ABSTRACT The Nitrogen solubility, turbidity, emulsion and foaming properties, and the heat stabil... more ABSTRACT The Nitrogen solubility, turbidity, emulsion and foaming properties, and the heat stability of a brewers' spent grain protein-enriched isolate (BSG-PI) was studied between pH 2.0-12.0. The effect of enzymatic hydrolysis using Alcalase, Corolase PP, Flavourzyme and Promod 144MG on these properties was also determined. BSG-PI demonstrated low solubility below pH 6.0, however, hydrolysis with all enzymes significantly increased BSG-PI solubility between pH 2.0-12.0. Flavourzyme, Corolase PP and Promod 144MG hydrolysates displayed an improved emulsion activity index (EAI) with an EAI of 466.69 m2 g À1 obtained for the Flavourzyme hydrolysates at pH 9.0. Improved foam expansion (FE) was observed above pH 9.0 in all samples while hydrolysis significantly reduced foam drainage stability (FS) of BSG-PI. BSG-PI was highly heat stable at 140 C above pH 6.0 even after >300 min heating. Hydrolysis of BSG-PI resulted in increased turbidity when aqueous suspensions were stored overnight at 4 or 20 C. The results demonstrate the potential of the alkaline extracted BSG-PI and its associated hydrolysates as a cereal derived source of technofunctional ingredients for the food industry.
International journal of food sciences and nutrition, Jan 11, 2015
Bioactivity of a snack-bar, chocolate-drink and yogurt fortified with brewers' spent grain (B... more Bioactivity of a snack-bar, chocolate-drink and yogurt fortified with brewers' spent grain (BSG) phenolic extracts (P2 or B2) or protein hydrolysates (barley protein hydrolysate (BPH), BPH < 3 kDa, BPH < 5 kDa, BPH > 5 kDa) was measured following gastrointestinal in vitro digestion. Concentrations of 0.5 and 0.1% (v/v) digestates were chosen for addition to Caco-2 and Jurkat T cells, respectively. Yogurt and B2 digestate protected against H2O2-induced DNA damage in Caco-2 cells (p < 0.05), by the comet assay. Snack-bar digestates possessed significant (p < 0.05) immunomodulatory effects, measured by ELISA in concanavalin-A stimulated Jurkat T cells. Addition of BPH enhanced (p < 0.05) the IFN-γ reducing capacity of the snack-bar while addition of BPH < 3 and < 5 kDa reduced IL-2 production to a greater extent than unfortified yogurt (p < 0.05). Selected BSG components can enhance the antioxidant and anti-inflammatory potential of foods.
Journal of the Science of Food and Agriculture, 2013
Large quantities of brewers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;a... more Large quantities of brewers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; spent grain (BSG), a co-product of the brewing industry, are produced annually. BSG contains hydroxycinnamic acids, and phenolic-rich extracts from BSG have previously demonstrated the ability to protect against oxidant-induced DNA damage. The present study investigated the anti-inflammatory potential of eight phenolic extracts from BSG: four pale (P1-P4) and four black (B1-B4) extracts. BSG extracts were more cytotoxic in Jurkat T than U937 cells, with lower IC₅₀ values in Jurkat T cells, measured using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Pale BSG extracts P2 and P3 showed the greatest anti-inflammatory potential, significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) reducing interleukin-2 (IL-2), interleukin-4 (IL-4, P2 only), interleukin-10 (IL-10) and interferon-γ (IFN-γ) production. In addition, extracts P1-P3 and B2-B4 showed significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) antioxidant effects, determined by the cellular antioxidant activity assays superoxide dismutase, catalase and glutathione content (GSH). Phenolic extracts from BSG, particularly the pale BSG extracts, have the ability to reduce a stimulated cytokine production and may also protect against cellular oxidative stress. Results of the present study highlight the potential of BSG phenolic extracts to act as functional food ingredients, providing an alternative use and improving the value of this brewing industry co-product.
International Journal of Food Science & Technology, 2014
ABSTRACT Two types of brewers&#39; spent grain (BSG), pale and black, were studied employing ... more ABSTRACT Two types of brewers&#39; spent grain (BSG), pale and black, were studied employing ultrafiltration (UF cut-off, 10 kDa) to obtain high-molecular-weight (HMW) and low-molecular-weight (LMW) phenolic fractions from one pale (P2) and one black (B2) BSG extracts. Of the four UF fractions obtained, the HMW B2 fraction had highest level of polyphenols (5.73 ± 0.25 mg GAE g−1 BSG dw) and protein (18.82 ± 0.41 mg protein g−1 BSG dw). Metal-chelating ability and antioxidative properties were also identified. Antioxidant activity evaluated using the DPPH and FRAP assays, indicated that activity in B2 extracts was associated mainly with the HMW fraction (3.10 ± 0.10 and 2.49 ± 0.09 TE g−1 BSG dw, respectively), whereas in P2 samples, antioxidant activity was highest in LMW fractions (0.58 ± 0.01 and 0.92 ± 0.03 TE g−1 BSG dw, respectively). The high antioxidant activity and metal-chelating ability observed for black BSG extracts may be attributed to the presence of coloured melanoidinic structures.
International Journal of Food Science & Technology, 2013
ABSTRACT Protein-enriched isolates and co-product fractions were obtained from sheared, pale and ... more ABSTRACT Protein-enriched isolates and co-product fractions were obtained from sheared, pale and black brewers&#39; spent grain (BSG) using sequential aqueous and alkaline (110 mM NaOH) extraction, followed by isoelec-tric precipitation at pH 3.8. A recovery of 59% of the original pale BSG protein and 15% of the black BSG protein was obtained for the final isolates. Gel permeation HPLC (GP-HPLC) revealed that 59% of the extracted pale BSG protein and only 6% of black BSG protein had a molecular mass &gt;10 kDa. Glutamine/glutamate and proline were the most abundant amino acids present in both isolates. Analysis of four co-product fractions obtained during fractionation from both pale and black BSG revealed the presence of phenolics, with higher concentrations in the black BSG extracts. These fractions possessed antioxidant and free radical scavenging activity when tested using the ferric reducing ability of plasma (0.16 AE 0.01 to 4.33 AE 0.11 mg Trolox equivalents g À1 BSG dry weight) and diphenylpicrylhydrazyl (12.85 AE 1.16% to 59.50 AE 3.47% DPPH sc) assays, respectively. The protein-enriched isolates and the phenolic-rich extracts may find use as value-added ingredients for incorporation into conventional and functional foods.
ABSTRACT Brewers&#39; spent grain (BSG) is a protein-rich by-product of the brewing industry.... more ABSTRACT Brewers&#39; spent grain (BSG) is a protein-rich by-product of the brewing industry. The present study examined the in vitro bioactivity of a BSG protein enriched preparation and its associated enzymatic hydrolysates (assigned A–J). Cytotoxicity was measured using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT assay in U937 and Jurkat T cells. IC50 values were lower in the U937 cell line, ranging from 4.93 to 9.27% v/v versus a range of 4.11% v/v to undetectable in Jurkat T cells. The superoxide dismutase (SOD) and comet assays were performed on U937 cells pre-incubated with test samples and subsequently exposed to an oxidant. Hydrogen peroxide (H2O2) significantly reduced SOD activity by 37.7% and none of the test samples provided protection. None of the samples protected against DNA damage induced by tert-butylhydroperoxide (t-BOOH); hydrolysate H, prepared with Alcalase at 60 °C, protected against H2O2-induced DNA damage. The total phenolic content (TPC) was found to range from 0.021 to 0.055 mg GAE/mg dry powder. The effect of the BSG-derived test samples on cytokine production (IL-2, IL-4, IL-10, IFN-γ) in Concanavalin A (conA) stimulated Jurkat T cells was measured using an enzyme linked immunosorbent assay (ELISA). The samples had no effect on IL-2 and IL-4 production. The unhydrolysed sample C significantly reduced IL-10, while the protein rich isolate, unhydrolysed control samples and hydrolysates D, E, F, and J significantly reduced IFN-γ production. The BSG preparations possess little antioxidant potential and exhibit selective immunomodulatory effects that may be of benefit in the control of inflammatory diseases.
ABSTRACT The in vitro α-glucosidase, α-amylase, dipeptidyl peptidase IV (DPP-IV) and angiotensin ... more ABSTRACT The in vitro α-glucosidase, α-amylase, dipeptidyl peptidase IV (DPP-IV) and angiotensin converting enzyme (ACE) inhibitory activities of pale brewers’ spent grain protein enriched isolate (BSG-PI) hydrolysates were studied. Eleven commercially available enzyme preparations derived from papaya, porcine pancreas, Aspergillus oryzae and Bacillus licheniformis were used to generate the hydrolysates. The hydrolysates had degree hydrolysis (DH) values ranging from 1.15 to 14.67% and the DH values obtained correlated well with hydrolysate molecular mass distribution profiles. Reverse-phase HPLC analysis of the BSG-PI and its hydrolysates demonstrated considerable variation in peptide composition. While tryptic digests of BSG-PI resulted in the greatest α-glucosidase inhibitory activity, no significant change in α-amylase inhibition was observed with the hydrolysates. Digestion with Corolase PP resulted in the highest DPP-IV inhibition (75 ± 3.06% at 3.5 mg mL- 1) while the Prolyve 1000 hydrolysate displayed highest ACE inhibition (89.25 ± 2.46% at 1 mg mL- 1). The results obtained highlight the potential role of the BSG-PI hydrolysates as functional food ingredients in the management of type II diabetes and hypertension.
The hydroxycinnamic acid (HA) content of starting barley for brewers&amp;amp;amp;amp;amp;amp;... more The hydroxycinnamic acid (HA) content of starting barley for brewers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; spent grains (BSG), whole BSG and phenolic extracts from BSG was measured using high performance liquid chromatography (HPLC) and correlated with antioxidant potential. The effect of BSG phenolic extracts on antioxidant activity of fruit beverages was also assessed (using the total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). The concentration of HA present in barley extract and BSG was in the order of ferulic acid (FA), p-coumaric acid (p-CA) derivatives, FA derivatives, p-CA, caffeic acid (CA) and CA derivatives. Results suggested that brewing and roasting decreased the HA content. Antioxidant activity was significantly (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) correlated with caffeic acid (R(2)=0.8309) and total HA (R(2)=0.3942) concentrations. Addition of extracts to fruit beverages resulted in a significant (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) increase in antioxidant activity of cranberry juice, measured by the FRAP assay. In vitro digestion significantly (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) reduced TPC, DPPH and FRAP activity of the fruit beverages.
The present study investigated the bioactivity of protein hydrolysates and fractionated hydrolysa... more The present study investigated the bioactivity of protein hydrolysates and fractionated hydrolysates prepared from brewers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; spent grain (BSG) using proteases, including Alcalase 2.4L, Flavourzyme and Corolase PP. Hydrolysates were designated K-Y, including fractionated hydrolysates with molecular weight (m.w.) &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 3, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5 and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5 kDa. Where computable, IC50 values were lower in U937 (1.38-9.78%) than Jurkat T cells (1.15-13.82%). Hydrolysates L, Q and R and fractionated hydrolysates of U and W (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5 kDa) significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) protected against hydrogen peroxide (H2O2)-induced reduction of superoxide dismutase (SOD) activity. A fractionated hydrolysate of W (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5 kDa) protected against H2O2-induced DNA damage, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01. Hydrolysates K, N, P, U, U &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 5 kDa, V, V &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 5 kDa, W, W &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 5 kDa significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) reduced a concanavlin-A (con-A) stimulated production of interferon-γ (IFN-γ). In conclusion, BSG protein hydrolysates demonstrate bioactivity in vitro; lower m.w. hydrolysates…
The primary objective of this study was to evaluate the potential of pale and black brewers’ spen... more The primary objective of this study was to evaluate the potential of pale and black brewers’ spent grain (BSG), brewery barley by-products, as starting materials for the generation of protein-enriched isolates (BSG-PI). A second objective was to characterise the resulting BSG-PI in terms of their technoand biofunctional properties. The effect of enzymatic hydrolysis of BSG-PI, using commercially available proteolytic preparations, on the technoand biofunctional properties was also studied. The technofunctional properties studied were Nitrogen solubility, heat stability, viscosity, turbidity, and emulsion and foaming properties. The biofunctional properties studied were α-amylase, α-glucosidase, angiotensin converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibitory activity. The stability of the in vitro biologically active BSG-PI hydrolysates to simulated gastrointestinal digestion (SGID) was determined. In addition, different peptide fractionation techniques were asses...
Brewers' spent grain (BSG) is a protein-rich by-product of the brewing industry. The present ... more Brewers' spent grain (BSG) is a protein-rich by-product of the brewing industry. The present study examined the in vitro bioactivity of a BSG protein enriched preparation and its associated enzymatic hydrolysates (assigned A–J). Cytotoxicity was measured using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT assay in U937 and Jurkat T cells. IC50 values were lower in the U937 cell line, ranging from 4.93 to 9.27% v/v versus a range of 4.11% v/v to undetectable in Jurkat T cells. The superoxide dismutase (SOD) and comet assays were performed on U937 cells pre-incubated with test samples and subsequently exposed to an oxidant. Hydrogen peroxide (H2O2) significantly reduced SOD activity by 37.7% and none of the test samples provided protection. None of the samples protected against DNA damage induced by tert-butylhydroperoxide (t-BOOH); hydrolysate H, prepared with Alcalase at 60 °C, protected against H2O2-induced DNA damage. The total phenolic content (TPC) w...
ABSTRACT The Nitrogen solubility, turbidity, emulsion and foaming properties, and the heat stabil... more ABSTRACT The Nitrogen solubility, turbidity, emulsion and foaming properties, and the heat stability of a brewers&#39; spent grain protein-enriched isolate (BSG-PI) was studied between pH 2.0-12.0. The effect of enzymatic hydrolysis using Alcalase, Corolase PP, Flavourzyme and Promod 144MG on these properties was also determined. BSG-PI demonstrated low solubility below pH 6.0, however, hydrolysis with all enzymes significantly increased BSG-PI solubility between pH 2.0-12.0. Flavourzyme, Corolase PP and Promod 144MG hydrolysates displayed an improved emulsion activity index (EAI) with an EAI of 466.69 m2 g À1 obtained for the Flavourzyme hydrolysates at pH 9.0. Improved foam expansion (FE) was observed above pH 9.0 in all samples while hydrolysis significantly reduced foam drainage stability (FS) of BSG-PI. BSG-PI was highly heat stable at 140 C above pH 6.0 even after &gt;300 min heating. Hydrolysis of BSG-PI resulted in increased turbidity when aqueous suspensions were stored overnight at 4 or 20 C. The results demonstrate the potential of the alkaline extracted BSG-PI and its associated hydrolysates as a cereal derived source of technofunctional ingredients for the food industry.
International journal of food sciences and nutrition, Jan 11, 2015
Bioactivity of a snack-bar, chocolate-drink and yogurt fortified with brewers' spent grain (B... more Bioactivity of a snack-bar, chocolate-drink and yogurt fortified with brewers' spent grain (BSG) phenolic extracts (P2 or B2) or protein hydrolysates (barley protein hydrolysate (BPH), BPH < 3 kDa, BPH < 5 kDa, BPH > 5 kDa) was measured following gastrointestinal in vitro digestion. Concentrations of 0.5 and 0.1% (v/v) digestates were chosen for addition to Caco-2 and Jurkat T cells, respectively. Yogurt and B2 digestate protected against H2O2-induced DNA damage in Caco-2 cells (p < 0.05), by the comet assay. Snack-bar digestates possessed significant (p < 0.05) immunomodulatory effects, measured by ELISA in concanavalin-A stimulated Jurkat T cells. Addition of BPH enhanced (p < 0.05) the IFN-γ reducing capacity of the snack-bar while addition of BPH < 3 and < 5 kDa reduced IL-2 production to a greater extent than unfortified yogurt (p < 0.05). Selected BSG components can enhance the antioxidant and anti-inflammatory potential of foods.
Journal of the Science of Food and Agriculture, 2013
Large quantities of brewers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;a... more Large quantities of brewers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; spent grain (BSG), a co-product of the brewing industry, are produced annually. BSG contains hydroxycinnamic acids, and phenolic-rich extracts from BSG have previously demonstrated the ability to protect against oxidant-induced DNA damage. The present study investigated the anti-inflammatory potential of eight phenolic extracts from BSG: four pale (P1-P4) and four black (B1-B4) extracts. BSG extracts were more cytotoxic in Jurkat T than U937 cells, with lower IC₅₀ values in Jurkat T cells, measured using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Pale BSG extracts P2 and P3 showed the greatest anti-inflammatory potential, significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) reducing interleukin-2 (IL-2), interleukin-4 (IL-4, P2 only), interleukin-10 (IL-10) and interferon-γ (IFN-γ) production. In addition, extracts P1-P3 and B2-B4 showed significant (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) antioxidant effects, determined by the cellular antioxidant activity assays superoxide dismutase, catalase and glutathione content (GSH). Phenolic extracts from BSG, particularly the pale BSG extracts, have the ability to reduce a stimulated cytokine production and may also protect against cellular oxidative stress. Results of the present study highlight the potential of BSG phenolic extracts to act as functional food ingredients, providing an alternative use and improving the value of this brewing industry co-product.
International Journal of Food Science & Technology, 2014
ABSTRACT Two types of brewers&#39; spent grain (BSG), pale and black, were studied employing ... more ABSTRACT Two types of brewers&#39; spent grain (BSG), pale and black, were studied employing ultrafiltration (UF cut-off, 10 kDa) to obtain high-molecular-weight (HMW) and low-molecular-weight (LMW) phenolic fractions from one pale (P2) and one black (B2) BSG extracts. Of the four UF fractions obtained, the HMW B2 fraction had highest level of polyphenols (5.73 ± 0.25 mg GAE g−1 BSG dw) and protein (18.82 ± 0.41 mg protein g−1 BSG dw). Metal-chelating ability and antioxidative properties were also identified. Antioxidant activity evaluated using the DPPH and FRAP assays, indicated that activity in B2 extracts was associated mainly with the HMW fraction (3.10 ± 0.10 and 2.49 ± 0.09 TE g−1 BSG dw, respectively), whereas in P2 samples, antioxidant activity was highest in LMW fractions (0.58 ± 0.01 and 0.92 ± 0.03 TE g−1 BSG dw, respectively). The high antioxidant activity and metal-chelating ability observed for black BSG extracts may be attributed to the presence of coloured melanoidinic structures.
International Journal of Food Science & Technology, 2013
ABSTRACT Protein-enriched isolates and co-product fractions were obtained from sheared, pale and ... more ABSTRACT Protein-enriched isolates and co-product fractions were obtained from sheared, pale and black brewers&#39; spent grain (BSG) using sequential aqueous and alkaline (110 mM NaOH) extraction, followed by isoelec-tric precipitation at pH 3.8. A recovery of 59% of the original pale BSG protein and 15% of the black BSG protein was obtained for the final isolates. Gel permeation HPLC (GP-HPLC) revealed that 59% of the extracted pale BSG protein and only 6% of black BSG protein had a molecular mass &gt;10 kDa. Glutamine/glutamate and proline were the most abundant amino acids present in both isolates. Analysis of four co-product fractions obtained during fractionation from both pale and black BSG revealed the presence of phenolics, with higher concentrations in the black BSG extracts. These fractions possessed antioxidant and free radical scavenging activity when tested using the ferric reducing ability of plasma (0.16 AE 0.01 to 4.33 AE 0.11 mg Trolox equivalents g À1 BSG dry weight) and diphenylpicrylhydrazyl (12.85 AE 1.16% to 59.50 AE 3.47% DPPH sc) assays, respectively. The protein-enriched isolates and the phenolic-rich extracts may find use as value-added ingredients for incorporation into conventional and functional foods.
ABSTRACT Brewers&#39; spent grain (BSG) is a protein-rich by-product of the brewing industry.... more ABSTRACT Brewers&#39; spent grain (BSG) is a protein-rich by-product of the brewing industry. The present study examined the in vitro bioactivity of a BSG protein enriched preparation and its associated enzymatic hydrolysates (assigned A–J). Cytotoxicity was measured using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT assay in U937 and Jurkat T cells. IC50 values were lower in the U937 cell line, ranging from 4.93 to 9.27% v/v versus a range of 4.11% v/v to undetectable in Jurkat T cells. The superoxide dismutase (SOD) and comet assays were performed on U937 cells pre-incubated with test samples and subsequently exposed to an oxidant. Hydrogen peroxide (H2O2) significantly reduced SOD activity by 37.7% and none of the test samples provided protection. None of the samples protected against DNA damage induced by tert-butylhydroperoxide (t-BOOH); hydrolysate H, prepared with Alcalase at 60 °C, protected against H2O2-induced DNA damage. The total phenolic content (TPC) was found to range from 0.021 to 0.055 mg GAE/mg dry powder. The effect of the BSG-derived test samples on cytokine production (IL-2, IL-4, IL-10, IFN-γ) in Concanavalin A (conA) stimulated Jurkat T cells was measured using an enzyme linked immunosorbent assay (ELISA). The samples had no effect on IL-2 and IL-4 production. The unhydrolysed sample C significantly reduced IL-10, while the protein rich isolate, unhydrolysed control samples and hydrolysates D, E, F, and J significantly reduced IFN-γ production. The BSG preparations possess little antioxidant potential and exhibit selective immunomodulatory effects that may be of benefit in the control of inflammatory diseases.
ABSTRACT The in vitro α-glucosidase, α-amylase, dipeptidyl peptidase IV (DPP-IV) and angiotensin ... more ABSTRACT The in vitro α-glucosidase, α-amylase, dipeptidyl peptidase IV (DPP-IV) and angiotensin converting enzyme (ACE) inhibitory activities of pale brewers’ spent grain protein enriched isolate (BSG-PI) hydrolysates were studied. Eleven commercially available enzyme preparations derived from papaya, porcine pancreas, Aspergillus oryzae and Bacillus licheniformis were used to generate the hydrolysates. The hydrolysates had degree hydrolysis (DH) values ranging from 1.15 to 14.67% and the DH values obtained correlated well with hydrolysate molecular mass distribution profiles. Reverse-phase HPLC analysis of the BSG-PI and its hydrolysates demonstrated considerable variation in peptide composition. While tryptic digests of BSG-PI resulted in the greatest α-glucosidase inhibitory activity, no significant change in α-amylase inhibition was observed with the hydrolysates. Digestion with Corolase PP resulted in the highest DPP-IV inhibition (75 ± 3.06% at 3.5 mg mL- 1) while the Prolyve 1000 hydrolysate displayed highest ACE inhibition (89.25 ± 2.46% at 1 mg mL- 1). The results obtained highlight the potential role of the BSG-PI hydrolysates as functional food ingredients in the management of type II diabetes and hypertension.
The hydroxycinnamic acid (HA) content of starting barley for brewers&amp;amp;amp;amp;amp;amp;... more The hydroxycinnamic acid (HA) content of starting barley for brewers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; spent grains (BSG), whole BSG and phenolic extracts from BSG was measured using high performance liquid chromatography (HPLC) and correlated with antioxidant potential. The effect of BSG phenolic extracts on antioxidant activity of fruit beverages was also assessed (using the total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays). The concentration of HA present in barley extract and BSG was in the order of ferulic acid (FA), p-coumaric acid (p-CA) derivatives, FA derivatives, p-CA, caffeic acid (CA) and CA derivatives. Results suggested that brewing and roasting decreased the HA content. Antioxidant activity was significantly (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) correlated with caffeic acid (R(2)=0.8309) and total HA (R(2)=0.3942) concentrations. Addition of extracts to fruit beverages resulted in a significant (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) increase in antioxidant activity of cranberry juice, measured by the FRAP assay. In vitro digestion significantly (P&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05) reduced TPC, DPPH and FRAP activity of the fruit beverages.
The present study investigated the bioactivity of protein hydrolysates and fractionated hydrolysa... more The present study investigated the bioactivity of protein hydrolysates and fractionated hydrolysates prepared from brewers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; spent grain (BSG) using proteases, including Alcalase 2.4L, Flavourzyme and Corolase PP. Hydrolysates were designated K-Y, including fractionated hydrolysates with molecular weight (m.w.) &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 3, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5 and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5 kDa. Where computable, IC50 values were lower in U937 (1.38-9.78%) than Jurkat T cells (1.15-13.82%). Hydrolysates L, Q and R and fractionated hydrolysates of U and W (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;3, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5, &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;5 kDa) significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01) protected against hydrogen peroxide (H2O2)-induced reduction of superoxide dismutase (SOD) activity. A fractionated hydrolysate of W (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;5 kDa) protected against H2O2-induced DNA damage, P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.01. Hydrolysates K, N, P, U, U &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 5 kDa, V, V &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 5 kDa, W, W &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt; 5 kDa significantly (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05) reduced a concanavlin-A (con-A) stimulated production of interferon-γ (IFN-γ). In conclusion, BSG protein hydrolysates demonstrate bioactivity in vitro; lower m.w. hydrolysates…
The primary objective of this study was to evaluate the potential of pale and black brewers’ spen... more The primary objective of this study was to evaluate the potential of pale and black brewers’ spent grain (BSG), brewery barley by-products, as starting materials for the generation of protein-enriched isolates (BSG-PI). A second objective was to characterise the resulting BSG-PI in terms of their technoand biofunctional properties. The effect of enzymatic hydrolysis of BSG-PI, using commercially available proteolytic preparations, on the technoand biofunctional properties was also studied. The technofunctional properties studied were Nitrogen solubility, heat stability, viscosity, turbidity, and emulsion and foaming properties. The biofunctional properties studied were α-amylase, α-glucosidase, angiotensin converting enzyme (ACE) and dipeptidyl peptidase IV (DPP-IV) inhibitory activity. The stability of the in vitro biologically active BSG-PI hydrolysates to simulated gastrointestinal digestion (SGID) was determined. In addition, different peptide fractionation techniques were asses...
Brewers' spent grain (BSG) is a protein-rich by-product of the brewing industry. The present ... more Brewers' spent grain (BSG) is a protein-rich by-product of the brewing industry. The present study examined the in vitro bioactivity of a BSG protein enriched preparation and its associated enzymatic hydrolysates (assigned A–J). Cytotoxicity was measured using the (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) MTT assay in U937 and Jurkat T cells. IC50 values were lower in the U937 cell line, ranging from 4.93 to 9.27% v/v versus a range of 4.11% v/v to undetectable in Jurkat T cells. The superoxide dismutase (SOD) and comet assays were performed on U937 cells pre-incubated with test samples and subsequently exposed to an oxidant. Hydrogen peroxide (H2O2) significantly reduced SOD activity by 37.7% and none of the test samples provided protection. None of the samples protected against DNA damage induced by tert-butylhydroperoxide (t-BOOH); hydrolysate H, prepared with Alcalase at 60 °C, protected against H2O2-induced DNA damage. The total phenolic content (TPC) w...
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