Retrogradation-induced physicochemical changes in pre-cooked rice noodles stored at different temperatures: a viewpoint from water dynamics and structure.

BACKGROUND: There has been significant interest in pre-cooked noodles that have a long shelf life and are convenient to cook. However, the thermal processes during preparation, and their high moisture content, can lead to significant quality deterioration during storage. Nevertheless, a comprehensive evaluation of these quality losses has not yet been conducted. RESULTS: The effects of different storage temperatures (25, 4, and -20 °C) on the retrogradation-related physicochemical changes in pre-cooked rice noodles were elucidated mainly from the water dynamics and structural viewpoints. Thermal analysis demonstrated that amylopectin recrystallization took place in the noodles stored at refrigerated temperature, followed by room temperature. The refrigerated storage accelerated the starch retrogradation that caused the water molecules to become entrapped within the crystalline structure by lowering the water hydration properties and weighted T2 relaxation times of the pre-cooked noodles. These water mobility patterns were correlated with the textural changes in the noodles (greater hardness and Rmax /extensibility). Furthermore, the higher structural density and thickness derived from starch retrogradation were observed in the tomographic and microscopic images of the refrigerated noodles. The principal component analysis demonstrated that various physicochemical changes of the pre-cooked noodles during storage showed high correlations with the degree of starch retrogradation (r > 0.83). CONCLUSION: The physicochemical features of the precooked noodles stored under refrigerated conditions were involved in the molecular dynamics of water, showing a notable water mobility reduction derived from the starch retrogradation, which contributed to their thermal, tomographical, and textural changes. © 2023 Society of Chemical Industry.

Artificial intelligence-based prediction of the rheological properties of hydrocolloids for plant-based meat analogues.

BACKGROUND: Methylcellulose has been applied as a primary binding agent to control the quality attributes of plant-based meat analogues. H owever, a great deal of effort has been made to search for hydrocolloids to replace methylcellulose because of increasing awareness of clean labels. In this study, a machine learning framework was proposed in order to describe and predict the flow behavior of six hydrocolloid solutions, and the predicted viscosities were correlated with the textural features of their corresponding plant-based meat analogues. RESULTS: Different shear-thinning and Newtonian behaviors were observed depending on the type of hydrocolloid and the shear rate. Methylcellulose exhibited an increasing viscosity pattern with increasing temperature, compared to the other hydrocolloids. The machine learning algorithms (random forest and multilayer perceptron models) showed a better viscosity fitting performance than the constitutive equations (power law and Cross models). In addition, three hyperparameters of the multilayer perceptron model (optimizer, learning rate, and the number of hidden layers) were tuned using the Bayesian optimization algorithm. CONCLUSION: The optimized multilayer perceptron model exhibited superior performance in viscosity prediction (R2 = 0.9944-0.9961/RMSE = 0.0545-0.0708). Furthermore, the machine learning-predicted viscosities overall showed similar patterns to the textural parameters of the meat analogues. © 2024 Society of Chemical Industry.

Elucidation of the reduced oil uptake of frying batters made from wheat and brown rice flour blends in terms of rheology and surface roughness.

BACKGROUND: Negative impressions toward fried foods are prevalent due to their high oil absorption and caloric values. A great deal of effort has been thus made to reduce the oil uptake of fried foods. In this study, the effect of wheat and brown rice flour blends on the oil uptake of frying batters was elucidated in terms of rheology and surface roughness. RESULTS: The blends with higher proportions of brown rice flour had higher values of pasting parameters and also exhibited a more elastic nature. When a food matrix was deep-fat-fried with frying batters made from wheat and brown rice flour blends, the oil uptake was significantly reduced by 28% compared to wheat flour batter. Based on imaging analysis, the surface properties of the fried crusts were quantitatively measured, demonstrating that the degree of surface roughness distinctly became lower with increasing levels of brown rice flour. Furthermore, the surface roughness parameters (Ra and Rq ) had a strong relationship with the reduced oil uptake. Also, a high proportion of brown rice flour in the blends produced fried samples with a firmer and crispy texture. CONCLUSIONS: A reduced oil uptake of batter-coated fried foods was distinctly observed with increasing levels of brown rice flour in the blends and well correlated with the degree of surface roughness (R2 > 0.85). © 2021 Society of Chemical Industry.

Effect of shortening replacement with oleogels on the rheological and tomographic characteristics of aerated baked goods.

BACKGROUND: A great deal of effort has been made to reduce the use of shortening owing to the high level of saturated fats as well as the presence of trans fats. Grape seed oil high in unsaturated fats was structured with candelilla wax to form solid-like oleogels that were utilized as a shortening replacer in aerated baked goods, specifically muffins. RESULTS: Muffin batters with greater amounts of oleogels exhibited lower viscosity, greater shear-thinning behavior and less elastic nature. The shortening replacement with oleogels significantly increased the specific gravity of the batters, consequently affecting the muffin volume after baking. X-ray tomography indicated a lower fragmentation index (i.e. a more connected solid structure) in the oleogel-incorporated muffins, which was correlated with more enclosed and isolated air cells. A stress relaxation test showed that the shortening replacement with oleogels produced muffins with a firmer and springier texture. Based on fatty acid compositions, the ratio of saturated to unsaturated fatty acids was significantly reduced from 2.81 to 0.41. CONCLUSION: Use of the oleogels as a shortening replacer at a ratio of 1:3 by weight was effective in producing muffins with comparable quality attributes to the control with shortening. © 2017 Society of Chemical Industry.

Machine learning identification of edible vegetable oils from fatty acid compositions and hyperspectral images.

Hyperspectral imaging analysis combined with machine learning was applied to identify eight edible vegetable oils, and its classification performance was compared with the chemical method based on fatty acid compositions. Furthermore, the degree of adulteration in vegetable oils was quantitatively investigated using machine learning-enabled hyperspectral approaches. The hyperspectral absorbance spectra of palm oil with a high degree of saturation were distinctly different from those of the other liquid oils. The flaxseed and olive oils exhibited the dominant hyperspectral intensities at 1170/1671 and 1212/1415 nm, respectively. Linear discriminant analysis demonstrated that two linear discriminants could explain a significant portion of the total variability, accounting for 96.0% (fatty acid compositions) and 98.9% (hyperspectral images). When the hyperspectral results were used as datasets for three machine learning models (decision tree, random forest, and k-nearest neighbor), several instances to incorrectly classify grapeseed and sunflower oils were detected, while olive, palm, and flaxseed oils were successfully identified. The machine learning models showed a great classification performance that exceeded 98.9% from the hyperspectral images of the vegetable oils, which was comparable to the fatty acid composition-based chemical method in identifying edible vegetable oils. In addition, the random forest model was the most effective in ascertaining adulteration levels in binary oil blends (R2 > 0.992 and RMSE < 2.75).

Effect of high pressure pretreatment on the inhibition of ice nucleation and biochemical changes in pork loins during supercooling preservation.

In this study, the effect of high pressure (HP) pretreatment on the stability of pork loins during supercooling (SC) preservation was investigated, and the freshness and postmortem metabolism of pork loins preserved by SC was evaluated. Based on the differential scanning calorimetry (DSC), the peak enthalpies of 200 MPa treatment were lower than those of 50 MPa treatment (P < 0.05). For the nuclear magnetic resonance (NMR) relaxometry, extramyofibrillar water in pork loins was decreased with increasing intermyofibrillar water at >100 MPa (P < 0.05). Compared to unpressurized control all HP treatment had less α-helix structure while random coil was dominated from the Fourier transform infrared (FTIR) spectroscopy (P < 0.05). A 200 MPa was selected to estimate the relationship between HP pretreatment and stability of SC preservation of pork loins. The HP-treated pork loins showed high stability during SC preservation under the relatively low temperature algorithm. Compared to fresh control, HP pretreatment caused physicochemical changes of pork loins which did not recover even after 2 weeks of preservation. Nevertheless, HP followed by SC preservation was able to reduce property changes better than pork loins preserved by normal refrigeration. According to the analyses of transmission electron microscopy (TEM), the HP pretreatment influenced the postmortem biochemical metabolism of pork loins, however, it did not affect the freshness and quality parameters of pork loins due to the subsequently applied low preservation temperature of SC. Therefore, this study demonstrated that moderate HP pretreatment was a potential pretreatment for SC preservation of pork loins.

Tomographical, rheological, and structural effects of soy protein concentrate in a gluten-free extruded noodle system.

Global interest in high-protein foods has been rapidly increasing and the gluten-free products are no exceptions. Gluten-free extruded noodles made from rice flour were thus fortified with soy protein concentrate (SPC) (0%, 15%, 30%, and 45% by weight), and the physicochemical properties of the noodles were characterized in terms of tomographical, rheological, and structural features. SPC-rice flour blends showed higher water absorption and swelling power at room temperature with increasing levels of SPC, which were reduced upon heating. The flour blends with high-levels of SPC also had lower pasting viscosities. Thermal analysis showed lower enthalpy values and higher temperatures derived from starch gelatinization. When the SPC-rice flour blends were applied to extruded gluten-free rice noodles, the noodles tomographically showed a dense and compact structure, that could be favorably correlated with their textural changes (increased hardness and reduced extensibility). FTIR analysis presented the structural changes of the noodles containing different levels of SPC by showing higher intensity of protein-related absorption peaks and lower starch peak intensity, which could be associated with the reduced cooking loss. Moreover, there existed two water components with different mobilities in the noodles whose spin-spin relaxation times had a tendency to increase with increasing SPC content. The results obtained from this study provided fundamental insights into the processing performance of protein-rich ingredients in gluten-free extruded noodles, probably promoting the development of a wider variety of protein-fortified gluten-free products.

Solid Fat Replacement with Canola Oil-Carnauba Wax Oleogels for Dairy-Free Imitation Cheese Low in Saturated Fat.

Canola oil was structured into oleogels with different amounts of carnauba wax, and their processing performances were assessed as an alternative to solid fat for imitation cheese low in saturated fat. The contents of solid fat in the oleogels were less vulnerable to the change in temperature than the palm oil. The replacement of palm oil with oleogels produced cheese samples with harder and more cohesive/chewy textures. Dynamic and transient viscoelastic measurements demonstrated that the use of oleogels was effective in increasing the elastic nature of the cheeses. Two distinct components with different proton mobilities were observed in the imitation cheeses, and longer T2 relaxation times were detected in the oleogel samples. The meltability of the cheese with palm oil was not significantly different from those with 3% and 6% oleogels. The saturated fat level of the oleogel cheese was significantly reduced from 45.70 to 5.20%. The application of canola oil-carnauba wax oleogels could successfully produce imitation cheese high in unsaturated fat and low in saturated fat. This study thus demonstrated that the health-functional properties of imitation cheese could be enhanced by using oleogels.

The thermal, rheological, and structural characterization of grapeseed oil oleogels structured with binary blends of oleogelator.

Combination of oleogelators has recently started to receive scientific attention since single oleogelator may not adequately compensate for the diverse roles of solid fat in a complicated food system. In this study, grapeseed oil oleogels were prepared with candelilla wax (CDW) and glyceryl monostearate (GMS) blends at varying mass ratios (100:0, 75:25, 50:50, 25:75, and 0:100 [w/w]), and their physicochemical characteristics were characterized in terms of thermal, rheological, and microstructural properties. The oleogel with CDW and GMS at a blending ratio of 75 and 25 (CDW-75:GMS-25) exhibited the lowest melting point, implying a eutectic behavior. The CDW-75:GMS-25 oleogel also had a harder texture, greater viscoelasticity, and lower oiling-off characteristics that were highly attributed to its small crystals and dense structural network observed from phase-contrast microscopic images. When GMS from different vendors were examined for melting behavior and hardness of oleogels, it was found that the oleogel properties were highly dependent on the detailed composition of GMS. NMR study showed that the ternary system of CDW, glyceryl 1-monostearate, and glyceryl 1,3-distearate was responsible for the eutectic behavior of the CDW-75:GMS-25 oleogel. This study reports the unique and improved melting and physical properties of oleogels with the mixture of CDW and GMS, which can increase the feasibility of the oleogel technology in actual food products. However, caution should be taken in selecting the oleogelators because their detailed composition and properties can vary depending on sources and processing conditions. PRACTICAL APPLICATION: Increasing attention has been paid to the combination of oleogelators since single oleogelator may not adequately compensate for the diverse roles of solid fat in a complicated food system. This study showed new eutectic characteristics at a specific blending ratio of candelilla wax and glyceryl monostearate that could be positively correlated with the increased hardness, viscoelasticity, and oiling-off features. The results may encourage the food industry to utilize this binary oleogelator blend as an alternative to solid fat high in saturated fat by providing new functional properties.

Optical, rheological, thermal, and microstructural elucidation of rutin enrichment in Tartary buckwheat flour by hydrothermal treatments.

Tartary buckwheat grains were subjected to hydrothermal treatments (steaming/boiling/autoclaving) whose effects on rutin enrichment in the buckwheat flour by rutin migration from the bran fraction were investigated in terms of optical, rheological, thermal, and microstructural properties. The highest amount of rutin was observed in the bran out of the native milling fractions (hull, bran, and flour). The hydrothermal treatments however increased the level of rutin in the flour, even showing a higher level of rutin than the bran in the autoclaved sample. Furthermore, rutin in the hydrothermally-treated flours was not degraded into quercetin by mixing with water. Scanning electron microscopic images demonstrated that the granules of buckwheat starch round in shape and grouped in lumps were disrupted by the hydrothermal treatments. The rutin contents of the buckwheat flour samples were linearly well-correlated with their pasting profiles (peak viscosity), colors (L and b values), and thermal parameters (gelatinization enthalpy and temperature).

Chiral enhancement in diethyl malonate addition by morphosynthesized L-proline mesoporous silica.

l-Proline was immobilized onto mesoporous silica through direct synthesis method via morphosynthesis possessing short channels and plugs in the pore structure which provided chiral enhancement in the diethyl malonate addition reaction.

Rheological and secondary structural characterization of rice flour-zein composites for noodles slit from gluten-free sheeted dough.

Rice flour-zein composites in a hydrated viscoelastic state were utilized to compensate for the role of wheat gluten in gluten-free sheeted dough. The use of zein above its glass transition temperature was able to form a viscoelastic protein network of non-wheat dough with rice flour. The mixing stability and development time of the rice dough were positively increased with increasing levels of zein. The protein secondary structural analysis by FTIR spectroscopy demonstrated that the rice doughs with high levels of zein showed significant increases in ß-sheet structures whose intensity was almost doubled by the use of 10% zein. The use of zein at more than 5% (w/w) successfully produced gluten-free dough sheets that could be slit into thin and long noodle strands. In addition, the composites were effective in improving the rheological characteristics of gluten-free noodle strands by increasing their maximum force to extension, compared to wheat-based noodles.

ADAM10 Is Involved in Cell Junction Assembly in Early Porcine Embryo Development.

ADAM10 (A Disintegrin and Metalloprotease domain-containing protein 10) is a cell surface protein with a unique structure possessing both potential adhesion and protease domains. However, the role of ADAM10 in preimplantation stage embryos is not clear. In this study, we examined the expression patterns and functional roles of ADAM10 in porcine parthenotes during preimplantation development. The transcription level of ADAM10 dramatically increased from the morula stage onward. Immunostaining revealed that ADAM10 was present in both the nucleus and cytoplasm in early cleavage stage embryos, and localized to the apical region of the outer cells in morula and blastocyst embryos. Knockdown (KD) of ADAM10 using double strand RNA did not alter preimplantation embryo development until morula stage, but resulted in significantly reduced development to blastocyst stage. Moreover, the KD blastocyst showed a decrease in gene expression of adherens and tight junction (AJ/TJ), and an increase in trophectoderm TJ permeability by disrupting TJ assembly. Treatment with an ADAM10 specific chemical inhibitor, GI254023X, at the morula stage also inhibited blastocyst development and led to disruption of TJ assembly. An in situ proximity ligation assay demonstrated direct interaction of ADAM10 with coxsackie virus and adenovirus receptor (CXADR), supporting the involvement of ADAM10 in TJ assembly. In conclusion, our findings strongly suggest that ADADM10 is important for blastocyst formation rather than compaction, particularly for TJ assembly and stabilization in preimplantation porcine parthenogenetic development.