Apple juice clarification by immobilized pectolytic enzymes in packed or fluidized bed reactors

Immobilization of Enological Pectinase on Magnetic Sensitive Polyamide Microparticles for Wine Clarification

The use of free pectinases as clarification biocatalysts constitutes a well-established practice in the large-scale production of various types of wines. However, when in the form of free enzymes, the recovery and reusability of pectinases is difficult if not impossible. To address these limitations, the present study focuses on the noncovalent adsorption immobilization of a commercial pectinolytic preparation onto highly porous polyamide 6 (PA6) microparticles, both with and without magnetic properties, prepared via activated anionic polymerization. The two pectinase complexes resulting after immobilization underwent comparative activity and kinetic studies, contrasting them with the free enzyme preparation. In comparison with the free enzyme, the PA6-immobilized pectinase complexes exhibited more than double the specific activity toward the pectin substrate. They displayed a slightly higher affinity to the substrate while acting as faster catalysts that were more resistant to inhibition. Furthermore, the immobilized complexes were applied in the clarification process of industrial rosé must, whereby they demonstrated accelerated performance as compared with the free enzyme. Moreover, the PA6-immobilized pectinase biocatalysts offered the potential for three consecutive cycles of reuse, achieving complete rosé must clarification within relevant timeframes in the range of 3-36 h. All these results suggest the potential industrial application of the pectinases noncovalently immobilized upon PA6 microparticles.

Proteases immobilized on nanomaterials for biocatalytic, environmental and biomedical applications: Advantages and drawbacks

Proteases have gained significant scientific and industrial interest due to their unique biocatalytic characteristics and broad-spectrum applications in different industries. The development of robust nanobiocatalytic systems by attaching proteases onto various nanostructured materials as fascinating and novel nanocarriers has demonstrated exceptional biocatalytic performance, substantial stability, and ease of recyclability over multiple reaction cycles under different chemical and physical conditions. Proteases immobilized on nanocarriers may be much more resistant to denaturation caused by extreme temperatures or pH values, detergents, organic solvents, and other protein denaturants than free enzymes. Immobilized proteases may present a lower inhibition. The use of non-porous materials in the immobilization prevents diffusion and steric hindrances during the binding of the substrate to the active sites of enzymes compared to immobilization onto porous materials; when using very large or solid substrates, orientation of the enzyme must always be adequate. The advantages and problems of the immobilization of proteases on nanoparticles are discussed in this review. The continuous and batch reactor operations of nanocarrier-immobilized proteases have been successfully investigated for a variety of applications in the leather, detergent, biomedical, food, and pharmaceutical industries. Information about immobilized proteases on various nanocarriers and nanomaterials has been systematically compiled here. Furthermore, different industrial applications of immobilized proteases have also been highlighted in this review.

Application of Immobilized Enzymes in Juice Clarification

Immobilized enzymes are currently being rapidly developed and are widely used in juice clarification. Immobilized enzymes have many advantages, and they show great advantages in juice clarification. The commonly used methods for immobilizing enzymes include adsorption, entrapment, covalent bonding, and cross-linking. Different immobilization methods are adopted for different enzymes to accommodate their different characteristics. This article systematically reviews the methods of enzyme immobilization and the use of immobilized supports in juice clarification. In addition, the mechanisms and effects of clarification with immobilized pectinase, immobilized laccase, and immobilized xylanase in fruit juice are elaborated upon. Furthermore, suggestions and prospects are provided for future studies in this area.

Application of natural fining agents to clarify fruit juices

The consumption of fruit juices has been increasingly growing all over the world. The clarification process is considered as one of the most important stages in fruit juice production, which can provide the products with desired clear visual appearance. Nowadays, the tendency of consumers to use the natural-clarified fruit juices encourages the researchers to allocate much attention on utilization of natural clarifying agents to clarify different fruit juices. This review article has first introduced the most frequent causes of turbidity in fruit juices including polysaccharides (i.e., cellulose, hemicelluloses, lignin, starch, and pectic substances), proteins and polyphenols (especially tannins) as well as their removal mechanisms. After that, a comprehensive summary of research on natural fining agents, including clay minerals, polysaccharides, proteins, enzymes (free and immobilized forms), and activated carbon is provided with a focus on their application in the juice clarification process. The chemical composition of natural substances, their efficiency on reduction of turbidity-causing compounds and the changes in properties of clarified juices such as turbidity (clarity), total phenolic content, total anthocyanins, viscosity, and sensory evaluation followed by their stability during the storage have been deeply discussed.

Fruit residues as biomass for bioethanol production using enzymatic hydrolysis as pretreatment

The commercialization of fruits in markets generates a large amount of waste because they are perishable and have a short shelf life, so, they are discarded. This study aimed to provide a noble end to discarded fruits that have fermentable sugars. Banana, apple, mango and papaya residues were collected from supermarkets and underwent an enzymatic hydrolysis process. The ability of four pectinases, two amylases, one xylanase and one cellulase to release reducing sugars from fruit biomass before fermentation with two yeast strains (S. cerevisiae CAT-1 and S. cerevisiae Angel) for bioethanol production was investigated, obtaining a total of RS (Reducing sugar) of 268.08 mg/mL in banana residues. A fermentation with yeast S. cerevisiae CAT-1 resulted in 98% consumption of RS and the production of a total of 28.02 g/L of ethanol. Furthermore, fermentation with the yeast S. cerevisiae Angel, resulted in 97% RS consumption and 31.87 g/L ethanol production, which was the best result obtained throughout all the tests of hydrolysis, highlighting the banana residue as a promising biomass for the production of bioethanol.

Isolation and characterization of pectinase-producing bacteria (Serratia marcescens) from avocado peel waste for juice clarification

BACKGROUND

Bacterial pectinase is an enzyme that could be employed in numerous sectors to break down pectin polysaccharide compounds. The goal of this study is to find pectinase-producing bacteria in avocado peel waste and see if the pectinase enzyme produced can be used to make fruit juice clarification.

RESULTS

The researchers isolated four different bacterial strains from avocado peel waste samples. The potential two bacterial isolates that were identified as being Serratia marcescens and Lysinibacillus macrolides. Finally, the analysis of pectinase production and its application in fruit juice clarification were performed using one of the bacterial strains of Serratia marcescens. The clear apple, lemon, and mango juices were further processed to assess each juice's properties. The highest antioxidant activity was recorded in lemon juice samples. The lemon juice showed the highest total titratable acidity and total phenol content. Apple juices contained the highest total soluble solids, reducing sugar content, and viscosity and the mango juices have the maximum pH value recorded.

CONCLUSIONS

The pectinase isolated from the bacterium Serratia marcescens could clear fruit juices. This pectinase needs to be studied more to make sure it works better in the fruit industry and other businesses.

Continuous Clarification of Barberry Juice with Pectinase Immobilised by Oxidized Polysaccharides

Research background

Barberry juice is a rich source of bioactive compounds and shows different health properties such as antioxidant and anticancer activities. Clarification, as the removal process of suspended material, is an important step in the production of fruit juice due to its significant effect on the appearance, flavour and commercialisation of juice. Pectinase is the most important enzyme applied in juice clarification that breaks down the pectin polymer structure and reduces the undesirable turbidity. Pectinase immobilisation is a way to overcome free enzyme drawbacks such as instability, high cost, the difficulty of recovery and recyclability. Also, continuous clarification process which is highly preferred in fruit juice industry is not possible without enzyme immobilisation.

Experimental approach

Pectinase enzymes were immobilised on the functionalised glass beads (glass bead with (3-aminopropyl)triethoxysilane) by glutaraldehyde, polyaldehyde derivatives of pullulan and kefiran and the barberry juice was clarified in the batch and continuous processes in a packed bed reactor (PBR). Also, the effect of clarification on the physicochemical and antioxidant properties of the barberry juice samples was evaluated.

Results and conclusions

The optimum conditions for clarification in the PBR were: flow rate 0.5 mL/min, temperature 50 °C and treatment time 63 min. Clarification led to a decrease in turbidity, pH, total soluble solid content, viscosity, total phenolic content and antioxidant activity of the juice samples. Also, this process increased the clarity, acidity, reducing sugar concentration and the lightness parameter of the barberry juice. The greatest effect of clarification on the studied properties of barberry juice was related to the pectinase immobilised by the polyaldehyde of kefiran in the continuous process and both new cross-linkers (polyaldehyde derivatives of pullulan and kefiran) immobilised the enzyme better than the common cross-linker (glutaraldehyde).

Novelty and scientific contribution

For the first time, barberry juice was clarified with pectinase immobilised by polyaldehyde derivatives of pullulan and kefiran and the obtained results showed that the pectinase immobilisation by these new cross-linkers was much more efficient than by the glutaraldehyde as a common cross-linker. These findings can be of use for an industrialised production of fruit juices.

Biocatalysis in the winemaking industry: Challenges and opportunities for immobilized enzymes

Enzymes are powerful catalysts already being used in a large number of industrial processes. Impressive advantages in enzyme catalysts improvement have occurred in recent years aiming to improve their performance under harsh operation conditions far away from those of their cellular habitat. Production levels of the winemaking industry have experienced a remarkable increase, and technological innovations have been introduced for increasing the efficiency at different process steps or for improving wine quality, which is a key issue in this industry. Enzymes, such as pectinases and proteases, have been traditionally used, and others, such as glycosidases, have been more recently introduced in the modern wine industry, and many dedicated studies refer to the improvement of enzyme performance under winemaking conditions. Within this framework, a thorough review on the role of enzymes in winemaking is presented, with special emphasis on the use of immobilized enzymes as a significant strategy for catalyst improvement within an industry in which enzymes play important roles that are to be reinforced paralleling innovation.

Immobilization of pectinase on chitosan-magnetic particles: Influence of particle preparation protocol on enzyme properties for fruit juice clarification

Magnetic-chitosan particles were prepared following three different protocols enabling the preparation of particles with different sizes - nano (Nano-CMag, Micro (Micro-CMag) and Macro (Macro-CMag) - and used for pectinase immobilization and clarification of grape, apple and orange juices. The particle size had a great effect in the kinetic parameters, Nano-CMag biocatalyst presented the highest V_max value (78.95 mg. min^-1), followed by Micro-CMag and Macro-CMag, with V_max of 57.20 mg.min^-1 and 46.03 mg.min^-1, respectively. However, the highest thermal stability was achieved using Macro-CMag, that was 8 and 3-times more stable than Nano-CMag and Micro-CMag biocatalysts, respectively. Pectinase immobilized on Macro-CMag kept 85% of its initial activity after 25 batch cycles in orange juice clarification. These results suggested that the chitosan magnetic biocatalysts presented great potential application as clarifying catalysts for the fruit juice industry and the great importance of the chitosan particles preparation on the final biocatalyst properties.

Hydrolyzation of mogrosides: Immobilized β-glucosidase for mogrosides deglycosylation from Lo Han Kuo

An immobilized enzyme system for bioconversion of Lo Han Kuo (LHK) mogrosides was established. β-Glucosidase which was covalently immobilized onto the glass spheres exhibited a significant bioconversion efficiency from pNPG to pnitrophenol over other carriers. Optimum operational pH and temperature were determined to be pH 4 and 30°C. Results of storage stability test demonstrated that the glass sphere enzyme immobilization system was capable of sustaining more than 80% residual activity until 50 days, and operation reusability was confirmed for at least 10 cycles. The Michaelis constant (K m) of the system was determined to be 0.33 mM. The kinetic parameters, rate constant (K) at which Mogrosides conversion was determined, the τ 50 in which 50% of mogroside V deglycosylation/mogroside IIIE production was reached, and the τ complete of complete mogroside V deglycosylation/mogroside IIIE production, were 0.044/0.017 min-1, 15.6/41.1 min, and 60/120 min, respectively. Formation of the intermediates contributed to the kinetic differences between mogroside V deglycosylation and mogroside IIIE formation.

Reduction of Phytic Acid in Soymilk by Immobilized Phytase System

In this study, three carriers (glass microsphere, cellulose beads and AlgNa/PVA beads) were evaluated as phytase solid carriers for reduction of phytic acid within soymilk. Phytase was covalently immobilized onto or entrapped within carriers for repeated use. Glass microsphere was chosen due to its high catalytic efficiency. Optimal operating condition (pH 6.0, 60 °C) was determined using 4-Nitrophenyl phosphate disodium salt hexahydrate as an indicator. Operational reusability was confirmed for more than seven batch reactions and the storage stability was capable of sustaining 70% of its catalytic activity for 40 days. The kinetic parameters including rate constant (K), time (τ₅₀ ) in which 50% of phytic acid hydrolysis was reached, and time (τ_complete ) required to achieve complete phytic acid hydrolysis, were 0.023 min^-1 , 35.7 min, 110 min. The current procedure provides a cheap as well as an easy way to carry out the reduction of phytic acid in soymilk, which has great potential in practical application.

Preparation and characterization of a Combi-CLEAs from pectinases and cellulases: a potential biocatalyst for grape juice clarification

Combi-CLEAs of pectinases and cellulases were prepared for grape juice clarification.

Application of decolourized and partially purified polygalacturonase and α-amylase in apple juice clarification

Polygalacturonase and α-amylase play vital role in fruit juice industry. In the present study, polygalacturonase was produced by Aspergillus awamori Nakazawa MTCC 6652 utilizing apple pomace and mosambi orange (Citrus sinensis var mosambi) peels as solid substrate whereas, α-amylase was produced from A. oryzae (IFO-30103) using wheat bran by solid state fermentation (SSF) process. These carbohydrases were decolourized and purified 8.6-fold, 34.8-fold and 3.5-fold, respectively by activated charcoal powder in a single step with 65.1%, 69.8% and 60% recoveries, respectively. Apple juice was clarified by these decolourized and partially purified enzymes. In presence of 1% polygalacturonase from mosambi peels (9.87 U/mL) and 0.4% α-amylase (899 U/mL), maximum clarity (%T_660nm = 97.0%) of juice was attained after 2 h of incubation at 50 °C in presence of 10 mM CaCl₂. Total phenolic content of juice was reduced by 19.8% after clarification, yet with slightly higher %DPPH radical scavenging property.

Biotechnological potential of pectinolytic complexes of fungi

Plant cell wall-degrading enzymes, such as cellulases, hemicellulases and pectinases, have been extensively studied because of their well documented biotechnological potential, mainly in the food industry. In particular, lytic enzymes from filamentous fungi have been the subject of a vast number of studies due both to their advantages as models for enzyme production and their characteristics. The demand for such enzymes is rapidly increasing, as are the efforts to improve their production and to implement their use in several industrial processes, with the goal of making them more efficient and environment-friendly. The present review focuses mainly on pectinolytic enzymes of filamentous fungi, which are responsible for degradation of pectin, one of the major components of the plant cell wall. Also discussed are the past and current strategies for the production of cell wall-degrading enzymes and their present applications in a number of biotechnological areas.