This study aimed to purify and identify antioxidant peptides from the low-molecular-weight fraction (SPH-I, MW < 3 kDa) of Alcalase-hydrolyzed soybean ( Glycine max L.) hydrolysate and further ...evaluate the cytoprotective effects of synthesized peptides against oxidative stress in human intestinal Caco-2 cells. After purification by gel filtration chromatography and reversed-phase HPLC, four major peptides were sequenced by nano-LC-ESI-MS/MS as VVFVDRL (847 Da, SPH-IA), VIYVVDLR (976 Da, SPH-IB), IYVVDLR (877 Da, SPH-IC), and IYVFVR (795 Da, SPH-ID). The antioxidant peptides were synthesized and displayed desirable DPPH radical-scavenging activity (from 16.5 ± 0.5 to 20.3 ± 1.0 μM Trolox equivalent (TE)/μM), ABTS
radical-scavenging activity (from 3.42 ± 0.2 to 4.24 ± 0.4 mM TE/μM), ORAC (from 143 ± 2.1 to 171 ± 4.8 μM TE/μM), and FRAP (from 54.7 ± 1.2 to 79.0 ± 0.6 mM Fe
/μM). Moreover, the synthesized peptides protected Caco-2 cells against H
O
-induced oxidative damage via significantly downregulating intracellular ROS generation and lipid peroxidation ( p < 0.05). Additionally, SPH-IC and SPH-ID statistically upregulated total reduced glutathione synthesis, enhanced activities of catalase and glutathione reductase, and suppressed ROS-mediated inflammatory responses via inhibiting interleukin-8 secretion ( p < 0.05).
Alcalase endo-protease enzyme was selected in this experiment to extract oil from pine kernel. The response surface analysis method was employed to optimize the parameters in the experiment. The ...optimum parameters are as follows: enzyme additive amount 1.97%, hydrolysis time 3.0h, hydrolysis temperature 51°C, materials to water rate 1:5, pH 8.4 and total oil extraction rate 89.12%. Factor contribution rate obtained from the F-test are as follows: x2>x1>x4>x3>x5. The fatty acid contents of pine kernel oil are as follows: palmitc acid 3.89%, oleic acid 19.44%, linoleic acid 50.09%, linolenic acid 0.58% and stearic acid 1.53%.
With rapid population growth and continued environmental degradation, it is no longer sustainable to rely on conventional proteins to meet human requirements. This has prompted the search for novel ...alternative protein sources of greater sustainability. Currently, proteins of non-conventional origin have been developed, with such alternative protein sources including plants, insects, algae, and even bacteria and fungi. Most of these protein sources have a high protein content, along with a balanced amino acid composition, and are regarded as healthy and nutritious sources of protein. While these novel alternative proteins have excellent nutritional, research on their structure are still at a preliminary stage, particularly so for insects, algae, bacteria, and fungi. Therefore, this review provides a comprehensive overview of promising novel alternative proteins developed in recent years with a focus on their nutrition, sustainability, classification, and structure. In addition, methods of extraction and potential safety factors for these proteins are summarized.
•The stability of thermal-treated anthocyanin solutions over storage was evaluated.•Elevated temperatures resulted in higher rates of color change.•A model was established for the color change of ...anthocyanin solutions.•The amount of anthocyanins in solutions over storage was measured.•The antioxidant capacity was affected by heating and subsequent storage.
Many anthocyanin-containing foods are thermally processed to ensure their safety, and stored for some time before being consumed. However, the combination of thermal processing and subsequent storage has a significant impact on anthocyanins. This study aimed to investigate the color, chemical stability, and antioxidant capacity of thermally treated anthocyanin aqueous solutions during storage at 4, 25, 45, and 65°C, respectively. Anthocyanin aqueous solutions were thermally treated before storage. Results showed that the degradation rate of anthocyanins in aqueous solutions was much faster than those in real food. The color of the anthocyanin aqueous solutions changed dramatically during storage. The anthocyanin aqueous solutions stored at 4°C showed the best chemical stability. Interestingly, the antioxidant capacity of the anthocyanin aqueous solutions stored at lower temperatures remained the same; however, the antioxidant capacity of those thermally treated at 120 or 140°C and stored at 45 or 65°C significantly decreased.
Display omitted
•Four types of divalent cations were used to cross-link alginate/SPI microgels.•Microgels cross-linked by Zn2+ had the lowest stability compared to the others.•Microgels cross-linked ...by Zn2+ exhibited burst release.•Microgels cross-linked by Cu2+, Ba2+ and Ca2+ showed continuous release.
In this study, sodium alginate/ soy protein isolate (SPI) microgels cross-linked by various divalent cations including Cu2+, Ba2+, Ca2+, and Zn2+ were fabricated. Cryo-scanning electron microscopy observations revealed distinctive structural variations among the microgels. In the context of gastric pH conditions, the degree of shrinkage of the microgels followed the sequence of Ca2+ > Ba2+ > Cu2+ > Zn2+. Meanwhile, under intestinal pH conditions, the degree of swelling was ranked as Zn2+ > Ca2+ > Ba2+ > Cu2+. The impact of these variations was investigated through in vitro digestion studies, revealing that all microgels successfully delayed the release of β-carotene within the stomach. Within the simulated intestinal fluid, the microgel cross-linked with Zn2+ exhibited an initial burst release, while those cross-linked with Cu2+, Ba2+, or Ca2+ displayed a sustained release pattern. This research underscores the potential of sodium alginate/SPI microgels cross-linked with different divalent cations as efficient controlled-release delivery systems.
Protein extraction from soybeans is a vital part of the soy industry. Traditionally, the extraction of soy protein has been done by alkaline extraction and isoelectric precipitation. With the ...advancement of technology, more extraction techniques have been developed, and are superior to this traditional method. In this review, the composition and classification of soy protein are summarized. Next, the current emerging technologies for soy protein extraction are highlighted. Three extraction technologies, namely reverse micellar, enzyme‐assisted and membrane ultrafiltration, are reviewed in detail. Finally, the research prospects and trends of soy protein extraction technology are also summarized.
Display omitted
•High moisture extrusion of soy protein concentration with gums is studied.•The influence of gums on the quality of extrudates is investigated.•Extrudates with 6% sodium alginate has ...the most abundant fibrous structures.•Disulfide and hydrogen bonds are important in constructing fibrous structures.•The addition of gums improves the rehydration rate and protein digestibility.
The influence of gums on the quality of extrudates prepared by the high moisture extrusion cooking of soy protein was studied. Three food gums, iota carrageenan (ICGN), carboxymethylcellulose sodium (CMC) and sodium alginate (SA), were investigated for their effects on promoting the fiber formation of extrudates. Results obtained indicated that lamellar structures were formed at the cooling zone for samples containing 6% CMC and 6% SA. The addition of 6% SA enhanced the quality of extrudates, such as improved rehydration rate and digestion rate. Furthermore, interactions between protein molecules over the extrusion process were also analyzed, and the importance of the type of molecular bonds responsible for the formation of extrudates was determined to be: disulfide bonds ≥ hydrogen interactions > hydrophobic interactions. Results of this work would be of importance in the design of meat analogs using soy protein concentrate, and more importantly, in the understanding of protein–protein interactions during extrusion for sustainable health.
High moisture extrusion of soy protein concentrate (SPC) and wheat gluten (WG) blends was conducted to investigate the potential use of this mixture in the production of meat analogs. Extrusion ...samples collected at different zones from the extruder barrel and extrudates were analyzed to determine their texture, microstructure, protein solubility, secondary structure, and mode of disulfide bonds present in the molecular structure. Results obtained from this study indicate that a blend of SPC-WG at 50/50 resulted in the best fibrous structures. In comparison, extrudates prepared by either SPC or WG did not contain any clear fibrous structures. Additionally, hydrogen and disulfide bonds play a major role over extrusion, with a transformation of disulfide bonds from the intramolecular to intermolecular mode. The analysis of the secondary structure shows that the transformation from α-helix to β-sheet and the maintenance of an ideal balance are crucial for the formation of the fiber structure. The extrudate obtained at SPC-WG ratio of 50/50 presented very good rehydration characteristics when immersed in water at 60 °C for 40 min, due to WG promoting the formation of fibrous structures.
•Extrusion of soy protein concentrate (SPC) and wheat gluten (WG) was studied.•SPC extrudate with 50% WG has a well fibrous structure.•Hydrogen and disulfide bonds play a major role over the extrusion process.•Disulfide bonds transformed from intra-to inter-molecular mode over extrusion.•The α-helix to β-sheet transformation promotes fiber formation during extrusion.
Seeking for healthier dietary foods without compromising their quality has become the first choice for consumers. Various components in foods are able to interact with each other and form conjugates ...to improve their functionality and nutritional value. The present study investigated on the formation and structural properties of covalently linked conjugates using soy protein isolate (SPI) and black rice anthocyanins at different ratios. The in vitro digestion fate of the conjugates under simulated gastrointestinal conditions was also evaluated. Fourier transform infrared spectroscopy analysis indicated that the secondary structures of SPI was changed upon conjugation with anthocyanins as there was a decrease in α-helix and β-sheet content. Three-dimensional fluorescence also revealed that the tertiary structure of SPI was less compact after conjugation with anthocyanins as a result of the unfolding of polypeptide chains. The conjugates were shown to have higher degree of hydrolysis than SPI. However, transepithelial transport of peptides across Caco-2 cell monolayer was decreased in SPI after conjugation with anthocyanins. The results of this study suggest that incorporation of anthocyanins in SPI is a way to reconcile consumer demand for healthier foods with better quality and functionality.
Display omitted
•The secondary structure of soy protein isolate (SPI) was altered by anthocyanins.•The tertiary structure of SPI was also affected by anthocyanins.•The SPI-anthocyanins conjugates exhibited higher antioxidant capacity than SPI.•The SPI-anthocyanins conjugates showed lower peptide permeability than SPI.
PDF
