Angiotensin‐converting enzyme‐inhibitory and antithrombotic activities of soluble peptide extracts from buffalo and cow milk Cheddar cheeses

The aim of the study was to evaluate potential role of a water‐soluble peptide (WSP) extracts derived from buffalo and cow milk Cheddar cheeses with special reference to their antihypertension and antithrombotic activities. The WSP fractions collected at different stages of ripening were tested to assess their degree of proteolysis, their peptides were profiled by RP‐HPLC and in vitro assays for potential bioactivity were conducted. The peptide peak development was observed with slight differences in peaks number, area and height. Both angiotensin‐converting enzyme‐inhibitory and antithrombotic activities increased progressively during ripening. In comparison, the highest activities were observed in peptide extracts obtained from buffalo milk Cheddar cheese, in a dose‐dependent fashion.     

Identification of antioxidant and ACE‐inhibitory peptides in fermented milk

The angiotensin‐converting enzyme (ACE)‐inhibitory activity and antioxidant properties of a commercial fermented milk from Europe were evaluated. This dairy product showed moderate ACE‐inhibitory activity and ABTS^?+ radical‐scavenging capacity. The peptides from most active fractions collected by reverse phase high‐performance liquid chromatography (RP‐HPLC) were sequenced by RP‐HPLC–tandem mass spectrometry. This technique allowed rapid identification of peptides included in the most active fractions, and various potentially active peptides were recognised according to previous studies of structure–activity relationship. Three of the identified sequences had previously been described as potent ACE inhibitors. The structure of some sequences substantiated the presence of peptides with ACE‐inhibitory, antioxidant and immunomodulatory activities. Copyright © 2005 Society of Chemical Industry     

The impact of fermentation and in vitro digestion on formation angiotensin converting enzyme (ACE) inhibitory peptides from pea proteins

Pea seeds were fermented by Lactobacillus plantarum 299v in monoculture under different time and temperature conditions and the fermented products were digested in vitro under gastrointestinal conditions. After fermentation and digestion ACE inhibitory activity was determined. In all samples after fermentation no ACE inhibitory activity was noted. Potentially antihypertensive peptides were released during in vitro digestion. The highest DH (68.62%) were noted for control sample, although the lowest IC₅₀ value (0.19 mg/ml) was determined for product after 7 days fermentation at 22 °C. The hydrolysate characterised by the highest ACE inhibitory activity was separated on Sephadex G10 and two peptides fractions were obtained. The highest ACE inhibitory activity (IC₅₀ = 64.04 μg/ml) for the first fraction was noted. This fraction was separated by HPLC and identified by LC–MS/MS and the sequence of peptide derived from pea proteins was determined as KEDDEEEEQGEEE.     

Angiotensin I‐converting enzyme inhibitory peptides in skim milk fermented with Lactobacillus helveticus 130B4 from camel milk in Inner Mongolia,China

BACKGROUND: Angiotensin I‐converting enzyme (ACE) is a dipeptidyl carboxypeptidase associated with the regulation of blood pressure. ACE inhibition results in a lowering of blood pressure. Lactic acid bacteria are known to produce ACE inhibitors during fermentation. Fermented camel milk is the main traditionally fermented dairy food for desert nomads. The beneficial effects of fermented camel milk, which include the prevention of such diseases and conditions as gastroenteritis, tuberculosis and hypertension, have been demonstrated experimentally. RESULTS: ACE inhibitory activity was observed in fermented milk containing Lactobacillus helveticus 130B4, a strain isolated from traditionally fermented camel milk. The peptide that inhibited ACE was purified from the fermented milk by reverse‐phase high‐performance liquid chromatography. The amino acid sequence of the peptide was identified as Ala‐Ile‐Pro‐Pro‐Lys‐Lys‐Asn‐Gln‐Asp (IC₅₀ = 19.9 µmol L^?1). The same Ala‐Ile‐Pro‐Pro‐Lys‐Lys‐Asn‐Gln‐Asp sequence was found in κ‐casein (κ‐CN) f107–115 from milk. The inhibitory activity of this nonapeptide (κ‐CN f107–115) was almost preserved even after successive digestion with pepsin, trypsin and chymotrypsin. Furthermore, the inhibitory activity of the purified peptide was completely preserved after heat treatment at 100 °C for 20 min. CONCLUSION: The fermented milk prepared with Lactobacillus helveticus 130B4 contained an ACE inhibitory peptide, κ‐CN 107–115. This fermented milk was expected to have anti‐hypertensive effect after ingestion because the peptide was stable to digestive protease and heat treatment in vitro. Copyright © 2008 Society of Chemical Industry     

乳酸菌发酵乳血管紧张素转化酶抑制活力的比较研究

以18种共计61株乳酸菌为研究对象,比较了乳酸菌发酵脱脂乳的血管紧张素转化酶抑制活力(ACE抑制活力),并探讨了ACE抑制活力与pH值、滴定酸度、蛋白水解度的关系。结果表明,乳杆菌ACE抑制活力最强,双歧杆菌次之,链球菌、乳球菌、明串珠菌和片球菌ACE抑制活力很低。ACE抑制活力最高的是Lacto- bacillus helveticus 6024,发酵28 h后ACEI%可达到80%以上,其OPA指数可达到0.800以上,而球菌的ACE抑制活力和蛋白水解能力都很低,甚至检测不到。乳酸菌产酸能力做为一个单一因素与ACE抑制率没有明显相关性(Spearman相关系数r_3=0.526),乳酸菌的蛋白水解能力与ACE抑制率具有显著的正相关性(Spearman相关系数r_3=0.938)。通过对2株产ACE抑制活力高的L.helveticus 6024和L.helveticus T16的研究发现,其共同特点是产酸能力和蛋白水解能力都很强。     

Effects of fermentation conditions on the potential anti‐hypertensive peptides released from yogurt fermented by Lactobacillus helveticus and Flavourzyme®

This study investigates the effects of fermentation conditions on the production of angiotensin‐converting enzyme inhibitory (ACE‐I) peptides in yogurt by Lactobacillus helveticus 881315 (L. helveticus) in the presence or absence of Flavourzyme^®, which is derived from a mould, Aspergillus oryzae and used for protein hydrolysis in various industrial applications. Optimal conditions for peptides with the highest ACE‐I activity were 4% (v/w) inoculum size for 8 h without Flavourzyme^® supplementation, and 1% inoculum size for 12 h when combined with Flavourzyme^®. The yogurt fermented by L. helveticus resulted in IC₅₀ values (concentration of inhibitor required to inhibit 50% of ACE activity under the assayed conditions) of 1.47 ± 0.04 and 16.91 ± 0.25 mg mL^?1 with and without Flavourzyme^® respectively. Seven fractions of ACE‐I peptides from the yogurt incorporated with L. helveticus and Flavourzyme^® were separated using the preparative high‐performance liquid chromatography. Fraction (F3) showed the highest ACE‐I activity with an IC₅₀ of 35.75 ± 5.48 μg mL^?1. This study indicates that yogurt may be a valuable source of ACE‐I peptides, which may explain the outcomes observed in the experimental and clinical studies and foresee the application of fermented milk proteins into functional foods or dietary supplements.     

Angiotensin I‐converting enzyme inhibitory peptides FQPSF and LKYPI identified in Bacillus subtilis A26 hydrolysate of thornback ray muscle

Angiotensin I‐converting enzyme (ACE) inhibitory peptides have been searched in thornback ray (Raja clavata) muscle hydrolysed with Bacillus subtilis A26 proteases until a hydrolysis degree of 18.35%. The hydrolysate showed an IC₅₀ of 0.83 mg mL^?1. To identify peptides responsible for this activity, the extract was eluted through size‐exclusion chromatography and fractions collected. The highest ACE inhibitory activity was found for fractions F2 and F3 which had IC₅₀ of 0.42 and 0.51 mg mL^?1, respectively. These fractions were analysed by nano‐liquid chromatography coupled to tandem mass spectrometry (nLC‐MS/MS). A total of 131 and 108 peptide sequences mainly derived from actin, myosin heavy chain and procollagen alpha 1 chain proteins were identified in fractions F2 and F3, respectively. FQPSF and LKYPI showed the best results with an IC₅₀ of 12.56 and 27.07 μM, respectively. These results prove the potential of thornback ray muscle hydrolysate as a source of ACE inhibitory peptides.     

Two Novel Bioactive Peptides from Antarctic Krill with Dual Angiotensin Converting Enzyme and Dipeptidyl Peptidase IV Inhibitory Activities

Inhibition of dipeptidyl peptidase IV (DPP‐IV) and angiotensin converting enzyme (ACE) are considered useful in managing 2 often associated conditions: diabetes and hypertension. In this study, corolase PP was used to hydrolyze Antarctic krill protein. The hydrolysate (AKH) was isolated by ultrafiltration and purified by size‐exclusion chromatography, ion exchange chromatography and reversed‐phase high‐performance liquid chromatography (RP‐HPLC) sequentially. The in vitro inhibitory activities of all AKHs and several fractions obtained against ACE and DPP‐IV were assessed. Two peptides, purified with dual‐strength inhibitory activity against ACE and DPP‐IV, were identified by TOF‐MS/MS. Results indicated that not all fractions exhibited dual inhibitory activities of ACE and DPP‐IV. The purified peptide Lys‐Val‐Glu‐Pro‐Leu‐Pro had half‐maximal inhibitory concentrations (IC₅₀) of 0.93±0.05 and 0.73±0.04 mg/mL against ACE and DPP‐IV, respectively. The other peptide Pro‐Ala‐Leu had IC₅₀ values of 0.64±0.05 and 0.88±0.03 mg/mL against ACE and DPP‐IV, respectively. This study firstly reported the sequences of dual bioactive peptides from Antarctic krill proteins, further provided new insights into the bioactive peptides responsible for the ACE and DPP‐IV inhibitory activities from the Antarctic krill protein hydrolysate to manage hypertension and diabetes.     

Influence of adjunct cultures on angiotensin‐converting enzyme (ACE)‐inhibitory activity,organic acid content and peptide profile of kefir

The angiotensin‐converting enzyme (ACE)‐inhibitory activities, peptide profiles and organic acid contents in kefir produced by kefir grains plus lactic acid bacteria as adjunct cultures were determined. All the kefir samples showed almost similar peptide profiles as detected by RP‐HPLC, but quantitative differences were observed during storage. The ACE‐inhibitory activities of different lactic cultures did not exhibit a linear tendency during storage period. After 7 days of storage, there was a significant increase in ACE‐inhibitory activity of the sample fermented with Lactobacillus helveticus. However, a kefir sample containing Streptococcus thermophilus, Lactobacillus acidophilus and Bifidobacterium animalis subsp. lactis exhibited a higher ACE‐inhibitory activity (92.23%) compared to the other samples.     

Isolation,purification and characterisation of angiotensin I‐converting enzyme–inhibitory peptides derived from catfish (Clarias batrachus) muscle protein thermolysin hydrolysates

The angiotensin I‐converting enzyme (ACE)‐inhibitory activities of catfish (Clarias batrachus) muscle protein hydrolysates were investigated. Thermolytic digests of C. batrachus sarcoplasmic and myofibrillar proteins exhibited inhibitory activity towards ACE and were purified with the aim of ultrafiltration, gel filtration and reversed‐phase high‐performance liquid chromatography (RP‐HPLC). The amino acid sequences of hydrolysates with the highest ACE‐inhibitory activities were determined using electrospray quadrupole time‐of‐flight tandem mass spectrometry (ESI‐TOFQ MS/MS). The sequences of GPPP (IC₅₀ = 0.86 μm ) and IEKPP (IC₅₀ = 1.2 μm ) corresponding to the fragments 986–989 and 441–445 of myosin‐I heavy chain were identified for the sarcoplasmic and myofibrillar protein hydrolysates, respectively. Peptide GPPP exhibited a mixed‐type inhibition whereas peptide IEKPP could only bind to the active sites of ACE. The results demonstrate that hydrolysates of C. batrachus muscle proteins obtained by thermolysin may contain bioactive peptides.     

Angiotensin I-converting enzyme inhibitory peptides in douchi,a Chinese traditional fermented soybean product

Douchi, a soybean product originating in China, produces angiotensin I-converting enzyme (ACE) inhibitors with the potential to lower blood pressure. The ACE inhibitory activities of douchi qu pure-cultured by Aspergillus Egyptiacus for 48 h, and 72 h were compared with douchi secondary-fermented for 15 d. The results showed that ACE inhibitory activities were improved following the fermentation. ACE inhibitory activities of 48 h-primary-fermented douchi qu did not change dramatically after preincubation with ACE, but increased greatly after preincubation with gastrointestinal proteases. The results suggest they were pro-drug-type or a mixture of pro-drug-type and inhibitor-type inhibitors. The ACE inhibitors in 48 h-fermented douchi qu were fractionated into four major peaks by gel filtration chromatography on Sephadex G-25. Peak 2, which had the highest activity, had only one peptide, composed of phenylalanine, isoleucine and glycine with a ratio of 1:2:5.     

Changes in yogurt fermentation characteristics, and antioxidant potential and in vitro inhibition of angiotensin-1 converting enzyme upon the inclusion of peppermint, dill and basil

The present study investigated the effects of peppermint (Mentha piperita), dill (Anethum graveolens) and basil (Ocimum basilicum) on yogurt formation, proteolysis and inhibition of angiotensin-1 converting enzyme (ACE). Herbal-yogurts had faster rates of pH reduction than plain-yogurt. All herbal-yogurts had higher (p < 0.05) antioxidant activities than plain-yogurt, both at the end of fermentation and throughout the storage period. The o-phthalaldehyde (OPA) peptides in herbal-yogurts increased by 28-36% after 7 days of storage. All herbal-yogurts showed higher anti-ACE activity than plain-yogurt at corresponding storage periods. M. piperita yogurt had highest inhibitory effect on ACE activity throughout the storage period. Peppermint, dill and basil may be used to modify microbial fermentation of milk with the intention of producing dairy products with higher antioxidant and enhanced anti-ACE activities.     

Separation of angiotensin I‐converting enzyme inhibitory peptides from bovine connective tissue and their stability towards temperature,pH and digestive enzymes

Bovine collagen was isolated from connective tissue, a by‐product in the meat processing industry and characterised by SDS‐PAGE. Alcalase and papain were employed to generate collagen hydrolysates with different degree of hydrolysis (DH). In vitro angiotensin I‐converting enzyme (ACE) inhibitory activities were evaluated and the two most potent hydrolysates from each enzyme were separated by two‐step purification. Both alcalase‐catalysed and papain‐catalysed hydrolysates exhibited strong ACE inhibitory capacities with IC₅₀ values of 0.17 and 0.35 mg mL^?1, respectively. Purification by ion‐exchange chromatography and gel filtration chromatography revealed higher ACE inhibitory activities in one fraction from each enzyme with IC₅₀ values of 3.95 and 7.29 μg mL^?1. These peptide fractions were characterised as 6‐12 amino acid residues by MALDI‐TOF/MS. The peptides retained their activity (>90%) after exposure to processing temperature and pH and in vitro simulated gastrointestinal digestion. The present results demonstrated that collagen peptides can be utilised for developing high value‐added ingredients, for example ACE inhibitory peptides.     

Antidiabetic,angiotensin-converting enzyme inhibitory and anti-inflammatory activities of fermented camel milk and characterisation of novel bioactive peptides from lactic-fermented camel milk with molecular interaction study

This study was to separate and purify antidiabetic and angiotensin-converting enzyme (ACE) inhibitory peptides from Lactiplantibacillus plantarum KGL3A fermented camel milk. After 48 h of fermentation at 37°C, ɑ-amylase inhibition, ɑ-glucosidase inhibition, lipase inhibition and ACE inhibitory activities were 80.94%, 64.45%, 63.93%, and 77.53%, respectively in fermented camel milk. Optimisation of growth condition for the evaluation of maximum peptide production was evaluated by measuring proteolytic activity (O-phthalaldehyde, OPA method) with different inoculation rates and incubation times and highest proteolytic activity (9.21 mg/mL) was observed after 48 h of fermentation at 2.5% rate of inoculation. The antidiabetic and ACE inhibitory activity of 3 kDa permeate fraction were higher as compared with other fractions. Purification of antidiabetic and ACE inhibitory peptides from fermented camel milks was performed through sodium dodecyl-sulphate polyacrylamide gel electrophoresis, and 2-dimensional polyacrylamide gel electrophoresis and maximum number of protein bands were present in between 25 and 10 kDa. The generated peptide sequences were matched with antihypertensive peptide database (AHTPDB) and BIOPEP databases for confirming the antidiabetic and ACE inhibitory activity. Peptides, that is. TDVMPQWW and MMSLVSLLLVGILFPTIQAK were having highest peptide ranker score among the all sequences. Furthermore, anti-inflammatory activity (TNF-α, IL-6 and IL-1β) of fermented camel milk was evaluated in macrophage cell line RAW 264.7 (Ralph and William's cell line). Furthermore, peptides were predicted to have improved binding affinity against Human Angiotensin converting enzyme (hACE) through molecular docking.     

Molecular Characterization and Identification of Bioactive Peptides Producing Lactobacillus sps. Based on 16S rRNA Gene Sequencing

In the present study, 3 bacterial cultures were isolated from faecal samples of human infant. The biochemical traits showed similarity with Lactobacillus sps and 16S rRNA sequence analyses, confirmed as Lactobacillus plantarum, Lactobacillus casei, and Lactobacillus rhamnosus. The cultures were screened for their proteolytic activity and good ability to release peptides from milk proteins was found. Hence, these bacteria were used as a proteolytic starter culture for the fermentation of skim milk and whey for the liberation of small peptides. Bioactive nature of the peptides released from whey and skim milk was tested, and results demonstrated that peptides obtained after fermentation of whey and skim milk by Lactobacillus strains showed antimicrobial activity against all the pathogens causing food borne infections in humans. These peptides also indicated antioxidant as well as ACE (angiotensin-converting enzymes) inhibitory activity.     

Isolation and characterisation of a novel angiotensin I‐converting enzyme‐inhibitory peptide derived from douchi,a traditional Chinese fermented soybean food

BACKGROUND: Douchi, a traditional fermented soybean food, has recently attracted a great deal of attention owing to its superior physiological activity. In the present study the angiotensin I‐converting enzyme (ACE)‐inhibitory activity of typical douchi procured from various regions of China was analysed. An ACE‐inhibitory peptide derived from the most potent douchi was also isolated and characterised. The pattern of ACE inhibition and resistance to hydrolysis by gastrointestinal proteases of this peptide are described. RESULTS: ACE‐inhibitory activities were detected in all douchi samples, with IC₅₀ values ranging from 0.204 to 2.011 mg mL^?1. Among the douchi samples, a Mucor‐type douchi exhibited the most potent ACE‐inhibitory activity (IC₅₀ = 0.204 mg mL^?1). A novel ACE‐inhibitory peptide was then isolated from this Mucor‐type douchi using ultrafiltration followed by Sephadex G‐25 column chromatography and reverse phase high‐performance liquid chromatography. The amino acid sequence of the purified peptide was identified by Edman degradation as His‐Leu‐Pro (IC₅₀ = 2.37 µmol L^?1). The peptide is a competitive inhibitor and maintained its inhibitory activity even after incubation with some gastrointestinal proteases. CONCLUSION: The present study shows that peptides derived from soybean fermentation during douchi processing could be the main contributor to the ACE‐inhibitory activity observed. Copyright © 2009 Society of Chemical Industry     

Characterization of the angiotensin-converting enzyme inhibitory activity of fermented milks produced with Lactobacillus casei

Our study assayed angiotensin-converting enzyme (ACE) inhibitory activity and fermentation characteristics of 41 food-originated Lactobacillus casei strains in fermented milk production. Twenty-two of the tested strains produced fermented milks with a high ACE inhibitory activity of over 60%. Two strains (IMAU10408 and IMAU20411) expressing the highest ACE inhibitory activity were selected for further characterization. The heat stability (pasteurization at 63°C for 30 min, 75°C for 25 s, and 85°C for 20 s) and resistance to gastrointestinal proteases (pepsin, trypsinase, and sequential pepsin/trypsinase treatments) of the ACE inhibitory activity in the fermented milks produced with IMAU10408 and IMAU20411 were determined. Interestingly, such activity increased significantly after the heat or protease treatment. Because of the shorter milk coagulation time of L. casei IMAU20411 (vs. IMAU10408), it was selected for optimization experiments for ACE inhibitory activity production. Our results show that fermentation temperature of 37°C, inoculum density of 1 × 10⁶ cfu/g, and fermentation time of 12 h were optimal for maximizing ACE inhibitory activity. Finally, the metabolite profiles of L. casei IMAU20411 after 2 and 42 h of milk fermentation were analyzed by ultra-HPLC electron spray ionization coupled with time-of-flight mass spectrometry. Nine differential abundant metabolites were identified, and 2 of them showed a strong and positive correlation with fermented milk ACE inhibitory activity. To conclude, we have identified a novel ACE inhibitory L. casei strain, which has potential for use as a probiotic in fermented milk production.     

Proteolytic and angiotensin‐converting enzyme‐inhibitory activities of selected probiotic bacteria

This study was carried out to examine the proteolytic and angiotensin‐converting enzyme (ACE‐I) activities of probiotic lactic acid bacteria (LAB) as influenced by the type of media, fermentation time, strain type and media supplementation with a proteolytic enzyme (Flavourzyme^®). Lactobacillus casei (Lc210), Bifidobacterium animalis ssp12 (Bb12), Lactobacillus delbrueckii subsp. bulgaricus (Lb11842) and Lactobacillus acidophilus (La2410) were grown in 12% of reconstituted skim milk (RSM) or 4% of whey protein concentrates (WPC‐35) with or without combination (0.14%) of Flavourzyme^® for 12 h at 37 °C. All the strains were able to grow in both media depending on type of strains used and fermentation time. All the strains showed higher proteolytic activity and produced more antihypersensitive peptides when grown in RSM medium at 12 h, when compared to WPC. Combination with Flavourzyme^® also increased LAB growth and proteolytic and ACE‐I activities. Of the four strains used, Bb12 and La2410 outperformed Lc210 and Lb11842. The highest ACE‐I activity and proteolytic activity were found in B. animalis ssp12 combined with Flavourzyme^®. Flavourzyme^® led to an increase in the production of bioactive peptides with ACE‐I activity during 12 h at 37 °C.     

Angiotensin-converting enzyme inhibitory activity of milk fermented by wild and industrial Lactococcus lactis strains

Angiotensin I-converting enzyme inhibitory (ACEI) activity was evaluated and compared in <3 KDa water-soluble extracts (WSE) isolated from milk fermented by wild and commercial starter culture Lactococcus lactis strains after 48 h of incubation. The highest ACEI activities were found in WSE from milk inoculated with wild L. lactis strains isolated from artisanal dairy products and commercial starter cultures. On the other hand, the lowest ACEI activities were found in WSE from milk inoculated with wild strains isolated from vegetables. Moreover, the IC₅₀ values (concentration that inhibits 50% activity) of WSE from artisanal dairy products were the lowest, indicating that these fractions were the most effective in inhibiting 50% of ACE activity. In fact, a strain isolated from artisanal cheese presented the lowest IC₅₀ (13 μg/mL). Thus, it appears that wild L. lactis strains isolated from artisanal dairy products and commercial starter cultures showed good potential for the production of fermented dairy products with ACEI properties.     

Antioxidant, antihypertensive and antimicrobial properties of ovine milk caseinate hydrolyzed with a microbial protease

BACKGROUND: Bioactive peptides might be released from precursor proteins through enzymatic hydrolysis. These molecules could be potentially employed in health and food products. In this investigation, ovine milk caseinate hydrolysates obtained with a novel microbial protease derived from Bacillus sp. P7 were evaluated for antioxidant, antimicrobial, and angiotensin I‐converting enzyme (ACE)‐inhibitory activities. RESULTS: Antioxidant activity measured by the 2,2′‐azino‐bis‐(3‐ethylbenzothiazoline)‐6‐sulfonic acid method increased with hydrolysis time up to 2 h, remaining stable for up to 4 h. Hydrolysates showed low 2,2‐diphenyl‐1‐picrylhydrazyl radical‐scavenging abilities, with higher activity (31%) reached after 1 h of hydrolysis. Fe²⁺‐chelating ability was maximum for 0.5 h hydrolysates (83.3%), decreasing thereafter; and the higher reducing power was observed after 1 h of hydrolysis. ACE‐inhibitory activity was observed to increase up to 2 h of hydrolysis (94% of inhibition), declining afterwards. 3 h hydrolysates were shown to inhibit the growth of Bacillus cereus, Corynebacterium fimi, Aspergillus fumigatus, and Penicillium expansum. CONCLUSION: Ovine caseinate hydrolyzed with Bacillus sp. P7 protease presented antioxidant, antihypertensive, and antimicrobial activities. Hydrolysis time was observed to affect the evaluated bioactivities. Such hydrolysates might have potential applications in the food industry. Copyright © 2011 Society of Chemical Industry