•A two-stage ceramic ultrafiltration process was proposed to purify bromelain from pineapple waste.•The UF process managed to achieve 96.8% enzyme recovery in stage.•Bromelain purity increased up to ...2.5-fold in stage 2.•Adjusting feed pH to 7.0 at room temperature enhanced flux and enzyme recovery.
Membrane technology is an attractive technique for purification of bromelain enzyme from pineapple. In this study, the feasibility of bromelain purification from pineapple's crude waste mixture (CWM) extract was investigated using a two-stage ceramic ultrafiltration (UF) scheme involving 75kDa and followed by 10kDa tubular ceramic membranes. Both UF stages were performed at specific processing conditions and determination on the permeate flux values and the extract properties of each UF stage were conducted. Observations were also employed at different feed pH and processing temperatures in both UF stages for processing optimization. Results showed the proposed technique managed to retain 96.8% enzyme recovery in the UF stage 1 and increase the bromelain purity up to 2.5-fold, which is within the targeted purity requirement, in the UF stage 2. The permeate flux values for UF stages 1 and 2 were 11.6 and 6.2kg/m2h, respectively. Higher VRF of the process in UF stage 2 leads to higher enzyme purity, thus the process can be adjusted depending on the enzyme final applications. For a better flux behaviour of the process and preservation of the bromelain enzyme during the process, this study suggests to adjust the feed pH to 7.0 and performing the process at room temperature (∼20°C).
The metabolic activities of
Lactobacillus acidophilus (LAFTI
® L10 and La4962)
Bifidobacterium (
lactis LAFTI
® B94 and
longum Bl536),
Lactobacillus casei (LAFTI
® L26 and Lc279),
Lactobacillus ...delbrueckii ssp.
bulgaricus Lb1466 and
Streptococuss thermophilus St1342 were assessed in soymilk. Strains were initially analyzed for α-galactosidase activity and organic acid production in MRS broth at 37
°C. Consequently, soymilk was fermented with each strain and cell growth, production of organic acid, metabolism of oligosaccharides and proteolytic and ACE-inhibitory activities were assessed during 48
h of incubation at 42
°C. All strains exhibited variable α-galactosidase activity, with
Bifidobacterium lactis B94 showing the highest activity. The oligosaccharide metabolism depended on α-galactosidase activity.
B. lactis B94,
S. thermophilus St1342 and
L. acidophilus La4962 reduced raffinose substantially by 77.4%, 64.5% and 55.9%, respectively. All strains reached the desired therapeutic level of 10
8
cfu/ml in soymilk after 48
h at 42
°C. The hydrolysis of protein in soymilk likely depended on strain (
P
<
0.0001) and time (
P
<
0.0001). The strains also released bioactive peptides with ACE-inhibitory activities between 17% and 43%.
The study examined chemical composition and rheological and sensory properties of probiotic soy yogurt during 28 day storage at 4 °C. Soymilk supplemented with 2% (w/v) inulin or 1% (w/v) each of ...raffinose and glucose was used as a base for soy yogurt manufacture. Viability of probiotic organisms and their metabolic activity measured as production of organic acids and aldehyde content responsible for beany flavor, as well as rheological and sensory properties of soy yogurt, were examined. Inulin or raffinose/glucose supplementation in soymilk increased the bacterial population by one log cycle and the amount of lactic acid. Probiotic bacteria metabolized more aldehyde than yogurt culture and substantially reduced the beaniness in soy yogurt as determined by sensory evaluation. The probiotic soy yogurts showed more viscous and pseudoplastic properties than the control soy yogurts, but the sensory evaluation results showed preference for the control soy yogurts which were slightly less viscous. Control soy yogurt provided better mouth feel than probiotic soy yogurts.
As a major cause of death, cancer has affected the world population, both directly and indirectly. There are however, growing numbers of cancer cases some of which could be prevented or even treated ...using natural compounds. Bioactive peptides from terrestrial and marine environment have been claimed to potentially reduce the risk of chronic diseases or maintain health. Fish processing industry produces more than 50% by-products which can be converted into valuable fish protein hydrolysate (FPH) by chemical or biochemical hydrolysis. This paper discusses the potency of fish by-products as sources of bioactive peptides with anticarcinogenic potential. Moreover, a short review about the antioxidant and anticancer activities of novel bioactive peptides isolated from fish by-products is presented.
Immuno-modulatory effects of seventeen lactic acid bacteria (LAB) and probiotic strains were assessed following stimulation with peripheral blood mononuclear cells. Pro- and anti-inflammatory ...cytokines including interleukin (IL)-2, IL-4, IL-10, IL-12 p70, interferon (IFN)-γ, tumor necrosis factor (TNF)-α and transforming growth factor (TGF)-β measured at different time points shows that all strains stimulated significant cytokines in varying concentrations and strain specific manner. Overall, TNF-α, IFN-γ, IL-10 and TGF-β were stimulated at high concentrations where Lactobacillus casei 290 and Streptococcus thermophilus M5 stimulated TNF-α and IFN-γ and Bifidobacterium strains stimulated maximum levels of IL-10 and TGF-β respectively. A significant increase in CD3+CD4+CD25+ and Treg population was observed where S. thermophilus M5 and 1342, B. animalis subsp. lactis BB12 and L. casei 290 showed seven-fold increase in FoxP3 expression. The study suggests that LAB and probiotics strains differ in their immuno-modulatory responses and functions, which necessitates their careful selection and characterization before applications.
► Proteolytic activity of studied enzymes was species dependent. ► Silver trevally demonstrated the highest calpain-like activity. ► Barracouta exhibited the highest endogenous activity of cathepsins ...B, D, H, and L. ► Cathepsins B and B+L activities were higher than cathepsin H in studied species.
The hydrolytic activity of major endogenous proteases, responsible for proteolysis of myofibrillar proteins during post-mortem storage, may be an indicator of the textural quality of fish which influences consumer purchasing behaviour and thus market value of the final product. Furthermore, it may also influence the type and bioactive properties of the peptides released during post-mortem proteolysis of myofibrillar proteins. This study compared the activities of cathepsins B, B+L, D, H and calpain-like enzymes in crude muscle extracted from 16 Australian underutilized fish species. Fish species had a significant effect on the activity of these enzymes with barracouta showing the highest cathepsins B, B+L, D and H activities. Activities of cathepsins B and B+L were higher than cathepsin H for all studied species. The more commercially important rock ling and tiger flathead demonstrated higher cathepsin B+L activity, whereas gemfish and eastern school whiting showed higher activity towards cathepsin B. Underutilized fish species showing higher endogenous protease activities may be suitable for fish sauce production, whereas those with lower protease activities for surimi processing.
Short-chain fatty acids (SCFAs) acetate, propionate, butyrate and lactate were determined in 12 % reconstituted skim milk (RSM) and RSM supplemented with inulin (RSMI). The fermentation was performed ...with
Bifidobacterium animalis
subsp.
lactis
(BB 12) and
Lactobacillus rhamnosus
LGG ATCC 53013. Fermentation culture activities produced substantial amounts of SCFAs, which were detected and quantitated using a HPLC-UV technique. Using HPLC-UV, we were able to detect low concentrations of lactate and SCFAs from fermented samples; lactate, acetate, propionate and butyrate were detected at 10.10, 12.06, 14.80 and 18.06 μg/mL, respectively. The retention time of all SCFAs and lactic acid were similar to the standard quality control (±0.05), and average recovery ranged between 89.73 and 91.03 %. The experimental conditions and sample preparation were applied to preparative HPLC to isolate and purify SCFAs with concentration range between 0.09 and 2.86 mg/mL. The purity of extracted SCFAs was confirmed using atmospheric pressure chemical ionization/mass spectrometry by determining the molecular masses of target purified compounds. The scaled up validated analytical HPLC-UV method will further enhance and improve the use of this approach to produce purified large-scale SCFAs.
About 60% of world's commercial enzyme products are proteases, giving promising opportunity to derive such enzymes sustainably from waste sources. Bromelain is a crude protease occurring naturally in ...pineapple, and it possesses properties of benefit for pharmaceutical, medical and food products. The production of bromelain involves a purification stage, normally performed by small-scale conventional operations which lead to high operating cost and low product recovery, while being difficult to scale up and produce polluting by-products. Membrane-based technology offers an alternative to produce high quality purified bromelain in a more efficient and sustainable process. This review identified the current state and future needs for utilising membrane processes for sustainable bromelain production at larger scales. It was found that declining membrane flux due to fouling have been reported, but may be effectively overcome with more appropriate (and advanced) membrane types and/or processing conditions. For example, interactions between macromolecules present in the pineapple derived bromelain mixture (particularly polysaccharides) and the membrane may cause performance limiting fouling, but can be overcome by enzymatic pre-treatment. Membrane fouling can be further reduced by the employment of ceramic membrane filters operating at optimised trans-membrane pressure, cross-flow velocity, feed pH and temperature. Two-stage ultrafiltration together with diafiltration or gas sparging was suggested as a means to reduce fouling and improve enzyme purity. Despite these promising technical findings, the review identified the need for a valid economic assessment to properly guide further work towards purifying bromelain from pineapple waste for sustainable production of commercial proteases.
The effect of change in pH at drainage (6.2, 5.9 and 5.6), rennet concentration (0.1 and 0.3) and casein to fat ratio (C/F) 0.60, 0.70 and 0.80) on texture and microstructure of salt-reduced Cheddar ...cheese was investigated. Cheeses with these treatments were prepared and analyzed for composition, texture profile and microstructure. At the same drainage pH, cheeses made with C/F ratio 0.6 had lower (P < 0.05) dry matter and protein content whereas, fat and ash % in dry matter were higher (P < 0.05) compared with at 0.7 and 0.8. The pH decreased significantly (P < 0.05) from day 0 to day 120 and then stabilized thereafter. In general, hardness of all cheeses increased from day 0 to day 60 of storage and then gradually decreased by the end of ripening (180 days). Cohesiveness showed an opposite trend to hardness. Adhesiveness significantly decreased during the storage period. Microstructure of cheese became denser, more compact and homogenous with small gaps at the end of storage (day 180) due to presence of peptides resulting from ripened cheese filling the matrix cavity.
