A review on the processing of functional proteins or peptides derived from fish by-products and their industrial applications.

To understand the production and characteristics of protein hydrolysates pertaining to individual fish species, we selected and analyzed the most important commercial fish species according to the market value based on the Statistics on International Exports of Fishery Commodities by Food and Agriculture Organization. Accordingly, salmon, shrimp, cod, tuna, squid, and herring are marine species with high global value. Peptides obtained from their by-products were predominant in hydrophobic amino acids such as alanine, phenylalanine, methionine, proline, valine, tyrosine, tryptophan, leucine, and isoleucine. Bioactive peptides are short with a length of 2-20 amino acids. They remain inactive when they are within their parent proteins. Low molecular weight (0.3-8 kDa) peptides from hydrolyzed protein are easily digestible, readily absorbed by the body and are water-soluble. The hydrophobic nature contributes to their bioactivity, which facilitates their interactions with the membrane lipid bilayers. Incomplete hydrolysis results in low yields of hydrophobic amino acids. The glycosylation type of the resulting peptide fragment determines the different applications of the hydrolysate. The degree of conservation of the glycosidic residues and the size of the peptides are influenced by the method used to generate these hydrolysates. Therefore, it is crucial to explore inexpensive novel methodologies to generate bioactive peptides. According to the current studies, a unified approach (in silico estimation coupled with peptidomics) can be used for the identification of novel peptides with diverse physiological and technological functions. From an industrial perspective, the reusability of immobilized enzymes and membrane separation techniques (e.g., ultrafiltration) on marine by-products can offer low operating costs and higher yield for large-scale production of bioactive peptides. This review summarizes the production processes and essential characteristics of protein hydrolysates from fish by-products and presents the advances in their application.

Anti-inflammatory and anti-pathogenic potential of Lacticaseibacillus rhamnosus IDCC 3201 isolated from feces of breast-fed infants.

OBJECTIVE: We investigated the anti-inflammatory and anti-pathogenic activities of Lacticaseibacillus rhamnosus IDCC 3201 isolated from the feces of breast-fed infants. METHODS: Cell viability, nitric oxide (NO) production, and expression of inflammatory markers by L. rhamnosus IDCC 3201 were quantitatively analyzed in lipopolysaccharide (LPS)-induced RAW 264.7 macrophages. The antibacterial and antifungal activities of L. rhamnosus IDCC 3201 against various pathogens were also investigated. RESULTS: Treatment of LPS-induced macrophages with cell-free supernatant of L. rhamnosus IDCC 3201 significantly decreased the expression levels of tumor necrosis factor (TNF-α) and interleukin-6 (IL-6). Nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) levels also significantly decreased in LPS-induced macrophages. Phenotypically, the treatment of L. rhamnosus IDCC 3201 reduced the production of nitric oxide (NO) in LPS-induced macrophages. Furthermore, L. rhamnosus IDCC 3201 was proven to have potent inhibitory activities against various pathogens responsible for inflammatory responses in the gastrointestinal tract (i.e., Bacillus cereus, Enterococcus faecalis, Staphylococcus aureus, and Salmonella Typhimurium), respiratory system (i.e., Streptococcus pneumoniae), and vagina (i.e., Candida albicans). CONCLUSION: L. rhamnosus IDCC 3201 has anti-inflammatory activity in terms of decreased expression of cytokines, inflammation-inducible enzymes in LPS-induced macrophages, and anti-pathogenic activity.

An effective datasets describing antimicrobial peptide produced from Pediococcus acidilactici - purification and mode of action determined by molecular docking.

Most of the probiotics Bacterial cells, express native antibacterial genes, resulting in the production of, antimicrobial peptides, which have various applications in biotechnology and drug development. But the identification of antibacterial peptide, structural characterization of antimicrobial peptide and prediction on mode of action. Regardless of the significance of protein manufacturing, three individual factors are required for the production method: gene expression, stabilization and specific peptide purification. Our protocol describes a straightforward technique of detecting and characterizing particular extracellular peptides and enhancing the antimicrobial peptide expression we optimized using low molecular weight peptides. This protocol can be used to improve peptide detection and expression. The following are the benefits of this method, (DOI - https://doi.org/10.1016/j.ijbiomac.2019.10.196 [1]). The data briefly describe a simple method in detection identification, characterization of antimicrobial extracellular peptide, predicating the mode of action of peptide in targeting pathogens (In-silico method), brief method on profiling of antimicrobial peptide and its mode of action [1]. Further the protocol can be used to enhance the specific peptide expressions, detection of peptides. The advantages of this technique are presented below:•Characterization protocol of specific antimicrobial peptide•The folded antimicrobial peptide expression were less expressed or non-expressed peptides.•Besides being low cost, less time-consuming, easy to handle, universal and fast to execute, the suggested technique can be used for multiple proteins expressed in probiotics (Lactobacillus species) expression system.

Review on Stress Tolerance in Campylobacter jejuni.

Campylobacter spp. are the leading global cause of bacterial colon infections in humans. Enteropathogens are subjected to several stress conditions in the host colon, food complexes, and the environment. Species of the genus Campylobacter, in collective interactions with certain enteropathogens, can manage and survive such stress conditions. The stress-adaptation mechanisms of Campylobacter spp. diverge from other enteropathogenic bacteria, such as Escherichia coli, Salmonella enterica serovar Typhi, S. enterica ser. Paratyphi, S. enterica ser. Typhimurium, and species of the genera Klebsiella and Shigella. This review summarizes the different mechanisms of various stress-adaptive factors on the basis of species diversity in Campylobacter, including their response to various stress conditions that enhance their ability to survive on different types of food and in adverse environmental conditions. Understanding how these stress adaptation mechanisms in Campylobacter, and other enteric bacteria, are used to overcome various challenging environments facilitates the fight against resistance mechanisms in Campylobacter spp., and aids the development of novel therapeutics to control Campylobacter in both veterinary and human populations.

Unveiling the potentials of bacteriocin (Pediocin L50) from Pediococcus acidilactici with antagonist spectrum in a Caenorhabditis elegans model.

Human-milk-based probiotics play a major role in the early colonization and protection of infants against gastrointestinal infection. We investigated potential probiotics in human milk. Among 41 Lactic acid bacteria (LAB) strains, four strains showed high antimicrobial activity against Escherichia coli 0157:H7, Listeria monocytogenes ATCC 15313, Bacillus cereus ATCC 14576, Staphylococcus aureus ATCC 19095, and Helicobacter pylori. The selected LAB strains were tested in simulated gastrointestinal conditions for their survival. Four LAB strains showed high resistance to pepsin (82%-99%), bile with pancreatine stability (96%-100%), and low pH (80%-94%). They showed moderate cell surface hydrophobicity (22%-46%), auto-aggregation abilities (12%-34%), and 70%-80% co-aggregation abilities against L. monocytogenes ATCC 15313, S. aureus ATCC 19095, B. cereus ATCC 14576, and E. coli 0157:H7. All four selected isolates were resistant to gentamicin, imipenem, novobiocin, tetracycline, clindamycin, meropenem, ampicillin, and penicillin. The results show that Pediococcus acidilatici is likely an efficient probiotic strain to produce < 3 Kda pediocin-based antimicrobial peptides, confirmed by applying amino acid sequences), using liquid chromatography mass spectrometry and HPLC with the corresponding sequences from class 2 bacteriocin, and based on the molecular docking, the mode of action of pediocin was determined on LipoX complex, further the 13C nuclear magnetic resonance structural analysis, which confirmed the antimicrobial peptide as pediocin.

Experimental validation and evaluation of electronic sensing techniques for rapid discrimination of electron-beam, γ-ray, and X-ray irradiated dried green onions (Allium fistulosum).

This study focuses on applicability of e-sensing methods in addition to direct epifluorescent filter technique (DEFT), aerobic plate counts (APC), and photostimulated luminescence (PSL) to discriminate e-beam, γ-ray, and X-ray irradiated green onions (scallions) at 1, 4, and 7 kGy for each irradiation treatment, along with two confirmatory analysis. Although low dose (1 kGy) reduced the APC (6.15-2.69 log CFU/g), no significant difference was observed in DEFT. Scallions with log DEFT/APC ratio of ≥ 5.2 can be suspected as irradiated at at least 1 kGy. Both non-irradiated (< 700 counts/min) and irradiated (> 5000 counts/min) scallions were identified by PSL. Besides distinct volatile compounds profile, cumulative e-nose discrimination of 92.06% from principle component analysis was apparent among irradiation conditions. Sensitivity to changes in perceived taste by e-tongue showed 96.07% variation. The e-sensing capability to discriminate irradiated scallions can be exploited for exposing counterfeit claims as either non-irradiated or irradiated within the recommended standards.

Effect of Rice Processing towards Lower Rapidly Available Glucose (RAG) Favors Idli, a South Indian Fermented Food Suitable for Diabetic Patients.

The Asian food pattern primarily embraces rice and rice-based products, which mainly comprise 90% starch. Among these various food products, Idli is mostly prepared through fermentation. It has high palatability, and the rapid and highly digestible nature of the food product results in a higher post-glucose level in diabetic patients. A heat-treated Idli rice sample was prepared by roasting parboiled rice at the temperature range of 155 to 165 °C for 65 to 75 s. Idli/rice-based Dokala made from heat-treated rice is better when compared to untreated rice in terms of its microbiological profile and physiochemical properties. The proximate composition of heat-treated parboiled rice Idli/Rice Dokala showed slightly higher values than the untreated parboiled rice Idli/Rice Dokala, which reveals that it has marginally higher nutritive value. Determination of the Rapidly Available Glucose (RAG) and Slowly Available Glucose (SAG) values, SEM analysis, resistant starch analysis, microbial assay, and in vivo studies were performed to determine the glycemic index (GI) and glycemic load in normal and diabetic persons. Sensory analysis also proved that heat-treated Idli/Rice Dokala is superior to untreated based on the color, flavor, appearance, taste, and texture.

Effects of electron-beam irradiation on the quality characteristics of mandarin oranges (Citrus unshiu (Swingle) Marcov) during storage.

Consumption and global utilization of mandarins is on the rise due to its easy-to-peel attribute compared to other citrus fruits. Mandarins are irradiated as an effective phyto-sanitary treatment for trade requirements. In this study, mandarins were irradiated with 0.4 and 1 kGy electron-beam as approved by United States Department of Agriculture (USDA), and changes in microbial and physicochemical characteristics during storage were monitored at 4 °C for 15 d. Microbial proliferation during storage was noticeable in non-irradiated fruits, whereas irradiated mandarins showed dose-dependent inhibition up to 15 d. Irradiation did not affect its moisture, total phenolics, and vitamin C. However, hardness, organic acids, hesperidin, radical scavenging activity, reducing and free sugars significantly decreased in all samples after 5 d of storage. Although, irradiation at 0.4 and 1 kGy could not prevent changes in stored mandarins, 0.4 kGy did not affect the major constituents and physical quality of mandarins, while providing microbial decontamination.

Storage stability of soluble pigments, chlorophylls, and carotenoids in electron-beam-irradiated edible lavers (Porphyra umbilicalis) with impact on microbial safety and sensory characteristics.

BACKGROUND: In this study, we investigated whether electron beam (e-beam) irradiation can inactivate microbial populations, including aerobic bacteria plate count, fungi, and coliforms, in two types of lavers (dried and roasted). The impact of e-beam doses of 4 and 7 kGy on microbial populations, color values, total soluble pigments, chlorophylls, and carotenoid content immediately and after storage at 4, 15, 25, and 35 °C for 4, 8, and 12 weeks was also evaluated. RESULTS: The initial microbial load of approximately 106 and 105 CFU g-1 in both dried and roasted lavers was reduced to 104 and 101 CFU g-1 , respectively, after irradiation at 7 kGy. No further proliferation was observed in irradiated dried lavers during 4 weeks of storage at 4 and 15 °C. When stored at low temperature, the shelf-life was extended for up to 12 weeks in 7 kGy irradiated dried and roasted lavers. High amounts of soluble pigments and carotenoids were observed during storage in the 7 kGy irradiated dried laver samples at the end of 12 weeks irrespective of temperature. Although the chlorophyll content decreased under the storage conditions, it was comparatively stable in the 7 kGy-irradiated dried laver. Maximum degradation of color was observed in laver samples subjected to the roasting process. CONCLUSION: Overall, this study indicated that e-beam irradiation of laver at 7 kGy maintains microbial safety as well as quality attributes during storage for up to 12 weeks. Further, dried laver had more essential compounds than roasted laver. © 2019 Society of Chemical Industry.

Dose rates of electron beam and gamma ray irradiation affect microbial decontamination and quality changes in dried red pepper (Capsicum annuum L.) powder.

BACKGROUND: Due to differences in radiation sources (electron beam from electron accelerator, gamma ray from 60 Co radionuclide) and energy delivery time (dose rate, kGy/time), the effects on foods are expected to be different with regard to chemical quality change and microbial decontamination. To better understand this impact, effects of variable dose rates of electron beam (EB, kGy s-1 ) and gamma rays (GR, kGy h-1 ) on microbial reduction, capsanthin content, and color parameters of red pepper (Capsicum annuum L.) powders (RPP) were determined. RPP samples were irradiated with 3 kGy absorbed dose, at variable dose rates of 1 and 5 kGy s-1 of EB (10 MeV/10 kW), and 1.8 and 9 kGy h-1 of GR (60 Co). RESULTS: Aerobic plate counts (APC) as well as yeast and mold counts of non-irradiated samples were 7.12 log CFU g-1 and 6.62 log CFU g-1 , respectively. EB and GR reduced these by 2-3 log CFU g-1 . A lower dose rate (1 kGy s-1 ) of EB was more effective for microbial reduction than a higher dose rate (5 kGy s-1 ). In contrast, a higher dose rate (9 kGy h-1 ) of GR efficiently decreased APC compared to a lower dose rate (1.8 kGy h-1 ). Higher EB and GR dose rates significantly decreased the capsanthin content and Hunter's red color (a* value). CONCLUSION: Low EB (kGy s-1 ) and high GR (kGy h-1 ) dose rates are recommended for microbiological safety of RPP with negligible changes in color attributes visible to the human eye, in contrast to the measured values. Thus the study demonstrates that the influence of absorbed dose is dependent on the applied dose rates. © 2018 Society of Chemical Industry.

Preservative effect of Chinese cabbage (Brassica rapa subsp. pekinensis) extract on their molecular docking, antioxidant and antimicrobial properties.

This study aimed at investigating the antimicrobial activity of different solvent extracts of Chinese cabbage Brassica rapa subsp. pekinensis (BRARP) and their antioxidant and cytotoxicity properties. Of the different solvents extracts, the chloroform extracts (CE) were significantly inhibited the bacterial pathogens at minimum inhibitory concentration (MIC) of 16.5 mg.mL-1. Biochemical analysis revealed that total phenol (62.6 ± 0.05 mg GAE.g-1) and flavonoids (27.6 ± 0.04 mg QE.g-1) were higher in the extracts of BRARP, which resulted in enhanced antioxidant activity in CE. A total of eight dominant compounds were detected in the potent antimicrobial extract from BRARP based on GC-MS analysis. The molecular interactions study revealed that, among the screened compounds the 1,2-benzenedicarboxylic acid and 2,3-dicyanopropionamide interacted with the active site of pathogenicity and survival related protein with lipopolysaccharide (LpxC) with higer binding energy. This work concluded that the 1, 2-Benzenedicarboxylic acid and 2, 3-Dicyanopropionamide from BRARP was reported to be good non-cytotoxic and antioxidant antimicrobials against bacterial pathogens.

In vitro and in vivo defensive effect of probiotic LAB against Pseudomonas aeruginosa using Caenorhabditis elegans model.

This study aimed to investigate in vitro and in vivo the probiotic characteristics of lactic acid bacteria (LAB) isolated from Korean traditional fermented foods. Caenorhabditis elegans  (C. elegans) was used for analytical assays of fertility, chemotaxis, life-span, worm-killing and bacterial colonization in the intestinal lumen of the worm. All 35 strains of LAB reduced fertility and slowed development in the worms. The worm-killing assay showed that LAB significantly increased the lifespan (P < 0.05) and reduced the susceptibility to virulent PA14; however, the heat-killed LAB did not. The bacterial colonization assay revealed that LAB proliferated and protected the gut of the worm against infection by Pseudomonas aeruginosa PA14. In addition, specific LAB Pediococcus acidilactici(P. acidilactici DM-9), Pediococcus brevis (L. brevis SDL1411), and Pediococcus pentosaceus (P. pentosaceus SDL1409) strains showed acid resistance (66-91%), resistance to pepsin (64-67%) and viability in simulated intestinal fluid (67-73%) based on in vitro probiotic analyses. Taken together, these results suggest that C. elegans may be a tractable model for screening efficient probiotics.

Evaluation of capsaicinoid profile and antioxidant properties in dried Korean red pepper (Capsicum annuum L.) as affected by variable dose rates of electron beam and gamma ray irradiation.

The application of food irradiation is based on the parameters including energy (MeV), dose rate (kGy/s or kGy/h), and absorbed dose (kGy). Red pepper powders were treated with different dose rates of 1, and 5 kGy/s electron beam (EB) as well as 1.8 and 9 kGy/h gamma ray (GR) in separate experiments. Constant absorbed dose (3 kGy) was maintained to observe whether different dose rates affect the product quality. Total and individual capsaicinoids increased at low EB and GR dose rates. Vitamin C content decreased at all dose rates, except at low GR dose rate, where no significant difference was observed. Low EB dose rate led to a marked increase (21%) in the total phenolics than high dose rate (13%). In contrast, high GR dose rate increased the total phenolics than low dose rate. Maximum antioxidants (1.36 mg TE/mL) were observed at high EB dose rate, although low dose rate also increased the antioxidant activity. Results indicated that different dose rates delivering the same absorbed dose had significant impact on the product quality and that the efficacy of absorbed dose is dependent on applied dose rates. In other words, a constant absorbed dose applied to the product is influenced by dose rate of the irradiation treatment.

Antibacterial, and antioxidant potentials of non-cytotoxic extract of Trichoderma atroviride.

Trichoderma species are a rich source of metabolites, but less known for biomedical potential. This work deals with antibacterial and antioxidant potentials of intracellular non-cytotoxic metabolites, extracted from Trichoderma atroviride (KNUP001). A total of 53 fractions was collected by column chromatography and tested for cytotoxicity by MTT assay. Only one fraction (F41) was found to be non-toxic to Vero cells with 95.4 ±â€¯0.61% of survival. The F41 was then subjected to chemical analysis, antibacterial and antioxidant assays. The F41 at 500 µg ml-1 showed the total antioxidant of 48.70 ±â€¯2.90%, DPPH radical scavenging activity of 37.25 ±â€¯2.25, nitric oxide (NO) radical scavenging activity of 54.55 ±â€¯1.95 and H2O2 radical scavenging activity of 43.75 ±â€¯3.21. The F41 at 25 µg ml-1 displayed antibacterial activity against E. coli (14.25 ±â€¯0.25 mm), Proteus mirabilis (10.40 ±â€¯0.60 mm), and Enterobacter aerogenes (5.60 ±â€¯0.40 mm). GC-MS analysis revealed the dominant presence of oleic acid C 18.1 (63.18%), n-hexadecanoic acid (6.17%), and ethyl oleate (4.93%) in the F41, and hence these fatty acids are likely responsible for the antioxidant and antibacterial activities of F41. Hence, further investigation deserves on purification and characterization of the active metabolites from T. atroviride strain KNUP001 towards developing molecular leads to effective antibacterial drugs, and non-toxic to host cells.

Chemical, microbial and antibiotic susceptibility analyses of groundwater after a major flood event in Chennai.

During floods, human exposure to pathogens through contaminated water leads to the outbreak of epidemic diseases. This research presents the first extensive assessment of surface and groundwater samples collected immediately after a flood (December 2015) and post-flood (April 2016) from the Adyar River of Chennai, a major city in India, for major ions, trace metals, bacterial population, and pathogens. Severe rains in a short period of time resulted in flooding which inundated the wells, allowing the entry of sewage contaminated river water into the groundwater zone. This has led to bacterial counts and chemical ions exceeding Bureau of Indian Standard's recommended limits in most flood affected areas. Pathogens isolated from the groundwater showed resistance to antibiotics, namely ceftriaxone, doxycycline and nalidixic acid. However, they were sensitive to chloramphenicol, ciprofloxacin, norfloxacin, and tetracycline. Determining the antibiotic susceptibility of pathogens will help in the treatment of humans affected by contaminated water through an appropriate selection of prescribed medication.

Accelerated fermentation of Idli batter using Eleusine coracana and Pennisetum glaucum.

The present study focuses on reduction in fermentation time of idli batter and its enrichment with calcium and iron using finger millet and pearl millet. Fermentation time decreased from 12 to 6 h with addition of finger millet and to 8 h with pearl millet. Rate of fermentation, bulk density, viscosity, microbial changes and particle morphology were assessed in the batter; nutritional quality, sensory, phytochemicals and internal characteristics of idli were investigated. The color and texture characteristics of both batter and idli were evaluated. The pH and titratable acidity of control batter at 6 h was 5.32 and 0.27%, addition of finger and pearl millet changed to 4.32, 0.45% and 4.53, 0.45% at respective fermentation times (6 and 8 h). The viable yeast, lactic acid bacteria and total bacterial count (log CFU g-1) in the batters increased with time, reaching 1.26, 3.85, 4.56 (control); 2.32, 9.84, 9.58 (finger millet) and 1.76, 7.34, 7.74 (pearl millet) respectively at the end of 6 h of fermentation. Addition of finger millet and pearl millet flour (10% w/w) to the batter enhanced the dietary fiber by 28 and 23%, calcium by 113 and 56%, iron by 51 and 258% in the respective idlies when compared with the control.

Evaluation of antimicrobial activity and probiotic properties of wild-strain Pichia kudriavzevii isolated from frozen idli batter.

The present research was undertaken to study the probiotic characteristics of Pichia kudriavzevii isolated from frozen idli batter. Polymerase chain reaction amplification with 18S rRNA primers confirmed Pichia kudriavzevii, a xylose-utilizing probiotic strain. It was resistant to physiological concentrations of bile salts, pepsin and pancreatic enzyme. It also showed efficient auto-aggregation as well as co-aggregation ability with four commercial probiotic yeasts and exhibited good hydrophobicity in xylene and toluene. The strain inhibited the growth of 13 enteropathogens and showed a commensal relationship with four commercial probiotic yeast and bacteria. Moreover, it was resistant to 30 antibiotics with different modes of action. The yeast exhibited thermotolerance up to 95 °C for 2 h. The cell-free supernatants were also found to be heat stable, indicating the presence of thermostable secondary metabolites. Hence it could be exploited as starter culture, co-culture or probiotic in the preparation of fermented products or incorporated in heatable foods as well. Copyright © 2016 John Wiley & Sons, Ltd.