1. The production of chicken meat has resulted in high volumes of byproducts, such as feathers, bones, skin, viscera, and feet. The structure of feathers is one of the most complex among vertebrates, with a central axis and lateral filamentary structures, providing rigidity, lightness, and flexibility. Chicken feathers are composed of proteins, lipids, and water, with the highest protein content, especially keratin, which is responsible for the material\'s rigidity.2. Industries still make little use of feathers, which are generally intended for the production of flour or organic fertilisers. These are low added value products, and discarded feathers can harm the environment.3. Keratin extraction techniques and resulting protein hydrolysates have been studied in chicken feathers. Acid, alkaline or enzymatic hydrolysis is the most commonly used method for obtaining molecules with functional properties such as antioxidant, antimicrobial, antihypertensive and antidiabetic activity.4. The development of keratin-based biodegradable films represents an area of interest for reducing the economic and environmental impacts caused by inappropriate disposal of feathers.

BACKGROUND: Polyketide synthases (PKSs) are classified into three types based on their enzyme structures. Among them, type III PKSs, catalyzing the iterative condensation of malonyl-coenzyme A (CoA) with a CoA-linked starter molecule, are important synthases of valuable natural products. However, low efficiency and byproducts formation often limit their applications in recombinant overproduction.
RESULTS: Herein, a rapid growth selection system is designed based on the accumulation and derepression of toxic acyl-CoA starter molecule intermediate products, which could be potentially applicable to most type III polyketides biosynthesis. This approach is validated by engineering both chalcone synthases (CHS) and host cell genome, to improve naringenin productions in Escherichia coli. From directed evolution of key enzyme CHS, beneficial mutant with ~ threefold improvement in capability of naringenin biosynthesis was selected and characterized. From directed genome evolution, effect of thioesterases on CHS catalysis is first discovered, expanding our understanding of byproduct formation mechanism in type III PKSs. Taken together, a whole-cell catalyst producing 1082 mg L-1 naringenin in flask with E value (evaluating product specificity) improved from 50.1% to 96.7% is obtained.
CONCLUSIONS: The growth selection system has greatly contributed to both enhanced activity and discovery of byproduct formation mechanism in CHS. This research provides new insights in the catalytic mechanisms of CHS and sheds light on engineering highly efficient heterologous bio-factories to produce naringenin, and potentially more high-value type III polyketides, with minimized byproducts formation.

Plant phenolics have been known for various biological activities. This study aims to extract and examine the presence of phenolics in Bao mango (Mangifera indica L. var.) peel ethanolic extract (MPE). Further, antioxidant, anti-diabetic (α-amylase, and α-glucosidase inhibitory activity), and anti- Alzheimer\'s disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase (BACE-1) inhibitory activity) efficacy of MPE were determined. The results indicated that mangiferin (8755.89 mg/ 100 g extract) was the major phenolic compound in MPE. An antioxidant mechanism revealed that MPE had a higher radical scavenging ability (4266.70 µmol TE/g extract) compared to reducing power (FRAP) or oxygen radical absorption capacity (ORAC). Further in-vitro enzyme inhibitory assay against diabetic and AD involved enzymes showed that MPE had stronger inhibitory action against an enzyme involved in diabetes compared to their standard drug (Acarbose) (P < 0.05). While a lower IC50 value was observed against AD-involved enzymes compared to their standard drug (donepezil) (P < 0.05). The results show that Thai Bao mango peel byproduct can be a potential source of nutraceuticals to lower diabetes and improve cognitive health.

UNASSIGNED: 2-Amino-1-methyl-6-phenylimidazole [4,5-b] pyridine (PhIP), a heterocyclic amine (HAA), is found in meat products heated at high temperatures. However, PhIP is a mutagenic and potential carcinogenic compound. Cassiae semen, a type of medicine and food homology plant, is abundant in China and has been less applied for inhibiting heterocyclic amines.
UNASSIGNED: To investigate the inhibitory effect of cassiae semen extract on PhIP formation within a model system and elucidate the inhibitory mechanism, an ultrasonic-assisted method with 70% ethanol was used to obtain cassiae semen extract, which was added to a model system (0.6 mmol of phenylalanine: creatinine, 1:1). PhIP was analyzed by LC-MS to determine inhibitory effect. The byproducts of the system and the mechanism of PhIP inhibition were verified by adding the extract to a model mixture of phenylacetaldehyde, phenylacetaldehyde and creatinine.
UNASSIGNED: The results indicated that PhIP production decreased as the concentration of cassiae semen extract increased, and the highest inhibition rate was 91.9%. Byproduct (E), with a mass-charge ratio of m/z 199.9, was detected in the phenylalanine and creatinine model system but was not detected in the other systems. The cassiae semen extract may have reacted with phenylalanine to produce byproduct (E), which prevented the degradation of phenylalanine by the Strecker reaction to produce phenylacetaldehyde.
UNASSIGNED: Cassiae semen extract consumed phenylalanine, which is the precursor for PhIP, thus inhibiting the formation of phenylacetaldehyde and ultimately inhibiting PhIP formation. The main objective of this study was to elucidate the mechanism by which cassiae semen inhibit PhIP formation and establish a theoretical and scientific foundation for practical control measures.

We aimed to evaluate the effects of different drying methods for banana residues on the energy metabolism and respirometry of growing lambs. Twenty Santa Inês x Dorper lambs were fed five experimental diets: Tifton 85 grass hay (Control), shade-dried banana leaf hay (LH Shade), shade-dried pseudostem banana hay (PH Shade), sun-dried banana leaf hay (LH Sun), and sun-dried banana pseudostem hay (PH Sun). Nutrient intake and digestibility were assessed in metabolic cages, whereas O2 consumption and CO2, methane, and heat production were measured in a respirometry chamber with animals fed at maintenance and ad libitum levels. Nutrient and energy intake was not influenced by diet. Pseudostem hay had higher apparent digestibility of dry matter (71.5%), organic matter (72.4%), and neutral detergent fiber (58.0%). However, this led to greater energy loss in the form of methane (12.1%). The banana residue hays and drying methods did not alter oxygen consumption, CO2 production, or heat production of animals fed ad libitum or during maintenance. On the other hand, the use of leaf hay resulted in a reduction of 24.7% in enteric methane production of animals fed ad libitum. The inclusion of pseudostem hay is recommended in sheep feedlot diet. This residue provided greater use of DM, however promoted a greater loss of energy in the form of methane, resulting in similar energy consumption. The drying methods did not reduce the availability of nutrients and the sun drying method is recommended, since it is a faster drying method.

The effects of seaweed cellulose (SC) on high fat-sugar diet (HFSD)-induced glucolipid metabolism disorders in mice and potential mechanisms were investigated. SC was isolated from dealginated residues of giant kelp (Macrocystis pyrifera), with a crystallinity index of 85.51 % and an average particle size of 678.2 nm. Administering SC to C57BL/6 mice at 250 or 500 mg/kg BW/day via intragastric gavage for six weeks apparently inhibited the development of HFSD-induced obesity, dyslipidemia, insulin resistance, oxidative stress and liver damage. Notably, SC intervention partially restored the structure and composition of the gut microbiota altered by the HFSD, substantially lowering the Firmicutes to Bacteroidetes ratio, and greatly increasing the relative abundance of Lactobacillus, Bifidobacterium, Oscillospira, Bacteroides and Akkermansia, which contributed to improved short-chain fatty acid (SCFA) production. Supplementing with a higher dose of SC led to more significant increases in total SCFA (67.57 %), acetate (64.56 %), propionate (73.52 %) and butyrate (66.23 %) concentrations in the rectal contents of HFSD-fed mice. The results indicated that highly crystalline SC microparticles could modulate gut microbiota dysbiosis and ameliorate HFSD-induced obesity and related metabolic syndrome in mice. Furthermore, particle size might have crucial impact on the prebiotic effects of cellulose as insoluble dietary fiber.

Crustaceans and mollusks are widely consumed around the world due to their delicacy and nutritious value. During the processing, only 30-40 % of these shellfish are considered edible, while 70-60 % of portions are thrown away as waste or byproduct. These byproducts harbor valuable constituents, notably chitin. This chitin can be extracted from shellfish byproducts through chemical, microbial, enzymatic, and green technologies. However, chitin is insoluble in water and most of the organic solvents, hampering its wide application. Hence, chitin is de-acetylated into chitosan, which possesses various functional applications. Recently, nanotechnology has proven to improve the surface area and numerous functional properties of metals and molecules. Further, the nanotechnology principle can be extended to nanochitosan formation. Therefore, this review article centers on crustaceans and mollusks byproduct utilization for chitosan, its nano-formation, and their food industry applications. The extensive discussion has been focused on nanochitosan formation, characterization, and active site modification. Lastly, nanochitosan applications in various food industries, including biodegradable food packaging, fat replacer, bioactive compound carrier, and antimicrobial agent have been reported.

Currently, levan is attracting attention due to its promising applications in the food and biomedical fields. Levansucrase synthesizes levan by polymerizing the fructosyl unit in sucrose. However, a large amount of the byproduct glucose is produced during this process. In this paper, an engineered oleaginous yeast (Yarrowia lipolytica) strain was constructed using a surface display plasmid containing the LevS gene of Gluconobacter sp. MP2116. The levansucrase activity of the engineered yeast strain reached 327.8 U/g of cell dry weight. The maximal levan concentration (58.9 g/l) was achieved within 156 h in the 5-liter fermentation. Over 81.2 % of the sucrose was enzymolyzed by the levansucrase, and the byproduct glucose was converted to 21.8 g/l biomass with an intracellular oil content of 25.5 % (w/w). The obtained oil was comprised of 91.3 % long-chain fatty acids (C16-C18). This study provides new insight for levan production and comprehensive utilization of the byproduct in levan biosynthesis.

The influence of applying hydrostatic high pressure (HHP) to red grape pomace cv. Tempranillo was studied to obtain an ingredient rich in bioactive compounds for the manufacture of food products. Four treatments were investigated: (i) 600 MPa/1 s; (ii) 600 MPa/300 s, and other two treatments with 2 cycles of HHP: (iii) 2 cycles of 600 MPa/1 s; and (iv) 1 first cycle of 400 MPa/1 s and a second cycle 600 MPa/1 s. Treated pomace was stored at different temperatures (4 and 20 °C). The application of two consecutive cycles had no effect on the microorganisms\' inactivation compared to only one cycle. Immediately after HHP, the phenolic compounds content was maintained. However, HHP had no influence on the polyphenol oxidase enzyme (PPO), and so the phenolic compounds were significantly reduced during storage. Hence, the shelf-life of red grape pomace was significantly reduced at both temperatures, although phenolic compounds were better preserved under refrigeration than at room temperature.

The ubiquitous occurrence of microplastics in water and wastewater is a growing concern. In this study, the chemical transformation and organic release of virgin and UV-aged thermoplastic polyurethane (TPU) polymers during chlorination were investigated. As compared to virgin TPU polymer, the UV-aged TPU polymer exhibited high chlorine reactivity with noticeable destruction on its surface functional groups after chlorination, which could be ascribed to the UV-induced activation of hard segment of TPU backbone and increased contact area. The concentrations of leached organics increased by 1.6-fold with obviously high abundances of low-molecular-weight components. Additives, monomers, compounds relating to TPU chain extension, and their chlorination byproducts contributed to the increased organic release. Meanwhile, the formation of chloroform, haloacetic acids, trichloroacetaldehyde, and dichloroacetonitrile increased by 3.8-, 1.7-, 4.9-, and 2.4-fold, respectively. Two additives and six chlorination byproducts in leachate from chlorinated UV-aged TPU were predicted as highly toxic, e.g., butyl octyl phthalate, palmitic acid, 2,6-di-tert-butyl-1,4-benzoquinone, and chlorinated aniline. Evaluated by human hepatocarcinoma cells, the 50% lethal concentration factor of organics released from chlorinated UV-aged TPU was approximately 10% of that from its virgin counterpart, indicating a substantially increased level of cytotoxicity. This study highlights that the release of additives and chlorination byproducts from the chemical transformation of UV-aged microplastics during chlorination may be of potentially toxic concern.