Phospholipases in food industry: a review

Case study of chemical and enzymatic degumming processes in soybean oil production at an industrial plant

The vegetable oil degumming process plays a critical role in refining edible oil. Phospholipids (PL) removal from crude extracted soybean oil (SBO) by the enzymatic degumming process has been investigated in this work. Enzymatic degumming of extracted SBO with microbial phospholipase A1 PLA-1 Quara LowP and Lecitase Ultra enzymes have also been studied comparatively. The main novelty of our work is the use of the enzymatic degumming process on an industrial scale (600 tons a day). Many parameters have been discussed to understand in detail the factors affecting oil losses during the degumming process. The factors such as chemical conditioning (CC) by phosphoric acid 85%, the enzyme dosage mg/kg (feedstock dependent), the enzymatic degumming reaction time, and the characteristics of the plant-processed SBO have been discussed in detail. As a main point, the degummed oil with a phosphorus content of < 10 mg/kg increases yield. Quara LowP and Lecitase Ultra enzymes are not specific for certain phospholipids PL; however, the conversion rate depends on the SBO phospholipid composition. After 4 h, over 99% of Phospholipids were degraded to their lysophospholipid LPL (lysolecithin). The results showed a significant effect of operating parameters and characteristics of different origins of SBO, fatty acids FFA content, Phosphorus content and total divalent metals (Calcium Ca, Magnesium Mg and Iron Fe mg/kg) content on the oil loss. The benefit of using enzymatic degumming of vegetable oils rather than traditional chemical refining is that the enzymatic degumming process reduces total oil loss. This decrease is known as enzymatic yield. The enzymatic degumming also decreases wastewater and used chemicals and running costs; moreover, it enables physical refining by lowering the residue phosphorus to < 10 mg/kg.

Computational Modelling and Molecular Docking of Industrial Leather Enzymes

Leather is one of the widely traded commodities globally. It is a strategically important sector for the economic and industrial development of the country. However, the leather industry is perceived as a highly polluting industry. It produces huge amounts of solid and liquid wastes, and if these wastes are not properly treated and disposed of, then it tends to deteriorate the quality of soil and water, as well as cause emanations of smell and noxious gases into the surrounding. The current paper provides information about industrial leather enzymes, primarily collagenase, tannase, and lecithinase. In this study, enzymes such as collagenase, tannase, and lecithinase had a pivotal role in leather industries and their action in the bioremediation of leather effluents was further analysed and docked with a diverse range of compounds (ligands), with an optimal binding affinity score was determined. All interactions between protein ligands were depicted, which will help us with future research. Furthermore, this method can be tested practically, and other parameters can be studied in the future. Further, applications of enzymes and their hydrolyse by-products have also been highlighted in a variety of industries, including the pharmaceutical, cosmetic, agricultural, medical, and food sectors. Subsequently, this finding provides an innovative and broader goal for various sectors in terms of sustainability, stabilisation, and identifying research gaps that can guide modern industries and research scientists.

Characterization of a novel thermostable phospholipase C from T. kodakarensis suitable for oil degumming

The implementation of cleaner technologies that minimize environmental pollution caused by conventional industrial processes is an increasing global trend. Hence, traditionally used chemicals have been replaced by novel enzymatic alternatives in a wide variety of industrial-scale processes. Enzymatic oil degumming, the first step of the oil refining process, exploits the conversion catalyzed by phospholipases to remove vegetable crude oils' phospholipids. This enzymatic method reduces the gums' volume and increases the overall oil yield. A thermostable phospholipase would be highly advantageous for industrial oil degumming as oil treatment at higher temperatures would save energy and increase the recovery of oil by facilitating the mixing and gums removal. A thermostable phosphatidylcholine (PC) (and phosphatidylethanolamine (PE))-specific phospholipase C from Thermococcus kodakarensis (TkPLC) was studied and completely removed PC and PE from crude soybean oil at 80 °C. Due to these characteristics, TkPLC is an interesting promising candidate for industrial-scale enzymatic oil degumming at high temperatures. KEY POINTS: • A thermostable phospholipase C from T. kodakarensis (TkPLC) has been identified. • TkPLC was recombinantly produced in Pichia pastoris and successfully purified. • TkPLC completely hydrolyzed PC and PE in soybean oil degumming assays at 80 °C.

Toxicological evaluation of Phospholipase D from Kitasatospora paracochleata

Phospholipases are used extensively in the production of food ingredients, typically as processing aids, to enzymatically convert glycerophospholipids and provide functional properties in meat products or baking confections. The current study examined the safety of Phospholipase D derived from Kitasatospora paracochleata (strain No. 362-PLD) for use as a processing aid in various food applications, where it may be present in the finished products at trace levels. The safety assessment of Phospholipase D included two in vitro genotoxicity studies and a 90-day subchronic toxicity study in rats. No evidence of genotoxicity was observed in a bacterial reverse mutation test or in a chromosome aberration test. In the subchronic toxicity study, no test article-related adverse effects were observed upon Phospholipase D administration to rats at doses levels of 0, 750, 1500, and 3000 mg/kg body weight/day throughout a 90-day study period. Thus, the no-observed-adverse-effect level (NOAEL) was considered to be 3000 mg/kg body weight/day. This safety assessment supports the safe use of Phospholipase D as a processing aid in food production and the presence of trace levels in finished products.

Antimicrobial Effects of Potential Probiotics of Bacillus spp. Isolated from Human Microbiota: In Vitro and In Silico Methods

The variable taxa components of human gut microbiota seem to have an enormous biotechnological potential that is not yet well explored. To investigate the usefulness and applications of its biocompounds and/or bioactive substances would have a dual impact, allowing us to better understand the ecology of these microbiota consortia and to obtain resources for extended uses. Our research team has obtained a catalogue of isolated and typified strains from microbiota showing resistance to dietary contaminants and obesogens. Special attention was paid to cultivable Bacillus species as potential next-generation probiotics (NGP) together with their antimicrobial production and ecological impacts. The objective of the present work focused on bioinformatic genome data mining and phenotypic analyses for antimicrobial production. In silico methods were applied over the phylogenetically closest type strain genomes of the microbiota Bacillus spp. isolates and standardized antimicrobial production procedures were used. The main results showed partial and complete gene identification and presence of polyketide (PK) clusters on the whole genome sequences (WGS) analysed. Moreover, specific antimicrobial effects against B. cereus, B. circulans, Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli, Serratia marcescens, Klebsiella spp., Pseudomonas spp., and Salmonella spp. confirmed their capacity of antimicrobial production. In conclusion, Bacillus strains isolated from human gut microbiota and taxonomic group, resistant to Bisphenols as xenobiotics type endocrine disruptors, showed parallel PKS biosynthesis and a phenotypic antimicrobial effect. This could modulate the composition of human gut microbiota and therefore its functionalities, becoming a predominant group when high contaminant exposure conditions are present.

Representative Bacillus sp. AM1 from Gut Microbiota Harbor Versatile Molecular Pathways for Bisphenol A Biodegradation

Human gut microbiota harbors numerous microbial species with molecular enzymatic potential that impact on the eubiosis/dysbiosis and health/disease balances. Microbiota species isolation and description of their specific molecular features remain largely unexplored. In the present study, we focused on the cultivation and selection of species able to tolerate or biodegrade the endocrine disruptor bisphenol A (BPA), a xenobiotic extensively found in food plastic containers. Chemical xenobiotic addition methods for the directed isolation, culturing, Whole Genome Sequencing (WGS), phylogenomic identification, and specific gene-encoding searches have been applied to isolate microorganisms, assess their BPA metabolization potential, and describe encoded catabolic pathways. BPA-tolerant strains were isolated from 30% of infant fecal microbial culture libraries analyzed. Most isolated strains were phylogenetically related to the operational taxonomic group Bacillus amyloliquefaciens spp. Importantly, WGS analysis of microbial representative strain, Bacillus sp. AM1 identified the four complete molecular pathways involved on BPA degradation indicating its versatility and high potential to degrade BPA. Pathways for Exopolysaccharide (EPS) and Polyhydroxyalkanates (PHA) biopolymer synthesis were also identified and phenotypically confirmed by transmission electronic microscopy (TEM). These microbial biopolymers could generally contribute to capture and/or deposit xenobiotics.

Efficient secretion expression of phospholipase D in Bacillus subtilis and its application in synthesis of phosphatidylserine by enzyme immobilization

Transphosphatidylation catalyzed by phospholipase D has gained increasing attention for producing phosphatidylserine (PS), which can be used in functional food and medicine. In this study, we investigated the effects of six signal peptides on the secretion of PLD (PLD_sa) from Streptomyces antibioticus TCCC 21059 in the food-grade GRAS bacterium Bacillus subtilis. It indicated that the optimal signal peptide DacB with an Ala-X-Ala sequence motif at the C-terminus showed the highest secretory expression ability, resulting in increased production of 2.84 U/mL PLD_sa. Then PLD_sa was immobilized on the epoxy-based carriers, and one of these carriers allowed PLD_sa loading of up to 2.7 mg/g. The immobilized PLD_sa was more stable over a wide range of pH value (4.5-7.5) and temperature (16 °C-60 °C) than free PLD_sa. Subsequently, the synthesis of PS from soybean phosphatidylcholine (PC) was carried out in purely aqueous solution using immobilized PLD_sa, leading to a high yield of 65%. The immobilized PLD_sa catalyst maintained a relative PS production of 60% after 5 recycles. Notably, the use of toxic solvent was completely eliminated in the whole process, which would be more profitable for the application of PS.

Lipases as Processing Aids in the Separation of Wheat Flour into Gluten and Starch: Impact on the Lipid Population, Gluten Agglomeration, and Yield

Three lipases with different hydrolysis specificities were tested in a laboratory-scale dough-batter wheat flour separation process in two concentrations. Lipolase specifically hydrolyzed nonpolar flour lipids. At the highest concentration tested, it significantly improved gluten agglomeration and yield, also when combined with a xylanase with hydrolysis specificity toward water-extractable arabinoxylan. We hypothesize that its action is due to the release of adequate levels of free fatty acids, which, because at least a part of them is dissociated, act as anionic surfactants. Lipolase at the lowest concentration, Lecitase Ultra, hydrolyzing both nonpolar and polar lipids, and YieldMAX, which specifically hydrolyzed phospholipids, had no or a negative impact on gluten agglomeration and yield. In conclusion, this study demonstrated that lipases with hydrolysis specificity toward nonpolar lipids can be used as processing aids in wheat flour separation in the absence or presence of added xylanases to maximize gluten agglomeration and yield.

Recent Advances in the Utilization of Natural Emulsifiers to Form and Stabilize Emulsions

Consumer concern about human and environmental health is encouraging food manufacturers to use more natural and sustainable food ingredients. In particular, there is interest in replacing synthetic ingredients with natural ones, and in replacing animal-based ingredients with plant-based ones. This article provides a review of the various types of natural emulsifiers with potential application in the food industry, including phospholipids, biosurfactants, proteins, polysaccharides, and natural colloidal particles. Increased utilization of natural emulsifiers in food products may lead to a healthier and more sustainable food supply. However, more research is needed to identify, isolate, and characterize new sources of commercially viable natural emulsifiers suitable for food use.

Effects of solid-state fermentation with two filamentous fungi on the total phenolic contents, flavonoids, antioxidant activities and lipid fractions of plum fruit (Prunus domestica L.) by-products

Evolutions of phenolic contents and antioxidant activities during solid-state fermentation (SSF) of plum pomaces (from the juice industry) and brandy distillery wastes with Aspergillus niger and Rhizopus oligosporus were investigated. The effect of fermentation time on the oil content and major lipid classes in the plum kernels was also studied. Results showed that total phenolic (TP) amounts increased by over 30% for SSF with Rhizopus oligosporus and by >21% for SSF with A. niger. The total flavonoid contents presented similar tendencies to those of the TPs. The free radical scavenging activities of methanolic extracts were also significantly enhanced. The HPLC-MS analysis showed that quercetin-3-glucoside was the major phenolic compound in both fermented plum by-products. The results also demonstrated that SSF not only helped to achieve higher lipid recovery from plum kernels, but also resulted in oils with better quality attributes (high sterol ester and n-3 PUFA-rich polar lipid contents).

Recombinant Lipases and Phospholipases and Their Use as Biocatalysts for Industrial Applications

Lipases and phospholipases are interfacial enzymes that hydrolyze hydrophobic ester linkages of triacylglycerols and phospholipids, respectively. In addition to their role as esterases, these enzymes catalyze a plethora of other reactions; indeed, lipases also catalyze esterification, transesterification and interesterification reactions, and phospholipases also show acyltransferase, transacylase and transphosphatidylation activities. Thus, lipases and phospholipases represent versatile biocatalysts that are widely used in various industrial applications, such as for biodiesels, food, nutraceuticals, oil degumming and detergents; minor applications also include bioremediation, agriculture, cosmetics, leather and paper industries. These enzymes are ubiquitous in most living organisms, across animals, plants, yeasts, fungi and bacteria. For their greater availability and their ease of production, microbial lipases and phospholipases are preferred to those derived from animals and plants. Nevertheless, traditional purification strategies from microbe cultures have a number of disadvantages, which include non-reproducibility and low yields. Moreover, native microbial enzymes are not always suitable for biocatalytic processes. The development of molecular techniques for the production of recombinant heterologous proteins in a host system has overcome these constraints, as this allows high-level protein expression and production of new redesigned enzymes with improved catalytic properties. These can meet the requirements of specific industrial process better than the native enzymes. The purpose of this review is to give an overview of the structural and functional features of lipases and phospholipases, to describe the recent advances in optimization of the production of recombinant lipases and phospholipases, and to summarize the information available relating to their major applications in industrial processes.

Total phenolic contents, antioxidant activities, and lipid fractions from berry pomaces obtained by solid-state fermentation of two Sambucus species with Aspergillus niger

The aim of this study was to investigate the effect of solid-state fermentation (SSF) by Aspergillus niger on phenolic contents and antioxidant activity in Sambucus nigra L. and Sambucus ebulus L. berry pomaces. The effect of fermentation time on the total fats and major lipid classes (neutral and polar) was also investigated. During the SSF, the extractable phenolics increased with 18.82% for S. ebulus L. and 11.11% for S. nigra L. The levels of antioxidant activity of methanolic extracts were also significantly enhanced. The HPLC-MS analysis indicated that the cyanidin 3-sambubioside-5-glucoside is the major phenolic compound in both fermented Sambucus fruit residues. In the early stages of fungal growth, the extracted oils (with TAGs as major lipid fraction) increased with 12% for S. nigra L. and 10.50% for S. ebulus L. The GC-MS analysis showed that the SSF resulted in a slight increase of the linoleic and oleic acids level.

Optimization of the degumming process for camellia oil by the use of phospholipase C in pilot-scale system

In present study, phospholipase C (PLC) was applied in camellia oil degumming and the response surface method (RSM) was used to determine the optimum degumming conditions (reaction time, reaction temperature and enzyme dosage) for this enzyme. The optimum conditions for the minimum residual phosphorus content (15.14 mg/kg) and maximum yield of camellia oil (98.2 %) were obtained at reaction temperature 53 ºC, reaction time 2.2 h, PLC dosage 400 mg/kg and pH 5.4. The application of phospholipase A (PLA) - assisted degumming process could further reduce the residual phosphorus content of camellia oil (6.84 mg/kg) to make the oil suitable for physical refining while maintaining the maximal oil yield (98.2 %). These results indicate that PLC degumming process in combination with PLA treatment can be a commercially viable alternative for traditional degumming process. Study on the quality changes of degummed oils showed that the oxidative stability of camellia oil was slightly deceased after the enzymatic treatment, thus more attention should be paid to the oxidative stability in the further application.

Bioanalysis for biocatalysis: multiplexed capillary electrophoresis-mass spectrometry assay for aminotransferase substrate discovery and specificity profiling

In this work, we introduce an entirely automated enzyme assay based on capillary electrophoresis coupled to electrospray ionization mass spectrometry termed MINISEP-MS for multiple interfluent nanoinjections-incubation-separation-enzyme profiling using mass spectrometry. MINISEP-MS requires only nanoliters of reagent solutions and uses the separation capillary as a microreactor, allowing multiple substrates to be assayed simultaneously. The method can be used to rapidly profile the substrate specificity of any enzyme and to measure steady-state kinetics in an automated fashion. We used the MINISEP-MS assay to profile the substrate specificity of three aminotransferases (E. coli aspartate aminotransferase, E. coli branched-chain amino acid aminotransferase, and Bacillus sp. YM-1 D-amino acid aminotransferase) for 33 potential amino acid substrates and to measure steady-state kinetics. Using MINISEP-MS, we were able to recapitulate the known substrate specificities and to discover new amino acid substrates for these industrially relevant enzymes. Additionally, we were able to measure the apparent K(M) and k(cat) parameters for amino acid donor substrates of these aminotransferases. Because of its many advantages, the MINISEP-MS assay has the potential of becoming a useful tool for researchers aiming to identify or create novel enzymes for specific biocatalytic applications.