A mechanistic investigation into combined influences of NaCl and extrusion temperature on fibrous structures of high-moisture textured yeast protein.

NaCl and extrusion temperature have an important influence on the qualities of high-moisture textured proteins, but the influence mechanism is still unclear. Therefore, this study prepared high-moisture textured yeast protein (HMTYP) with different NaCl contents (0%-4%) under different extrusion temperatures (170 °C, 180 °C) and characterized their physicochemical properties. The results showed that the HMTYP containing 1% and 2% NaCl prepared at 180 °C contained a strong fibrous structure. The possible mechanism was as follows: YP could not be sufficiently melted at 170 °C after adding NaCl, causing a decrease in the structural strength; however, at 180 °C, YP still reached a fully molten state even though 1%-2% NaCl was added. After YP sufficiently melted, NaCl enhanced the cross-linking and aggregation of proteins during cooling, which improved the textural properties of HMTYP. Accordingly, NaCl and extrusion temperature could combine to adjust the fibrous structure and texture of HMTYP.

Effect of electrohydrodynamic (EHD) drying on active ingredients, textural properties and moisture distribution of yam (Dioscorea opposita).

This paper systematically investigates the changes in material properties during electrohydrodynamic (EHD) drying, the discharge characteristics of the EHD system as well as the active ingredients, textural properties (hardness, adhesiveness, etc.) and moisture distribution of yam under EHD, air drying and hot air drying were investigated. The results showed that the active particles and the ionized wind generated during the discharge process of the electrohydrodynamic drying device had a significant effect on the drying. Compared to thermal drying, 21 kV drying resulted in the most complete cellular structure, the best internal bound water content as well as textural properties of yam. It played a positive role in the retention of internal nutrients in yam, and the total phenol and allantoin contents were increased by 25.74% and 81.99%, respectively. These results elucidate the advantages of electrohydrodynamic drying in yam drying and provide a reference for the application of EHD in drying.

Impact of soluble soybean polysaccharide on the gelatinization and retrogradation of corn starches with different amylose content.

Polysaccharides have a significant impact on the physicochemical properties of starch, and the objective of this study was to examine the effect of incorporating soluble soybean polysaccharide (SSPS) on the gelatinization and retrogradation of corn starches (CS) with varying amylose content. In contrast to high-amylose corn starch (HACS), the degree of gelatinization of waxy corn starch (WCS) and normal corn starch (NCS) decreased with the addition of SSPS. The inclusion of SSPS resulted in reduced swelling power in all CS, and led to a decrease in gel hardness of the starches. The intermolecular forces between SSPS and CS were primarily hydrogen bonding, and a gel network structure was formed, thereby retarding the short-term and long-term retrogradation of CS. Scanning electron microscopy results revealed that the addition of SSPS in starches led to a loose network structure with larger poles and a reduced ordered structure after retrogradation, as observed from the cross-section of formed gels. These findings suggested that SSPS has great potential for applications in starchy foods, as it can effectively retard both gelatinization and retrogradation of starches.

The formation mechanism and textural properties of a complex gel based on soybean glycinin-chitosan complex coacervates: Effects of pH, heat treatment temperature and centrifugation.

The soybean glycinin (11S)-chitosan (CS) complex gels with various textural properties were successfully constructed. The process involved the initial formation of 11S-CS coacervates through electrostatic interactions, followed by a heating treatment to obtain the final complex gels. The impacts of pH, heating temperature, and centrifugation on 11S-CS complex gel properties were investigated. The results indicated that the pore arrangement of the gel formed at pH 7.3 was more tightly and uniformly packed than those formed at pH 6.8 and 7.8. Centrifugation facilitated denser and more ordered gel structures at the three pH values, while increasing the heating temperature exhibited the opposite trend at pH 6.8 and 7.8. These structural differences were also reflected in the rheological and textural properties of the gel. The 11S-CS complex gels exhibited an elasticity-based gel property. The textural properties of gels formed at pH 6.8 were stronger compared to those formed at pH 7.3 and 7.8. However, when the 11S-CS coacervates were heated without centrifugation, the resulting gels were weak. This study emphasizes the potential of using protein/polysaccharide associative interactions during gel formation to alter the microstructure of the gel, meeting various production requirements.

Application of emerging thermal and nonthermal technologies for improving textural properties of food grains: A critical review.

Emerging nonthermal and thermal food processing technologies are a better alternative to conventional thermal processing techniques because they offer high-quality, minimally processed food. Texture is important in the food industry because it encompasses several product attributes and plays a vital role in consumer acceptance. Therefore, it is imperative to analyze the extent to which these technologies influence the textural attributes of food grains. Physical forces produced by cavitation are attributed to ultrasound treatment-induced changes in the conformational and structural properties of food proteins. Pulsed electric field treatment causes polarization of starch granules, damaging the dense outer layer of starch granules and decreasing the mechanical strength of starch. Prolonged radio frequency heating results in the denaturation of proteins and gelatinization of starch, thus reducing binding tendency during cooking. Microwave energy induces rapid removal of water from the product surface, resulting in lower bulk density, low shrinkage, and a porous structure. However, evaluating the influence of these techniques on food grain texture is difficult owing to differences in their primary operation mode, operating conditions, and equipment design. To maximize the advantages of nonthermal and thermal technologies, in-depth research should be conducted on their effects on the textural properties of different food grains while ensuring the selection of appropriate operating conditions for each food grain type. This article summarizes all recent developments in these emerging processing technologies for food grains, discusses their potential applications and drawbacks, and presents prospects for future developments in food texture enhancement.

Esterified wheat bran: Physicochemical properties, structure and quality improvement of Chinese steamed bread during refrigerated storage.

To develop the application of wheat bran and improve the nutrition and anti-staling capacity of Chinese steamed bread (CSB), oleic acid-esterified wheat bran (OWB) was prepared by esterification of wheat bran with oleic acid, and its physicochemical properties, structure, and quality improvement for CSB during refrigerated storage were investigated. The hydrophilic-lipophilic balance value of OWB was 16.0, the maximum degree of substitution was 0.146, and its emulsifying capacity was similar to that of glycerol monostearate. The starch gelatinization degree of CSB containing 3 % OWB and the control decreased by 19.55 % and 27.12 % within 7 days of refrigerated storage, respectively, while the hardness of CSB with OWB was lower than that with wheat bran. OWB inhibited starch recrystallization and increased bound water in the corresponding CSB, which effectively delayed starch retrogradation. OWB had a positive emulsifying capacity and showed potential as a functional material for preventing retrogradation of starch-based foods.

Effects of barley seedling powder on rheological properties of dough and quality of steamed bread.

In order to find the optimal share of barley seedling powder (BSP) to improve the rheological properties of wheat dough and physico-chemical properties of steamed bread (SB), BSP was added with wheat flour at various proportions (2-10%). Results showed that with the increasing amount of BSP additive, the farinograph index (86.33-123), dough stability (9.37-12.63 min), and dough development time (6.23-7.63 min) in blend flour increased. Similarly, with the increasing BSP, SB became darker and more greenish, and the total flavonoid content increased. The content of chlorophyll-b, and total chlorophyll demonstrated a faster increase than that of chlorophyll-a. The hardness and chewability of SB improved as well whereas the springiness increased first and then decreased. The best springiness and gumminess of SB were found with 2% and 8% BSP additives respectively. 2%, 4%, and 6% addition of BSP resulted in a slight fluctuation in the bound water quantity than 8% and 10% BSP additive. No new compound formation was confirmed by Infrared analysis and there was only a heat and mass transfer process. Results from this study indicated that SB with improved quality attributes can be prepared from wheat flour fortified with BSP at 2-4%.

Combined Effect of High Hydrostatic Pressure, Sous-Vide Cooking, and Carvacrol on the Quality of Veal, Plant-Based, and Hybrid Patties during Storage.

The effect of carvacrol added to patties stored at 4 °C for 14 days, previously pressurized and vacuum-cooked (HPP-SVCOOK), was investigated. Three formulations were prepared (veal, plant-based product, and hybrid product). An emulsion made with olive and linseed oils was added. The physicochemical and microbiological qualities were assessed. Microbial tests indicated negligible growth of spoilage organisms in treated patties. No significant effect of carvacrol on the microbial loads of patties was noticed. Sulfite-reducing clostridia and Enterobacteriaceae were absent in the treated patties, whereas, in the treated veal and hybrid samples, 3 and 2 units of log cfu/g reduction for lactic acid bacteria and molds and yeasts were noted, respectively. On day 7 of storage, veal patties exhibited a significant reduction (p < 0.05) in the L* (53.9−49.3), hardness (32.3−21.4 N), springiness (0.8−0.7 N), cohesiveness (0.49−0.46), and chewiness (12.2−7.1) and a hike in the a* value (5.3−9.4). No significant changes in L* (59.1−58.6), a* (8.57−8.61), hardness (11.6−10.6 N), or cohesiveness (0.27−0.26) were observed in plant-based patties over the storage times, whereas reductions in springiness (0.5−0.4), chewiness (1.9−1.3), and b* (26.6−29.1) were noted in them. In hybrid patties, the L* (53.9−52.5) and b* values (24.9−24.3) were consistent but had a significant decrease in a* value (5.9−3.5) along the days of storage under study. The texture parameters of the hybrid patties altered were similar to those of veal patties during the 14-day storage time. In all samples, pH decreased with storage time. HPP-SVCOOK was effective on rendering safe and shelf-stable, ready-to-eat patties regardless of their matrix formulation. The addition of carvacrol had limited effects on the textural qualities of the HPP-SVCOOK products. Future studies need to be undertaken to assess the treated patties' consumer acceptability and sensory profile. The study provides the basis for the development of novel meat-based and plant-based products that are microbiologically safe, with minimum physicochemical alterations during storage.

Optimization of Conditions for a Freeze-Dried Restructured Strawberry Block by Adding Guar Gum, Pectin and Gelatin.

With its high moisture content and tender texture, fresh strawberry is very susceptible to mechanical damage and microbial infection. Drying is one of the most frequently employed methods to extend its shelf life, and freeze-dried restructured strawberry block (FRSB) is an emerging popular food. Here, in order to enhance the quality of FRSB, edible gums of guar gum, pectin, and gelatin were added and the combination was optimized using response surface methodology (RSM) with chewiness, hardness, and organoleptic evaluations of the dried sample as the response indicators. The results showed that the combination addition of 0.10% guar gum, 0.22% pectin, and 0.30% gelatin contributed to the highest comprehensive quality of the dried sample. Compared with the untreated sample, the optimal combination addition of the three edible gums resulted in a higher moisture content for the dried sample (increased by 0.8%), and increased the chewiness, hardness, and porosity by 82.04%, 27.09%, and 3.01%, respectively, while maintaining more original color and forming a denser porous microstructure. The findings in the current work will be useful for the application of edible gums in freeze-dried restructured fruits and vegetables.

Quality Characterization of Different Parts of Broiler and Ligor Hybrid Chickens.

The quality characterization of different parts of male and female Ligor hybrid chickens was investigated and compared with those of commercial broiler. Genotypes, muscle types, and sex had effects on the composition, physicochemical, and textural properties of chicken samples. Ligor hybrid chicken contained higher percentages of protein, moisture, ash, and collagen content but lower fat content than those of commercial broiler (p < 0.05), except in the case of breast, where no significant difference in moisture and ash was observed (p ≥ 0.05). The pH in breast meat of both chickens was lower than that of thigh meat. The color (L*, a*, and b*) values of male and female chickens were not significantly different, except for the L* value of broiler chicken, which was higher in female chickens than in male chickens. Higher cooking loss and shear force were found in male Ligor hybrid chicken. A similar protein pattern was observed for the protein from the same muscle type, irrespective of sex and genotype tested. It was observed that Ligor hybrid chicken contained higher glutamic acid and aspartic acid than commercial broilers. Therefore, Ligor hybrid chicken is a promising new source of nutrition, which can be beneficial for consumers.

Effects of pullulanase enzymatic hydrolysis on the textural of acorn vermicelli and its influencing mechanism on the quality.

The effect of pullulanase enzymatic hydrolysis time on the textural properties of acorn vermicelli was investigated by texture analyzer. And the influencing mechanism was revealed by exploring the physicochemical properties of acorn starch under the optimum enzymatic hydrolysis time by texture analyzer, scanning electron microscopy, X-ray diffraction and brabender viscograph. After acorn starch was hydrolyzed by pullulanase for 14 h, acorn vermicelli had excellent textural properties. In addition, the enzymatic hydrolysis transformed the acorn starch from spherical particles with smooth surface to polygonal particles with rough surface, as well as transformed the crystal structure of acorn starch from C-type to B-type. Compared with native acorn starch, enzyme hydrolyzed acorn starch had higher amylose content, better freeze-thaw stability, lower swelling power and, breakdown viscosity, stronger gel strength and, higher light transmittance. These excellent properties contributed to the exceptional textural properties and quality of acorn vermicelli. The results of this study may provide valuable information on the preparation of acorn vermicelli.

Modulation of soy protein isolate gel properties by a novel "two-step" gelation process: Effects of pre-aggregation with different divalent sulfates.

A novel pre-aggregation process prior to gelation was applied to modulate the aggregation and gelation pathway of soy protein isolate (SPI). SPI dispersions were pre-aggregated with CaSO4, MgSO4 or ZnSO4 at 0-15 mM and then gelled by adding CaSO4 up to a final salt concentration of 35 mM. Compared with the sample without pre-aggregation, the storage modulus of SPI gels pre-aggregated with 10 mM CaSO4, 10 mM MgSO4, and 2.5 mM ZnSO4 were increased by 50.5%, 35.7%, and 63.6%, respectively. The fracture stress, texture profile analysis parameters, and water holding capacity were markedly improved by an appropriate level of pre-aggregation. To a certain extent, pre-aggregation could promote the formation of uniform structure with thicker strands, whereas over-aggregation resulted in a coarser network, which was correlated with the volume-mean diameter (D4,3) of pre-aggregated SPI particles. The results are of great value for further understanding of gelation mechanism of proteins.

Catalytic pyrolysis of film waste over Co/Ni pillared montmorillonites towards H2 production.

The transformation of plastic waste into valuable fuel products via catalytic pyrolysis is a promising and eco-friendly strategy. Herein, a series of Co/Ni pillared montmorillonites were developed as low-cost and effective catalysts for the pyrolysis of post-consumer film waste, which is one of the representative plastic wastes in nature. The best-performing catalyst produced 80.2% of liquid product, with a high selectivity of 43.5% of hydrocarbons at C10-C13 range, and 42.0 vol% of H2 which is nearly increased by 40-fold as compared to that in non-catalytic run. The improved results were ascribed to the pillared structure, the oxidation state of Co/Ni, and the distribution of acid sites. Particularly, the Lewis acidity (which governs the cyclization and alkanisation) coupled with high surface area and uniform dispersion of transition metallic sites, were found to promote the selectivity of condensable product. The pyrolytic mechanism towards H2 production was explored by theoretical calculations. The lattice oxygen bonded to both Ni and Co in an octahedral environment was found to promote the adsorption of the fragment of polymer in dehydrogenation. Additionally, the solid residues are potentially applied for the production of valuable carbonaceous materials since they displayed high heating value. This work is expected to provide a direction for the development of pyrolysis technology for fuel production with sustainability and economic viability.

Effect of different starch acetates on the quality characteristics of frozen cooked noodles.

The physicochemical properties of starch acetates with an equal degree of substitution prepared from pea, corn, and wheat starch and their effects on frozen cooked noodle (FCN) quality were investigated. The result showed that the three kinds of starch acetates had different effects on the quality of FCN due to their different blue values, freeze-thaw stability, and crystalline morphology analyzed by XRD (p < .05). The FCN with the addition of 20% CAS exhibited slow deterioration of textural properties during holding for 30 min. The analysis of the changes in the content of free SH group and glutenin macropolymer (GMP) demonstrated that the addition of CAS promoted protein disulfide cross-linking and decreased protein mobility during holding. Fourier transform infrared spectroscopy (FT-IR) revealed that FCN with the addition of CAS had low decrement in α-helix and ß-sheet during holding, indicating that starch acetates contributed to the maintenance of the gluten network structure.

Effects of Konjac glucomannan with different viscosities on the rheological and microstructural properties of dough and the performance of steamed bread.

Konjac glucomannan (KGM) is used as an additive to improve the properties of wheat products. The effects of three types of KGM on the rheological properties and microstructure of dough, as well as the performance of steamed bread were investigated in this study. Particularly, dough with KGM displayed new features such as reduced peak viscosity, breakdown and setback. As the viscosity of KGM increased, the stability of the dough structure increased, while the viscosity and fluidity of the dough decreased. More interestingly, the gluten film of dough also increased with increasing substitution level and viscosity of KGM. Consistently, KGM with higher viscosity improved the quality of steamed bread. Generally, three types of KGM have different effects on the rheological characteristics and microstructure of dough, as well as the performance of steamed bread, which provide useful information for the proper application of KGM in wheat-based foods.

Development and Characterization of Crackers Substitution of Wheat Flour With Jellyfish.

The objective of this study was to investigate the possibility of using jellyfish (Lobonema smithii) for the production of nutritionally improved crackers. In this study, ground jellyfish were incorporated into different levels (20, 30, and 40%) to replace wheat flour in cracker formula. Physicochemical characteristics (linear expansion, hardness, and color) and sensory quality of the developed crackers were examined and compared with control crackers. The crackers with jellyfish were found significantly darker, with more brittleness, and less consumer accepted than the control samples (p < 0.05). Moisture content, a w, and thiobarbituric acid reactive substances (TBARS)-values of jellyfish crackers increased while the hardness of the jellyfish crackers decreased with increasing the storage time for both crackers stored at 35 and 45°C. The substitution of wheat flour with jellyfish led to high protein content in the crackers. The cracker with 30% of jellyfish gained characteristics of cracker, liking scores, as well as the subjective quality of the final product and had good physical and chemical conditions, being able to be consumed for 12 weeks stored at 35°C.

Effects of Citrus Peel Hydrolysates on Retrogradation of Wheat Starch.

Retrogradation is the principal cause for bread staling and, therefore, it has attracted a lot of interest from the food industry. In this study, the inhibitory effect of citrus peel hydrolysates (CPH) on retrogradation of wheat starch (WS) in the presence of sucrose was investigated. The pasting properties showed that further addition of CPH caused a lower setback value than the addition of sucrose alone. Hardness of the gel, retrograded at 4 °C for five days, showed a similar tendency, which was reduced more in CPH addition than WS itself or sucrose addition alone. The low retrogradation enthalpy of the CPH including starch gel also indicated the positive effect of CPH on retarding retrogradation. These results suggested that incorporation of CPH in starch-based foods would be effective for inhibiting retrogradation, preventing the deterioration of the quality of food products.

A comparative study on the textural and nutritional profile of high pressure and minimally processed pineapple.

High pressure processing of pineapple has potential implication in food industry. The impact of high pressure (HP) processing and minimal processing, on quality parameters of pineapple was analysed. Changes in the pineapple quality in terms of texture, colour, total flavonoids, total polyphenols, vitamin C and sensory properties were investigated within the domain of 100-300 MPa and 5-20 min. Quality changes induced by HP processing was compared with the minimally processed pineapple. High pressure processing significantly (p < 0.0001) affect the firmness, total flavonoids, total polyphenols, vitamin C and colour values and were significantly increased in HP processed samples, while in minimal processed samples, these quality attributes exhibited a major degradation. On the basis of quality analysis, microbial quality and sensory assessment, high pressure treatment at 300 MPa for 10 min was found to be suitable for preserving the quality of pineapple up to 16th day in refrigeration condition.

Effect of Black Tea Infusion on Physicochemical Properties, Antioxidant Capacity and Microstructure of Acidified Dairy Gel during Cold Storage.

The impacts of black tea infusion on physicochemical properties, antioxidant capacity and microstructure of stirred acidified dairy gel (ADG) system have not been fully explored. These impacts were studied during a 28-day cold storage (4 °C) period to explore the feasibility and technical boundaries of making acidified dairy gels in which black tea infusion (BTI) is incorporated. Reconstituted skim milks containing different proportions of BTI were acidified by GDL (glucono-δ-lactone) at 35 °C for making ADG systems. Both textural properties and structural features were characterized; antioxidant capacity was determined through three assays. They are (1) free radical scavenging ability by DPPH (2,2-diphenyl-1-picrylhydrazyl) assay; (2) ABTS [2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)] assay and (3) ferric reducing antioxidant power (FRAP) assay. The microstructure of the ADGs was observed using SEM (scanning electron microscopy) and CLSM (confocal laser scanning microscopy). Results showed that BTI significantly increased the antioxidant capacity of the gel systems and the gel containing 15% BTI was as stable as the control gel in terms of syneresis rate. However lower phase stability (higher syneresis rate) was observed in the ADG with a higher portion of BTI (30% to 60%). The microstructure of the ADGs observed may explain to the phase stability and textural attributes. The results suggested that tea polyphenols (TPs) improved antioxidant capacity in all samples and the interactions between BTI and dairy components significantly altered the texture of ADGs. Such alterations were more pronounced in the samples with higher proportion of BTI (60%) and/or longer storage time (28 days).

Effect of amaranth and quinoa seed flour on rheological and physicochemical properties of goat meat nuggets.

An attempt was made through the present study to prepare gluten free goat meat nuggets by replacing refined wheat flour from product formulation with healthy, dietary fibre rich amaranth (A) and quinoa (Q) flour at different levels. A total of five different treatments viz., AI (1.5% amaranth), AII (3% amaranth), QI (1.5% quinoa) and QII (3% quinoa) were prepared. The physicochemical, colour, texture, sensory and rheological properties of these pseudocereal-added products were evaluated against control (3% refined wheat flour). Emulsion stability of meat batter was significantly affected (P < 0.05) due to addition of amaranth flour (1.5% and 3%) and quinoa (3%). Treatment groups AII and QI had significantly low (P < 0.05) moisture content with respect to control while the amount of fat content showed a reverse trend. Addition of amaranth and quinoa significantly increased (P < 0.05) the dietary fibre in meat products. Rheology of meat batter was affected by types and level of pseudocereal incorporation. Treatment AII had low (P < 0.05) hunter colour lightness value, whereas redness value was low for treatment QI. Effect of added amaranth and quinoa flour was observed on the textural parameters like adhesiveness, cohesiveness, gumminess and chewiness. High scores for almost all the sensory parameters were recorded in pseudocereal-added meat products. Though, all the products were very much acceptable, product with 1.5% quinoa flour was found to have high (P < 0.05) overall acceptability score.