Sequential Enzymatic Hydrolysis and Ultrasound Pretreatment of Pork Liver for the Generation of Bioactive and Taste-Related Hydrolyzates.

In the study of protein-rich byproducts, enzymatic hydrolysis stands as a prominent technique, generating bioactive peptides. Combining exo- and endopeptidases could enhance both biological and sensory properties. Ultrasound pretreatment is one of the most promising techniques for the optimization of enzymatic hydrolysis. This research aimed to create tasteful and biologically active pork liver hydrolyzates by using sequential hydrolysis with two types of enzymes and two types of ultrasound pretreatments. Sequential hydrolyzates exhibited a higher degree of hydrolysis than single ones. Protana Prime hydrolyzates yielded the largest amount of taste-related amino acids, enhancing sweet, bittersweet, and umami amino acids according to the Taste Activity Value (TAV). These hydrolyzates also displayed significantly higher antioxidant activity. Among sequential hydrolyzates, Flavourzyme and Protana Prime hydrolyzates pretreated with ultrasound showed the highest ferrous ion chelating activity. Overall, employing both Alcalase and Protana Prime on porcine livers pretreated with ultrasound proved to be highly effective in obtaining potentially tasteful and biologically active hydrolyzates.

Structures, gelatinization properties and enzyme hydrolyses of starches from transparent and floury grains of rices subjected to field natural extreme high temperature.

Three rice varieties underwent the field natural extreme high temperature (EHT) with daily average temperature over 30 °C from 21 to 89 days after sowing, and had transparent, chalky and floury grains. The structures, gelatinization properties and enzyme hydrolyses of starches from transparent and floury grains were investigated. Compared with control transparent grains, floury grains subjected to EHT markedly decreased the contents of amylose molecules, amylopectin A chains and amylopectin B1 chains and increased the contents of amylopectin B2 and B3+ chains and the average branch-chain length of amylopectin. Both transparent and floury grains had A-type starches, but floury grain starches exhibited higher relative crystallinity, gelatinization temperature, retrogradation and pasting viscosities than transparent grain starches. Floury grain starches had lower hydrolysis rates than transparent grain starches. Native starches were more resistant to digestion but gelatinized and retrograded starches were more prone to digestion in floury grains than in transparent grains.

Encapsulation of chrysin and rutin using self-assembled nanoparticles of debranched quinoa, maize, and waxy maize starches.

Chrysin and rutin are natural polyphenols with multifaceted biological activities but their applications face challenges in bioavailability. Encapsulation using starch nanoparticles (SNPs) presents a promising approach to overcome the limitations. In this study, chrysin and rutin were encapsulated into self-assembled SNPs derived from quinoa (Q), maize (M), and waxy maize (WM) starches using enzyme-hydrolysis. Encapsulation efficiencies ranged from 74.3 % to 79.1 %, with QSNPs showing superior performance. Simulated in vitro digestion revealed sustained release and higher antioxidant activity in QSNPs compared to MSNPs and WMSNPs. Variations in encapsulation properties among SNPs from different sources were attributed to the differences in the structural properties of the starches. The encapsulated SNPs exhibited excellent stability, retaining over 90 % of chrysin and 85 % of rutin after 15 days of storage. These findings underscore the potential of SNP encapsulation to enhance the functionalities of chrysin and rutin, facilitating the development of fortified functional foods with enhanced bioavailability and health benefits.

Role of Lactic Acid Bacteria in Insecticide Residue Degradation.

Lactic acid bacteria are gaining global attention, especially due to their role as a probiotic. They are increasingly being used as a flavoring agent and food preservative. Besides their role in food processing, lactic acid bacteria also have a significant role in degrading insecticide residues in the environment. This review paper highlights the importance of lactic acid bacteria in degrading insecticide residues of various types, such as organochlorines, organophosphorus, synthetic pyrethroids, neonicotinoids, and diamides. The paper discusses the mechanisms employed by lactic acid bacteria to degrade these insecticides, as well as their potential applications in bioremediation. The key enzymes produced by lactic acid bacteria, such as phosphatase and esterase, play a vital role in breaking down insecticide molecules. Furthermore, the paper discusses the challenges and future directions in this field. However, more research is needed to optimize the utilization of lactic acid bacteria in insecticide residue degradation and to develop practical strategies for their implementation in real-world scenarios.

Advances in Gluten Hypersensitivity: Novel Dietary-Based Therapeutics in Research and Development.

Gluten hypersensitivity is characterized by the production of IgE antibodies against specific wheat proteins (allergens) and a myriad of clinical allergic symptoms including life-threatening anaphylaxis. Currently, the only recommended treatment for gluten hypersensitivity is the complete avoidance of gluten. There have been extensive efforts to develop dietary-based novel therapeutics for combating this disorder. There were four objectives for this study: (i) to compile the current understanding of the mechanism of gluten hypersensitivity; (ii) to critically evaluate the outcome from preclinical testing of novel therapeutics in animal models; (iii) to determine the potential of novel dietary-based therapeutic approaches under development in humans; and (iv) to synthesize the outcomes from these studies and identify the gaps in research to inform future translational research. We used Google Scholar and PubMed databases with appropriate keywords to retrieve published papers. All material was thoroughly checked to obtain the relevant data to address the objectives. Our findings collectively demonstrate that there are at least five promising dietary-based therapeutic approaches for mitigating gluten hypersensitivity in development. Of these, two have advanced to a limited human clinical trial, and the others are at the preclinical testing level. Further translational research is expected to offer novel dietary-based therapeutic options for patients with gluten hypersensitivity in the future.

Physicochemical properties of starches from sweet potato root tubers grown in natural high and low temperature soils.

Three sweet potato varieties grew in natural high temperature (HT) and low temperature (LT) field soils. Their starch physicochemical properties were affected similarly by HT and LT soils. Compared with LT soil, HT soil induced the increases of granule size D[4,3] from 18.0-18.7 to 19.9-21.8 µm and amylopectin average branch-chain length from 21.9-23.1 to 24.1-24.7 DP. Starches from root tubers grown in HT and LT soils exhibited CA- and CC-type XRD pattern, respectively. Starches from root tubers grown in HT soil exhibited stronger lamellar peak intensities (366.8-432.0) and higher gelatinization peak temperature (72.0-76.8 °C) than those (176.2-260.5, 56.4-63.4 °C) in LT soil. Native starches from root tubers grown in LT soil were hydrolyzed more easily (hydrolysis rate coefficient 0.227-0.282 h-1) by amylase than those (0.120-0.163 h-1) in HT soil. The principal component analysis exhibited that starches from root tubers grown in HT and LT soils had significantly different physicochemical properties.

Effect of bi-enzyme hydrolysis on the properties and composition of hydrolysates of Manchurian walnut dreg protein.

Walnut dreg (WD) active peptides are an important source of dietary antioxidants; however, the products of conventional hydrolysis have limited industrial output owing to poor flavour and low bioactivity. To this end, in this study, we aimed to employ bvLAP, an aminopeptidase previously identified in our research, as well as commercially available Alcalase for bi-enzyme digestion. The flavour, antioxidant activity, and structures of products resulting from various digestion methods were compared. The results showed that the bi-enzyme digestion products had enhanced antioxidant activity, increased ß-sheet content, and reduced bitterness intensity from 9.65 to 6.93. Moreover, bi-enzyme hydrolysates showed a more diverse amino acid composition containing 1640 peptides with distinct sequences. These results demonstrate that bi-enzyme hydrolysis could be a potential process for converting WD into functional food ingredients. Additionally, our results provide new concepts that can be applied in waste processing and high-value utilisation of WD.

Dual Action of Reduced Allergenicity and Improved Memory of Instant Soybean Powder Hydrolysates.

Soy allergens are susceptible to inducing allergic reactions in infants and young animals, which have an impact on the effective daily utilization of proteins. In this study, we used Alcalase-hydrolyzed instant soybean powder (ISP) to clarify the sensitization changes of instant soybean powder hydrolysates (ISPH), and we explored the assisted memory-enhancing effects. BALB/c mice in the ISPH group showed significant improvement in the allergy symptoms, with their allergy symptom scores decreasing to (1.57 ± 0.53) and their specific serum IgE and IgG1 binding capacity decreasing by 28.00 and 25.73% (P < 0.05), which suppressed the mast cell degranulation rate. Meanwhile, the plasma HIS and IL-4 levels decreased by 12.59 and 25.32%, and the plasma INF-γ and IL- 10 levels increased by 30.64 and 27.79%, which obviously regulated the imbalance of Th1/Th2 cells and attenuated the tissue damage (P < 0.05). Furthermore, ISPH improved behavioral characteristics, increased cholinergic system activity, reduced neuronal cell damage or apoptosis, and increased the number of Nissl bodies to help improve memory in Kunming mice (P < 0.05). In general, alcalase-hydrolyzed ISP had the dual effects of reducing allergenicity and aiding in memory improvement.

Simultaneous determination of twelve natural estrogens in dairy milk using liquid-liquid extraction and solid-phase extraction coupled with gas chromatography-mass spectrometry.

There have been many analytical methods for natural estrogens in commercial dairy milk samples, but in most of which, only four major estrogens (estrone (E1), 17ß-estradiol (E2), estriol (E3), and 17α-estradiol (αE2)) were included. This work developed an effective GC-MS analytical method for simultaneous analysis of twelve natural estrogens in commercial dairy milk sample, in which eight far-less well-known natural estrogens (2-hydroxyestone (2OHE1), 4-hydroxyestrone (4OHE1), 2-hydroxyestradiol (2OHE2), 4-hydroxyestradiol (4OHE2), 16-epiestriol (16epiE3), 16α-hydroxyestrone (16αOHE1), 16-ketoestradiol (16ketoE2) and 17epiestriol (17epiE3)) were included besides the four major natural estrogens. With liquid-liquid extraction and solid phase extraction, twelve natural estrogens in commercial dairy milk could be effectively extracted. The established method showed good linearity (R2 > 0.9991), low limits of detections (LODs, 0.02-0.11 ng/g), as well as excellent recoveries (64-117%) with satisfactory low relative standard deviations (RSDs, 0.8-14.7%). This established method was applied to seven commercial dairy milk samples, and all the twelve natural estrogens were frequently detected except for 4OHE2 without detection in any sample. Our results showed that the concentration contribution ratios of the eight far-less well-known natural estrogens in commercial dairy milk samples contributed to 32-83%, while the corresponding contribution ratios based on estrogen equivalence (EEQ) were 21-62%. This work highlighted the high abundance of the eight far-less well-known natural estrogens in commercial dairy milk based on both concentration and EEQ, which has been neglected for a long time.

Enzymatic hydrolysis of single-use bioplastic items by improved recombinant yeast strains.

Single-use bioplastic items pose new challenges for a circular plastics economy as they require different processing than petroleum-based plastics items. Microbial and enzymatic recycling approaches could address some of the pitfalls created by the influx of bioplastic waste. In this study, the recombinant expression of a cutinase-like-enzyme (CLE1) was improved in the yeast Saccharomyces cerevisiae to efficiently hydrolyse several commercial single-use bioplastic items constituting blends of poly(lactic acid), poly(1,4-butylene adipate-co-terephthalate), poly(butylene succinate) and mineral fillers. The hydrolysis process was optimised in controlled bioreactor configurations to deliver substantial monomer concentrations and, ultimately, 29 to 78% weight loss. Product inhibition studies and molecular docking provided insights into potential bottlenecks of the enzymatic hydrolysis process, while FT-IR analysis showed the preferential breakdown of specific polymers in blended commercial bioplastic items. This work constitutes a step towards implementing enzymatic hydrolysis as a circular economy approach for the valorisation of end-of-life single-use bioplastic items.

Rugulopteryx okamurae: Effect of hydrothermal acid pretreatment on the saccharification process.

The biological invasion caused by the invasive macroalga Rugulopteryx okamurae is causing increasing concern in southern Europe. To reduce its impact, this brown alga can be treated from a biorefinery approach. In this study, the macroalga is used as raw material to obtain fermentable sugars, which can be converted into high value-added products. The alga was exposed to hydrothermal and hydrothermal acid pretreatment and the pretreated biomass was used for enzymatic hydrolysis, achieving a hydrolysate with a reducing sugar concentration of almost 25 g/L (49.2% more than with non-pretreated alga). In addition, the combined severity factor was calculated to identify the best pretreatment conditions, finding the optimum in those pretreatments performed with 0.2 N HCl concentration and 15 min reaction time. Based on the results, it would be interesting to carry out new studies using the saccharified medium obtained under optimal conditions to obtain value-added compounds by fermentation.

Ten bisphenol analogues in Chinese fresh dairy milk: high contribution ratios of conjugated form, importance of enzyme hydrolysis and risk evaluation.

This study investigated concentration levels of ten bisphenols (BPs) in 13 Chinese commercial fresh low temperature dairy milk samples (fresh milk) of main local and national brands with or without enzyme hydrolysis. The results showed that at least two BPs were detected in each fresh milk sample without enzyme hydrolysis and the respective mean concentrations of bisphenol AF (BPAF), bisphenol B (BPB), bisphenol C (BPC), bisphenol F (BPF), bisphenol A (BPA), bisphenol S (BPS), bisphenol AP (BPAP), bisphenol PP (BPP), bisphenol Z (BPZ), and bisphenol E (BPE) were 0.73, 0.61, 1.86, 0.87, 0.42, 0.11, 1.06, 1.42, 1.5, and 0.04 ng/mL, while their respective detection frequencies ranged from 23.1-92.3%. These results indicated the frequent detection of BPs in fresh milk samples. With enzyme hydrolysis, the respective mean concentrations of BPAF, BPA, BPB, BPC, BPF, BPS, and BPAP were increased 7.1-107.1%, indicating the long-ignored importance of enzyme hydrolysis. The respective average estimated daily intakes (EDIs) of BPA by adult and children in China via fresh milk were 32.5 and 37.5 ng/kg bw/d, indicating that BPA in fresh milk was a crucial source to human. Six out of nine other BPs had higher average EDIs than that of BPA, among which the EDI of BPAP was almost three times that of BPA, suggesting the widespread contamination of other BPs in Chinese fresh milk.

Insights into the mechanisms involved in the fungal degradation of plastics.

Fungi are considered among the most efficient microbial degraders of plastics, as they produce salient enzymes and can survive on recalcitrant compounds with limited nutrients. In recent years, studies have reported numerous species of fungi that can degrade different types of plastics, yet there remain many gaps in our understanding of the processes involved in biodegradation. In addition, many unknowns need to be resolved regarding the fungal enzymes responsible for plastic fragmentation and the regulatory mechanisms which fungi use to hydrolyse, assimilate and mineralize synthetic plastics. This review aims to detail the main methods used in plastic hydrolysis by fungi, key enzymatic and molecular mechanisms, chemical agents that enhance the enzymatic breakdown of plastics, and viable industrial applications. Considering that polymers such as lignin, bioplastics, phenolics, and other petroleum-based compounds exhibit closely related characteristics in terms of hydrophobicity and structure, and are degraded by similar fungal enzymes as plastics, we have reasoned that genes that have been reported to regulate the biodegradation of these compounds or their homologs could equally be involved in the regulation of plastic degrading enzymes in fungi. Thus, this review highlights and provides insight into some of the most likely regulatory mechanisms by which fungi degrade plastics, target enzymes, genes, and transcription factors involved in the process, as well as key limitations to industrial upscaling of plastic biodegradation and biological approaches that can be employed to overcome these challenges.

Preparation and identification of a novel peptide with high antioxidant activity from corn gluten meal.

The antioxidant activity of corn peptides is related to their molecular weight and structure. Corn gluten meal (CGM) was hydrolyzed using a combination of Alcalase, Flavorzyme and Protamex, and the hydrolysates were subjected to antioxidant activity analysis after further fractionation. Corn peptides with molecular weights less than 1 kDa (CPP1) exhibited excellent antioxidant activity. A novel peptide, Arg-Tyr-Leu-Leu (RYLL), was identified from CPP1. RYLL displayed preferable scavenging capacities for ABTS radicals and DPPH radicals, with IC50 values of 0.122 mg/ml and 0.180 mg/ml, respectively. Based on quantum calculations, RYLL had multiple antioxidant active sites, and tyrosine was the main active site due to the highest energy of the highest occupied molecular orbit (HOMO). Moreover, the simple peptide structure and hydrogen bond network of RYLL contributed to the exposure of the active site. This study elucidated the antioxidant mechanism of corn peptides, which could provide an understanding for CGM hydrolysates as natural antioxidants.

Partial enzymolysis affects the digestion of tamarind seed polysaccharides in vitro: Degradation accelerates and gut microbiota regulates.

Two hydrolyzed fractions of tamarind seed polysaccharide (TSP), denoted ETSP1 (176.68 kDa) and ETSP2 (34.34 kDa), were prepared by partial degradation via endo-xyloglucanase, and then characterized and evaluated by simulated gastrointestinal digestion in vitro. The results showed that the hydrolyzed TSPs remained indigestible in gastric and small intestinal media, and were fermented by gut microbiota, similar to the native TSP (Mw = 481.52 kDa). Although the degradation of hydrolyzed TSPs was accelerated during fermentation with a decreasing degree of polymerization, the content of produced total short-chain fatty acids (SCFAs) decreased. After fermentation, the gut microbiota composition was modified, esp. the Firmicutes/Bacteroidetes ratio decreased (1.06 vs. 0.96 vs. 0.80) with a decreasing degree of polymerization, which implied that the potential anti-obesity prebiotic effect was enhanced. At the genus level, hydrolyzed TSPs maintained similar roles as native TSP, including promoting beneficial bacteria (Bifidobacterium, Parabacteroides, and Faecalibacterium) and inhibiting enteropathogenic bacteria (Escherichia-Shigella and Dorea). Moreover, ETSP1 had additional potential due to abundant Bacteroides vulgatus (LDA = 4.68), and ETSP2 might perform better as related to Bacteroides xylanisolvens (LDA = 4.40). All these results indicated the prebiotic potential of hydrolyzed TSP with detailed information about changes in degradation and gut microbiota based on enzyme-hydrolysis.

Engineered yeast for the efficient hydrolysis of polylactic acid.

Polylactic acid (PLA) is a major contributor to the global bioplastic production capacity. However, post-consumer PLA waste is not fully degraded during non-optimal traditional organic waste treatment processes and can persist in nature for many years. Efficient enzymatic hydrolysis of PLA would contribute to cleaner, more energy-efficient, environmentally friendly waste management processes. However, high costs and a lack of effective enzyme producers curtail the large-scale application of such enzymatic systems. This study reports the recombinant expression of a fungal cutinase-like enzyme (CLE1) in the yeast Saccharomyces cerevisiae, which produced a crude supernatant that efficiently hydrolyses different types of PLA materials. The codon-optimised Y294[CLEns] strain delivered the best enzyme production and hydrolysis capabilities, releasing up to 9.44 g/L lactic acid from 10 g/L PLA films with more than 40% loss in film weight. This work highlights the potential of fungal hosts producing PLA hydrolases for future commercial applications in PLA recycling.

Quality Characteristics of Sweet Potato Jelly Prepared Using the Enzymatic Saccharification Method.

In this study, jelly was prepared using saccharified sweet potatoes without sugar, and its quality characteristics were compared according to the sweet potato cultivar. Three sweet potato varieties, namely Juwhangmi (orange color), Sinjami (purple color), and Daeyumi (yellow flesh color), were used. The total free sugar and glucose contents of the hydrolysate were found to increase during the enzyme treatment. However, no differences in the moisture, total soluble solids, or textural properties were found among the sweet potato cultivars. Sinjami had high total polyphenol and flavonoid contents of 446.14 mg GAE/100 g and 243.59 mg CE/100 g, respectively, and it had the highest antioxidant activity among the cultivars. Based on the sensory evaluation, an overall preference appeared in the order of Daeyumi, Sinjami, and Juwhangmi cultivars. This result shows that jelly can be manufactured by saccharifying sweet potatoes, and it was confirmed that the characteristics of raw sweet potatoes had a great influence on the quality characteristics of the jelly. Further, the characteristics of raw sweet potatoes had a remarkable influence on the quality characteristics of the jelly.

Comparison of Functional Properties of Blood Plasma Collected from Black Goat and Hanwoo Cattle.

Slaughterhouse blood is a by-product of animal slaughter that can be a good source of animal protein. This research purposed to examine the functional qualities of the blood plasma from Hanwoo cattle, black goat, and their hydrolysates. Part of the plasma was hydrolyzed with proteolytic enzymes (Bacillus protease, papain, thermolysin, elastase, and α-chymotrypsin) to yield bioactive peptides under optimum conditions. The levels of hydrolysates were evaluated by 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis. The antioxidant, metal-chelating, and angiotensin I-converting enzyme (ACE) inhibitory properties of intact blood plasma and selected hydrolysates were investigated. Accordingly, two plasma hydrolysates by protease (pH 6.5/55°C/3 h) and thermolysin (pH 7.5/37°C/3-6 h) were selected for analysis of their functional properties. In the oil model system, only goat blood plasma had lower levels of thiobarbituric acid reactive substances than the control. The diphenyl picrylhydrazyl radical scavenging activity was higher in cattle and goat plasma than in proteolytic hydrolysates. Ironchelating activities increased after proteolytic degradation except for protease-treated cattle blood. Copper-chelating activity was excellent in all test samples except for the original bovine plasma. As for ACE inhibition, only non-hydrolyzed goat plasma and its hydrolysates by thermolysin showed ACE inhibitory activity (9.86±5.03% and 21.77±3.74%). In conclusion, goat plasma without hydrolyzation and its hydrolysates can be a good source of bioactive compounds with functional characteristics, whereas cattle plasma has a relatively low value. Further studies on the molecular structure of these compounds are needed with more suitable enzyme combinations.

Critical review of biochemical pathways to transformation of waste and biomass into bioenergy.

In recent years, biofuel or biogas have become the primary source of bio-energy, providing an alternative to conventionally used energy that can meet the growing energy demand for people all over the world while reducing greenhouse gas emissions. Enzyme hydrolysis in bioethanol production is a critical step in obtaining sugars fermented during the final fermentation process. More efficient enzymes are being researched to provide a more cost-effective technique during enzymatic hydrolysis. The exploitation of microbial catabolic biochemical reactions to produce electric energy can be used for complex renewable biomasses and organic wastes in microbial fuel cells. In hydrolysis methods, a variety of diverse enzyme strategies are used to promote efficient bioethanol production from various lignocellulosic biomasses like agricultural wastes, wood feedstocks, and sea algae. This paper investigates the most recent enzyme hydrolysis pathways, microbial fermentation, microbial fuel cells, and anaerobic digestion in the manufacture of bioethanol/bioenergy from lignocellulose biomass.

Quantitative enzymatic-mass spectrometric analysis of the chitinous polymers in fungal cell walls.

Chitin is an essential structural component of complex and dynamic fungal cell walls. It may be converted by partial or full deacetylation to yield chitosan. Here, we describe a method to quantify N-acetyl d-glucosamine (GlcNAc, A) and d-glucosamine (GlcN, D) units and, thus, total amount and average fraction of acetylation (x̅ FA) of the chitinous polymers by complete enzyme hydrolysis of the polymers followed by mass spectrometric analyses of the monomers. First, the native polymers were isotopically N-acetylated, then enzymatically hydrolyzed to A and R (2H3N-acetyl-d-glucosamine - former D) monomers. Relative abundances of A and R units were used to calculate x̅ FA, and a double-isotopically labeled internal standard R* ([13C2,2H3] N-acetyl-d-glucosamine) monomer was used to calculate the absolute amounts of GlcNAc and GlcN units present in the fungal samples. The method was validated using known chitosan polymers and is suitable for both purified cell walls and whole mycelia.