The aim of this meta‐analysis is to investigate the sources of heterogeneity in randomized clinical trials examining the effects of curcumin supplementation on liver aminotransferases in subjects ...with nonalcoholic fatty liver disease (NAFLD). We conducted a systematic search of the PubMed, SCOPUS, and Web of Science databases for randomized clinical trials and identified 15 studies (n = 835 subjects). We used random‐effects models with DerSimonian‐Laird methods to analyze the serum levels of alanine aminotransferase and aspartate aminotransferase enzymes. Our results indicate that curcumin did not affect serum alanine aminotransferase, but it did reduce aspartate aminotransferase levels. Notably, both outcomes showed high heterogeneity (p < 0.01). Subgroup analysis revealed that adding piperine to curcumin did not benefit aminotransferase levels in NAFLD patients. Additionally, we found a negative correlation between the duration of the intervention and the relative (mg/kg/day) curcumin dose with the reduction in liver aminotransferases. In summary, the sources of heterogeneity identified in our study are likely attributed to the duration of the intervention and the relative dose of curcumin. Consequently, longer trials utilizing high doses of curcumin could diminish the positive impact of curcumin in reducing serum levels of aminotransferases in patients with NAFLD.
Microwave radiation (MW) is an environment-friendly technology used to physically modify flours. Rice flour was MW-treated at different moisture content (MC) (3 %, 8 %, 13 %, 15 %, 20 % and 30 %). In ...vitro starch digestibility was determined and related to the changes caused by MW treatment to flours' structure and thermal properties, which were influenced by MC. A reduction of 49 % and 65 % in the gelatinization enthalpy of samples treated at 20 % and 30 % MC denoted a partial gelatinization. A loss of granular crystallinity in treated samples was confirmed by XR-diffraction and FTIR, particularly at 15 %, 20 % and 30 % MC. MW promoted the formation of random-coil, α-helix and β-turn protein structure, and the disappearance of LF-β-sheet. Morphological differences were found between samples treated at 8 % MC (loss of polygonal structure, protein layer covering granules' surface and small holes) and 30 % MC (rounded and aggregated granules, covered with exudate amylose). In vitro starch digestibility revealed that samples treated at 20 % and 30 % MC showed 40 % and 47 % higher rapidly digestible starch, 48 % and 70 % lower slowly digestible starch and 90 % lower resistant starch than the untreated flour. Flour MC in MW-treatment allowed the modulation of structural and thermal characteristics of rice flour and consequently its starch hydrolysis rate.
•Microwave treatment (MWT) modified the intensity of rice flour X-ray diffractograms.•Signs of partial gelatinization were found in samples treated at 20 and 30 % humidity.•The MWT decreased the 1047:1022 ratio in FTIR spectra regardless the flour humidity.•The MWT promoted the formation of random coil, α-helix and β-turn protein structure.•The flour humidity during the MWT determined the rate of starch hydrolysis.
Ultrasonic (USC) treatments have been applied to starches, flours and grains to modify their physicochemical properties and improve their industrial applicability. The extent of the modification ...caused by USC treatment depends on the treatment conditions and the natural characteristics of the treated matter. Cavitation leads to structural damage and fragmentation and partial depolymerization of starch components. The amorphous regions are more susceptible to being disrupted by ultrasonication, while the crystalline regions require extended USC exposure to be affected. The increased surface area in USC-treated samples has a higher interaction with water, resulting in modification of the swelling power, solubility, apparent viscosity, pasting properties and gel rheological and textural properties. Starch digestibility has been reported to be modified by ultrasonication to different extents depending on the power applied. The most important treatment variables leading to more pronounced modifications in USC treatments are the botanical origin of the treated matter, USC power, time, concentration and temperature. The interaction between these factors also has a significant impact on the damage caused by the treatment. The molecular rearrangement and destruction of starch structures occur simultaneously during the USC treatment and the final properties of the modified matrix will depend on the array of treatment parameters. This review summarizes the known effects of ultrasonic treatments in modifying starches, flours and grains.
The modification of flours by ultrasound (US) treatments requires excess water to suspend the sample to be treated, which must be removed after treatment to recover the ultrasonicated flour. The aim ...of this study was to determine the influence that the water removal method has on the final characteristics of US-treated gluten-free flours (rice, brown tef, corn and quinoa). US treatment parameters were constant, and two water removal methods were studied: freeze-drying and centrifugation + drying. The elimination of water by centrifugation resulted in the loss of solubilized compounds from the treated flours, which led to important differences between the final characteristics of US-treated flours. Ultrasonication resulted in the reduction of flours' particle size and modification of their color parameters. Techno-functional properties were modified by US treatment, where the water removal method was more influential in whole grain samples (brown tef and quinoa). Few differences were found in thermal properties among pairs of US-treated samples, indicative that the effect caused to starch was mainly attributed to ultrasonication conditions than to the drying method. The water removal method markedly influenced the pasting properties of US-treated flours, resulting in lower profiles when freeze-drying was applied and higher profiles when flours were retrieved by centrifugation. Gels made with tef, corn and quinoa presented reduced tan(δ)₁ values after sonication, while gels made with rice did not show any modification. The water removal method is a decisive step in US treatments, defining the final characteristics of the treated matter, and having a great influence in the modification attributed to ultrasonication.
Fonio (
) is an ancient African cereal that represents a rich source of carbohydrate, fat, fiber, vitamins, minerals, and sulfur-containing amino acids. Processing and utilization of fonio require ...adequate knowledge of its structural, chemical, and nutritional characteristics. The present work evaluates the structural, techno-functional, and gelling properties of fonio and compares them to other major gluten-free cereals (rice, maize, sorghum, and millet). Fonio flour presented significantly higher water absorption index and swelling power, while it scored a lower water solubility index than the reference flours. The pasting viscosity profile of fonio was similar to that of rice, with equivalent peak viscosity but a breakdown viscosity 24% lower than rice, indicative of higher stability and resistance to shearing and heating. Rheological properties demonstrated that fonio generates gels with remarkably strong structures. At 15% concentration, fonio gel withstood stress 579% higher than those observed in the reference flours without breaking its structure. Fonio flour presented the highest gelatinization enthalpy (11.45 J/g) and a narrow gelatinization temperature range (9.96 °C), indicative of a better-packed starch structure than the other analyzed flours. The texture of the gels made with fonio showed higher firmness over the evaluated period. These combined results suggest that fonio is a suitable ingredient for gel-like food formulations.
Tef flour comes from a nutritionally-rich ancient grain gaining increasing interest in gluten-free market. Gluten-free sources are modified by different means to improve their functionality. ...Ultrasound treatment (US) alters flours' structure and leads to physically modified flours with a wider application range. The aim of the present work was to evaluate the impact of US treatments of moderate treatment time, 10 min, and high concentration of the aqueous flour dispersion, 25%, on the microstructural, starch damage, apparent amylose content, techno-functional, pasting and rheological properties of two tef flour varieties, white and brown. Temperature was varied (20, 40, 45, 50, and 55 °C) to modulate the impact of sonication. US treatments led to general particle fragmentation which markedly increased starch damage and lightness (L*) values. Apparent amylose content was higher after ultrasonication, as consequence of molecular fragmentation due to cavitation. Increased starch granules’ exposed area led to enhanced interaction with water, promoting the water absorption index (WAI) and swelling power (SP) of treated flours. Pasting properties showed increased pasting temperatures as well as decreased viscometric profiles with lower breakdown viscosities, indicative of starch rearrangement improved by increasing temperature. Rheological properties indicated higher consistency in gels after US treatments, with improved ability to withstand stress and lower values of tan(δ)1 reflecting a higher solid-like behavior and higher strength of the gel. Temperature was found to be a crucial variable during US treatments, showing an improved degree of modification at higher temperatures in ultrasonicated tef flours, following the same trend in both varieties.
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•Higher treatment temperature decreased particle size that raised water interaction.•Ultrasound incremented apparent amylose content by partial starch depolymerization.•Ultrasound increased pasting temperatures indicating strengthened starch structures.•Ultrasonication led to gels with thermodynamically more stable structure.•Temperature is a crucial variable modulating the effect of ultrasound modification.
Ultrasonication (US) is a green technology used to physically modify flours to increase their industrial range of applicability. The aim of this work was to study the combined effect that dual US and ...annealing (ANN) treatments have on starch and protein structure of rice flour, at 20, 40, 50 and 60 °C. Results showed clear modifications of functional, thermal and pasting properties of flours, as well as rheological properties of gels made from them. US + ANN led to generation of small-size particles, which markedly increased the swelling power and starch damage. X-Ray Diffraction and FTIR indicated that starch crystallinity and protein secondary structure was affected by the shear forces of cavitation. The combination of US + ANN improved the crystalline structure arrangement within the starch granules, causing narrowing of the gelatinization temperature range (ΔT). Pasting viscosities were significantly decreased by ultrasonication, following an increasing trend with increasing temperature, while pasting temperature was increased, agreeing in the achievement of a thermodynamically more stable structure. The rheological properties indicated a reduction of the elastic (G′) and viscous (G″) moduli after ultrasonication, as well as lower values of tan (δ), reflecting a higher predominance of elastic modulus versus viscous one than the non-sonicated flours. The rice flour's properties were found to be highly sensitive to the applied treatment conditions, showing a synergetic effect when sonicating at the highest studied temperature.
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•Ultrasound intensifies the impact of annealing on the modification of rice flour.•Morphology and particle size distribution was affected by ultrasound cavitation.•Unfolding of proteins secondary structure resulted from treatments.•Ultrasound + annealing treatments led to rearrangement of starch structure.•Pasting viscosities were reduced by the combination of ultrasound and annealing.
Acoustic cavitation has been shown to cause physical damage and partial starch depolymerization in ultrasound-treated flours. However, the promising effects of this modification on bread-making ...performance of gluten-free flour are still unexplored. Based on this hypothesis, sonicated rice flour (2–20 min) was used to replace 30% native flour in the control formulation of gluten-free bread. Breadmaking performance was characterized by doughs' pasting, thermal, and rheological properties, and physical quality of breads. Ultrasonication time presented a direct correlation with particle fragmentation. Doughs’ rheology presented reduced tan(δ)₁ values (up to −11%) and improved recovery after the application of stress (up to +14%), denoting an enhanced elastic behavior with respect to the control dough. Rheo-fermentative tests demonstrated that ultrasonication accelerated the generation of CO2 and its retention within the dough structure, as consequence of eased accessibility of yeast to simpler sugars after starch depolymerization. The small-size particles (∼10 μm) in ultrasonicated flours seem to have enhanced their Pickering emulsifying ability and led to breads with higher specific volumes (up to 24%), softer crumbs, and delayed hardening during storage. Ultrasonication, a low-cost technology, has been shown to significantly improve the fermentative and viscoelastic behavior of rice flour dough and its breadmaking performance.
•Structural damage after ultrasound treatment facilitated fermentation.•Doughs containing ultrasonicated flours showed improved elastic behavior.•Recovery capacity in doughs was improved using US-treated flours in the formulation.•Doughs containing ultrasonicated flour were able to better retain CO2 from proofing.•Ultrasonication led to breads with higher specific volumes and softer crumbs.
Physical modifications of flours are an environment-friendly technology receiving increasing attention for widening the range of utilization of these raw materials. Rice flour was modified with ...ultrasound treatments at a frequency of 24 kHz and varying treatment time (2–60 min) and flour concentration (5–30%) in the dispersion. The effect of the modification was measured in the flours' physical, functional, pasting and rheological properties. Particle size of treated samples was reduced, and particle's disruption was observed by SEM; this had an impact on the water absorption ability, as shown by a sharp increase of swelling power. The thermal properties showed a significant reduction of gelatinization enthalpy, as well as narrowing of the gelatinization temperature range, characteristic of better packed starch crystalline structures after sonication. Modified patterns in starch and proteins were obtained with XRD and FTIR, which indicated impact to their crystalline and amide I secondary structures as a consequence of ultrasonication. Pasting profiles were found to be reduced with increasing treatment time, while higher concentrations did not significantly change the modification achieved. The pasting temperature was found to be significantly increased in all treated samples. Ultrasound treatment led to gels with higher strength, obtaining lower values of tan δ with increasing sonication time and flour concentration. Ultrasound allowed the modulation of rice flour functionality, being the effect independent on the concentration of the treated flour dispersion, up to 30%, and increased by treatment time up to 10 min; for longer treatments not many differences were found.
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•Pasting curves of rice flour decreased significantly with the ultrasound treatment.•Pasting and gelatinization temperatures increased in sonicated flours.•Ultrasound treatment changed particle size and surface area of rice granules.•Sonicated rice flour led to stronger and more elastic gels than native one.•Ultrasounds modified XRD and FTIR patterns of starch and proteins in rice flour.
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