Synergistic effect of the locust bean gum on the thermal phase transitions of κ-carrageenan gels

Synergism between κ-carrageenan and locust bean gum (LBG) was studied using the photon transmission technique. Synergistic effects in these polymeric mixtures strongly affected the physical properties of the gel structure. The transmitted light intensities, I_tr, versus temperature variations were investigated during the gelation and liquefaction processes. Slight synergistic peaks were detected in gel–sol and sol–gel transition temperatures for high κ-carrageenan/LBG ratios (approx. 80/2). Moreover, apparent synergistic peaks were observed in gel–sol and sol–gel transition activation energies for the mixtures approximately with the ratios of 80/10.     

Segregative interactions and competitive binding of Ca in gelling mixtures of whey protein isolate with Naκ-carrageenan

Gelling mixtures of Na⁺κ-carrageenan with whey protein isolate (WPI) at pH 7.0 have been studied rheologically and by differential scanning calorimetry (DSC), with comparative measurements for the individual constituents of the mixtures. The concentration of WPI was held fixed at 10.0 wt% and carrageenan concentration was varied in the range 0.05–3.0 wt%. Ca²⁺ cations, which have been shown previously to be particularly effective in inducing gelation of κ-carrageenan, were introduced as CaCl₂. The concentration of CaCl₂ used in most of the experiments was 8 mM, but other concentrations were also studied. Mixtures were prepared in the solution state at 45 °C, and showed no evidence of either phase separation or complex formation. Rheological changes were monitored by low-amplitude oscillatory measurements of storage modulus, G′, during (i) cooling (1 °C/min) and holding at 5 °C, to induce gelation of the carrageenan in the presence of non-gelled WPI; (ii) heating and holding at 80 °C to dissociate the carrageenan network and induce gelation of WPI; (iii) cooling and holding again at 5 °C, to give composite networks with both components gelled; and (iv) re-heating to 80 °C to dissociate the carrageenan network. Gel structure was characterised further by creep–recovery measurements at the end of each holding period, and by torsion measurements at 5 °C, before and after thermal gelation of WPI.     

Enrichment of β -glucan in Oat Bran by Fine Grinding and Air Classification

Oats contain soluble dietary fiber, a major component of which is β -glucan. Oat bran is an oat dry milling fraction enriched in β -glucan. Our objective was to optimize β -glucan enrichment from oat bran by an inexpensive method. The defatted oat bran was ground 1×9,000, 1×14,000, or 3×14,000 rpm in a pin mill. Analysis of β -glucan for fine and coarse fractions for each milling speed indicated the highestβ -glucan content was obtained in fractions larger than 30 μ m from 3×14,000 rpm. This fraction accounted for 393 g/kg of defatted oat bran, and it contained 188 g/kg β -glucan and 302 g/kg protein. With further fractionation of this fraction by sieving, it was observed that fractions of particle size greater than 90μ m contained 200 g/kg β -glucan and less than 100 g/kg of starch. The enriched β -glucan fraction was obtained in good yield and has commercial potential as a food ingredient or for further processing.     

Stability of α-tocotrienol and α-tocopherol in salami-type sausages and curing brine depending on nitrite and pH

We studied the stability of the valuable vitamer nutrients α-tocotrienol and α-tocopherol and options for their protection in salami-type sausages (blended with α-tocotrienol-rich barley oil) and curing brine. Four different sausage formulations were produced containing nitrite curing salt; nitrite curing salt and ascorbic acid (300 mg/kg); nitrite curing salt and carnosic acid (45 mg/kg); or sodium chloride. Initial vitamer contents (100 mg/kg) did not decrease significantly during ripening and decreased only slightly during storage. Ascorbic acid and carnosic acid were found to be effective in preserving the vitamers in fresh sausages. Freeze-drying of sausages resulted in a significant loss of vitamers (97%), particularly after 14-day storage at room temperature, even in the presence of shielding gases. The vitamer content in the curing brine decreased with decreasing pH in the presence of nitrite. A nitrite concentration of 136 mg/L at pH 4 resulted in significant loss (90%) of the vitamers. Sufficient stability of the vitamers in salami-type sausage and curing brine can be achieved by processing, formulation, and storage conditions.     

Influence of glycerol and sorbitol on thermally induced droplet aggregation in oil-in-water emulsions stabilized by β-lactoglobulin

The influence of polyol cosolvents (glycerol and sorbitol) on the flocculation stability of hydrocarbon oil-in-water emulsions stabilized by a globular protein was examined. Salt (150 mM NaCl) and polyols (0–40 wt%) were added to n-hexadecane oil-in-water emulsions stabilized by β-lactoglobulin (β-Lg, pH 7.0) either before or after isothermal heat treatments (30–90 °C for 20 min). When salt was added to emulsions before heat treatment, appreciable droplet flocculation was observed below the thermal-denaturation temperature of the adsorbed β-Lg (T_m∼70 °C), and more extensive flocculation was observed above T_m. On the other hand, when salt was added after heat treatment, appreciable droplet flocculation still occurred below T_m, but little flocculation was observed above T_m. Addition of cosolvents to the emulsions increased the temperature where extensive droplet flocculation was first observed when they were heated in the presence of salt, which was attributed to their ability to increase T_m and to reduce the droplet collision frequency, with sorbitol being more effective than glycerol. Our results are interpreted in terms of the influence of the cosolvents on protein conformational stability, protein-protein interactions and the physiochemical properties of aqueous solutions. This study has important implications for the formulation and production of protein stabilized oil-in-water emulsions for industrial applications, such as foods, pharmaceuticals and cosmetics.     

Hydrolysis of soybean isoflavone glycosides by a thermostable β-glucosidase from Paecilomycesthermophila

The β-glucosidase from Paecilomyces thermophila J18 was found to be capable of hydrolysing daidzin and genistin in a previous study. This report further evaluated the thermostability and hydrolysis of soybean isoflavone glycosides. The enzyme was found to be very stable at 50 °C, and retained more than 95% of its initial activity after 8 h at 50 °C. It converted isoflavone glycosides, in soybean flour extract and soybean embryo extract, to their aglycones, resulting in more than 93% of hydrolysis of three isoflavone glycosides (namely, daidzin, genistin and glycitin) after 4 h of incubation. Also, addition of the β-glucosidase greatly increased the contents of isoflavone aglycones in the suspended soybean flour and soymilk. The results indicate that the thermostable β-glucosidase may be used to increase the isoflavone aglycones in soy products. This is the first report on the potential application of fungal β-glucosidases for converting isoflavone glycosides to their aglycones in soy products.     

Phase behaviour of oat β-glucan/sodium caseinate mixtures varying in molecular weight

The isothermal phase behaviour at 5 °C of mixtures of sodium caseinate and oat β-glucan isolates varying in molecular weight (MW) was investigated by means of phase diagram construction, rheometry, fluorescence microscopy and electrophoresis. Phase diagrams indicated that the compatibility of the β-glucan/sodium caseinate system increases as β-glucan MW decreases. Images of mixtures taken at various biopolymer concentrations revealed phase separated domains. Results also revealed that at the state of thermodynamic equilibrium, lower MW samples yielded considerable viscosity in the mixture. At equivalent hydrodynamic volume of β-glucan in the mixtures, samples varying in molecular weight exhibited similar flow behaviour. A deviation dependent on the protein concentration was observed for the high MW sample in the concentrated regime due to the size of β-glucan aggregates formed. Results demonstrate that by controlling the structural features of β-glucan in mixtures with sodium caseinate, informed manipulation of rheological properties in these systems can be achieved.     

Structural modification by different pretreatment methods to enhance microwave-assisted extraction of β-carotene from carrots

Since the structure of a material is a key factor influencing the extraction efficiency, any means to modify the structure to enhance extraction is attractive. As limited information is available on the effect of sample pretreatment prior to extraction on the extractability of a bioactive compound, the effects of selected pretreatment methods, i.e., soaking in citric acid, blanching in water as well as in citric acid, on the sample structure and subsequent microwave-assisted extraction (MAE) were investigated; carrots and β-carotene (as well as carotenoids) were selected as the test material and bioactive compound, respectively. A suitable condition to extract β-carotene in terms of the microwave power and extraction time was determined. Comparison between MAE and Soxhlet extraction was also made. At the optimized condition the contents of β-carotene and total carotenoids extractable from carrots blanched in water (29.74 and 58.04 mg/100 g dry basis) and in citric acid (32.08 and 61.62 mg/100 g dry basis) were significantly higher than those from the untreated carrots (23.26 and 51.79 mg/100 g dry basis). The antioxidant activities of the extracts obtained from carrots blanched in water and in citric acid were also higher than that from carrots with no pretreatment. Comparison between MAE and Soxhlet extraction revealed that the extract from MAE contained lower amounts of β-carotene and total carotenoids and exhibited lower antioxidant activity; the required MAE time was significantly shorter, however.     

Improving the rheological and thermal properties of wheat dough by the addition of γ-polyglutamic acid

The rheological and thermal properties of wheat dough with the addition of γ-polyglutamic acid (PGA) (0.5, 1.0, 5.0 g kg⁻¹, w/w) was evaluated by the measurements of farinography, rapid visco analysis and differential scanning calorimetry. Adding 5.0 g kg⁻¹ PGA in wheat dough increased the mixing stability and raised the pasting temperature from 75.8 to 84.4 °C, but decreased the peak viscosity and breakdown. The water holding capacity of wheat dough increased with the addition of 5.0 g kg⁻¹ of PGA. At 5.0 g kg⁻¹ level, PGA caused significant declines in the enthalpy, onset and peak temperatures of ice-melting transition of wheat dough. Scanning electron microscopy showed that wheat bread with the addition of 1.0 and 5.0 g kg⁻¹ PGA exhibited microstructures with smoother surfaces. During storage, PGA retarded the staling process of wheat bread.     

Polyphenol characterization and encapsulation in β-cyclodextrin of a flavonoid-rich Hypericum perforatum (St John's wort) extract

Purified methanolic extracts of Hypericum perforatum (HP) from Northern Greece were very rich in flavonoids. Among simple polyphenols determined by GC-MS, epicatechin, catechin and quercetin predominated, their concentrations being 118.9 ± 20.6, 8.7 ± 1.4 and 5.8 ± 0.8 mg/g extract. LC-MS analysis revealed that the HP extract was mainly consisted of quercetin glucosides, catechin and quercetin. Among anthocyanins, malvidine was present at 1.96 ± 0.2 mg/g. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and the ferric reducing antioxidant power (FRAP) assays showed that the HP extract exerted significant antioxidant activity. The inclusion complex of HP with β-cyclodextrin (β-CD) was prepared by mixing 1:4 mass ratios of its components in aqueous media and subsequent freeze-drying. The encapsulation was verified by differential scanning calorimetry (DSC) and NMR studies, and encapsulation efficiencies were 27.5, 30.0 and 35.0% for catechin, epicatechin and quercetin respectively. DSC after thermal oxidation indicated that the inclusion complex remained intact at temperatures where the free HP extract was oxidized. It is concluded that the encapsulation in β-CD improves the thermal stability of nutraceutical antioxidants present in St John's wort extract, suggesting that the inclusion complex could serve as a flavonoids-rich food supplement or a novel additive to enhance the antioxidant capacity of fresh or thermally processed food.     

A comparative study of analytical methods for alkali-soluble β-glucan in medicinal mushroom, Chaga (Inonotus obliquus)

Crude β-glucan content in the medicinal mushroom Chaga (Inonotus obliquus) was measured by different extraction and analytical methods, and the results were compared. The alkali extraction (AE) method or enzymatic digestion (ED) method followed by a gravimetric analysis was employed to determine the crude β-glucan content. The amount of crude β-glucan in Chaga obtained by either AE or ED was 13.7 g/100 g or 15.3 g/100 g of the sample, respectively. Crude β-glucan content of Chaga obtained by the above preparation methods were corrected by chemical composition analysis and HPLC analysis. After composition analysis, the amounts of β-glucan measured in the 100 g Chaga samples were corrected to 10.1 g for ED and 10.7 g for AE method. β-glucan contents calculated by the amount of glucose in the HPLC analysis were 8.3 g/100 g and 8.1 g/100 g for ED and AE preparation methods, respectively. Although extraction method did not affect β-glucan content in Chaga as indicated by no significant difference (P>0.05) between extraction method, significant differences (P<0.05) were noted between the correction methods. The discrepancies of the result indicate a need for standardization of analytical method for β-glucan measurement in Chaga     

Caudatin attenuates inflammatory reaction by suppressing JNK/AP-1/NF-κB/caspase-1 pathways in activated HMC-1 cells

Food Science and Biotechnology - One of the interfering factors in Coronavirus disease 2019 (COVID-19) is the cytokine storm, which contributes to hyperinflammation. Mast cells cause COVID-19...     

Study by LC/ESI/MS and ESI/HR/MS of SO2 interactions in flavanols–aldehydes nucleophilic reactions

The study concerns the interactions between (+)-catechin and a representative oak wood aldehyde (5-(hydroxymethyl)furfuraldehyde for furanic aldehydes and vanillin for phenolic aldehydes) in a wine-like model solution in presence or not of SO₂. The formed condensation products were characterised by LC/MS, LC/ESI/MSⁿ, and ESI/HR/MS and we studied the effect of SO₂ on these condensation reactions.     

The effect of injectable butaphosphan and cyanocobalamin on postpartum serum β-hydroxybutyrate, calcium, and phosphorus concentrations in dairy cattle

The objective of this study was to determine the effect of an injection of 10% butaphosphan and cyanocobalamin (Catosal, Bayer, Shawnee Mission, KS) on the day of calving and 1 d later on the prevalence of subclinical ketosis in dairy cattle in the early postpartum period. Cows from 4 herds (n = 1,122) were randomized to receive either 25 mL of 10% butaphosphan and cyanocobalamin or 25 mL of sterile water subcutaneously on both days. Each milliliter of Catosal contained 0.05 mg of cyanocobalamin and 100 mg of butaphosphan, which provided 17.3 mg of P in the form of [1-(butylamino)-1-methylethyl]-phosphonic acid. Serum was sampled for β-hydroxybutyrate (BHBA) concentration at calving (pretreatment) and again between 3 and 10 d in milk. A subset of samples from mature cows was also evaluated for serum Ca and P concentrations. When cows from all age groups were included in the analysis, there was no difference between the median serum BHBA concentrations of cows in the 2 treatment groups, and no difference in the proportion of hyperketonemic cows (serum BHBA ≥1,200 μmol/L) during the first week postpartum. When the analysis was restricted to mature cows (lactation ≥3), both the median BHBA concentration and the proportion of hyperketonemic cows were significantly lower in the treatment group than in the placebo group. Serum Ca and P concentrations did not differ between treatment groups. Our results suggest that injection of butaphosphan and cyanocobalamin on the day of calving and 1 d later may decrease the prevalence of subclinical ketosis during the week after calving in mature dairy cows, but not in first- and second-lactation animals.     

Toona sinensis and its major bioactive compound gallic acid inhibit LPS-induced inflammation in nuclear factor-κB transgenic mice as evaluated by in vivo bioluminescence imaging

In the present study, we investigated the anti-inflammatory effects of a nutritious vegetable Toona sinensis (leaf extracts, TS) and its major bioactive compound gallic acid (GA) by analysing LPS-induced NF-κB activation in transgenic mice, using bioluminescence imaging. Mice were challenged intraperitoneally with LPS (1 mg/kg) and treated orally with TS or GA (100 or 5 mg/kg, respectively). In vivo and ex vivo imaging showed that LPS increased NF-κB luminescence in the abdominal region, which was significantly inhibited by TS or GA. Immunohistochemical and ELISA analyses confirmed that TS and GA inhibited LPS-induced NF-κB, interleukin-1β, and tumour necrosis factor-α expression. Microarray analysis revealed that biological pathways associated with metabolism and the immune responses were affected by TS or GA. Particularly, LPS-induced thioredoxin-like 4B (TXNL4B) 2 expression in the small intestine, and TXNL4B, iNOS, and COX-2 expression in RAW 264.7 cells were significantly inhibited by TS or GA. Thus, the anti-inflammatory potential of TS was mediated by the downregulation of NF-κB pathway.     

Pregnancy outcomes after change in dose delivery of prostaglandin F2α and time of gonadotropin-releasing hormone injection in a 5-day timed artificial insemination program in lactating dairy cows

We demonstrated that 50 mg of PGF_2α on d 6 successfully induced luteolysis in lactating dairy cows enrolled in a traditional 5-d Ovsynch-72 program [GnRH injection 5 d before (d 0; GnRH-1) and 56 (p.m. on d 7; GnRH-2) or 72 h (d 8; GnRH-2) after a 25-mg injection of PGF_2α (d 5 and 6 after GnRH injection); timed artificial insemination (AI) on d 8]. Our current objective was to determine pregnancy outcomes in lactating dairy cows after a 50-mg injection of PGF_2α on d 6 or a 25-mg injection of PGF_2α on d 5 and 6 in a 5-d Ovsynch program. Cows in herd 1 diagnosed not pregnant between 30 and 36 d since last AI were enrolled to receive either a 50-mg injection of PGF_2α on d 6 (1 × 50; n = 134) or a 25-mg injection of PGF_2α on d 5 and 6 (2 × 25; n = 139) after GnRH-1 (d 0), with GnRH-2 at 72 h after PGF_2α injection (d 5), concurrent with timed AI (d 8). Cows in herd 2 diagnosed not pregnant between 34 and 40 d were treated similarly: even-tagged cows received the 2 × 25 (n = 422) treatment, and odd-tagged cows received the 1 × 50 (n = 450) treatment, except that GnRH-2 was administered at 56 h. Blood collected from cows in herd 1 at d 0, 5, 6, and 8 was assayed for progesterone. Luteolysis was defined to occur when progesterone concentration was ≥1 ng/mL on d 5, and 72 h later (d 8) was either <0.5 ng/mL or <1 ng/mL. Progesterone concentrations did not differ between treatments on pretreatment d 0 and 5, but were greater in 1 × 50 than 2 × 25 cows on d 6 (4.7 ± 0.2 vs. 1.1 ± 0.2 ng/mL) and d 8 (0.43 ± 0.04 vs. 0.19 ± 0.04 ng/mL), respectively. Luteolysis was greater in the 2 × 25 versus 1 × 50 treatment when the cut point was 0.5 ng/mL, whereas no difference was detected when the cut point was <1 ng/mL on d 8. Lack of complete luteolysis was greater in cows classified as early cycle on d 0 or having a new corpus luteum after d 0 because progesterone concentration was greater on d 5 and 6 than for cows classified as late cycle on d 0 or cows having low progesterone on d 0 and 5. Pregnancy per AI at 30 to 40 d did not differ between 2 × 25 and 1 × 50 cows having luteolysis by d 8 or in all cows (37.2 vs. 33.3%) in herd 1, respectively, but differed in herd 2 (24.7 vs. 19.5%; no treatment by herd interaction). We conclude that incomplete luteolysis by d 8 was greater in 1 × 50 cows using a cut point of <0.5 ng/mL at AI. The difference in pregnancy outcome in herd 2 may have resulted from insufficient time for complete luteolysis before GnRH-2 at 56 h compared with GnRH-2 at 72 h (at AI) in herd 1.     

Modulation of the bovine innate immune response by production of 1α,25-dihydroxyvitamin D3 in bovine monocytes

In cattle, the kidney has been the only known site for production of 1,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃] from 25-hydroxyvitamin D₃ [25(OH)D₃] by 1α-hydroxylase (1α-OHase). Based on human studies, it was hypothesized that bovine monocytes could produce 1,25(OH)₂D₃ upon activation and 1,25(OH)₂D₃ would regulate expression of vitamin D-responsive genes in monocytes. First, the effects of 1,25(OH)₂D₃ on bovine monocytes isolated from peripheral blood were tested. Treatment of nonstimulated monocytes with 1,25(OH)₂D₃ increased expression of the gene for the vitamin D 24-hydroxylase (24-OHase) enzyme by 51 ± 13 fold, but 1,25(OH)₂D₃ induction of 24-OHase expression was blocked by lipopolysaccharide (LPS) stimulation. In addition, 1,25(OH)₂D₃ increased the gene expression of inducible nitric oxide synthase and the chemokine RANTES (regulated upon activation, normal T-cell expressed and secreted) in LPS-stimulated monocytes 69 ± 13 and 40 ± 12 fold, respectively. Next, the ability of bovine monocytes to express 1α-OHase and produce 1,25(OH)₂D₃ was tested. Activation of monocytes with LPS, tripalmitoylated lipopeptide (Pam3CSK4), or peptidoglycan caused 43 ± 9, 17 ± 3, and 19 ± 3 fold increases in 1α-OHase gene expression, respectively. Addition of 25(OH)D₃ to LPS-stimulated monocytes enhanced expression of inducible nitric oxide synthase and RANTES and nitric oxide production in a dose-dependent manner, giving evidence that activated monocytes convert 25(OH)D₃ to 1,25(OH)₂D₃. In conclusion, bovine monocytes produce 1,25(OH)₂D₃ in response to toll-like receptor signaling, and 1,25(OH)₂D₃ production in monocytes increased the expression of genes involved in the innate immune system. Vitamin D status of cattle might be important for optimal innate immune function because 1,25(OH)₂D₃ production in activated monocytes and subsequent upregulation of inducible nitric oxide synthase and RANTES expression was dependent on 25(OH)D₃ availability.