Effect of superfine grinding on properties of ginger powder

Novel insights into the mechanism of dynamic changes in microstructure and physicochemical properties of corn straw pretreated by ball milling and feasibility analysis of anaerobic digestion

In this study, the effects of Ball milling (BM) pretreatment (0-240 min) on the microstructure, physicochemical properties and subsequent methanogenesis performance of corn straw (CS) were explored, and the feasibility analysis was carried out. The results showed that BM pretreatment destroyed the dense structure of the CS, and the particle size was significantly reduced (D50: 13.85 μm), transforming it into a cell-scale granular form. The number of mesopores increased, the pore volume (PV) (0.032 cm3/g) and specific surface area (SSA) (4.738 m2/g) considerably increased, and the water-absorbent property was improved. The crystalline order of cellulose was disrupted and the crystallinity (CrI) (8.61 %) and crystal size (CrS) (3.37) were remarkably reduced. The cross-links between lignocelluloses were broken, and the relative content and functional groups did not alter obviously. The bulk density (BD), repose angle (RA) and slip angle (SA) dramatically increased. As a result, CS was more readily accessible, attached and utilized by microorganisms and enzymes, causing the hydrolysis and acidification of AD to be greatly facilitated. Compared with the untreated group, the cumulative methane production (CMP) increased by 35.83 %-101.97 %, and the lag phase time (λ) was shortened by 33.04 %-71.17 %. The results of redundancy analysis, Pearson analysis and Mantel test showed that BM pretreatment affects the process of AD by changing the physicochemical factors of CS. The normalization analysis showed that particle size (D90) and BD can be used as direct indicators to evaluate the performance of AD and predict the threshold of biodegradation of CS. Energy analysis and energy conversion assessment showed that BM is a green and efficient AD pretreatment strategy. This result provides a theoretical basis for the industrial application of BM pretreatment towards more energy-efficient and sustainable development.

Effect of ultrafine grinding on the structure and physical properties of pregelatinized rice starch

This study used a combination method of ultrafine grinding and pregelatinization to modify rice starch (RS) to delay its retrogradation and provide a rationale for prolonging rice product shelf life. The structure and physicochemical properties of the pregelatinized ultrafine grinding rice starch (PURS) were compared with those of RS, ultrafine grinding rice starch (URS), and pregelatinized rice starch (PRS). The microstructure, molecular weight, branched starch length distribution, short-range order, crystal structure, and physical properties of RS, URS, PRS, and PURS were analyzed, respectively. Results showed that RS, URS, PRS, and PURS granules exhibited similar spherical or polygonal shapes, and the content of amylose and short-branched starch in PURS increased compared with RS, URS, and PRS. Furthermore, the cross-polarization of PRS and PURS disappeared. Long-chain amylopectin and average molecular weight of PURS decreased significantly after ultrafine grinding. Our study suggested reduced breakdown value and setback value and improved gel stability, and PURS was beneficial for delaying retrogradation compared to RS, URS, and PRS. The ultrafine grinding method improved the water swelling capacity (WSC), solubility, pasting properties, and gelation properties of PRS. The hardness of PURS was reduced by ultrafine grinding. These suggest that the combination of ultrafine grinding and pregelatinization could improve the properties of RS. Pearson's correlation analysis showed that the structure of PURS significantly influenced the physicochemical properties. The present study was helpful in better understanding the importance of ultrafine grinding in improving the anti-retrogradation of PURS and provided new insights into extending the shelf life of rice products by ultrafine grinding and pregelatinization.

Exploring conventional and emerging dehydration technologies for slurry/liquid food matrices and their impact on porosity of powders: A comprehensive review

The contribution of dehydration to the growing market of food powders from slurry/liquid matrices is inevitable. To overcome the challenges posed by conventional drying technologies, several innovative approaches have emerged. However, industrial implementation is limited due to insufficient information on the best-suited drying technologies for targeted products. Therefore, this review aimed to compare various conventional and emerging dehydration technologies (such as active freeze, supercritical, agitated thin-film, and vortex chamber drying) based on their fundamental principles, potential applications, and limitations. Additionally, this article reviewed the effects of drying technologies on porosity, which greatly influence the solubility, rehydration, and stability of powder. The comparison between different drying technologies enables informed decision-making in selecting the appropriate one. It was found that active freeze drying is effective in producing free-flowing powders, unlike conventional freeze drying. Vortex chamber drying could be considered a viable alternative to spray drying, requiring a compact chamber than the large tower needed for spray drying. Freeze-dried, spray freeze-dried, and foam mat-dried powders exhibit higher porosity than spray-dried ones, whereas supercritical drying produces nano-porous interconnected powders. Notably, several factors like glass transition temperature, drying technologies, particle aggregation, agglomeration, and sintering impact powder porosity. However, some binders, such as maltodextrin, sucrose, and lactose, could be applied in controlled agglomeration to enhance powder porosity. Further investigation on the effect of emerging technologies on powder properties and their commercial feasibility is required to discover their potential in liquid drying. Moreover, utilizing clean-label drying ingredients like dietary fibers, derived from agricultural waste, presents promising opportunities.

Characterization of fruit pulp-soy protein isolate (SPI) complexes: Effect of superfine grinding

Superfine grinding (SG), as an innovative technology, was conducted to improve the physicochemical and structural properties of fruit pulps. Nectarine, apple, and honey peach were selected as the materials. With the increase in SG frequency, the soluble solids content, viscosity, D[4, 3], D[3, 2], G' and G″ of fruit pulps were evidently decreased, whereas the turbidity was increased. The smallest D[4, 3] (294.90 µm) and D[3, 2] (159.67 µm) were observed in nectarine pulp under SG at 50 Hz. The highest turbidity (266.33) was shown in honey peach pulp under SG at 50 Hz. The active groups of the fruit pulps with SG were exposed by Fourier transform infrared spectroscopy (FT-IR). Notably, the excessive destruction in structure was confirmed in SG with 50 Hz. With soy protein isolate (SPI) addition, D[4, 3] and D[3, 2] of complexes decreased, whereas G' and G″ increased. The formation of new fruit pulp-SPI complexes was demonstrated by FT-IR and LF-NMR analysis. The dense and uniform structure was found in complexes prepared by SPI and fruit pulp with 30 Hz SG. Especially, apple-SPI complex with 30 Hz SG showed the highest water-holding capacity (WHC) (0.75) and adhesiveness (7973.00 g s). A significant correlation between fruit pulps and the complexes was revealed. Taken together, the impact of SG modification on fruit pulps would enhance WHC, rheology, and textural properties of the fruit pulp-SPI complexes, especially for SG with 30 Hz. PRACTICAL APPLICATION: This research provided a comprehensive exploration of the potential of SG technology to modify fruit pulps, solving the diversity of textural customization problems and offering valuable insights for the development of semisolid food products.

Effects of pre-drying treatment and particle sizes on physicochemical and structural properties of pumpkin flour

The objective of this study is to investigate the effect of pre-drying treatment and particle size on pumpkin flour's compositional, functional, pasting, thermal, and structural properties. Pre-drying treatment and reducing the size of particles have led to an increase in the levels of crude fiber, phytochemicals, and functional properties. However, the amounts of moisture and lightness of color decreased with pretreatment, but improved with particle size reduction. Among the samples, those that were finely milled after pre-treatment showed the highest viscosities, while the untreated samples that were coarsely milled had lower viscosities. The pre-drying treatments yielded notable reductions in both gelatinization temperature and enthalpy of the flour matrix, in comparison to untreated flours. FTIR analysis has indicated that no new functional groups were produced. XRD analysis suggests that while pre-drying treatment leads to decreases in crystallinity index, fine milling leads to increments. The morphological pattern suggested that pretreatment effectively altered the original surface structure of the flour, but particle size reduction did not.

Enhancement of cation exchange and glucose binding capacity, flavonoids release and antioxidant capacity of Tartary buckwheat powder with ultrafine grinding

The objective of this paper was to study the effects of ultrafine grinding on the cation exchange capacity, glucose binding capacity and in vitro digestion characteristics of Tartary buckwheat powder. The results showed that the cation exchange ability and glucose binding strength of Tartary buckwheat powder, Tartary buckwheat bran powder and Tartary buckwheat core powder increased significantly with the increase of crushing frequency (20, 40 and 60 Hz), and the Tartary buckwheat bran powder was the highest. The results of in vitro digestion showed that ultrafine grinding improved the flavonoid release and antioxidant activity of Tartary buckwheat bran powder in the in vitro digestion process. The correlation analysis indicated that the amount of flavonoids released in digestive fluid was significantly related to antioxidant activity. This study may provide a theoretical basis for improving the physicochemical properties and functions of Tartary buckwheat by ultrafine grinding technology.

Effects of superfine grinding sweet potato leaf powders on physicochemical and structure properties of sweet potato starch noodles

Sweet potato leaves (SPLs) containing abundant functional components are consumed primarily as fresh vegetables worldwide. This study investigated the physical properties of superfine grinding SPLs powder, and their effects on cooking, texture, and sensory properties, micro- and molecular structures of starch noodles were also explored. The results showed that the bulk and tapped density (from 0.34 to 0.28 g/mL3 and from 0.69 to 0.61 g/mL3), repose and slid angle (from 42.15 to 30.96° and from 48.67 to 22.00°), water-holding capacity and swelling capacity (from 8.66 to 4.94 g/g and from 10.03 to 7.77 mL/g) of SPLs powders were decreased with milling time increased. The cooking loss, swelling index, texture, and sensory properties of SPLs sweet potato starch noodles (SPLSNs) were improved as the particle size of SPLs decreased. XRD and FT-IR showed that SPLSNs contained less complete crystallites (from 28.85% to 14.19%) and lower proportion of crystalline region (R 1047/1017 from 0.96 to 0.81, R 1017/994 from 0.41 to 0.43). SEM revealed that SPLSNs exhibited fewer ordered arrays and smooth cross sections. Our findings provide a foundation for utilizing SPLs and developing functional starch noodles.

Interpreting the variation in particle size of ground spice by high-resolution visual and spectral imaging: A ginger case study

High-resolution (HR) visual imaging and spectral imaging are common computer vision-based techniques used for food quality analysis and/or authentication based on the interaction of light and material surface and/or composition. The particle size of ground spices is an important morphological feature that affects the physico-chemical properties of food products containing such particles. This study aimed to interpret the impact of particle size of ground spice on its HR visual profile and spectral imaging profile using ginger powder as a representative spice powder model. The results revealed an increase in the light reflection with the decrease of particle size of ginger powder, which was manifested by the lighter colour (higher percentage of the colour code with lighter yellow colour) of the HR visual image and stronger reflection with spectral imaging. The study also revealed that, in spectral imaging, the influence of the particle size of ginger powder increased with rising wavelengths. Finally, the results indicated a relationship between spectral wavelengths, ginger particle size, and other natural variables of the products which might be generated from cultivation to processing. Ultimately, the impact of natural variables arising during the food production process on the physico-chemical properties of the product should be fully considered or even additionally evaluated prior to the application of specific food quality and/or authentication analytical techniques.

Proximate composition and mineral content of spices increasingly employed in the Mediterranean diet

The present study aimed to investigate the nutritional constituents of common market available spices in the United Arab Emirates. Seven commonly consumed spices namely, ginger (Zingiber officinale), cinnamon (Cinnamomum verum), black seed (Nigella sativa), fenugreek (Trigonella foenum-graecum), cardamom (Elettaria cardamomum), cloves (Syzygium aromaticum) and saffron (Crocus sativus) were obtained from local markets. Proximate analyses were performed according to AOAC procedures. Assessment of major (Ca, K, Mg, Na, P and S) and minor (Co, Cu, Fe, Mn and Zn) elements was conducted using inductively coupled plasma optical emission spectrometry (ICP-OES). Findings revealed varying macronutrient, micronutrient and mineral contents which are highly valuable for dietary purposes. The present study demonstrates that these edible spices could be used for nutritional support, due to their micro and macronutrient contents.

Probabilistic risk assessment of exposure to multiple mycotoxins in consumers of packaged and unpackaged spices in Iran

The current study assessed the risk posed to Iranian consumers by oral exposure to a mixture of ten mycotoxins in 138 packaged and unpackaged spices collected from the Iran market. Concentrations of mycotoxins in samples were quantified by liquid chromatography, tandem mass spectrometry with triple quadrupole, and ion trap. Probabilistic health risks of oral exposure to these mycotoxins for Iranians were assessed under percent tolerable daily intake (TDI) and cancer risk scenarios. Mean concentrations of mycotoxins in both packaged and unpackaged spice samples showed statistically significant variation among different spice samples. Based on a Monte Carlo simulation model, at the 50th, 80th, and 95th centiles, oral consumption of the analyzed samples poses no carcinogenic risk for exposure to aflatoxin. Moreover, in both packaged and unpackaged samples, while the percent TDIs for ochratoxin A, deoxynivalenol, zearalenone, patulin, fumonisin B1, and fumonisin B2 were below 1.0 at the 50th, 80th, and 95th centiles, the value was above 1.0 for aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 at each of these centiles.

Effect of vacuum freeze drying and hot air drying on dried mulberry fruit quality

Two different drying methods (vacuum freeze-drying and hot-air drying) were used to dry mulberry of three varieties 'Baiyuwang'(D1), 'Longsang'(D2) and 'Zhongshen.1'(D3), and the fresh fruit of each variety was used as the control. The effects of different processing conditions on the physical characteristics, nutrients, functional components and antioxidant activity of mulberry fruit were analyzed. The results show that after different drying methods, after vacuum freeze-drying, the physical properties of dried mulberry fruit such as wettability, hygroscopic property and water retention, soluble protein, ascorbic acid and other nutrients, functional components such as polyphenols, resveratrol, chlorogenic acid and anthocyanin, and antioxidant activities such as DPPH free radical scavenging ability and ABTS free radical scavenging ability were superior to hot air drying (P < 0.01). It was concluded that vacuum freeze drying was more beneficial for retaining the original quality of mulberry than hot air drying. This study can provide a retaining theoretical basis for mulberry deep processing and comprehensive development and utilization.

Fermentation Kinetics of Gluten-Free Breads: The Effect of Carob Fraction and Water Content

In this study, gluten-free doughs with rice flour, substituted by 15% fractions of different carob seed flours, were prepared by varying their water content. The coarse carob fraction A (median particle size of flour, D₅₀: 258.55 μm) was rich in fibers, fraction B (D₅₀: 174.73 μm) was rich in protein, C (D₅₀: 126.37 μm) was rich in germ protein, and fraction D (D₅₀: 80.36 μm) was a mix, reconstituted from the other fractions and pulverized using a jet mill. Τhe experimental data of the dough's volume over time were fitted to the Gompertz model for each carob fraction and water content. The calculated parameters of the model were the maximum relative volume expansion ratio (a), the maximum specific volume growth rate (μ), and the time lag of the leavening process (t_lag). Gompertz's equation adequately described the individual experimental curves. In the next step, a composite model was applied for each carob fraction where the parameters a and t_lag were expressed as quadratic functions of water content levels (W), while μ was linearly dependent on W. Each carob fraction presented an optimum water content level for which dough height was maximized and time lag was minimized. Optimized dough volume could be predicted by the composite model; it was shifted to lower values as finer carob flour was used. In respect to baked products, softer breads were produced using finer carob flour and porosity values were higher at optimum water content levels. The investigated fermentation kinetics' models provide significant information about the role of water and carob flour on gluten-free dough development and bread volume expansion.

The moisture adsorption, caking, and flowability of silkworm pupae peptide powders: The impacts of anticaking agents

This study aimed to explore the impacts of different anticaking agents on the moisture adsorption, caking, and flowability of silkworm pupae peptide powders (SPPP). The characteristics of water distributions in SPPP with anticaking agents were investigated by LF NMR. The morphological observation of powders was analyzed by scanning electron microscope. Moisture sorption curves and moisture sorption isotherm curves indicated that calcium stearate, silicon dioxide and calcium silicate of 20 % reduced hygroscopicity and increased critical relative humidity. The angle of repose analysis revealed that anticaking agents could also increase flowability (45°-49°). LF NMR analysis indicated that anticaking agents reduced the moisture adsorption ability of SPPP. Scanning electron microscope observations demonstrated different shapes and surface morphology of SPPP using different anticaking agents. Notably, silicon dioxide served as the most effective anticaking agent by forming a physical barrier. Overall, anticaking agents can effectively delay moisture adsorption and deliquescence of SPPP by different anticaking fashions.

Characterization of an active film prepared with Lentinus edodes (shiitake) polysaccharide and its effect on post-harvest quality and storage of shiitake

The aim of this study was to prepare a film based on shiitake (Lentinus edodes) stalk polysaccharides (LEP) for mushroom preservation. The effects of different LEP concentrations on physical, mechanical, antioxidant, and antimicrobial properties of the prepared film were evaluated. Using scanning electron microscopy, it was revealed that the addition of 1.5 % LEP resulted in homogeneous distribution in the prepared film, as well as greatly improved its antimicrobial properties. Moreover, LEP film resulted in superior mushroom preservation by regulating enzyme activities related to mushroom browning and softening, thereby decaying these processes. In addition, the prepared film maintained mushroom quality by reducing the accumulation of H₂O₂ and activating the regulatory system against oxidative stress. Collectively, the findings of the present study highlight the potential benefits of LEP films as a strategy to improve mushroom quality and prevent post-harvest spoilage, hence constituting a novel prospect for the development of shiitake by-products.

Effect of fermentation with Lactobacillus fermentum FL-0616 on probiotic-rich bean powders

Plant-based diets have received considerable attention for balancing human health and environmental sustainability. This study investigated the effects of fermentation with Lactobacillus fermentum FL-0616 on probiotic-rich mung bean, chickpea and tiger skin kidney bean powders. A particle size distribution experiment showed that the particle size of probiotic-rich bean powder was significantly reduced and the specific surface area was increased. This was critical for improving the dissolution rate, wettability and dispersibility. Simultaneously, the angles of repose and slide of the fermented bean powder were significantly reduced. Scanning electron microscopy confirmed that particle size of the bean powder decreased and became more uniform after fermentation. The results of dynamic and static rheology jointly demonstrated that fermentation improved the flowability of probiotic-rich bean powder, which was related to its decreased particle size. This study provides a technical foundation for the deep processing of bean resources.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05668-5.

Qualitative and Quantitative Correlation of Microstructural Properties and In Vitro Glucose Adsorption and Diffusion Behaviors of Pea Insoluble Dietary Fiber Induced by Ultrafine Grinding

Ultrafine grinding is an important pretreatment to achieve the physical modification of dietary fiber. In this study, ultrafine grinding treatments were performed for different times to give pea insoluble dietary fiber (PIDF) samples with varied particle sizes (D50). The correlations and quantitative relationships between the microstructures of multi-scales PIDF and its in vitro glucose adsorption and diffusion behaviors were comprehensively evaluated. The results indicated that the specific surface area (SSA), pore volume (PV) and oxygen-to-carbon surface ratio (O/C) of PIDF were significantly increased by ultrafine grinding at the cellular scale, while D50 and cellulose crystallinity (CrI) were significantly decreased. These changes significantly improved the glucose adsorption capacity (GAC) of PIDF. The order of importance of microstructural changes on GAC was O/C > PV > SSA > CrI > D50. GAC showed positive exponential relationships with SSA, PV, and O/C and showed a negative linear relationship with CrI. The ability to retard glucose diffusion increased significantly with decreased fiber particle size because of improved adsorption and interception of glucose and the dense physical barrier effect of PIDF. The quantitative equation of maximum glucose dialysis retardation index was GDRImax = −1.65 ln(D50) + 16.82 ln(GAC) − 68.22 (R2 = 0.99). The results could provide theoretical support for quantitative and targeted intervention of dietary fiber structure for blood glucose control.

Effect of superfine grinding on physical properties, bioaccessibility, and anti-obesity activities of bitter melon powders

BACKGROUND

Bitter melon is widely applied to the treatment of diabetes and obesity, but few studies focus on the processing procedure of bitter melon. The differences in physical properties, bioaccessibility, and anti-obesity activity of bitter melon powder (BMP) produced with or without superfine grinding were investigated to optimize an effective processing procedure.

RESULTS

Results showed that superfine grinding could improve the physical properties of BMP, represented by greater bulk density, lower water-holding capacity, and higher bioactive compounds' solubilities. Superfine grinding remarkably affected the bioaccessibility of phenolics and the antioxidant capacity of bitter melon during in vitro digestion. Meanwhile, after a 4 week treatment, 25 μm BMP showed a greater anti-obesity activity with reduction in the serum insulin levels from 16.47 to 13.10 mIU L^-1 , reversing high-fat-diet-induced glucose intolerance, decreasing levels of serum lipids and hepatic lipid accumulation compared with the high-fat diet group.

CONCLUSION

In conclusion, superfine grinding was beneficial for improving the physical properties and bioaccessibility, simultaneously facilitating the anti-obesity activity of bitter melon, which will provide a reference for direct utilization of bitter melon as a health food to relieve symptoms of obesity. © 2022 Society of Chemical Industry.

Investigating particle-size-induced changes in composition, physical, rheological, and bioactive properties of black tea powder

BACKGROUND

People brew tea to drink an infusion that only contains 25% water-soluble constituents, leading to most of the insoluble materials being wasted. Tea powder could be drunk directly by mixing with water without producing any waste. Tea powder can also be used as a natural additive to improve the flavour and taste in beverages and foods. Much detailed information on the particle properties of tea powder is required with its increasing consumption. The aim of this study was to investigate the effects of particle size ranging from median diameter D₅₀  = 4.32 to 26.59 μm on the composition, physical, rheological, and bioactive properties of black tea powder.

RESULTS

The results indicate that large powder sizes had high bulk density and flowability, whereas small powder sizes possessed good swelling ability and wettability. The contents of water extract, total polyphenols, crude fibre, catechins, and thearubigins reduced with a decrease in particle size. To change the particle size and concentration could adjust the elastic modulus and the viscous modulus of the black tea powder suspension. Moreover, black tea powder with small particle size could regulate blood lipids in a hyperlipidaemic rat model by lowering triacylglycerols and elevating high-density lipoprotein cholesterol, whereas large particles presented an advantage in reducing body weight.

CONCLUSION

Our investigation extended the knowledge of commercial black tea powder in composition, physical, rheological, and bioactive properties. These results lay the foundation for future exploration of the use of tea powder in the food industry. © 2022 Society of Chemical Industry.

Flowability, Rehydration Behaviour and bioactive Compounds of an Orange Powder Product as Affected by Particle Size

By offering a powder that ensures the healthy value of the fruits, a proper flowability and adequate viscosity after rehydration, there could be an opportunity to promote fruit consumption. The particle size is of critical importance with regard to the properties of a powder. But the separation of a product by particle size is usually associated with compositional changes. In this study, an orange powder product with the same composition but different particle size was compared. The particle sizes considered (269 ± 4, 189 ± 4, 118 ± 3 µm) offer a product with the same bioactive compound content and guarantee a good powder flowability: angle of repose, compressibility, density, porosity and Hausner’s and Carr’s indexes. Nevertheless, grinding can be used as a simple green technology with which to adjust the particle size so as to obtain rehydrated products with differing viscosities and, therefore, powders with different applications: the smaller the particle size, the lower the viscosity.

Flowability, Rehydration Behaviour and bioactive Compounds of an Orange Powder Product as Affected by Particle Size

By offering a powder that ensures the healthy value of the fruits, a proper flowability and adequate viscosity after rehydration, there could be an opportunity to promote fruit consumption. The particle size is of critical importance with regard to the properties of a powder. But the separation of a product by particle size is usually associated with compositional changes. In this study, an orange powder product with the same composition but different particle size was compared. The particle sizes considered (269 ± 4, 189 ± 4, 118 ± 3 µm) offer a product with the same bioactive compound content and guarantee a good powder flowability: angle of repose, compressibility, density, porosity and Hausner’s and Carr’s indexes. Nevertheless, grinding can be used as a simple green technology with which to adjust the particle size so as to obtain rehydrated products with differing viscosities and, therefore, powders with different applications: the smaller the particle size, the lower the viscosity.

Preparation of deer oil powder and its effect on acute gastric mucosal injury in rats

In this paper, deer oil was used as a raw material to prepare deer oil powder by microencapsulation technology to study the potential protective activity of deer oil powder on ethanol-induced acute gastric mucosal injury in rats. The results show that the best process for preparing deer oil powder is: the solids account for 25% of the system content, the wall material Whey Milk Protein Isolate-Maltodextrin ratio is 1:5, the Sodium Stearyl Lactate-Glycerides of Monostearate and Distearate compound emulsifier content is 0.8%, the ratio is 1:1, and the deer oil accounts for 30% of the solid content, and the spray drying inlet temperature is 180°C. Deer oil powder can reduce total stomach injury, gastric mucosal congestion area, and injury score index. Without affecting the blood lipid level, it can reduce the content of Myeloperoxidase, enhance the activity of Superoxide Dismutase and Glutathione Peroxidase, and has good antioxidant activity. Enhance the expression of defense factors Estradiol, Epidermal Growth Factor, and Somatostatin. At the same time, it reduces the levels of Interleukin-1β and Interleukin-6 pro-inflammatory cytokines in gastric tissue and enhances the expression of anti-inflammatory factors Interleukin-4 and Interleukin-10. These results indicate that the gastric protection mechanism of deer oil powder may be related to the enhancement of mucosal defense factors, inhibition of inflammation, and oxidative stress. PRACTICAL APPLICATIONS: This study screened the optimal formula for preparing microencapsulated deer oil powder and proved for the first time that deer oil powder has a strong gastroprotective effect on ethanol-induced acute gastric injury in rats. The gastric protective mechanism of deer oil powder is mainly to reduce oxidative stress, inflammatory cytokine accumulation and to increase the content of defense factors. Therefore, deer oil powder can be used as a new source of gastric treatment drugs.

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.

Effect of different superfine grinding technologies on the physicochemical and antioxidant properties of tartary buckwheat bran powder

The effect of shear crushing, airflow comminution, and wet grinding on the physical and chemical properties of Tartary buckwheat bran (TBB) powder was compared. Superfine grinding significantly reduces the particle size of bran (1.644 μm), while increasing the protein content (23.60%), water-holding capacity (4.38 g g^-1), solubility (21.077 g 100 g^-1), bulk density (0.34 g mL^-1), and tap density (0.53 g mL^-1) providing good processing characteristics. The antioxidant properties of bran powder prepared by the three methods mentioned above were compared. The results showed that different bran powders subjected to superfine grinding displayed varying levels of antioxidant capacity. The quercetin content (2.18 g 100 g^-1) of the wet-grinding bran powder (WGBP) was twice that of the control group, while no rutin was detected. The total flavonoid content (TFC) and total phenolic content (TPC) were significantly different from those of other groups. The DPPH, ˙OH, and ABTS⁺ removal rates were 60.74%, 86.62%, and 92.98%, respectively, while that of ˙OH was significantly higher than in the other treatment groups. The control group, shear crushed, and airflow comminution bran exhibited no significant differences in TFC, TPC, and oxidation resistance, except for the ability to remove ˙OH. TBB powder obtained via superfine grinding displayed superior taste and functional characteristics, providing a theoretical reference for the processing of this bran.

Effects of superfine grinding using ball-milling on the physical properties, chemical composition, and antioxidant properties of Quercus salicina (Blume) leaf powders

BACKGROUND

Quercus salicina (Blume) leaves are traditionally used as folk medicine in some Asian countries. The aim of this study was to evaluate the effects of ball milling for different periods (0, 6, 12, 18, and 24 h) on the physicochemical properties of superfine Quercus salicina (Blume) leaf (QSL) powders.

RESULTS

The particle sizes, water-holding capacity, angle of repose, and redness of the superfine QSL powder decreased with increasing ball-milling times, whereas the water solubility index, bulk density, tapped density, brightness, and yellowness were found to increase. Significantly higher (P > 0.05) total phenolic and flavonoid contents, and antioxidant activities, were observed for the superfine QSL powders obtained after 24 h ball-milling time. A total of 12 phenolic compounds in free and cell-wall-bound forms were quantified in the superfine QSL powder. Free phenolics such as protocatechuic acid, caffeic acid, rutin, and p-coumaric acid were increased and all cell-wall-bound phenolics were decreased with increasing ball-milling times. The antioxidant activity of the free phenolics increased with increasing ball-milling times, and the cell-wall-bound forms decreased.

CONCLUSION

Superfine grinding by ball milling for 24 h can thus be used to produce superfine QSL powder with higher free phenolic metabolite content and antioxidant activity, and improved water solubility index, color, bulk, and tapped densities. This study will be useful for the food / nutraceutical / pharmaceutical industries in the manufacturing of active food ingredients or value-added products using QSL powders. © 2020 Society of Chemical Industry.

Impact of wheat bran micronization on dough properties and bread quality: Part I - Bran functionality and dough properties

This study aimed to investigate the effect of wheat bran micronization on its functionality including physicochemical and antioxidant properties, and dough properties. Coarse bran (D₅₀ = 362.3 ± 20.5 μm) was superfine ground to medium (D₅₀ = 60.4 ± 10.1 μm) and superfine (D₅₀ = 11.3 ± 2.6 μm) bran, accompanied with increasing specific surface area and breakdown of aleurone layers. Bran micronization increased its soluble dietary fibre content, ferulic acid liberation, and antioxidant properties including total polyphenol content, ABTS•+ and DPPH• scavenging activities, while decreased its water retention capacity and insoluble dietary fibre content. Moreover, bran micronization impacted dough rheological properties. The dough with superfine bran had higher water absorption and gelatinization temperature, peak viscosity, final viscosity and setback value, lower stability time, resistance to extension, and extensibility than the dough with coarse bran. This dough furthermore exhibited more solid-like properties characterized by decreased loss moduli and frequency dependence (n').

Effects of superfine grinding on the physicochemical properties and antioxidant activities of Sanchi (Panax notoginseng) flower powders

Sanchi flowers were traditionally used as functional medicinal ingredient in materials. The study was aimed at evaluating superfine powder product of Sanchi flower, hence in this study, five fractions of dried Sanchi flower powders (SFP) were prepared at variable particle sizes by superfine grinding and evaluated for changes in various properties. Superfine powder with median particle diameter of 25.57 μm was produced through grinding. It was evident from the environmental scanning electron microscopy analysis that during superfine grinding, mechanical shear stress played its crucial role in breakdown of the SFP and causes increases in surface area owing to reduction of particle sizes. Superfine grinding could improve solubility, oil holding capacity, and brightness, but decrease the fluidity of SFP. SFP with smallest particle size exhibited highest saponin, minerals, total phenolic, and flavonoid contents accompanied with the best antioxidant activities. Size reduction beyond M200 and M400 led to increasing tendency in IR signature band patterns and marked differences in peak intensities while the powdered samples showed resemblance with respect to peak shapes. Differential scanning calorimetry indicated the lowest melting temperature for SFP fraction with smallest particle size. Conclusively, superfine SFP due to inherent improvement in properties may render several potential applications in manufacturing of food and pharmaceutical additives to impart improved functionalities of finally finished products with uniformity.

Oral processing preference affects flavor perception in dark chocolate with added ingredients

Chocolate has specific rheological behavior during oral processing that delivers its distinct sensory characteristics. When incorporating functional or flavoring ingredients into chocolate, these properties must be maintained to meet consumer expectation. Water-soluble and fat-soluble ingredients have a potential effect on the properties of chocolate; therefore, successfully adding functional supplements in this medium can have challenges. This study investigated the effect of functional or flavoring ingredients on chocolate microstructure, mouthfeel (texture), and flavor release, during oral processing. Participants were classified by their oral processing "pattern": a chewing preference (CP), a sucking preference (SP), and a mixed group who had a preference for both chewing and sucking (MP). Chocolate samples (72% dark chocolate) were prepared with different flavor ingredients (water-soluble: ginger powder and fat-soluble: menthol). Instrumental testing of chocolate viscosity and hardness showed no significant differences in chocolate with low concentrations of added ingredients (0.5% ginger and 0.1% mint), while chocolate with higher concentration (2.5% ginger and 0.5% mint) showed a significant difference compared to standard chocolate. Modified Qualitative Descriptive Analysis (MQDA) tests showed no significant differences in sensory perception of texture between the formulations, or the oral processing behavior groups. There was an impact on flavor perception both from composition and from oral processing behavior. The CP group rated the chocolate with the lowest flavoring concentration as also having the lowest cocoa flavor intensity. Moreover, the MP and SP groups showed a similar perception of cocoa flavor intensity.

Physicochemical properties improvement and structural changes of bamboo shoots (Phyllostachys praecox f. Prevernalis) dietary fiber modified by subcritical water and high pressure homogenization: a comparative study

In presented study, the effects of subcritical water (SW) and high pressure homogenization (HPH) treatments on the physicochemical and structural characteristics of dietary fibers (DFs) from bamboo shoots (Phyllostachys praecox f. Prevernalis) were investigated. The soluble dietary fiber (SDF) content was dramatically increased in SW and HPH treated DFs. Compared with HPH, SW modification enhanced higher physicochemical properties including water holding capacity (WHC), oil holding capacity (OHC) and swelling capacity (SC) of DFs. The abilities of DFs to absorb cholesterol and nitrite ions were both greatly increased after treatments. The results of Scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and X-ray diffraction (XRD) showed that the structure of DFs were changed by SW and HPH. In conclusion, SW treatment showed better effects on improvement of physicochemical properties of bamboo shoot DFs than that of HPH, and the modified DFs could be a potential new functional foods or food additives.

Effects of particle size on structural, physicochemical, and functional properties of potato residue from starch isolation and quality characteristics of residue-based starch noodles

The structural, physicochemical, and functional properties of potato residue with different mesh sizes (<180 µm, <150 µm, <106 µm, <75 µm, ultrafine) obtained from starch isolation were investigated, and its effects on the shear strength, tensile strength, cooking time, and in vitro digestibility of 5% potato residue-based starch noodles were further compared. The results showed that the protein, ash, dietary fiber, water holding capacity, and water solubility of fractionated potato residue were decreased with decreasing particle size, while the starch, fat, polyphenols, and α-amylase activity inhibition ratio were increased. Ultrafine particles exhibited the highest phenolic content (2.26 mg chlorogenic acid equivalent/g), glucose adsorption capacity (7.03 mmol/g), cholesterol adsorption capacity (16.54%), and better performance on starch noodles formulation. However, oil holding capacity and microstructure did not show any significant differences. Therefore, potato residues with desired particle sizes could be successfully used to develop fiber-enriched food products for reducing food waste.

Nutrition and aroma challenges of green tea product as affected by emerging superfine grinding and traditional extraction

Green tea, superfine green tea powder (SGTP), and tea extract were prepared to determine their chemical components and antioxidant activity. The nutrition and aroma challenges of green tea during traditional extract technique and superfine grinding were profiled in this study. The traditional extract technique took advantage over superfine grinding in L-theanine and glutamic acid (Glu) preservation, but not in other 16 essential amino acids. SGTP preserved a maximum of elements from green tea, whereas tea extract greatly changed the elements ratio. Tea extract contained higher VB2 and VC contents and doubled the tea polyphenol (TP) content in comparison with green tea and SGTP. Additionally, tea extract contained more favorable aroma compounds and maintained stronger antioxidant activity in comparison with green tea and SGTP. This study profiled an important basis for the comprehensive utilization of green tea resources by consumers and manufacturers.