for further application in foods.

The structural and functional characteristics of soluble dietary fibers modified from tomato pomace with increased content of lycopene

The tomato pomace, a by-product of tomato processing, was rich in nutrients such as lycopene (Lyc), vitamins, phenols and soluble dietary fibers (SDF). Homogenization combined with enzymatic hydrolysis (HE) was firstly applied to obtain HE-pomace. The yield of Lyc was raised by 57.2% after HE treatment by the optimal condition. The extraction rate of HE-SDF was increased by 73.4%. In order to clarify the relationship between the SDF and the release of Lyc, SDFs were characterized by structural analysis and morphological determination. The results suggested that HE-SDF possessed smaller molecular weight and loose microstructure with shorter chains. It implied that the degradation of dietary fiber led to the release of Lyc molecules. Besides, HE-SDF exhibited stronger capacity of water-holding, glucose adsorption and bile acid binding. In conclusion, HE treatment possessed the potential to be applied as an excellent modification method, which improved the nutritional and economic value of tomato pomace.

Comparison the Structural, Physicochemical, and Prebiotic Properties of Litchi Pomace Dietary Fibers before and after Modification

Litchi pomace, a by-product of litchi processing, is rich in dietary fiber. Soluble and insoluble dietary fibers were extracted from litchi pomace, and insoluble dietary fiber was modified by ultrasonic enzymatic treatment to obtain modified soluble and insoluble dietary fibers. The structural, physicochemical, and functional properties of the dietary fiber samples were evaluated and compared. It was found that all dietary fiber samples displayed typical polysaccharide absorption spectra, with arabinose being the most abundant monosaccharide component. Soluble dietary fibers from litchi pomace were morphologically fragmented and relatively smooth, with relatively high swelling capacity, whereas the insoluble dietary fibers possessed wrinkles and porous structures on the surface, as well as higher water holding capacity. Additionally, soluble dietary fiber content of litchi pomace was successfully increased by 6.32 ± 0.14% after ultrasonic enzymatic modification, and its arabinose content and apparent viscosity were also significantly increased. Further, the soluble dietary fibers exhibited superior radical scavenging ability and significantly stimulated the growth of probiotic bacterial species. Taken together, this study suggested that dietary fiber from litchi pomace could be a promising ingredient for functional foods industry.

Comparisons of the micronization, steam explosion, and gamma irradiation treatment on chemical composition, structure, physicochemical properties, and in vitro digestibility of dietary fiber from soybean hulls

The objective of this study was to compare the effects of the micronization (MT), steam explosion (SE), and gamma irradiation (GI) treatment on the chemical composition, structure, physicochemical properties, and in vitro digestibility of dietary fiber from soybean hulls. GI (1200 kGy) treatment exerted the optimum effects on improving soluble dietary fiber content, in vitro gross energy digestibility (IVGED), and reducing sugar yield (RS) in the three modification methods, increased by 342.88%, 55.24%, and 117.02%, respectively. Compared with GI treatment, MT-GI combined treatment could further enhance the degradation effect of irradiation and improve the physicochemical properties (p＜0.05) in soybean fibers. From the results of correlation analysis, RS was a significant positive correlation (p＜0.05) with IVGED, and RS = -112.24 + 4.90 × IVGED (r2 = 0.82, p＜0.01). In summary, MT-GI combined treatment could be considered the ideal modification method to improve the quality of soybean fiber.

Delving into the Role of Dietary Fiber in Gluten-Free Bread Formulations: Integrating Fundamental Rheological, Technological, Sensory, and Nutritional Aspects

The evidenced relevance of dietary fibers (DF) as functional ingredients shifted the research focus towards their incorporation into gluten-free (GF) bread, aiming to attain the DF contents required for the manifestation of health benefits. Numerous studies addressing the inclusion of DF from diverse sources rendered useful information regarding the role of DF in GF batter’s rheological properties, as well as the end product’s technological and nutritional qualities. The presented comprehensive review aspires to provide insight into the changes in fiber-enriched GF batter’s fundamental rheological properties, and technological, sensory, and nutritional GF bread quality from the insoluble and soluble DF (IDF and SDF) perspective. Different mechanisms for understanding IDF and SDF action on GF batter and bread were discussed. In general, IDF and SDF can enhance, but also diminish, the properties of GF batter and bread, depending on their addition level and the presence of available water in the GF system. However, it was seen that SDF addition provides a more homogenous GF batter structure, leading to bread with higher volumes and softer crumb, compared to IDF. The sensory properties of fiber-enriched GF breads were acceptable in most cases when the inclusion level was up to 7 g/100 g, regardless of the fiber type, enabling the labeling of the bread as a source of fiber.

Effects of Airflow Ultrafine-Grinding on the Physicochemical Characteristics of Tartary Buckwheat Powder

Five different ultrafine milled flours (UMFs) were prepared from Tartary buckwheat via airflow ultrafine-grinding at different grinding pressures. The airflow ultrafine-grinding resulted in marked differences in particle size (from 100 to 10 μm). The UMFs were all brighter in appearance (higher L*) than Tartary buckwheat common flour (TBCF). Illustrated by the example of 70 °C, the UMFs were also found to have a greater water holding capacity (from 4.42 g/g to 5.24 g/g), water solubility (from 12.57% to 14.10%), and water solubility index (from 5.11% to 6.10%). Moreover, as the particle sizes reduced, the moisture content decreased (from 10.05 g/100 g DW to 7.66 g/100 g DW), as did the total starch content (from 68.88 g/100 g DW to 58.24 g/100 g DW) and the protein content (from 13.16% to 12.04%). However, the grinding process was also found to have negative effects on the mineral content of the Tartary buckwheat. Additionally, several substantial variations were found in their hydration properties along with grinding pressure changes in the differently ground UMFs. Consequently, fine Tartary buckwheat powders of a bright yellow color, with superior food processing properties, were prepared in this study by airflow ultrafine-grinding.

Brewers' spent grain in food systems: Processing and final products quality as a function of fiber modification treatment

The nutritional properties of brewers' spent grain (BSG) have been widely studied, considering its potential as a healthy food ingredient. Because of its fiber composition (amount and ratio), however, adding BSG into the food matrix to bring about changes in physical properties has been believed to impact negatively on the acceptability of the final products' properties, particularly color and texture. Fiber modification can enhance the quality of fiber and can be applied to BSG. Although it appears challenging, modifying fiber composition requires further study, particularly if the acceptability of the final products is to be improved. Furthermore, the level of fiber degradation during the modification treatment needs to be examined to meet the increased demand for BSG in final food products. This concise synthesis provides a new perspective for increasing the use of BSG as a food ingredient that is characterized by high nutrition and acceptability.

The variability of physico-chemical properties of brewery spent grain from 8 different breweries

This research aimed to identify the differences in brewer's spent grains, which were collected from eight breweries for their physicochemical properties. The spent grains were dried until they reached stable weights, grounded to pass through a 385-μm sieve, vacuum-packed in nontransparent packaging, and kept in room temperature conditions for further analysis. The physicochemical properties, including proximate, color, water activity, water-holding capacity, oil-holding capacity, and density were evaluated. The results showed some differences in all measured quality parameters between all eight different spent barley grain samples. A similar pattern was noted in some properties studied. Hence, mathematical modeling of these studied properties should be undertaken with further qualities, such as fiber composition, mechanical properties, and thermal stability.

Effects of ultrasound-assisted enzyme hydrolysis on the microstructure and physicochemical properties of okara fibers

This work focuses on the effects of different ultrasound power densities on the microstructural changes and physicochemical properties of okara fibers, which are composed of carbohydrate-based polymers. Okara suspensions were treated with ultrasound at different power densities (0, 1, 2, 3, 4, and 5 W/mL) for 30 min, after which the ultrasound-treated okara were hydrolyzed by trypsin to obtain okara fibers. The ultrasound treatment of the okara fibers induced structural disorganization and changes, evidenced mainly in their morphological characteristics and their relative crystallinity degrees. Increasing the ultrasound power broke the okara fibers into flaky and stacked structures. When the ultrasound power density reached 4 W/mL, the parenchyma became compact and the hourglass structure fractured. The mean particle size of the okara fiber was reduced from 82.24 µm to 53.96 µm, and the homogeneity was enhanced significantly. The relative crystallinity of the okara fibers was reduced from 55.14% to 36.47%. The okara fiber surface charge decreased when the ultrasound power was increased. However, after ultrasound treatment at 4 W/mL (800 W), the okara fiber suspension exhibited the highest viscosity value and a higher swelling capacity, water-holding capacity, and oil-holding capacity. Therefore, the results indicated that the selection of processing conditions for okara fibers is critical and that okara fiber modification using a high ultrasound treatment might improve their use in potential applications.

High Hydrostatic Pressure Assisted by Celluclast® Releases Oligosaccharides from Apple By-Product

A novel and green procedure consisting of high hydrostatic pressure (HHP) aided by a commercial cellulase (Celluclast^®) has been applied to valorise the apple by-product, a valuable source of dietary fibre but mainly composed by insoluble fibre. Optimal conditions for solubilisation of dietary fibre were first determined at atmospheric pressure as 2% (w/v) of substrate concentration and 20 Endo-Glucanase Units of cellulase. Monitoring of polysaccharides and oligosaccharides released from apple by-product was carried out by means of a newly validated HPLC method with refractive index detector. A synergistic effect was observed when the combined HHP plus cellulase treatment was used. Thus, the application of 200 MPa at 50 °C for 15 min enabled a significant increase in the release of water-soluble polysaccharides (1.8-fold) and oligosaccharides (3.8-fold), as well as a considerable decrease in the time required (up to 120-fold), compared to control at 0.1 MPa. Therefore, this technology could be a promising alternative approach to transform an industrial by-product into a novel rich-in-oligosaccharide food ingredient and a step forward into shaping the world of prebiotics.