The development of hybrid polysaccharide-protein complexes as Pickering emulsion stabilizers has attracted increasing research interest in recent years. This work presents an eco-friendly surface modification strategy to functionalize hydrophilic cellulose nanocrystals (CNC) using hydrophobic soy protein isolate (SPI) via mussel adhesive-inspired poly (l-dopa) (PLD) to develop improved nanoconjugates as stabilizers for oil-in-water Pickering emulsion. The physicochemical properties of the CNC-PLD-SPI nanoconjugate were evaluated by solid-state 13C NMR, FT-IR, TGA, XRD, contact angle analysis, and TEM. The modified CNC (conjugation content of 38.22 ± 1.21%) had lowered crystallinity index, higher thermal stability, and more hydrophobic than unmodified CNC, with an average particle size of 309.9 ± 8.0 nm. Use of amphiphilic CNC-PLD-SPI nanoconjugate with greater conformational flexibility as Pickering stabilizer produced oil-in-water emulsions with greater physical stability.
The direct consumption of vegetable proteins in food products has been increasing over the years because of animal diseases, global shortage of animal protein, strong demand for wholesome and religious (halal) food, and economic reasons. The increasing importance of legume and oilseed proteins in the manufacturing of various functional food products is due to their high-protein contents. However, the greatest obstacle to utilizing these legumes and oilseeds is the presence of antinutrients; but these antinutrients can be successfully removed or inactivated by employing certain processing methods. In contrast, the potential negative impact of the antinutrients is partially balanced by the fact that they may have a health-promoting role. Legumes and oilseeds provide well-balanced amino acid profiles when consumed with cereals. Soybean proteins, wheat gluten, cottonseed proteins, and other plant proteins have been used for texturization. Texturized vegetable proteins can extend meat products while providing an economical, functional, and high-protein food ingredient or can be consumed directly as a meat analog. Meat analogs are successful because of their healthy image (cholesterol free), meat-like texture, and low cost. Mycoprotein is fungal in origin and is used as a high-protein, low-fat, health-promoting food ingredient. Mycoprotein has a good taste and texture. Texturized vegetable proteins and a number of mycoprotein products are accepted as halal foods. This article summarizes information regarding the molecular, nutritional, and functional properties of alternative protein sources to meat and presents current knowledge to encourage further research to optimize the beneficial effects of alternative protein sources.
The Asian population whose soy intake is higher compared to Western populations shows a significantly lower incidence of osteoporotic fracture. Several meta-analyses have revealed that supplementation of soy isoflavones improve bone health status in women. This review examined the current evidence as to whether soy could exhibit similar bone protective effects on the male population. In vivo studies revealed that supplementation of soy protein or soy isoflavones improved bone health in both normal and osteoporotic male rodents. Cell culture studies showed that soy isoflavones influenced osteogenesis and osteoclastogenesis through mechanisms such as estrogen receptor binding activity, antiinflammatory activity and anti-parathyroid hormone activity. Soy isoflavones also affected calcium channel signaling and might exhibit direct effects on the osteoblastogenesis modulator, core binding factor 1. However, limited clinical trials involving soy intervention in males generally showed insignificant results. This could be attributed to the short duration of intervention, characteristics of the subjects or method of bone health assessment. More well-planned clinical trials are required to establish possible bone protective effects of soy in men.
In this study, four different selected wall materials (namely gelatin, soy protein isolate, maltodextrin and Arabic gum) were applied for blueberry anthocyanin extract encapsulation. The effect of these wall material types on the release and degradation of anthocyanin and the modulation of gut microbiota during in vitro simulated gastrointestinal digestion and colonic fermentation were investigated. It was found that the encapsulation of anthocyanin extract using appropriate wall material could significantly enhance the colonic accessibility of anthocyanins. Soy protein isolate and gelatin delayed the release of anthocyanins, whereas the other two wall materials displayed no significant effect on the release time of anthocyanins. Gut microbiota mainly metabolized some phenolic compounds such as 4-hydroxycinnamic acid and chlorogenic acid. Meanwhile, different fermented anthocyanin extract microcapsule broth could significantly decrease the composition and abundance of Firmicutes and increase that of Bacteroidetes. Furthermore, the presence of anthocyanin extract microcapsules, especially those encapsulated with soy protein isolate, promoted the biosynthesis of short-chain fatty acids by gut microbiota. It is concluded that, amongst the wall materials studied, soy protein isolate appeared to be a functional and suitable candidate to delay anthocyanin release and prevent disease through the promotion of gut health.
As a protein-rich, underutilized crop, green soybean could be exploited to produce hydrolysates containing angiotensin-I converting enzyme (ACE) inhibitory peptides. Defatted green soybean was hydrolyzed using four different food-grade proteases (Alcalase, Papain, Flavourzyme and Bromelain) and their ACE inhibitory activities were evaluated. The Alcalase-generated green soybean hydrolysate showed the highest ACE inhibitory activity (IC50: 0.14 mg/mL at 6 h hydrolysis time) followed by Papain (IC50: 0.20 mg/mL at 5 h hydrolysis time), Bromelain (IC50: 0.36 mg/mL at 6 h hydrolysis time) and Flavourzyme (IC50: 1.14 mg/mL at 6 h hydrolysis time) hydrolysates. The Alcalase-generated hydrolysate was profiled based on its hydrophobicity and isoelectric point using reversed phase high performance liquid chromatography (RP-HPLC) and isoelectric point focusing (IEF) fractionators. The Alcalase-generated green soybean hydrolysate comprising of peptides EAQRLLF, PSLRSYLAE, PDRSIHGRQLAE, FITAFR and RGQVLS, revealed the highest ACE inhibitory activity of 94.19%, 99.31%, 92.92%, 101.51% and 90.40%, respectively, while their IC50 values were 878 μM, 532 μM, 1552 μM, 1342 μM and 993 μM, respectively. It can be concluded that Alcalase-digested green soybean hydrolysates could be exploited as a source of peptides to be incorporated into functional foods with antihypertensive activity.
In a bid to produce rice flour noodles with improved texture and reduced cooking time, rice flour-soy protein isolate noodles (RNS) were structurally enhanced by a combined treatment (COM) of microbial transglutaminase (MTG) with glucono-δ-lactone (GDL). The RNS-COM was either dried using superheated steam (SHS) to yield RNS-COM-SHS or steamed for 10 min (S10) before air drying to produce RNS-COM-S10 noodles. Control samples were SHS-dried rice flour (RN-SHS) and air-dried RN-S10 noodles. In general, textural and microstructural properties indicated higher textural properties and a more robust network in RNS-COM-SHS and RNS-COM-S10 than in other noodles. However, optimum cooking time (P < 0.5) was in the order; RN-SHS, RNS-COM-SHS < RN-S10 < RNS-COM-S10. As a result of the COM treatment, structurally enhanced noodles were more resistant to cooking. As applied in RNS-COM-SHS noodles, SHS was able to improve cooking quality, probably through the formation of bigger and evenly spread pores that had promoted faster gelatinisation of starch, with a high order of relative starch crystallinity.
A study on the binding interaction of lectins from Artocarpus heterophyllus (jacalin), Glycine max and Sambucus nigra with standardised quantity of IgA from the IgA nephropathy patients and normal controls was performed. The Glycine max lectin demonstrated higher affinity towards the serum IgA of IgAN patients as compared to normal controls. However, the affinity binding was lower in cases ofjacalin and the Sambucus nigra lectin. When serum samples were treated with neuraminidase, the differential jacalin affinity binding between IgA1 of patients and normal controls was abrogated. Our data are in support of the view that the O-linked oligosaccharide moieties of the patients IgA1 were generally lacking in galactose and sialic acid residues.
Processing of soybeans to other products and consumption of soy products is increasing worldwide mainly due to acclaimed health benefits. Processing can alter soybean sensory appeal, nutritive value and potentially affect consumer health. Rhizopus oligosporus was used to ferment soybean for 3 days. The tempeh flour (TF) was produced form tempeh while defatted tempeh flour (DTF) was then produced from TF by immersing in hexane solvent while soy protein isolate (SPI) was prepared from DTF by using alkali and acid followed by neutralization treatment. In this study, nutritional properties and amino acid content of tempeh, TF, DTF and SPI were determined. Therefore, the objective of this study is was to evaluate the effect of each treatment on the chemical composition and amino acid content for all the samples. The results showed that the nutritional properties (total ash, moisture, crude fat, total carbohydrate and crude fibre) were reduced significantly (p < 0.05) except for protein content. Protein content was significantly (p < 0.05) increased by 50.5% in SPI. For amino acid content, the results obtained showed that SPI contain highest amount of essential and non-essential amino acid followed by DTF, Tempeh and TF. Glutamic acid was found to be the highest amino acid component in all samples. The evaluation from the results showed that SPI can be considered as potential functional food ingredients.
Protein Efficiency Ratio (PER) is the most widely used method for determining protein quality. The studies involved a few category of products as raw materials namely poultry products, beef burger products, fish and fish products, soy products and palm kernel cake in animal diet preparation were compiled to compare the data. Data from the proximate analysis showed that protein content in soy protein isolate (SPI) was the highest (95.00%) followed by meat such as mackerel fish (89.09%) and beef (88.60%). Results from feed consumption and total protein consumed showed that the rats fed with mechanically deboned poultry meat (MDPM) products (excluding broiler back) consumed more feed, ranging from 469.2g to 422.3g during the study while the lowest total feed consumed (157.7g) was recorded in the rat fed a diet of fermented palm kernel cake (fPKC). The total protein consumed by rat for diets of fish and fish products such as canned sardine was 62.36g, mackerel 61.76g and anchovy at 58.91g, followed by MDPM products. Tempeh (14.72g) and fPKC diet (16.3g) were among the lowest total protein consumed by the rats. Growth and PER data for rats fed a diet of canned sardine, anchovy and mackerel, as well as mechanically deboned turkey meat (MDTM) and mechanically deboned chicken meat (MDCM) had higher mean body weight (154.80g, 145.20g, 144.81g, 148.7g and 142.5g respectively) compared to rats fed with plant protein diet such as SPI, tempeh and PKC (34.79g, 16.34g and 16.60g respectively) whereas rats fed diets containing fPKC had a mean body weight loss of 24.4g. MDPM showed higher PER value (ranging from 3.01 to 3.34) compared to hamburger group, pure beef and fish group. Tempeh and SPI had lower PER of 1.02 and 1.52 respectively while the lowest PER of 0.50 and -1.50 were shown in PKC and fPKC. The highest digestibility was shown in mackerel (96.99%), followed by canned sardine (96.88%), tempeh (91.41%), meat (90.79%) and pure beef burger (90.04%) while digestibility of PKC and fPKC were much lower (45.70% and 22.60%). Lipid profile of rats fed with palm based fat beef burger showed that palm fat(PF) and red PF did not affect the total cholestrol concentration but resulted in higher high density lipoprotein (HDL)- cholesterol concentration in their blood serum. In summary, the utilization of PF and red PF in beef burger increased the HDL-cholesterol and has no effect on the concentration of total cholesterol in rat blood serum.
Malaysia, Biosafety Bill 2006 was approved by Parliament in July 2007, and labeling legislation will be implemented soon. In this study, duplex polymerase chain reaction (PCR) was carried out to detect
endogenous soybean lectin gene and exogenous cp4-epsps (5’-enolpyruvylshikimate-3-phospate synthase) gene simultaneously. Additionally, real-time PCR utilizing SYBR Green fluorescence dye were established for the quantitative analysis of Roundup Ready soybean (RRS), which is based on the two established calibration curve from cloned fragment of cp4-epsps gene and lectin gene respectively. Approximately, 39.5% (45/114) of the samples examined in this study contain RRS, animal feeds (31), processed food (13) and raw soybean (1). Additionally, 75.6% (34/45) of the positive samples were found contained RRS above 0.9%. The sensitive GMO quantitative approach described in this study enable the analysis of various samples and this will facilitate the labeling process.
Protein efficiency ratio (PER) and protein digestibility are important parameters used in protein quality determination. Protein nutritive values of selected protein sources: buffalo meat, casein, soy protein isolate, and tempeh, with sodium caseinate as a reference formulation, were evaluated. Determination of proximate analysis, protein quality and protein digestibility were monitored. Procedures for evaluation of protein quality and digestibility included PER using the rat bioassay and in vivo Apparent Protein Digestibility (APD). The rats fed with buffalo meat had the highest mean increase in body weight (102.73g±8.95) while rats fed with tempeh had the lowest mean for increase in body weight (16.34g±9.11). Although the mean for body weight gained showed significant differences between all treatments (P0.05) found between casein and soy protein isolate for total food intake. For the PER value, buffalo meat had the highest value (2.99), followed by sodium caseinate (2.41), casein (1.93), soy protein isolate (1.52) and tempeh (1.10). The PER value for buffalo meat (2.99) was higher than sodium caseinate (2.41) while the rest of the treatment were comparatively lower than sodium caseinate. For the in vivo apparent protein digestibility, tempeh had the highest value (91.41%±3.76), followed by casein (91.34%±3.15), buffalo meat (90.79%±1.44), soy protein isolate (89.52%±2.96) and sodium caseinate (89.47%±2.31).
The physical attributes (pH and colour), cooking yield, textural and mechanical properties (firmness, tensile and texture profiles analyses) and structural breakdown properties (multiple extrusion cell with added artificial saliva) of five yellow alkaline noodle (YAN) formulations were studied. Samples used were noodles with (a) typical formulation (control), (b) soy protein isolate (SPI), (c) soy protein isolate plus microbial transglutaminase enzyme (SPI/MTGase), (d) green banana pulp flour (GBPu) and (e) green banana peel flour (GBPe). Compared to other noodles SPI/MTGase noodle showed significantly (P < 0.05) higher values in terms of textural, mechanical and breakdown properties. Incorporating SPI, banana pulp and peel flours into the noodles had imposed some differences on most of the mechanical and textural parameters from the control YAN. However, these noodles could not be clearly distinguished in term of structural breakdown properties.
Mung bean is considered a ‘green pearl’ for its relatively high protein content; however, it has limited application as a raw material for industrial food products. As the potential use of mung beans relies on its protein behavior, this study characterized the functional properties of mung bean protein isolates and the results were compared with soy protein isolates. The protein isolates were prepared from mung bean and soy bean flours via extraction with 1 N NaOH, precipitated at pH 4, and subsequently freeze-dried. The amino acid profile as well as the hydrophilic and hydrophobic ratio of mung bean protein isolate, had been comparable with soy protein isolate. The water and oil absorption capacities as well as the denaturation temperature of mung bean protein isolate, were found to be similar with those of soy bean protein isolate. However, foaming capacity (89.66%) of mung bean protein isolate was higher than that of soy protein isolate (68.66%). Besides, least gelation concentration (LGC) of mung bean protein isolate (12%) was also close to LGC of soy protein isolate (14%), while the protein solubility was comparable between both the isolated proteins. The physical features of the textured mung bean were close to the commercial textured soy protein, which showed a heterogeneous and porous network like matrix when the mung bean flour was extruded to measure its potentiality to produce textured vegetable protein.all seaweed extracts. Results showed that extraction parameters had significant effect (p < 0.05) on the antioxidant compounds and antioxidant capacities of seaweed. Sargassum polycystum portrayed the most antioxidant compounds (37.41 ± 0.01 mg GAE/g DW and 4.54 ± 0.02 mg CE/g DW) and capacities (2.00 ± 0.01 μmol TEAC/g DW and 0.84 ± 0.01 μmol TEAC/g DW) amongst four species of seaweed.
Lactobacillus sp. FTDC 2113, L. acidophilus FTDC 8033, L. acidophilus ATCC 4356, L. casei ATCC 393, Bifidobacterium FTDC 8943 and B. longum FTDC 8643 were incorporated into soymilk supplemented with fructooligosaccharides (FOS), inulin, mannitol, maltodextrin and pectin. The objective of the present study was to evaluate the effects of prebiotics on the bioactivity of probiotic-fermented soymilk. Proteolytic activity was increased in the presence of FOS, while the supplementation of inulin and pectin increased the angiotensin I-converting enzyme inhibitory activity accompanied by lower IC(50) values. The beta-glucosidase activity was also enhanced in the presence of pectin. This led to higher bioconversion of glucosides to aglycones by probiotics, especially genistin and malonyl genistin to genistein. Results from this study indicated that the supplementation of prebiotics enhanced the in-vitro antihypertensive effect and production of bioactive aglycones in probiotic-fermented soymilk. Therefore, this soymilk could potentially be used as a dietary therapy to reduce the risks of hypertension and hormone-dependent diseases such as breast cancer, prostate cancer and osteoporosis.
Cross-linked soy protein isolate (SPI) gels were produced via single-treatment of SPI with microbial transglutaminase (MTG) for 5 h or 24 h, or with ribose for 2 h, or via combined-treatments of SPI with MTG followed by heating with ribose. Assessment of gel strength and solubility concluded that measures which increased protein cross-links resulted in improved gel strength; however, in most cases the digestibility and amino acid content of the gels were reduced. The combined treated gel of SPI/MTG for 24 h/ribose was more easily digested by digestive enzymes and retained higher amounts of amino acids compared with the control Maillard gels of SPI with ribose. MTG consumed lysine and glutamine and reduced the availability of amino acids for the Maillard reaction with ribose. MTG was able to preserve the nutritional value of SPI against the destructive effect of the Maillard reaction and cross-links.
Nine formulations were processed into bologna with different ratios of soy protein isolate (SPI):sodium caseinate (SCA), i.e. 1:1, 1:2.5, 1:5, 5:1, 5:2.5, 5:5, 10:1, 10:2.5 and 10:5. The products were evaluated for yields, emulsion stability, physical measurements (shearforce-kgf and folding test) and taste panel evaluation. Formulations with 5:1 and 5:5 SPI:SCA had lower liquid loss resulting in higher yields while the others had poor emulsion stability and high liquid loss. Firmer texture was exhibited by formulations 1:1, 5:1 and 10:1 SPI:SCA but formulation with 1:1 SPI:SCA showed better gelation followed by 1:2.5, 1:5, 5:1, and 5:2.5. The other formulations had poor gelation and binding properties, especially formulation with 10:5 SPI:SCA. Sensory evaluation was carried out using 30 untrained panelists. Attributes evaluated were aroma, texture, chewiness, juiciness, saltiness, chicken taste and overall acceptance. Formulation with 5:1 SPI:SCA was more acceptable for texture, chicken taste and overall acceptance while formulation with 1:1 SPI:SCA was more acceptable for the chewiness, juiciness and saltiness attributes. There was no significant difference (P > 0.05) in aroma attribute, for all formulations.
The purpose of the study was to investigate whether a combination of sago and soy protein ingested during moderate-intensity cycling exercise can improve subsequent high-intensity endurance capacity compared with a carbohydrate in the form of sago and with a placebo. The participants were 8 male recreational cyclists with age, weight, and VO2max of 21.5 +/- 1.1 yr, 63.3 +/- 2.4 kg, and 39.9 +/- 1.1 ml . kg(-1) . min(-1), respectively. The design of the study was a randomized, double-blind placebo-controlled crossover comprising 60 min of exercise on a cycle ergometer at 60% VO2max followed by a time-to-exhaustion ride at 90% VO2max. The sago feeding provided 60 g of carbohydrate, and the sago-soy combination provided 52.5 g of carbohydrate and 15 g of protein, both at 20-min intervals during exercise. Times to exhaustion for the placebo, sago, and sago-soy supplementations were 4.09 +/- 1.28, 5.49 +/- 1.20, and 7.53 +/- 2.02 min, respectively. Sago-soy supplementation increased endurance by 84% (44-140%; p < .001) and by 37% (15-63%; p < .05) relative to placebo and sago, respectively. The plasma insulin response was elevated above that with placebo during sago and sago-soy supplementations. The authors conclude that a combination of sago and soy protein can delay fatigue during high-intensity cycling.
The present study aims to design a milk fat globule membrane (MFGM)-inspired structured membrane (phospholipid- and protein-rich) for microencapsulation of docosahexaenoic acid (DHA) oil. DHA-enriched oil emulsions were prepared using different ratios of sunflower phospholipid (SPL), proteins [whey protein concentrate (WPC), soy protein isolate (SPI), and sodium caseinate (SC)], and maltodextrin and spray-dried to obtain DHA microcapsules. The prepared DHA oil emulsions have nanosized particles. SPLs were found to affect the secondary structure of WPC, which resulted in increased exposure of the protein hydrophobic site and emulsion stability. SPL also reduced the surface tension and viscosity of the DHA oil emulsions. In vitro digestion of the spray-dried DHA microcapsules showed that they were able to effectively resist gastric proteolysis and protect their bioactivity en route to the intestine. The DHA microcapsules have a high lipid digestibility in the small intestine with a high DHA hydrolysis efficiency (74.3%), which is higher than that of commercial DHA microcapsules.
Probiotic delivery system was developed via the use of microbial transglutaminase (MTG) cross-linked soy protein isolate (SPI) incorporated with agrowastes such as banana peel (BE), banana pulp (BU), and pomelo rind (PR). Inoculums of Lactobacillus bulgaricus FTDC 1511 were added to the cross-linked protein matrix. The incorporation of agrowastes had significantly (P<0.05) reduced the strength, pH value, and the lightness of the SPI gel carriers, while sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles revealed that the occurring cross-links within the SPI gel carriers were attributed to the addition of MTG. Scanning electron microscope micrographs illustrated that SPI carriers containing agrowastes have exhibited a less-dense protein matrix. All the SPI carriers possessed maximum swelling ratio at 4 to 4.5 within 15 min in simulated gastric fluid (SGF), whereas the maximum swelling ratios of SPI/BE, SPI/BU, and SPI/PR were higher compared to that of control in simulated intestinal fluid (SIF). Additionally, SPI carriers in SGF medium did not show degradation of structure, whereas a major collapse of network was observed in SIF medium, indicating controlled-release in the intestines. The addition of agrowastes into SPI carriers led to a significantly (P<0.0001) lower release of L. bulgaricus FTDC 1511 in SGF medium and a higher release in SIF medium, compared to that of the control. SPI carriers containing agrowastes may be useful transports for living probiotic cells through the stomach prior to delivery in the lower intestines.
Soy protein isolate (SPI) gels were produced using single cross-linking agents (SCLA) of microbial transglutaminase (MTG) via incubation for 5 or 24 h (SCLA-MTG). When powdered SCLA-MTG gels were heated for 2 h with ribose (R2) (2 g/100 mL), dark brown gels were formed, and these were designated as combined cross-linking agent (CCLA) gels: MTG5(R2) and MTG24(R2). The results showed that the levels of Maillard-derived browning and cross-links of MTG5(R2) and MTG24(R2) gels were significantly (P < 0.05) lower than a control gel produced without MTG (SCLA-R2) even though the percentage of ribose remaining after heating of these gels was similar, indicating that a similar amount of ribose was consumed during heating. epsilon-(gamma-glutamyl)lysine bonds formed during incubation of SPI with MTG may have reduced the free amino group of SPI to take part in the Maillard reaction; nevertheless, ribose took part in the Maillard reaction and initiated the Maillard cross-linkings within the CCLA gels.