Sequential Biorefining of Bioactive Compounds of High Functional Value from Calafate Pomace (Berberis microphylla) Using Supercritical CO2 and Pressurized Liquids.

A biorefinery process was developed for a freeze-dried pomace of calafate berries (Berberis microphylla). The process consisted of extraction of lipophilic components with supercritical CO2 (scCO2) and subsequent extraction of the residue with a pressurized mixture of ethanol/water (1:1 v/v). scCO2 extracted oil from the pomace, while pressurized liquid extraction generated a crude extract rich in phenols and a residue rich in fiber, proteins and minerals. Response surface analysis of scCO2 extraction suggested optimal conditions of 60 °C, 358.5 bar and 144.6 min to obtain a lipid extract yield of 11.15% (d.w.). The dark yellow oil extract contained a good ratio of ω6/ω3 fatty acids (1:1.2), provitamin E tocopherols (406.6 mg/kg), and a peroxide index of 8.6 meq O2/kg. Pressurized liquid extraction generated a polar extract with good phenolic content (33 mg gallic acid equivalents /g d.w.), anthocyanins (8 mg/g) and antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl test = 25 µg/mL and antioxidant activity = 63 µM Te/g). The extraction kinetics of oil by scCO2 and phenolic compounds were optimally adjusted to the spline model (R2 = 0.989 and R2 = 0.999, respectively). The solid extracted residue presented a fiber content close to cereals (56.4% d.w.) and acceptable values of proteins (29.6% d.w.) and minerals (14.1% d.w.). These eco-friendly processes valorize calafate pomace as a source of ingredients for formulation of healthy foods, nutraceuticals and nutritional supplements.

Protective Effect of Red Algae (Rhodophyta) Extracts on Essential Dietary Components of Heat-Treated Salmon.

Salmon paste contains nutritious components such as essential fatty acids (EPA, DHA), vitamin E and astaxanthin, which can be protected with the addition of red algae extracts. Phenolic extracts were prepared with an ethanol: water mixture (1:1) from the red seaweeds Gracilaria chilensis, Gelidium chilense, Iridaea larga, Gigartina chamissoi, Gigartina skottsbergii and Gigartina radula, obtained from the Pacific Ocean. Most algae had a high content of protein (>7.2%), fiber (>55%) and ß-glucans (>4.9%), all expressed on a dry weight basis. Total polyphenols (TP), total flavonoids (TF), antioxidant (DPPH, FRAP) and antibacterial power of the extracts were measured. In addition, the nutritional components of the algae were determined. Results showed that the content of TP in the six algae varied between 2.6 and 11.3 mg EAG/g dw and between 2.2 and 9.6 for TF. Also, the extracts of G. skottsbergii, G. chamissoi, G. radula and G. chilensis showed the highest antiradical activity (DPPH, FRAP). All samples exhibited a low production of primary oxidation products, and protection of the essential components and the endogenous antioxidants tocopherols and astaxanthin, particularly in the case of G. skottsbergii, G. chamissoi, G. radula and G. chilensis. Furthermore, all algae had inhibitory activity against the tested microorganisms, coincident with their antioxidant capacity. Results show that the extracts may have future applications in the development and preservation of essential dietary components of healthy foods.

The concept of alimentation and transdisciplinary research.

Although the term 'alimentation' has existed in the English language since the late 16th century, its use is infrequent. In Latin languages, particularly French, 'alimentation' conveys a holistic notion of the process by which humans produce, procure, prepare, share, indulge in, and digest their foods. Thus, the concept of alimentation encompasses and integrates human, technological, sociocultural, and environmental domains. This article delves into the origins of the term 'alimentation' and its use in the foreign scientific literature, and particularly in the social sciences. Unlike 'food and nutrition', alimentation provides a broader frame for the grand challenges of what, how, and with whom we eat. This approach should lead to transdisciplinary research (TDR) interfacing several knowledge domains (e.g., environmental, technological, socio-cultural, nutritional, etc.) and involving key stakeholders. Possible outcomes of TDR in alimentation are inspiring and meaningful collaborations, innovative methodologies for integrating knowledge, transformative learning of researchers, enriched educational experiences for students, focused community action, and improved public policy. The term 'alimentation' is appropriately used in French and other Latin languages. Alimentation embraces human, technological, sociocultural, and environmental issues This holistic concept views agriculture, food, and nutrition as parts of a broader process Transdisciplinary research interfaces several dimensions of food and eating. © 2020 Society of Chemical Industry.

Mechanical, rheological and structural properties of fiber-containing microgels based on whey protein and alginate.

Dietary fiber (DF) - inulin (IN), bacterial cellulose nanofibers (BC), crystalline cellulose (CC) and oat fiber (OF) - were added at a concentration of 5% (2.5% for OF) to a whey protein isolate (WPI)/sodium alginate (NaAlg) dispersion. Gel microparticles (GMP) were formed by cold gelation followed by mechanical shearing. Compression stress-strain curves of bulk gels were similar for GMP-CC and GMP-OF but different from GMP-IN and GMP-BC. The soluble fiber IN did not change the aggregated matrix of the parent WPI/NaAlg gel, while other sources of DF became incorporated into the microgel matrix. Rheological tests (20 °C) revealed that GMP with added DF had a predominantly elastic behavior. Texture profile analysis suggested that GMP and GMP-IN had advantages over a commercial thickener in terms of adhesiveness and cohesiveness. GMP with added DF may find applications in foods for the elderly as texturizer and/or a carrier of fiber.

Properties of microparticles from a whey protein isolate/alginate emulsion gel.

Designing soft, palatable and nutritious texture-modified foods for the elderly is a challenge for food technologists. The aim of this work was to produce and characterize emulsion-gelled microparticles (EGM) made from whey protein isolate (WPI) and sodium alginate (NaAlg) that may be used to modify the rheology of liquid foods and as carriers of lipids and lipophilic nutrients and bioactives. Olive oil microdroplets became embedded in the WPI/NaAlg gel matrix in the form of an emulsion produced by ultrasound (US) or high-speed blending (HSB). Oil microdroplets were obtained by US and HSB, with an average equivalent diameter varying between 2.0-3.2 µm and 4.5-6.7 µm, respectively. Oil incorporation increased compression stress of bulk emulsion gels at small deformations compared to the no-oil microgel, but this effect was reversed at high strains. EGM were prepared by shear-induced size reduction. Rheological tests at 20 ℃ and 40 ℃ showed that US-EGM and HSB-EGM exhibited a predominant elastic behavior, with G' > G″ throughout the frequency range. However, when HSB-EGM were heated at 60 ℃ their rheological behavior changed to a more fluid-like condition, but not that of US-EGM. Consequently, EGM have the properties needed to improve food texture for people with masticatory/swallowing dysfunctions or needing special nutrition.

Porous matrix of calcium alginate/gelatin with enhanced properties as scaffold for cell culture.

Hydrophilic polysaccharides can be used to prepare porous matrices with a range of possible applications. One such application involves acting as scaffolds for cell culture. A new homogeneous and highly porous biopolymeric porous matrix (BPM) of calcium alginate/gelatin was produced by following a simple process. The key to this process was the selection of the porogen (aerated gelatin). The preparation technique comprises the following steps: incorporating the porogen into the solution of alginate (3%), molding, cross-linking the alginate in 1.41% CaCl2 (maximum gel strength; Cuadros et al., 2012. Carbohydr. Polym. 89, 1198-1206), molding, leaching and lyophilization. Cylinders of BPM were shown to have a relative density of 0.0274 ± 0.002, porosity of 97.26 ± 0.18%, an average internal pore size of 204 ± 58 µm and enhanced mechanical properties, while imbibing more than 11 times their dry weight in water. In vitro cell culture testing within BPM using mesenchymal stem cells was demonstrated by MTT assays and expression of alkaline phosphatase. The BPM provided a suitable microenvironment for seeding, adhesion, proliferation and osteogenic differentiation of cells. The preparation technique and resulting porous matrix represent potential tools for future study and further applications.

Changes on image texture features of breakfast flakes cereals during water absorption.

Normally breakfast cereal flakes are consumed by pouring them into a bowl and covering them with fresh or cold milk. During this process the liquid uptake causes changes in the surface and internal matrix of breakfast cereals that influence texture and integrity. Some breakfast cereal as flakes have a translucent structure that could provide information about the solid matrix and air cells and how they change during liquid absorption. The objective of the study was to assess the image texture changes of corn flakes and frosted flakes during water absorption at 5, 15 and 25 °C, employing 11 image feature textures extracted from grey-level co-occurrence matrix and grey-level run length matrix (at three directions) and to relate the fractal dimension (FD) of images with rupture force (RF) reduction during soaking of both flakes at 5 °C. The most relevant result from principal component analysis calculated with a matrix of 54 (soaking times) × 22 (texture features), shows that it was possible to distinguish an isolated group consisting of different soaking times at the same water temperature in each breakfast cereal flakes evaluated, corroborating that superficial liquid imbibition is important during the liquid absorption process when flakes are soaked. Furthermore, standardized FD could be related to RF in the period when samples tend to search for an equilibrium state.

Mechanical properties of calcium alginate fibers produced with a microfluidic device.

Fibers are important microstructural elements in many foods. The main objective of this research was to produce calcium alginate fibers with uniform diameters (about 300 and 550 µm) using a microfluidic device (MFD) and to study the effect of concentration of sodium alginate [Alg] and calcium chloride [CaCl2] on their mechanical properties (MP). Moisture content (MO) and MP as maximum tensile stress (σmax), tensile strain at break (ΔL/L0) and apparent Young's modulus (E) of fibers were determined and a statistical model and surface responses were developed as a function of [Alg] and [CaCl2]. As [CaCl2] increased first a strengthening and then a weakening of fibers were observed. Furthermore, σmax increased with the addition of Ca(2+) and a maximum of σmax was obtained for a [CaCl2] around 1.4% (exceeding several times the stoichiometric requirements of the carboxylate groups of the polymer). Such behavior prompted a molecular explanation of what happens during gelation based on the "egg-box model" and this model is tried to complete. Moreover, fibers with [Alg] ≥1.8% showed high extensibility (ΔL/L0 around 100%) and low values of MO. High values of E (∼0.5 MPa) were obtained for [CaCl2] close to 1.4%. A greater understanding is needed of the interaction between cation-polysaccharide-water, taking into account [Alg] and [CaCl2] to predict the mechanical behavior of fibers. Calcium alginate fibers are important in food engineering as texture and microencapsulation agents.

Physical properties and microstructural changes during soaking of individual corn and quinoa breakfast flakes.

The importance of breakfast cereal flakes (BCF) in Western diets deserves an understanding of changes in their mechanical properties and microstructure that occur during soaking in a liquid (that is, milk or water) prior to consumption. The maximum rupture force (RF) of 2 types of breakfast flaked products (BFP)--corn flakes (CF) and quinoa flakes (QF)--were measured directly while immersed in milk with 2% of fat content (milk 2%) or distilled water for different periods of time between 5 and 300 s. Under similar soaking conditions, QF presented higher RF values than CF. Soaked flakes were freeze-dried and their cross section and surface examined by scanning electron microscopy. Three consecutive periods (fast, gradual, and slow reduction of RF) were associated with changes in the microstructure of flakes. These changes were more pronounced in distilled water than in milk 2%, probably because the fat and other solids in milk become deposited on the flakes' surface hindering liquid infiltration. Structural and textural modifications were primarily ascribable to the plasticizing effect of water that softened the carbohydrate/protein matrix, inducing partial collapse of the porous structure and eventually disintegration of the whole piece through deep cracks.

Uptake of tritiated liquids by individual breakfast cereal flakes.

Surface liquid adhesion (SLA) and liquid absorption (LA) of tritiated liquids, including water and skim, low-fat, whole, and fat-enriched milks, by cornflakes (CF) and frosted flakes (FF) were determined by scintillation counting using water-[(3)H] at 0.5 microCi/mL. SLA or the liquid adhering to individual flakes after a short immersion period was the same for CF and FF in the case of water (approximately 0.011 microL mm(-2) of flake) but were always higher for CF than for FF and increased as the fat content in milks augmented. LA of individual flakes, followed for 300 s of soaking, increased with time and was always higher for CF than for FF (for the same liquid), however, data did not follow a regular pattern. Flakes showed quite compact outer surfaces and an internal porous matrix composed of air cells of various sizes separated by dense walls of different thicknesses. This heterogeneous microstructure of individual flakes may be the cause of the lack of a simple kinetics during the soaking process. Previous results obtained by soaking a mass of flakes overestimated the uptake of fluid by individual because they included the liquid occluded between the flakes.

Determination of a representative volume element based on the variability of mechanical properties with sample size in bread.

Quantitative analysis of food structure is commonly obtained by image analysis of a small portion of the material that may not be the representative of the whole sample. In order to quantify structural parameters (air cells) of 2 types of bread (bread and bagel) the concept of representative volume element (RVE) was employed. The RVE for bread, bagel, and gelatin-gel (used as control) was obtained from the relationship between sample size and the coefficient of variation, calculated from the apparent Young's modulus measured on 25 replicates. The RVE was obtained when the coefficient of variation for different sample sizes converged to a constant value. In the 2 types of bread tested, the tendency of the coefficient of variation was to decrease as the sample size increased, while in the homogeneous gelatin-gel, it remained always constant around 2.3% to 2.4%. The RVE resulted to be cubes with sides of 45 mm for bread, 20 mm for bagels, and 10 mm for gelatin-gel (smallest sample tested). The quantitative image analysis as well as visual observation demonstrated that bread presented the largest dispersion of air-cell sizes. Moreover, both the ratio of maximum air-cell area/image area and maximum air-cell height/image height were greater for bread (values of 0.05 and 0.30, respectively) than for bagels (0.03 and 0.20, respectively). Therefore, the size and the size variation of air cells present in the structure determined the size of the RVE. It was concluded that RVE is highly dependent on the heterogeneity of the structure of the types of baked products.

Image analysis of representative food structures: application of the bootstrap method.

Images (for example, photomicrographs) are routinely used as qualitative evidence of the microstructure of foods. In quantitative image analysis it is important to estimate the area (or volume) to be sampled, the field of view, and the resolution. The bootstrap method is proposed to estimate the size of the sampling area as a function of the coefficient of variation (CV(Bn)) and standard error (SE(Bn)) of the bootstrap taking sub-areas of different sizes. The bootstrap method was applied to simulated and real structures (apple tissue). For simulated structures, 10 computer-generated images were constructed containing 225 black circles (elements) and different coefficient of variation (CV(image)). For apple tissue, 8 images of apple tissue containing cellular cavities with different CV(image) were analyzed. Results confirmed that for simulated and real structures, increasing the size of the sampling area decreased the CV(Bn) and SE(Bn). Furthermore, there was a linear relationship between the CV(image) and CV(Bn) (.) For example, to obtain a CV(Bn) = 0.10 in an image with CV(image) = 0.60, a sampling area of 400 x 400 pixels (11% of whole image) was required, whereas if CV(image) = 1.46, a sampling area of 1000 x 100 pixels (69% of whole image) became necessary. This suggests that a large-size dispersion of element sizes in an image requires increasingly larger sampling areas or a larger number of images.

In vitro digestibility and glycemic response of potato starch is related to granule size and degree of gelatinization.

Starch granule microstructure affects the digestion of starch and its nutritional impact; however, the exact relationship between both factors is not clear. This study reports quantitative relationships between granule size (length and polygonal area), degree of gelatinization (DG), in vitro digestibility (by enzymatic methods), and glycemic response of potato starch granules gelatinized to various extents by heating at several constant temperatures in the range of 55 to 65 degrees C. DG measured by differential scanning calorimetry was closely related with heating temperature (R(2)= 0.997), size parameters of granules (measured by image analysis), in vitro digestion, and in vivo glycemic response (R(2) of adjusted models > 0.9); shape parameters of granules (measured by image analysis) were not related with DG. Results demonstrate that DG of starch strongly affects its digestibility in vitro, and may influence the postpandrial glycemic response. Future studies should be performed to investigate the effect of potato starch gelatinization on the nutritional impact at other temperatures and in more complex matrices.

Internal snapping hip syndrome: treatment by endoscopic release of the iliopsoas tendon.

PURPOSE: The internal snapping hip syndrome is caused by slippage of the iliopsoas tendon over the iliopectineal eminence or the femoral head. Open surgical techniques have been successfully used to treat this condition. More recently, endoscopic techniques have become available to address this problem. The purpose of this study was to investigate an endoscopic technique for release of the iliopsoas tendon and its short-term results. TYPE OF STUDY: Consecutive case series. METHODS: Six patients (7 hips) with an average age of 38.5 years had an endoscopic release of the iliopsoas tendon for internal snapping hip syndrome. Hip arthroscopy was performed in every patient. Special inferior portals were used for psoas bursoscopy. The iliopsoas tendon was identified and released at the level of the lesser trochanter in all cases. RESULTS: Intra-articular concomitant injuries were identified and treated in 4 cases. No snapping symptoms were present in any patient after surgery nor at the last follow-up at, on average, 21 months. Significant loss of flexion strength was present after surgery but had improved by 8 weeks. CONCLUSIONS: In our hands, the endoscopic technique for iliopsoas tendon release was effective and reproducible and our results compare well with results of open procedures in the short term. LEVEL OF EVIDENCE: Level IV.

Hip arthroscopy after previous acetabular osteotomy for developmental dysplasia of the hip.

PURPOSE: The purpose of this study was to examine the arthroscopic findings in the hips of patients with long-term follow-up of Chiari osteotomies. TYPE OF STUDY: Prospective consecutive series of patients. METHODS: Seven consecutive patients (1 male, 6 female; average age, 23 years) having a Chiari osteotomy performed in 1 hip during childhood or adolescence for developmental dysplasia of the hip were studied. They presented mechanical hip symptoms and had adequate head coverage as a result of the osteotomy with preservation of joint space. Hip arthroscopy was performed in all cases. RESULTS: A massive labral tear dislocated in the midportion of the joint was found in all cases with varying degrees of cartilage damage in the acetabulum or femoral head. The labral tear was resected, cartilage lesions were repaired, and microfracturing of the exposed subchondral bone was performed. Mechanical symptoms improved after surgery and all of the patients were able to go back to activities of daily living. CONCLUSIONS: In the Chiari osteotomy, medial displacement of the acetabulum leaves the labrum in the center of the load-bearing area of the resulting acetabulum. Over time this can produce a tear of the labrum, which may be the cause of the mechanical symptoms in our series. It has been documented that labral tears can lead to early degenerative hip disease and, combined with the cartilage lesions, may explain in part the long-term bad results of the Chiari osteotomy. LEVEL OF EVIDENCE: Level IV.

An aiming guide for anterior portal placement in hip arthroscopy.

Hip arthroscopy has become a standard surgical procedure. Specific portals and portal placement techniques are well described and routinely used. The anterior portal placement relies on the ability of the surgeon to introduce a needle into the joint from the landmark located at the crossing of a vertical line from the anterior superior iliac spine and a horizontal line from the greater trochanter. Directing the needle at 30 degrees medially and 45 degrees proximally is recommended, but some adjustment is always necessary to access the joint. Multiple punctures are often needed to place the needle in the correct path into the hip. This increases the risk of injury by puncture of the structures adjacent to the site of the anterior portal and increases surgical time. This study reports the use of a guide device we developed to assist anterior portal placement. The device consists of an intra-articular probe attached to an extra-articular aiming guide that introduces the needle into the hip joint. The needle enters at the previously described landmark and is directed towards the tip of the probe inside the joint. Early clinical results are presented.

Microscopy and calorimetry as complementary techniques to analyze sugar crystallization from amorphous systems.

A comparison of microscopic and macroscopic techniques to evaluate sugar crystallization kinetics is presented using amorphous lactose and lactose-trehalose mixtures. Polarized light video microscopy (PLV) and differential scanning calorimetry (DSC) were applied to measure crystallization kinetics, induction times and time for complete sugar crystallization at different storage temperatures (60-95 degrees C). DSC was also employed to measure the glass transition temperature (T(ag)) of the systems. PLV permitted direct observation, in real time, of growth of individual crystals and morphological aspects at a scale not detected by DSC. Taking the average of several microscopic observations, the results for temperature dependence of crystallization rate and time to complete lactose crystallization were similar to those obtained by DSC. Both PLV and DSC techniques showed that the presence of trehalose delayed lactose crystallization, without affecting the T(ag) value. For the analysis of sugar crystallization in amorphous systems, PLV and DSC proved to be complementary techniques. Validation of results obtained by PLV with results from DSC opens a new area of microstructural analysis of crystallizing systems.