Application of membrane-based technology for purification of bromelain

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

FIZIKALNA TERAPIJA U SVJETLU BIOLOŠKE TERAPIJE I TERAPIJE MALIM MOLEKULAMA

Membrane technology has been successfully applied for the purification of bromelain, a protease enzyme from pineapple. However, the current system operates less optimally in terms of flux and separation primarily due to properties of the feed, such as viscosity. Hence, in this study, enzymatic pretreatment and diafiltration operation were employed in a two-stage ultrafiltration (UF) system to enhance the performance of the purification and concentration process of bromelain enzyme from an extract of pineapple crude waste mixture (CWM). Pretreatment of the CWM extract using either pectinase or cellulase, or the combination of both, was applied and compared regarding the apparent viscosity reduction. Diafiltration step was introduced in UF stage 2 and observations on the flux performance, enzyme recovery and enzyme purity were made. A 12% apparent viscosity reduction was achieved when the CWM extract was pretreated with pectinase which led to 37-38% improvement in the flux performance of both UF stages, as well as higher enzyme recovery in UF stage 1. The introduction of diafiltration mode in UF stage 2 managed to sustain high flux values while yielding 4.4-fold enzyme purity (higher than a 2.5-fold purity achieved in our previous work); however, high diluent consumption was needed. The outcomes of this study showed that the flux performance and bromelain separation can be enhanced by reducing the viscosity with the employment of enzymatic pretreatment and diafiltration operation. Thus, both techniques can be potentially applied in a large-scale membrane-based process for bromelain production

Proteolytic profiles and angiotensin-I converting enzyme and α-glucosidase inhibitory activities of selected lactic acid bacteria

This study was conducted to examine the growth, proteolytic profiles as well as angiotensin-I converting enzyme (ACE) and α-glucosidase (α-glu) inhibitory potentials of selected strains of lactic acid bacteria (LAB). Two strains each of yogurt bacteria (Streptococcus thermophilus—1275 and 285, and Lactobacillus delbrueckii ssp. bulgaricus—1092 and 1368), and probiotics (L. acidophilus—4461 and 33200, and L. casei—2607 and 15286, and 1 strain of Bifidobacterium longum 5022), were cultivated in reconstituted skim milk (RSM) at 37◦C and their proteolytic profiles and ACE aswell as α-glu inhibitory activitieswere determined. Among all the strains of lactic acid bacteria studied, yogurt bacteria grew very well, with the exception of L. delbrueckii ssp. bulgaricus 1368 which showed a slower growth during the initial 3 h of incubation. The growth pattern corresponded well with the decrease in pH for the organisms. All the organisms showed an increase in proteolysis with time. The variations in proteolytic capabilities translated into corresponding variations in ACE inhibitory potential of these organisms. Bifidobacterium longum 5022 showed the highest ACE inhibitory potential followed by L. delbrueckii ssp. bulgaricus 1368, L. casei 15286, S. thermophilus 1275, and L. acidophilus 4461. Organisms with high intracellular enzymatic activities grew well. Also, aminopeptidases of strains of L. acidophilus 4461 and S. thermophilus 1275 that could better utilize proline containing substrates showed enhanced ACE inhibitory potential. Lactic acid bacteria possessed the ability to inhibit α-glu activity, which endowed them an antidiabetic property as well

Effect of Addition of Versagel® on Microbial, Chemical, and Physical Properties of Low-fat Yogurt

The objective of this study was to examine the effect of VersagelR® on the growth and proteolytic activity of Streptococcus thermophilus 1275 and Lactobacillus delbrueckii ssp. bulgaricus 1368 and angiotensin-I converting enzyme inhibitory activity of the peptides generated thereby as well as on the physical properties of low-fat yogurt during a storage period of 28 d at 4◦C. Three different types of low-fat yogurts, YV0, YV1, and YV2, were prepared using Versagel as a fat replacer. The fermentation time of the low-fat yogurts containing Versagel was less than that of the control yogurt (YV0). The starter culturesmaintained their viability (8.68 to 8.81 log CFU/g of S. thermophilus and 8.51 to 8.81 log CFU/g of L. delbrueckii ssp. bulgaricus) in all the yogurts throughout the storage period. There was some decrease in the pH of the yogurts during storage and an increase in the concentration of lactic acid. However, the proteolytic and ACE-inhibitory potential of the starter cultures was suppressed in the presence of Versagel. On the other hand, the addition of Versagel had a positive impact on the physical properties of the low-fat yogurt, namely, spontaneous whey separation, firmness, and pseudoplastic properties

Effect of exopolysaccharides on the proteolytic and angiotensin-I converting enzyme-inhibitory activities and textural and rheological properties of low-fat yogurt during refrigerated storage

The aim of this study was to examine the influence of using exopolysaccharide (EPS) producing strain of Streptococcus thermophilus on the viability of yogurt starters, their proteolytic and angiotensin-I converting enzyme-inhibitory activities, and on the textural and rheological properties of the low-fat yogurt during storage at 4°C for 28d. The use of an EPS-producing strain of S. thermophilus did not have influence on pH, lactic acid content, or the angiotensin-I converting enzyme-inhibition activity of low-fat yogurt. However, EPS showed a protective effect on the survival of Lactobacillus delbrueckii ssp. bulgaricus. Presence of EPS reduced the firmness, spontaneous whey separation, yield stress, and hysteresis loop area but not the consistency and flow behavior index of low-fat yogurt

Influence of addition of Raftiline HP® on the growth, proteolytic, ACE- and a-glucosidase inhibitory activities of selected lactic acid bacteria and Bifidobacterium

This study examined the influence of Raftiline HP®, added at the rate of 1, 2 and 3 g 100 mL-1 to reconstituted skim milk, on the growth and biochemical activities of selected strains of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus casei, Lactobacillus acidophilus and Bifidobacterium longum. The growth of B. longum and S. thermophilus was improved in reconstituted skim milk (RSM) containing 1 g 100 mL-1 Raftiline HP®. All the organisms except for S. thermophilus produced more lactic acid and acetic acid in the presence of Raftiline HP® than in the control. L. acidophilus and B. longum showed improvement in the proteolytic capabilities at all the three levels of Raftiline HP® addition. L. delbrueckii ssp. bulgaricus showed maximum percent ACE inhibition in RSM containing 2 g 100 mL-1 Raftiline HP® while B. longum exhibited this potential in RSM containing 3 g 100 mL-1 Raftiline HP®. All organisms, except L. delbrueckii ssp. bulgaricus, however, showed improvement in the α-glucosidase inhibitory activity in RSM containing Raftiline HP®. © 2009 Elsevier Ltd.link_to_subscribed_fulltex

Characterization of functional, biochemical and textural properties of synbiotic low fat yogurts during refrigerated storage

This study examined the influence of exopolysaccharides (EPS) produced in situ on the viability of Streptococcus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus and probiotics, the proteolytic and ACE-inhibitory activities, and textural and rheological properties of inulin-containing probiotic yogurt during refrigerated storage. Two types of yogurt were prepared using strains of S. thermophilus not producing EPS (NEPY) and producing EPS (EPY). The yield of crude EPS increased (by 2.4 times) until day 21 of storage. Presence of EPS showed a protective effect on the survival of L. delbrueckii ssp. bulgaricus and Lactobacillus acidophilus but not on S. thermophilus, Lactobacillus casei and Bifidobacterium longum. No changes in post-acidification, lactic acid content or the ACE-inhibition activity of the two types of yogurt were observed. Overall, EPS containing yogurts exhibited higher proteolysis in the presence of inulin and probiotics (0.698 units) than the corresponding control (0.563 units). The storage and loss moduli (Pa), yield stress (Pa), consistency index (Pa s) and thixotrophic behaviour (Pa s�1) of both samples were similar at day 1 and the influence of EPS was observable only after day 7. Such a variation of the effect of EPS on the textural and rheological properties of low-fat yogurt appears to be partially due to the presence of probiotics

Yogurt Can Beneficially Affect Blood Contributors of Cardiovascular Health Status in Hypertensive Rats

Abstract: Cardiovascular disease is the single leading cause of death in the world and elevated blood pressure is one of the major independent risk factors. Angiotensin-I-converting enzyme-inhibitors have received considerable attention for their effectiveness in both the prevention and the treatment of hypertension. To confirm the antihypertensive effect, the influence of yogurt- and probiotic yogurt-based diets on the weight gain, serum lipid profile, and blood pressure (BP) were investigated in spontaneously hypertensive rats (14 wk old). A total of 3 dietary treatments were fed for 8 wk: skim milk diet (Feed-C), skim milk diet supplemented with freeze dried low fat yogurt (Feed-Y), and with freeze dried low-fat probiotic yogurt (Feed-PY). The total weight gain for the 8-wk period was maximum in rats fed Feed-C (90 g) followed by those fed Feed-PY (85.7 g) and Feed-Y (78.7 g), indicating that the overall weight gains were lesser (statistically non-significant) in the groups fed yogurt containing diets. At the end of the feeding period the reduction in systolic BP of rats fed Feed-Y was 3.7% (–9.5 mm Hg) and 2.7% (–6.4 mm Hg) in those fed Feed-PY while reduction in diastolic BP was 30% (–9.4 mm Hg) and 44% (–13.8 mm Hg), respectively, in comparison to those fed Feed-C. The levels of total cholesterol and low density lipoprotein-cholesterol of rats fed the supplemented diets were lower than those fed Feed-C while no changes in the levels of high density lipoprotein-cholesterol were observed. It was concluded that feeding diets supplemented with yogurts exhibited antihypertensive and hypocholesterolemic effects in spontaneously hypertensive rats